At the 2025 Parowan Soaring Camp, organized by the Auxiliary Powered Sailplane Association (ASA), I succeeded in defending last year’s win of the Pete Williams Trophy.  In this article, I will examine the rules of this contest and take an analytical look at the flights that helped me secure this second win. In particular, I want to see what can be learned from these and other competitors’ flights and how pilots can “best play” at this particular contest.  The lessons learned can also be used for improved task setting in 2026.

The Pete Williams Trophy

2-Hour Speed Category

We’ll start with the 2-hour speed score which is taken straight from OLC.  It is the only one of the four flight categories that never involves any time-based pro-rating irrespective of the duration of the flight.  OLC automatically analyzes each flight and identifies the greatest 4-leg distance flown in exactly 2 flight hours without a loss in altitude.  OLC reports the raw flying speed over these two flight hours, and it applies the glider handicap to calculate the 2-hour “Speed/League” score.

Triangle Category

• Use the available time of 6 hours (at least) to make the greatest possible triangle.  As a rule of thumb it is a good idea to spend at least six full hours on the triangle.
• If six hours have lapsed since takeoff, land quickly after completing the triangle to avoid that the triangle distance gets pro-rated down.  Both Anders and I successfully avoided penalization because we did not add empty miles beyond the 6 hours. Jim flew less than 6 hours, was not penalized, but did not make full use of the available time.
• Flying longer than 6 hours to make a bigger triangle does not hurt one’s score, provided that the average triangle speed does not suffer as a result.  In fact, flying longer than 6 hours may be helpful because the “unproductive” time at the beginning (taking off and climbing out) and at the end (to descend and land) is on average the same for everyone, irrespective of the length of the flight overall.  Longer flights (more than six hours) may actually be advantageous because as a percentage of overall flight time, more of the time can be used “productively” (e.g. to make a bigger triangle).

• Clemens: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10226389&f_map=
• Anders: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10227240&f_map=
• Jim: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10216164&f_map=

Distance Away from Home Category

On Day 10 of the meet, I succeeded in setting several new Utah State records with a declared 1001 km Out and Return flight from Parowan to Wyoming and Idaho and back to to Parowan.  (The furthest point from home was 510.9 km away and the six-leg OLC distance was 1090 km.)  Although this was a very long flight with a duration of 8:40 hours (and therefore heavily pro-rated), it still earned me the greatest distance score of the meet. My average O&R Speed was 117.9 kph calculated over the entire duration of the flight from takeoff to landing (510.9 * 2 / 8.667 hours).

My 511 distance kms were pro-rated to an Adjusted Distance score of 354 points (511 * 6/8.66).  As Distance Category Winner, this translated of course to 1000 Williams Trophy Points.

In second place was the duo of Bill Feiges and Michael Stieber (flying Bill’s Arcus M) who used the same day to fly 374km away from home.  Their flight duration was 6:39 hours, which means the 374 km were adjusted to 337 points (374 * 6/6.65), which was good for 950 Williams Trophy Points.   Their average O&R Speed was 112.5 kph (using the same calculation methodology: from takeoff to landing).

It’s important to note that making a much longer flight than anyone else that day was not the reason as to why I was able to win the Distance Category.  Once the flight was 6 hours long, the only thing that mattered for the Williams Trophy was the greater average speed.

In third place that day was Chris Esselstyn with a 7:01 hour flight at an average O&R speed of 107.13 kph that took him 383 km from home. Pro-rated, this was good for 329 points (383 * 6/7.01)  and translated to 928 Williams Trophy Points.  This means, Bill & Michael scored more Williams Trophy Points that Chris despite flying a slightly shorter distance.  Why?  They did so at a higher average speed.

• For flights that last six hours or less, the winner is simply determined by who flies the greatest distance away from home.
• However, as is also the case when flying triangles, once a flight is 6 hours long (or longer), flying a greater distance ceases to be an advantage.
• One can still win the  Distance Category (or the Triangle Category) with flights that are much longer than 6 hours, but to do so one must achieve a greater average speed (over the course of the entire flight from takeoff to landing), not a greater distance!

Important Note: based on the current rules, the best distance score can easily be achieved by flying a straight out flight and landing far away from home (instead of returning back to Parowan).  Anyone who is willing to do this will not only score the greatest distance score but has a very good chance of winning the Williams Trophy outright!  The advantage obtained from the distance score alone could easily be 500 Williams Trophy Points (if flying at the same average speed as the best Out and Return Flight). It would be nearly impossible to make this up in the three other categories combined! I will get back to this oddity in my critique of the current rules.

• Clemens: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10228268&f_map=
• Bill/Micheal: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10228147&f_map=
• Chris: https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=10228162&f_map=

OLC Plus Category

Overall Results

Overall Lessons

Pilots who follow the following recommendations will improve their chances of scoring well in competing for the Williams Trophy:

1. Fly on the best days of the contest.  (You can take multiple rest days during the two weeks but don’t do so on days when conditions are particularly favorable to score highly in any of the 4 Categories).
2. Each flight should be at least six hours long.  In fact, it is best if you spend the full six hours “on task” – either flying a long Out&Return Flight, or a long Triangle Flight.
3. Out and Returns are best suited to score well in the Distance Category and in the 2-hour Speed Category. Use days with a substantial tail wind along the best energy lines to obtain a good speed score.  To do so, fly at least two full hours with the wind at your tail.
4. Big triangles are best suited to score well in the Triangle and in the OLC+ Category.
5. Land immediately after completing your task (i.e. your Out and Return Flight, or your Triangle) provided that you have been flying for at least 6 hours.  Adding extra miles after completing your task will rarely help and could even be very disadvantageous.  The only score it could possibly improve is the OLC Plus score, and only if these extra miles are flown substantially faster than the prior part of the flight (because they won’t receive additional bonus points for triangle or distance). Any Triangle score or Distance score will suffer because the longer you’re up flying the more they will get pro-rated.
6. There is no inherent disadvantage in flying Out and Returns or Triangles that last longer than six hours provided that your average speed will not suffer.
7. Do not launch so early that “getting up and out” will take a long time.  This is because the six hour flight time begins at takeoff and ends with the landing.  If you spend an hour climbing out this will hurt your score substantially.  Another way to put this is that the performance of every climb counts, even that of the very first climb after launch and before you are leaving on task.

Daily Task Setting

In 2025 we introduced an optional daily task intended to help pilots achieve good results for the Williams Trophy Contest.  Tasks used the AAT (assigned turn area) format and were usually either Out and Return or Triangle tasks, making use of the best weather of the day as forecast by Skysight. Task minimum time was typically 5 hours.  The minimum task distance was usually just under 500km so that lower performance gliders could make it around, and the maximum distance was typically in the range of 700-900 km so that high performance gliders would be able to spend 6 hours on task and not run out of space.  To support these tasks we used the Local Competition feature on WeGlide which automatically scored the flights.

Pilots reported that this was a fun addition to the contest.  Tasks were strictly optional.  I.e. pilots were able to design their own flight route without limitation if they thought that would help them do better than the suggested task. Most pilots made use of the task on at least some of the days.

Based on the analysis in this article, the task format for 2026 can be slightly adjusted based on the following guidelines:

1. Weather permitting, increase the minimum task distance to 5:30 hours and/or slightly increase the required task distance.  This will help prevent early finishes and help pilots use the available time to achieve optimum Williams Trophy results. Pilots should be encouraged to spend at least 5:30 hours on task to minimize the need for “empty miles” at the end to fill up the 6 hours.
2. Use only use Out and Return and Triangle tasks unless the weather dictates otherwise.
3. The best weather days should be used to declare triangle tasks.  Weather permitting, there should be more triangle tasks than O&R tasks.
4. O&R tasks are best used on days with a good tail wind (normally on the outbound leg to the NNE as the prevailing winds at Parowan are from the SSW) and strong energy/convergence lines.  This will also help optimize the 2-hour speed score.  The turn point needs to be far enough away from home that even the highest performing gliders can fly more than 2 hours with a tail wind.
5. Continue to set big turn areas, generally with the maximum possible 50km turn radius.  (The 50km max size limitation for turn areas on WeGlide is a bit problematic for O&R tasks because the difference between min and max task distance is only 200km.  The min distance may be somewhat long for low performance gliders and the max distance possibly too short for high performance ones.  For triangle tasks it is less of an issue because there are two turn areas to use for shortening/extending the flight.)
6. Keep the Start/Finish as a ring with a 10km radius around Valentine Peak.  This seems to work well and allows everyone to easily get a valid start and finish.

Review of the Williams Trophy Contest Format

Safety First

1. The rule according to which flights of more than 6 hours are pro-rated is an effective tool to minimize pilot fatigue.  It means that pilots don’t have to fly longer than six hours to score well.
2. The six hour rule also discourages flights in marginal conditions early or late in the day.  This is of particular relevance in Parowan because of very poor or non-existent land-out options in some parts of the task area.
3. There is no pressure to fly every day or in marginal conditions because only the best 4 flights of each pilot count.   In fact, it is possible to win the event even if one flies on four days only.  Keith Essex proved this in 2018 when he only attended the event for a short time, flying exactly on four days, and winning the Williams Trophy.  Why go to a flying even and only fly when the weather is good?  Easy: the area around Parowan also offers tremendous sights to see on the ground: Zion National Park, Bryce Canyon National Park, Grand Canyon National Park, Capitol Reef National Park, Grand Escalante Staircase, Lake Powell, the Tushar Mountains, just to name a few.

Longer Flights Can Still Lead to Success

Some have criticized the six hour rule, arguing that it all but eliminates 1000km or other long flights.  This is not necessarily the case.  Here’s why:

1. Flying more than six hours is not a disadvantage if the extra flight time is used wisely (e.g. to achieve a bigger triangle or a greater Out and Return distance) and provided that the pilot is able to maintain a good average speed throughout the flight.  E.g., if Pilot A flies a 1000km triangle and takes 8 hours to do so (from takeoff to landing), she will receive the same score as Pilot B who flies a 750km triangle in exactly six hours (also from takeoff to landing).
2. Now assume that Pilots A and B each take 25 minutes to launch and climb before heading on task, and that each take 5 minutes to descend and land after completing their task.  For simplicity, assume that no scoring distance at all is flown during these 30 minutes of launching and landing (25+5).   This means Pilot A had 7:30 hours to fly the 1000km triangle, while Pilot B only had 5:30 hours to fly the 750 km triangle.  Now calculate the average speed required: Pilot A had to achieve an average speed of 133 kph (1000/7.5), but Pilot B had to fly slightly faster at and average speed of 136.4 kph (750/5.5).  Had Pilot A flown her triangle at the same average speed as Pilot B, she would have completed it 2.5% sooner, finishing the task in 7:19 hours instead of 7:30 hours and winning the day.  In other words: because launching and landing takes the same time irrespective of the time spent on task, flying longer tasks (more than 6 hours) can be a slight advantage because one can actually fly a little slower to achieve the same score.
3. Of course the small advantage of flying longer tasks has its limits.  Starting or ending the flight in weaker conditions would quickly cause a disadvantage because the average attainable speed would quickly diminish.

The Quirks of Daily Optimizations

One peculiar and particular oddity of the Williams Trophy scoring format is the quirkiness of daily score-reruns due to optimizations.  This can be very entertaining even though there’s nothing unfair or otherwise inherently wrong with it.

But consider: your score can go down throughout the contest!  This is a logical consequence of the fact that only the best 4 days count, and that the best score in one category is determined by all flights flown during the entire event, and not just those flown on a particular contest day.

A simple example will illustrate this.  Say Pilot A wins on each of the first four contest days.  She will then have a preliminary score of 4000 Williams Trophy Points.  On Day 5 she does not fly at all and Pilot B scores 20% higher than the best score of Pilot A in one of the 4 categories.  Pilot A will lose 200 of her 1000 points for that category and will now only have 3800 points.

As you may expect, this feature of the scoring format leads to endless and often humorous discussions at daily pilot meetings, dinners, and breakfasts.  Consider that it’s possible that a pilot may improve in rank in the standings even on a day they did not fly, simply because the scores of some other pilots were knocked down more than his own! How and why this happens can be exceedingly difficult to understand, let alone explain.  It’s not wrong, it is just a consequence of the rules.

I see this as a fun albeit peculiar feature of the contest format.  However, it would be nearly impossible to apply at a more competitive event where contestants would demand a detailed explanation of what is happening to their scores, day by day.

What About Straight Out Flights?

We have seen above that the current rules provide a powerful incentive to fly a straight out flight (landing someplace else) in order to maximize the Distance score.  Doing so would provide a tremendous advantage and could easily result in winning the contest outright.  The reason for this is that the entire outbound flight time would be used to maximize the distance score.  If the pilot flies at the same average speed as the best scoring Out and Return flight, the Outbound flight would earn 1000 Williams Trophy Points and the best Out and Return flight would only earn 500.  Days with a strong tailwind component on the outbound leg would amplify this advantage even further resulting in a possible point differential in this category of well over 500 points.  Such a difference would be nearly impossible to make up in all the other three categories combined.

From a contest perspective, the only disadvantage of pursuing this strategy is that the pilot would likely forego the opportunity to compete on the following day.  That’s because only flights that originate at Parowan count for the contest, and presumably the pilot would need (at least) the next day to return to Parowan.  However, since only the best four flights count for the overall results, it would be a small price to pay during a two week event. Of course the real prize is the inconvenience and actual costs involved in buying another hotel room etc.

In my opinion, this rule oddity could (and perhaps should) be eliminated by counting the distance score twice for successful O&R flights.  If the pilot would land elsewhere or use the engine to return back home, only the outbound leg would count.  I think that this would be more appropriate in the context of a social meet where pilots are encouraged to be back at home, but it is a policy decision and can be made either way.  At least pilots should know that this oddity currently exists.

The Real Limitations of the Williams Trophy Contest Format

Although attendees greatly enjoy the event there are some real issues associated with the scoring format, which would also not hold up in a more competitive setting.

1. A better engine leads to a better score.  That’s because the 6-hour rule is measured from takeoff to landing.  If Glider A takes 15 minutes to launch and climb and Glider B only takes 10 minutes, this means that the pilot of Glider B has 5 extra minutes to score.  5 minutes does not sound like much, but it still amounts to 1.4% of the 6-hour time window (or 14 points on the daily 1000 point Williams Trophy Point scale).  (This advantage is irrelevant for the 2-hour speed category, so the total advantage would be 42/4000 Williams Trophy Points or about 1% for the entire contest.)
2. A rapid descent and landing improves the score.  It doesn’t feel quite right that after finishing fast and high one must pull the spoilers and get on the ground quickly to avoid that one’s score gets discounted.  It can also be problematic when one is incentivized to land quickly while other gliders are trying to do the same.   The race really should be over when the finish line is reached and not continue throughout the landing procedure.  In practice I have not seen this being a major problem but that’s mainly because no one takes the contest serious enough to worry about losing what might be 0.5-1% of the daily score. However, in a more competitive setting this would be a real issue.
3. While the category scores for OLC Plus and 2-hour Speed correctly account for glider handicaps, the category scores for Triangle Distance and Distance Away from Home are based on raw distance flown and therefore do not.   This creates a substantial disadvantage for pilots flying lower performance gliders because only two of their four category scores benefit from glider handicaps.

While these three issues are easy to recognize, they are unfortunately difficult to fix.  The data used for scoring the contest are directly taken from a spreadsheet that OLC reports for flights from from a specific location, in this case Parowan.

The OLC location spreadsheet only reports Total OLC Plus Points, km flown (based on 6 legs), FAI km flown in km, distance km flown in km, as well as start time and finish time of the flight.  To solve the issues noted above, additional data would be needed.  OLC has more data available (e.g. bonus points awarded for triangles and distance away from home could be used in lieu of km flown to correctly account for glider handicaps in all 4 categories).  However, unless OLC could be convinced to report additional information in spreadsheet format it is complicated and time consuming to obtain.

Using WeGlide instead of OLC as a data source currently does not solve this problem either.  However, if there is more interest in a time-capped contest format in general, perhaps WeGlide would be willing to make the required additional data more easily available.  What’s needed would be a location-based spreadsheet that reports for each flight: date, name, total points for the flight, O&R distance, FAI triangle distance, 2-hour Sprint score, as well as glider and glider handicap.

Even better would it be for WeGlide to build on their Local Competition format and perhaps develop a new scoring format for a time-capped contest with multi-day automatic scoring that would eliminate any manual scoring requirements.  Just asking for a friend 😉

Socializing

The Williams Trophy Format is great for socializing.  The typical soaring day starts with a joint group breakfast at 7:30am followed by a pilot’s meeting at 9am.  Then pilots ready their gliders and typically launch around 11 am and normally return by 6pm.  Group dinner is normally at 7pm in the hangar and everyone has a chance to get enough sleep to go at it again the next day.

Days off are usually spent hiking or hanging out with your soaring friends.

The fact that there are far more pilots interested in joining the Parowan Camp than there is available space to accommodate them demonstrates the appeal and attractiveness of the format.  Pilots are experienced XC pilots who are looking for a great soaring experience with friends, rather than for 2 weeks of hard core racing.

Parowan is not a substitute for the competitive racing circuit but an excellent complement.  Many pilots I talked to wish that despite the quirks and shortcomings of the Williams Trophy there would be more events like it.

Most recently I explained why I chose a V3M as my first self-launching motor glider. This article explores what it means to me to fly one.  Everyone can readily see that motor gliders bring independence from tow planes: pilots can take off when they want and from where they want.  But does the impact go further than that.  My initial experience shows that, yes, it does.

The Psychology of Flying a Motor Glider

Motorized gliders have stirred emotions since they became a thing more than 50 years ago.   Although some 90% of new gliders are now equipped with engines, some purists still seem to consider them cheating machines that help the feeble-minded obtain an unfair advantage.  In response, defensive motor glider pilots have suggested that the greater fixed ballast and the necessarily higher decision altitude for land-outs might actually slow them down.

In my mind this squabbling is not only fruitless but it largely misses the point.  There are many differences among gliders (e.g. wing profile, wing loading, winglets, instrumentation, fuselage design, etc…) that can give a pilot a competitive advantage without igniting a philosophical debate.  And with all other things (including wing-loading) being held equal, it is difficult to see how the mere presence of a motor could make one glider go faster than another.

Nevertheless, after my first season in a real motor glider (the turbo sustainer in my prior V2cxT was of limited practical use at the lofty altitudes of Colorado), I can say that having a capable motor does in fact make a big difference.

No, it does not affect how fast I can go, but still, it is of great relevance to me.  The effect is psychological. Think of it this way: what if you had a pre-paid, dedicated, and selfless ground crew automatically following you around on every flight? And what if that ground crew also possessed a magic wand to instantly fix any damage that your glider might incur during a potential landout?

Neither the crew nor its magic wand would make your glider go any faster. However, its constant presence would certainly make you more willing to conduct flights that you would not attempt otherwise.  That’s what the presence of an engine does.  The effect is in your brain.

I should add a caveat:  since engines are still not working as reliably as we’d wish them to, you have to allow for the possibility that on some random occasion your crew and its wand would simply fail to show up even though you expect them to come along every single time.  This caveat is important because it forces motor glider pilots to always keep a safely landable field in glide just like any pilot of a pure glider.

Also, lest anyone gets carried away by their imagination, even the most reliable motor is not a “bail-out device” when conditions go south.  Sometimes I see comments on accidents reports such as “why didn’t the pilot use the engine?”  Usually there is a good reason for that.  E.g., in my V3M, one of the best climbing motor-gliders, the best climb rate is between 400 and 500 fpm.  Now imagine flying into an area of heavy sink.  Downwind of mountain ridges, in a microburst event, or in the sink zone of mountain wave, downdrafts routinely exceed 1000 fpm and can be as severe as 3000 fpm or even more.   What good would the engine do in such heavy sink? Attempting to use it would only make a bad situation worse because it dramatically limits your speed range, effectively forcing you to stay in sink much longer than otherwise necessary.  In my V3M, the best climb rate is attained at 54 kt.  Try to go faster and the engine will overspeed and you will no longer climb.  Go faster still and it may shut off altogether, turning a 55:1 glider into a 15:1 flying brick. The best thing to do in heavy sink is to keep the propeller tugged away, put the nose down, and fly out of the sink as fast as you can, near redline if necessary.  But do not look to your engine for help!

So, why then does the mere presence of a capable engine make so much difference?  Let’s consider some real examples.

Flights that Would Not Have Happened Without An Engine

In my first season with the V3M I can identify numerous flights that almost certainly would not have happened the same way if I did not have a motor glider.

Roundtrip to Utah – 1154 km

On June 13, 2024 I became the first pilot to fly from Boulder to Utah and back in a single flight.  My declared turn point was Mount Peale, the highest peak in the La Sal Mountains, just east of Moab.

On the first 300 km or so having a motor made no difference.  I was flying over familiar terrain, there were reasonable clouds and I was confident of a viable return. Things changed after I had gotten low near Montrose and with another 100 km to go to my turn point.

The Uncompahgre Plateau ahead was overdeveloping and I had to find a line between virga shafts to get to my turn point and back.  There was no way of knowing whether this would work or not.  I decided that continuing would not be unsafe because the cells were scattered and there was (yet) too little vertical development to create a risk of thunderstorms.  However, it was also far from certain that the weather would hold up long enough to also permit a safe return.

Safety on the way out was assured by the proximity of Hopkins Field which I would be able to keep in glide at all times.  But I had to be mindful of the possibility that the weather would further deteriorate and force me to land.

What does this have to do with the engine?  Well, nothing or everything. It depends how you look at it.

Consider that there are no tow planes at Hopkins Field (or at any other airport in the area).  The shortest road distance between Boulder and Hopkins is 368 miles and it takes about eight hours to get there, perhaps more when pulling a glider trailer. One way.  If I were to land at Hopkins, I’d have to spend the night and the earliest someone might be able to come and get me would be in the afternoon on the next day.  Provided I could rally a volunteer to get on the road for 16+ hours.

Hopkins Field, like much of western Colorado, is in a pretty remote place. There are a few small private hangars at the airfield but otherwise no infrastructure. Definitely no rental cars.  The only restaurant is a three mile walk away to the village of Nucia, population 585. Nucia has no hotel and only one Bed and Breakfast place with 4 rooms.  These could easily be sold out.  Would my cell phone work on the ground?  Unlikely.

Now be honest with yourself: let’s say you estimate the odds of having to land at Hopkins Field at 50:50, would you continue on without an engine?  You might say, sure, that’s part of the adventure of soaring. In this case, having an engine really does not matter to you. And I greatly admire your attitude and spirit of adventure.

For me at least, the impact is profound. Thanks to the engine, my thought process went about like this: it’s quite possible that I sink out and have to divert to Hopkins.  In that case I’d start my engine over the airport and then look for a way around the virga cells to the north.  In all likelihood I will be able to reconnect with lift, stow the engine away and continue my flight, heading back home.  The risk of having to land and spend a night or two in Nucia would drop from 50% to perhaps 2 or 3%.  To me that’s a totally different equation which made it easy for me to continue with the flight.

Such thoughts helped me continue on and everything worked out just fine.  I made it through between the virga cells, I did not have to divert, I rounded my turn point, and I had a successful flight back to Boulder.  Towards the end I was even able to extend the flight into Wyoming and thereby became the first pilot to fly from Boulder into Utah and Wyoming in a single flight.  My 1154 km flight included a 928 km FAI triangle and was good for 1174 points on WeGlide.  It was the longest flight in the world on that particular day. All of this could have been accomplished without an engine and the flight would have been neither faster nor slower.  However, most likely I would not have done it at all.

You can find the flight trace and my post-flight report here: https://www.weglide.org/flight/417542

Across the Great Divide Basin – 864 km

On July 5, 2024 I became the first pilot to fly from Boulder across the Great Divide Basin to the foot of the Wind River Range and back to Boulder.  The scenery was absolutely spectacular.  Very few people are familiar with this area. Even most Coloradans have never been there.

Prior to this flight you could search the entire flight history from Boulder on OLC and only find a handful of flights that ever even entered the Great Divide Basin of Wyoming. And not one of them went beyond glide range to Rawlins’ airport.

There are good reason for that: the Great Divide Basin is a dry, desolate, and windy place.  More than 10,000 square kilometer in size, it has a population of 203, concentrated in the only “town” of Wamsutter, essentially a refueling stop along Highway I-80.  Although it’s median elevation is 6500 ft MSL, the Basin is surrounded by higher terrain such that precipitation cannot flow to the sea.  If there was enough water, the Basin would be one big lake. But there isn’t and the Basin is a dry, dusty, desert.

The idea of perhaps having to land in the Basin is not exactly pleasant.  The terrain is undulating and scarred by drainages. The ground is rocky and sandy and mostly covered by sagebrush.  There are no people, no infrastructure, and the only roads are dirt tracks, most of which are only traversable by off-road vehicles.

Putting a glider down in this terrain is unlikely to kill or seriously harm the pilot. The glider, however may not  get off so easily. Who knows if and when you’ll be able to use it again.  You might also be out there for a while.  In addition to a satellite communication device, you better bring sufficient water, food, and warm clothing. The nights in the desert can get cold, even in summer.

Like other desert regions (e.g. in Namibia, Morocco, Nevada, etc.), the Basin can be a great place for thermal soaring.  However, the wind can be a limiting factor for it often blows so hard that it rips the thermals apart.

Over the past few years, I have often thought about flights across this area. I even spent hours on Google Maps looking for areas where dirt tracks are straight enough, and the terrain flat enough, to limit the hazards if forced to land out.

But I didn’t actually do it until I had a capable motor glider. What made the difference?  Even on a good thermal day marked by cumulus, I was not comfortable that I could reduce the risk of a landout far enough to fly across this terrain.  For me, personally, even a 2 % risk of a landout (a 1 in 50 chance) is too great for a flight over such forbidding terrain.

How does the presence of a capable and relatively reliable engine (such as the one in my V3M) change this equation?  It’s important to realize that it cannot eliminate the risks.  Let’s say the risk of an engine failure is 1% (i.e. the engine won’t start in 1 out of 100 attempts), this reduces a 2% risk of a landout (a 1 in 50 chance) to a 0.02% risk (a 1 in 5000 chance).  In my subjective assessment this is low enough to be acceptable to me.

I respect anyone who draws different conclusions for themselves.  If you watch the (in)famous soaring movie “The Sunship Game” (which features competition flying over similar terrain in Texas), you’ll see that for some pilots a 2% risk of having to land somewhere where they might wreck their glider is clearly perfectly acceptable.  (If you’re one of them you also won’t need a motor glider.) Others will say that even a 0.02% risk is too high for them.

I’m not judging either the one or the other and I am certainly not saying that my own assessment is the one to adopt.  Ultimately everyone has to make their own risk assessment and be comfortable with it.  I would just remind everyone that soaring is a relatively dangerous sport where we can work to minimize the risks but we cannot possibly reduce them to zero.  We are likely to make better decisions if we do our best to understand them for what they are and remain honest with ourselves as to what’s acceptable (or not acceptable) to us.

You can find the flight trace and my post-flight report here: https://www.weglide.org/flight/430267

Pushing From First Lift Until Sunset – 1286 km

On July 12, 2024 I succeeded in surpassing the greatest 6-leg distance ever flown from Boulder with a 1286 km flight including a 928 km FAI triangle.  The flight was good for 1353 points on OLC and 1282 points on WeGlide.

During this flight I was always able to keep airports or landable fields in glide and there’s no question the same flight could have been safely done in a pure glider.  Still, I don’t believe that I would have done it if I didn’t have a motor glider.

I’ll illustrate this by highlighting three particular phases of the flight:

Phase 1: timing of the start.  The day was late to develop.  The wind was howling from the NNW.  There were no thermals yet, and my first climb of the day was in rotor lift over the lower foothills, just west of Boulder.  I could see the first thermal clouds far to the south, approx. 40-50 miles away.  Perhaps, I thought, my 14,000 ft altitude (~ 6,000-7000 ft above the foothill terrain) would be good enough to get there, thanks in part to the ~20 kt tailwind. But I could not be sure.

Should I start on task  immediately or should I wait another 30 minutes or so for the convergence to work and the wind to calm down a little?  If I wanted a chance at a record distance flight I could not waste a minute.  But what if I didn’t connect with the lift to the south before I would run out of altitude?  There are no airports in this direction and coming back into a 20 kt headwind would not be an option either.  In other words, in a pure glider I would have no choice but to land in one of the farm fields south of Chatfield Reservoir, or perhaps at the nearby RC airplane field as one of my friends had done the year before.  In either case, a great soaring day would be over before it had really begun.

Thanks to the engine of the V3M, my calculation was different.  There was the same risk that I would not connect with the lift to the south in time. But if that happened, instead of landing out, I would start the engine above one of the fields, motor to the clouds, and re-start my soaring flight from there.

Phase 2: flying into a poor airmass. After I had passed Crested Butte on my second leg, heading into the north-westerly wind, I could readily see that a murky airmass lay over the Colorado River Valley.  I had previously rounded my first turn point and was still hopeful that I could complete my declared 1050 km FAI triangle.  But to have a chance, I would need to fly into the murky, thermally unreliable air ahead.

I had no idea if it would work and the only way to find out was to try.  Garfield County airport at Rifle was in easy glide so there was no safety risk.  But would I have left the good air behind, had I been in a pure glider?  Chances are that I would have quit my attempt at a record flight and changed directions to stay in better air to not risk the considerable inconvenience of a ground retrieve for myself and for others.

Phase 3: pushing until sunset.  When I came back to Boulder on my fourth leg it was already past 6pm and I had been flying for 7 1/2 hours.  Should I continue to fly away from Boulder again to add another two legs just to see how far I could push it?

The convergence line to the south looked promising but how long would the lift last?  Without an engine, my practice in the past had been to stay within glide range of Boulder when extending my flights in the evening when there was a chance that the thermals would quit on me.  In a pure glider that’s the only practical way to eliminate the risk of having to land in some farm field right when the sun goes down, perhaps forcing me to spend the night in the cockpit.

Again, the equation is subtly different in a motor glider.  Thanks to having an engine I only needed to time my last turn such that I could still get back home under power before the sun would officially set.  On this particular flight this calculation allowed me to fly just a little further to the south – perhaps by 30 km or so – than I otherwise would have.  But those 30 km represent a 60 km roundtrip.  And without these 60km, my 1286 km flight would not have broken the prior 1254 km record for the greatest distance flown from Boulder.  The thermals lasted until the end and the same flight could have been achieved in a pure glider as well.  But somehow I doubt that I would have done it.

You can find the flight trace and my post-flight report here: https://www.weglide.org/flight/434838

Other Examples

So far we looked at three examples of flights that probably would not have happened this way without an engine. For those interested, there were at least three more that you can look up:

1026 km on August 3:  completion of the Colorado Border-to-Border Challenge via an unusual route along the Southern San Juan Mountains. Without engine I would likely not have continued to my first turn point.  https://www.weglide.org/flight/455212

856 km on August 16: perhaps my most difficult flight to date in very challenging conditions with low thermal tops, strong winds, and big stretches under blue skies without any thermal markers. This flight was very satisfying because I was trying things I hadn’t done before even though there was never even a remote chance of breaking any records.  I definitely would not have done it without engine. https://www.weglide.org/flight/467435

709 km on Aug 27: this flight included an (ultimately unsuccessful) attempt to ridge-soar the Northern Sangres (which I would not have tried without an engine). https://www.weglide.org/flight/474491

What Do All These Flights Have in Common?

Reflecting back on all of the flights that “would not have happened this way” without an engine, there are essentially two reasons for that:

(1) Flights I would not have executed this way because of a significant land-out risk that would have resulted in great inconvenience.  This was the case in the vast majority of the examples provided.  All of these flights can happen just the same in a pure glider if the pilot’s motivation to complete them is so great that he or she is prepared to put up with the inconveniences in case of failure.  If you are willing to do them regardless (and I know there are pilots who readily will), you can feel free to judge me for my lower tolerance of inconveniences or my comparatively inferior ambition and motivation.

(2) Flights I would not have undertaken because they led across hostile terrain with very poor landout options.  The only flight that falls into this category is the one across the Great Divide Basin.  This one, too, could have happened with a pure glider, but failure here has greater consequences than mere inconvenience since it could easily result in damage to the aircraft.  Having a reasonably reliable motor reduces this risk by almost two orders of magnitude but it does not eliminate it. Whether to conduct such flights does not just require comparing your motivation against your convenience but also against your risk tolerance.

What About the Impact of the Engine on Speed?

In 2024 I also set three new state speed records:

Open Class 750km Speed Triangle in Utah: https://www.weglide.org/flight/422726

Open Class 500km Speed Triangle in Colorado: https://www.weglide.org/flight/476006

Open Class 750km Speed Triangle in Colorado: https://www.weglide.org/flight/478660

It’s a fair question to ask what role, if any, the engine played in these flights.

In the case of the 500 km speed triangle in Colorado, I think the presence of the engine had no impact whatsoever.  There were good thermals marked by clouds, bases were high, and I never perceived there to be a real land out risk.  There is no doubt in my mind that this flight would have happened just the same, with or without engine.

In the case of the 750 km speed triangle in Colorado, I am inclined to come to the same conclusion even though this flight was more challenging due to the lower cloud bases, which kept me below 16,000 ft for the first two thirds of the flight. Ultimately, however, I believe that my motivation was strong enough that even in a pure glider I would have overcome the relatively small doubt that I may have had about my ability to continue the flight to completion.

The case of the 750 km speed triangle in Utah is a different matter.  The route led over very remote terrain in the Great Basin that I was not familiar with.  I had done my homework and knew where I could safely land. I was also careful to always keep a landable place in glide.  However, good stretches over the Great Basin were entirely blue. Without a crew, landing in the Great Basin would have been a major inconvenience.  So it is fair to assume that I would not have done this flight without an engine.

Therefore, in my assessment, I think it is fair to say that the engine does provide an advantage in the sense that even some speed record flights would simply not have happened if the pilot had to fly a pure glider.

On the other hand, I still believe that that the presence of the engine has no real impact on the attainable speed.  Unquestionably, the glider does not fly faster because it has an engine. Plus, importantly, the presence of the motor did not make me press any harder on any of these flights than I would have done without it.

What About Other Benefits of Motor Gliders?

Of course motor gliders afford other benefits to their owners.  Most of them are obvious because the motor makes you independent of a tow plane.  This means you can fly from where you want and when you want. This sense of independence is the main reason why pilots are willing to shell out a lot of money for that noisy contraption behind the cockpit.

This article doesn’t attempt to list all benefits and disadvantages of motor gliders.  (And yes, the disadvantages exist, too.  Think much greater complexity, more involved maintenance, higher costs, etc.)  This article only explored the more subtle question whether motor gliders provide a competitive advantage.

Conclusion

Do motor gliders provide a competitive advantage over pure gliders?  In my view the answer depends on what you mean by “competitive advantage”.

Based on my first season with the V3M I am confident that the motor does not make me faster. If that’s your definition of competitive advantage, the answer is “no.”

However, the very presence of an engine has surely helped me undertake and complete flights that I would not have executed the same way with a pure glider.  To me this is a powerful benefit that makes me glad I spent all that extra money even though in Boulder we normally have easy access to a tow plane.

Could this advantage play a role in a contest?  I think it can.  Imagine a day where the land out risk is very high.  Some pilots may not decide to fly the task at all or return prematurely.  It would be easy to see that those would be the ones that neither have an engine nor a crew ready to bring them back.

Which brings me back to the beginning.  Having an engine is like having a crew that’s ready and willing to follow you around.  If having a crew in a contest is unfair, then having a motor is unfair, too.

Perhaps future seasons will allow me to form a more nuanced view. In the meantime, I’m curious about your perspective.  Please share it in the comments below.

Now that my Ventus 2cxT has found a new home, I’m ready to share the reasons that led me to buy a new Ventus 3M directly from the factory.  It’s not often in life that we get to splurge on a hobby like that so this was a carefully considered decision.  In this article I share what led me to this decision. Plus, now that my first season in the new ship is behind me, I have a better perspective on whether it was the right choice for me.

My Decision Criteria

• • XC Performance. I was very happy with my Ventus 2cxt.  However, at high speeds the V2 could not fully keep up with the latest generation of 18m and 21m gliders (JS3, JS1, AS33, V3) and I was hoping to be competitive should I decide fly in contests. Although it’s natural to focus on performance, it’s necessary to consider other criteria as well, some of which may actually be more critical, depending on the circumstances.
  • Self-launch from high-altitude airports, not just from Boulder but also after a possible landout at another airport. Boulder is at 5,300 ft, Salida at 7,500, Leadville at 10,000. The density altitude can be several thousand feet higher.  Boulder conditions often require long tows or motor runs with climbs to >11,000 ft under power to get out of the inverted airmass over the eastern plains and into the buoyant mountain air.  Plus, I wanted sufficient energy for self-retrieve when necessary, including the ability to climb to >13,000ft to cross high mountain passes.
  • Access to quality service and maintenance. I am neither a mechanic nor a “tinkerer” and rely on professionals.  For motorized gliders where your life depends on the engine running reliably, this is a major consideration.
  • Quality workmanship. New glider models and/or new engines often suffer from teething issues and its not until a substantial number of a particular model have been built, that these issues are worked out.
  • Easy rigging and ground handling. There are no hangars for gliders in Boulder and tie down space is limited.  Easy rigging is therefore a necessity, not just something that’s nice to have.  Heavy motor-gliders also need a steerable tailwheel to operate without assistance, e.g. after a landout at another airport. It took me a while to realize just how important this is.
  • Value retention. Quality gliders tend to retain their value remarkably well, especially if they meet the other criteria above.

Options

The considerations above narrowed my list to the following four options:

• • JS3 RES: 15/18m with electric self-launch engine

• • AS 33Me: 15/18m with electric self-launch engine

• • AS 35Mi: 18/20m with IAE 50R-AA Wankel 41 kW self-launch engine

• • V3M: 18m with Solo 2625 01i 45 kW two-stroke self-launch engine

Note: Neither the V3E nor the JS2 were announced at the time I made my decision (see below).

Decision Process

In my heart I was heavily drawn to electric self-launchers, which would have meant a choice between the JS3 RES (which was already available), or the AS 33ME (which had been announced but none had been built at the time).  The V3E had not yet been announced.  It would definitely have made it into my consideration set.

Electric engines are much simpler and require less maintenance, they produce lower noise than combustion engines, and are much more eco-friendly.  All of these greatly appealed to me.  The climb performance is also quite strong, at least for take off when the battery is fully charged and not too hot.  However, the more I researched, the more my heart had to yield to my brain: I came to the conclusion that electric gliders were not (yet) ready for my critical use cases. While they had sufficient energy for a self-launch, even to 11,000 ft,  they would then not have enough energy left for a second self-launch at another airport (following a possible landout). In addition, the chargers were too bulky to bring along in the cockpit.  Even taxiing needed to remain limited in order to conserve power and prevent the battery from overheating. (This may have been a reason why Schleicher does not even offer a steerable tailwheel for its electric self-launchers, the AS33Me and the AS34Me.)  Similarly, I was concerned that the energy remaining after a typical self-launch from Boulder would not suffice to cross one of the tall Colorado mountain passes in order to self-retrieve.  These had been real practical constraints that I experienced with my Ventus 2cxT with its sustainer engine that I was determined to get away from.

Once I had come to the important conclusion that electric gliders simply did not sufficiently address my use cases yet, my choice narrowed down to V3M and AS35Mi.

The AS35Mi will be the successor of the very successful AS31Mi.  The emphasis here is on will be because at the time I made my decision none had yet been built.  Two years on, I believe this is still the case.  In addition to timing I was also concerned about takeoff performance.  The AS35Mi will have the same Wankel engine as the AS31Mi and the AS32Mi (a two seat self-launcher).  While the engine is certainly adequate for the AS31Mi, in the heavier AS 32Mi it is at best marginal at Boulder’s field elevation.  (I had first hand experience from flying one with a friend.)  Given that the AS35Mi will be considerably heavier than the AS31Mi (at least at maximum takeoff weight), I became concerned about its takeoff and climb performance at high-altitude airfields such as Boulder. All that plus my aversion to buying a glider with a low serial number (because initial kinks are likely inevitable) made it easy to focus my attention on the V3M.

Evaluation

Now that I have flown the V3M for more than 200 hours, I have a good sense how it holds up to my criteria.

XC Performance.  Because the V3 has a slightly greater wing area than the JS3 or the AS 33, fully ballasted it may not run quite as fast.  (Although Simon Schröder’s 2nd place finish at the World Championships in Uvalde shows that the V3 can certainly keep up with the JS3 and AS33.)  However, even if there may be a small difference in booming conditions, days when full ballast is beneficial from morning to late are few and far between. I concluded that in practical terms this simply isn’t a significant issue.  I routinely fly the V3M about 5-10 kt faster that the V2 without noticing any degradation in glide performance.  This is a substantial improvement and is confirmed by the statistics:  my average XC speed in 2023 (flying the Ventus 2cxt) was 109 kph, whereas in 2024 (with the V3M) it was 118 kph.  While some of this may be due to continued pilot improvements, a more than 8% improvement is remarkable!  In thermals the V3M is even easier and more stable than the V2 (which requires more rudder to remain coordinated).

Self-launch from high altitude airports.  There’s nothing that can beat the V3M in climb performance except for highly powered airplanes without glider in tow.  The water-cooled and fuel-injected Solo engine runs great at our altitude.  I out-climb not just all other self-launchers at the field – especially the Wankel powered AS gliders – but even the 265hp Pawnees when they have a glider in tow.  My climb rate is typically in the range of 400-500 fpm and only drops to 300 fpm above 10,000 ft.  Even at 13,000 ft it still runs smoothly and continues to climb at rates around 200 fpm.

Access to quality maintenance.  While I wish that U.S. Schempp-Hirth dealer Garrett Willat wasn’t as far away as Southern California (a two-day drive from Boulder) I have to give him very high praise for responsiveness and quality of service.  There are now at least four Ventus 3Ms in Colorado and this may make it easier to coordinate maintenance in order to get work done in Colorado rather than having all of us trailer our gliders to California.

Quality workmanship.  I’m really happy to have a glider with a serial number >200 and Schempp-Hirth has been living up to its great reputation for finish quality.  So far, everything has been working as expected.  Talk to other motor glider owners to find out how unusual this can be.

Easy rigging and ground handling. All motor gliders are heavy and the V3M is no exception.  However, thanks to a high quality Cobra trailer, rigging is just as easy as for the Ventus 2.  A lifting aid is required to mount and remove the tail dolly which is a bit of a nuisance.  The steerable tailwheel turns out to be even more essential than I had imagined:  it allows me to get into the cockpit at my parking position and conduct all pre-flight checks before taxiing onto the runway for immediate takeoff.  Upon landing I can clear the runway and steer the glider right into its parking position before getting out of the cockpit, usually without having to start the engine at all.  At our busy airport these are real safety benefits and not mere conveniences.

Value Retention.  15/18 m gliders from Schempp-Hirth and Schleicher have both done very well at retaining their value and I am confident that this won’t be any different with the V3M.

What If I Were Deciding Today

There’s no question in my mind that I made the right decision when I sent off my order 2+ years ago.

Since then, two new options have become available:

• • V3E: 18m electric self-launch

• • JS2 18/21m with Solo 2625 02i 47 kW self-launch engine

I still think that electric self-launchers are premature for Boulder and my specific use cases.  However, if I were to consider an electric glider I would want to have the batteries in the fuselage (for easy charging and also to remove them during the very cold Colorado winter) and I would insist on a steerable tail wheel for taxiing.  These attributes would give the Ventus 3E an edge over the AS 33Me and the JS3 RES for my personal use cases. However, since electric gliders remain out for me, my choice would be between the V3M and the new JS2.

The JS2 18/21m is a brand new option that I would consider carefully against my criteria.  It is likely that it would score highly on performance (likely beating the V3M in 21m configuration) and I would enjoy that it provides the option of flying with 18 and 21 m wings as this would give me the option to realistically compete in Open Class as well as in 18m class.

With essentially the same Solo engine as the V3M it is likely just as powerful as the V3M on self-launch capability (Jonkers claims to get 2 additional kW out of it) .  Likewise, rigging and ground handling are likely similar in complexity.  I don’t have enough experience to speak to maintenance and local service capability and I would want to do my due diligence by talking to other JS owners to satisfy myself before taking the plunge.  There’s also less history to assess value retention over time but I suspect Jonkers gliders will do just as well as long as the company continues to prosper.

My main concern would be about buying a glider with a low serial number.  While the wings are proven from the JS1, the fuselage is new and my understanding is that Jonkers made additional modifications to the engine.  I’d definitely feel better if there were at least a few dozen gliders already in use with the same engine and the owners reported being satisfied with it.  Nevertheless, the glider is in my view the most viable alternative to a V3M and I would give it careful consideration.

My Advice

High performance gliders have never offered more performance and more convenience and safety features.

For anyone lucky enough to afford one of these beauties, my main advice is to be honest with yourself and carefully consider your specific use cases and their relative importance to you before you make a decision.  If winning the world championships is your ultimate objective and you’re willing to do what it takes to get there you may make a different decision than if your primary objective is to achieve great flights from wherever and whenever you want.

In any case, there are great choices to make.  Enjoy the process.  Be inspired and dream.  But also, be realistic. You’re not buying a car with an 8 or 9 digit serial number and a nearby dealership that can fix any potential issue within a few hours. Gliders are still hand made, and when you buy a low serial number machine you are essentially buying a prototype. Maybe that is exactly what you want. But maybe you’re like me and value the incremental reliability of a serial number greater than hundred more than the 0.1% performance improvement a retractable (but not steerable) tailwheel may afford.  If you rarely need more than a 2000 ft tow and have easy access to a hanger with electricity than an electric self-launcher may be perfect for you.  But maybe not.  Although all these gliders are amazing machines with similar performance, try to fully understand what you’re committing to when you put your name on that dotted line…

Whether you’re contemplating getting a new glider or have a different perspective or diverging decision criteria, please feel free to share your perspective in the comments.

Edit (November 2024): V1 has found a great new home and will continue to soar high above the American West. If you’re looking for a similar high performance glider, look at the classifieds on Wings and Wheels. You can also contact the various airplane dealers as they may know in advance of gliders that may come onto the market. Good Luck!

If you’ve been following me on Facebook, WeGlide, or OLC you’ll know that I have recently taken delivery of a new Ventus 3M.  This means that my trusted Ventus 2cxT, the glider I’ve flown in all my YouTube videos, is now for sale.

“V1” is an amazing sailplane.  Please click on the links below to learn more about it. The information provided should answer most of your questions. If you think you want to own this beautiful glider or if there’s something else you want to know first, please contact me at ChessInTheAir@gmail.com.

Adventures Await

Click on the images below to learn more about the glider, the instrumentation, and the trailer:

The Glider

Instrumentation

The Trailer

Contact

The glider is available for inspection and pickup at the airport (KBDU) in Boulder, Colorado, USA.

A refundable deposit check of $1,000 holds the glider for inspection or 10 days. If more time is needed for inspection please contact me to arrange as needed. A cashier check made payable to “Clemens Ceipek” closes the deal.

Asking price for the entire package (glider, trailer, instrumentation) as described is $124,500.

The glider and trailer are in very good condition – just as as described. The reason for selling is that I have recently taken delivery of a new Ventus 3M.

If you think you would like to own this beautiful glider please contact me at ChessInTheAir@gmail.com

Only serious enquiries, please.

Clemens Ceipek

Here are some of the beautiful places where this glider has been. Where will you take it?

You can find full details of my flights with V1 on WeGlide at: https://www.weglide.org/user/2037

After another successful soaring season in 2022, here are my goals for 2023.

If you’re interested in setting your own soaring goals, you can find some tips towards the end of this article from last year.

1. Stay Safe by always heeding my own advice.

This goal remains unchanged.  Flying safely is essential and the pre-requisite for anything else.  Pilots often let their safety margins erode as they gain experience.  I now have more than 1000 hours in gliders and I know that I must not let that happen.  Here are the metrics I will  continue to use:

• • Zero accidents (no damage)
  • Zero near misses or other incidents (i.e., almost accidents)
  • Zero violations of personal minima and zero “99% safe” maneuvers (e.g. low safe attempt below personal minimum)
  • Zero flights where a safe outcome depends entirely on Plan A working as hoped (i.e. I must have a viable and safe Plan B/C at all times; the alternative plan must include a known safe place to land at all times)
  • Zero takeoffs without a clear pre-defined emergency plan specific to the airport and conditions of the day

2. Continue to Improve My Soaring Skills

I will continue to focus on the metrics that matter most to performance soaring: cruise and climb performance.   My objective is to make further improvements against my own performance in comparable conditions rather than to achieve specific absolute performance numbers or rankings.

• • Continue to improve my glide performance in cruise flight (performance goal)
    • The key to improving glide performance is to become even better at flying in rising air during cruise portions of the flight.  I believe I can continue to do so by building my habit of using S-turn explorations along energy lines to find and follow the best rising air, basing decision primarily on evidence of the day and less on perceived prior experience.
    • The best way to track progress is through the “netto” value.  Unfortunately this metric is usually not easily available.
    • I will use the following metric as a close proxy:  In 2022 my average glide ratio on legs 2, 3, 4, and 5 (excluding 1 and 6) was 81:1 while cruising at 178 kph.  An improvement would be either an improved glide ratio at the same speed, or a greater cruise speed while maintaining the same glide ratio.  Either one would mean that I am getting better at flying in lift.  I.e., I will measure my progress by tracking the product of these two numbers.  The 2022 benchmark is 81×178 = 14,418.  I would like the 2023 value to be 14,750 or greater.  E.g., this would mean increasing the cruise speed to 182 kph while maintaining the same glide ratio of 81:1 (or increasing the glide ratio to 83:1 at the same cruise speed.)
    • My flight analysis suggests that my inter-thermal cruise speed is well below that of other pilots flying similar gliders.  I will therefore try to primarily increase the cruise speed, without overly sacrificing glide ratio.
    • I will only use flights in Colorado to calculate this benchmark to avoid distortions.
• • Continue to improve climb performance (performance goal)
  • • I will try to improve my thermalling performance by further tightening my turns with the goal to reach 39-41 degrees on average (the 2022 average was 37 degrees).  I will also try to improve my thermal exit: omit the unnecessary last circle near the top of the thermal (or airspace); and complete the last circle with steep bank, then accelerate (do not become sloppy in the last turn and begin to accelerate within the surrounding sink during the turn.)
    • I will measure overall progress by tracking my average achieved climb rate.  In 2022 it was 2.15 m/s during legs 2, 3, 4, and 5 (excluding legs 1 and 6) of all my flights.  I will seek to improve on this benchmark in 2023.
    • I will only use flights in Colorado to calculate this benchmark to avoid distortions.

• • Reduce thermaling attempts (performance goal)
    • Thermalling attempts during legs 2, 3, 4, and 5 (excluding legs 1 and 6) of all my flights accounted for 2.32% of my flight time.  The average climb rate during these attempts was 0.37 m/s.  I would like to reduce the time spent on thermalling attempts to less than 2% of the total flight time by being more selective when to turn.

3. Flight Achievement Goals

I will apply these skills towards attaining a set of specific flight achievement goals. I continue to be more interested in completing interesting and challenging flights than in competing in set competition tasks. However, I am considering to fly in one or two contests; this would also provide more comparative metrics on my performance.

Because specific flight objectives are necessarily subject to suitable weather conditions I will not limit myself to a few specific goals but continue to take a portfolio approach.  I.e.,  I will aim to accomplish five of the following objectives:

• • Distance Objectives:

    • Reach some of the San Juan 14ers and/or the Blanca Massif 14ers from Boulder; Stretch goal is to accomplish all 14er flights from Boulder.
    • Complete Border to Border Challenge (from Boulder to NM, WY, and return)
    • Reach another state line from Boulder (UT, SD, KS, OK, TX, AZ, MT)
    • Accomplish a one-way goal flight to a glider port in a neighboring state (e.g., Nephi, UT; Moriarty, NM; Hutchinson, KS, Driggs, ID)
    • One flight greater than 1100 km per OLC+ rules; my stretch goal is to break the Colorado state record of 1273 km
    • Top 20 in the global Barron Hilton Cup and/or top 10 in the US
    • Top 50 in global OLC+ Championship and/or top 25 in the US
    • Set another Colorado Distance Record (e.g., Goal Distance 340mi, 3TP distance 633 mi, declared O&R distance 489 mi, free O&R distance 578 mi)

• • Speed and Contest Objectives:

    • Set another Colorado speed record (e.g., 500 km Triangle Speed 81.45 mph; 300 km Triangle Speed 86.4 mph)
    • If flying in contests, finish among the top 33% in a regional contest; or among top 50% in a national contest.  (I am currently considering the Region 9 contest in El Tiro, AZ and the 18m Nationals in Uvalde, TX.  However, I have not yet decided whether to fly in any of them.)
    • When flying on Speed-League weekends from Boulder, score among the top 3 Boulder pilots 100% of the time.

4. Giving Back

Just like last year, I will continue to put energy towards inspiring others worldwide to join our sport, to develop, excel, and stay safe.  I will do this through:

• • • Writing – follow me on ChessInTheAir.com and on Facebook
    • Presentations and Podcast Contributions – to local, national, and international audiences
    • Videos – subscribe to my ChessInTheAir YouTubeChannel, and
    • Serving for soaring organizations such as the Soaring Society of Boulder

Want to set your own soaring goals?  Take a look at the tips at the bottom of this article.

A little later than planned, here’s a review of my progress against the soaring goals I had set myself for 2022.  Overall, I am pleased with my continued progress.

Goal #1 – Stay Safe by Heeding My Own Advice

I think I can give myself an “A” on this one.  In 2022, I flew more than 23,000 cross-country kilometers including 14,500 FAI triangle kilometers in 210 flight hours without accident or incident.  I also cannot recall a situation that was objectively dangerous or even subjectively scary.  I came close to landing out on two occasions but in both instances I had a suitable field picked out and within easy reach.  I want to keep it that way.

Goal #2 – Continue to Improve My Soaring Skills

This one gets a “B+”.  I flew 32 cross-country flights with an average flight distance per flight of 689 km.  I did not fly any contests last year which means that the magnitude of my improvement is a bit difficult to measure.  Among Boulder-based pilots I had the highest average cross-country speed at 116 kph for the year.  My average for the 2.5 hour Speed League Segments was 130 kph,  a major improvement over my 2021 average of 110 kph.  I think key contributions to my speed improvements were my focus on flying more precisely during cruise portions of the flight, and flying a bit lower along powerful lift lines to minimize situations where I had to destroy energy near the top of the permissible airspace.  This used to be a significant issue for me in prior years but only occurred rarely in 2022.

Of note is the glide performance for the entire year with an average achieved glide ratio of 64:1 across all flights while cruising at an average speed of 178 kph.  In still air, my glider’s glide ratio at this speed is 33:1 so I obviously did a reasonably good job at cruising in lift.  If I remove the first and the last leg of each flight (the first is usually focused on climbing out after tow release and the last one often destroys energy by returning high and descending with spoilers) my actual achieved glide ratio was even higher at 81:1 – definitely a key contributor to the good average speed.

My thermaling also got better.  I spent 22% of my flight time thermalling and another 2% in thermaling attempts.  My average climb rate for the entire year was 2.2 m/s (4.3 kt).  I still thermaled a bit more to the right than to the left but my comfort level with left hand turns improved considerably.  My average bank angle for all thermals throughout the entire year was 37 degrees, perhaps still a few degrees less from what many consider the “ideal” of 40 degrees.  My average thermalling speed adjusted to sea level was 102 kph, just ~3 kph above my glider’s stall speed at 37 degree bank and full wing loading (99 kph at sea level with flaps in neutral).   Considering that most thermalling is in flap position +2 (and not in neutral) I might still be going slightly too fast in the turns – but certainly not by much!

[Here’s the math for anyone interested: my actual average thermalling speed for the whole year was 134 kph at an average altitude of ~14,000 ft.  Adjusted to sea level this is ~102 kph depending on air temperature.  My glider’s stall speed in straight flight at max wing loading is 93 kph with flaps in neutral position.  At a bank angle of 37 degrees the load factor is 1.066 (1 divided by cos(37)), i.e. the turning stall speed with neutral flaps is 93 x 1.066 = 99 kph.  My actual altitude-adjusted speed of 102 kph is about 3 kph faster than stall speed with neutral flaps.  This is estimated 10 kph faster than stall speed with flaps in position +2.   The polar drops off sharply as stall speed is approached, so flying at 5-10 kph above stall speed in +2 flaps is probably ideal for circling so my average thermalling speed seemed to be about right.]

Some of my other specific performance goals turned out a bit hard to measure.   E.g., one important goal was to avoid weak thermals and measure this by calculating the time spent in weak thermals.  My specific target metric was to spend less than ~25% of thermalling time (after task start) in climbs that are less than 50% of the average climb rate for the day.

Unfortunately, I did not find an analysis tool that could easily calculate this. WeGlide provides the climb performance for each leg of each flight.  Looking at that, I could not find any glaring issues.  However, what would be needed is a tool that groups together the time spent in weak thermals and compare that weak thermal average to the thermal average of the day.  Perhaps a software provider could develop such a tool.  I would find it very insightful.

To get a better sense of the magnitude of my improvements I will need to fly more contests and obtain more direct comparisons with other pilots.

Goal #3 – Flight Achievement Goals

I can give myself an “A” in this category.  I had set the goal to achieve 5 of a portfolio of 12 ambitious achievement goals.  I accomplished 6 of them and overachieved on some of these goals:

• I became the first pilot to complete a declared 1000 km FAI triangle in Colorado; thereby setting new Colorado open class distance records for overall distance, free triangle distance, and distance of up to 3 turnpoints. This flight also earned me rank #9 for the year in the worldwide OLC Barron-Hilton-Cup competition.
• Set new Colorado open class speed records for 500 km out and return speed, 750km triangle speed, and 1000km triangle speed
• Not only bagged some additional 14ers peaks but completed the entire Colorado 14er Challenge
• Achieved my 1000 km Diplome
• Completed not one but two return flights from Boulder to the border of New Mexico
• Became the second pilot to successfully circumnavigate the Denver Class B airspace

The portfolio goals that I did not accomplish were:

• Border to Border Challenge (Boulder to NM, WY and return) – tried and failed three times
• Flight from Boulder to Nephi, UT or to Moriarty, NM – and returning the next day – never tried
• In the OLC+ Championship worldwide I finished in position 68, missing my goal of getting into the top 50; in the US I finished in position 13, missing my goal of breaking into the top 10
• In the OLC Speed Championship worldwide I finished in position 57, missing my goal of breaking into the top 50; and in the US I finished in position 20, accomplishing my target of breaking into the top 25.
• I flew no contests in 2022.

My Speed League contribution was a bit mixed.  I only flew on 7 Speed League Weekends.  When I did, I managed to always score among the top three Boulder pilots, achieving my goal of scoring among the top 3 Boulder pilots at least 75% of the time.   Bob Faris made once again the biggest contribution to SSB’s Speed League result by flying on 12 weekends and scoring first 5 times.

Goal #4 – Giving Back

I would say this one gets an “A-“.  I did not write nearly as much as I had hoped but I was able to reach worldwide audiences with my presentations at Late Night Soaring and at the annual Austrian glider pilot’s convention.  I also presented to individual clubs and some of my articles were translated into French and Spanish.  In addition, a tremendous amount of work went into community work in Boulder to address local challenges as club president.

Coming Next: My Soaring Goals for 2023

A few weeks ago I had a scary situation when towing fully ballasted behind a Piper Pawnee.  I had my camera running and published a short instructional video about the incident. I hope that it helps others avoid similar situations in the future.  Here is the video:

The comments indicate that these incidents are relatively common and occur most frequently when the tow pilot is used to pulling very light gliders that only require a low tow speed. A clear and deliberate briefing of the tow pilot before the flight is essential. You can also find a similar incident in one of Bruno Vassel’s videos.

Moreover, Dave Nadler gave a safety briefing on this very topic a few years ago at a US Soaring contest.  In it he explains that the glider’s stall speed on tow is actually higher than it is in free flight.  And why the problem is exacerbated behind short-winged tow planes such as Pawnees.  Please take a few minutes to also watch Dave’s video.  You can find it here.

A few good questions came up in this context, which I would like to address here.

Why did you not release immediately?  Would you release if a similar situation were to happen again?

I’ve spent a lot of time thinking about this question.  At the moment I was too afraid that the glider might stall and drop hard to the ground if I pulled the release.

However, perhaps the safest response for everyone involved would have been the following:

• • Rather than trying to climb with the tow plane, I should have stayed in ground effect while communicating the request for a greater airspeed.  Staying in ground effect protects the glider from a stall because of lower induced drag.  It also reduces the consequences of a possible drop to the ground because of the very low altitude.
  • Hopefully the tow pilot would react before the glider reaches the “low tow” position.  (We don’t practice low tow in the US except when practicing “boxing the wake”. In some countries the low tow position is used more routinely for towing because it protects the tow pilot from a glider pulling the tow plane’s tail up and forcing the tow plane into the ground.)
  • Once the glider has reached the low tow position, and the tow plane continues to climb at an insufficient air speed, pull the release.  (Hanging on for longer would put the tow plane in danger.) Immediately release stick pressure and simultaneously move the flaps into landing configuration.  Land straight ahead and only extend the spoilers once the glider is on the ground.

This plan only works if there is enough runway left for landing straight ahead. In Boulder we definitely have enough space available.

My main concern with this strategy is whether staying in ground effect until the low tow position is reached could be pulling the tow plane’s tail down to the point where it becomes difficult for the tow plane to get its nose down and pick up speed.  However, considering that low tow is a normal tow position in some countries, I assume it should not be a problem, at least unless the tow plane itself is close to stall speed.

If you have additional thoughts on this subject, please add them in the comments below. I am especially interested to hear from glider pilots who normally fly in low tow position.

PS: Dave Nadler’s explanation is very compelling and illustrates that a glider’s stall speed is actually higher on tow than it is in free flight.  This gives me more confidence to release immediately in the future because releasing is unlikely to lead to an immediate stall because the stall speed comes back down.  So my plan is to release, release stick pressure while simultaneously moving the flaps into landing configuration, then land straight ahead with the spoilers closed (and only open them as soon as the glider is on the ground.)

“Faster, Faster, Faster” is not clear communication. It would be better to say “Up 5” or “Up 10” or “Up 15” or “Up 20” (which is what I needed).

Maybe.  The thing with urgent communications is that the best one to use is the one that is instantly understood.  I readily admit that “Faster!” is not precise and may sound unprofessional but I think it conveyed a sense of urgency that “Up 20” may not have.  I am also not certain that the tow pilot would have instantly understood and responded to “Up 20”.  The lesson here, at least in my mind, is that tow pilot and glider pilot should make communications part of the briefing so both parties are in synch on what language to use.  I’m curious what you think the best protocol should be when you need an instant reaction.

The communication should have included the call sign of the tow plane.

Yes.  In principle this is certainly true.  A clear and non-ambiguous communication would be something like “X-Ray Yankee Zulu, 10 more knots.” (And then ask for another 5-10 knots if necessary.)  However, in the stress of the situation I did not remember the call sign even though I had said it myself only two minutes earlier.  (We have 5 different tow planes at the field.  I’ll definitely try to remember it better the next time.)

Also, if you watch the video you’ll notice that I had to communicate in a fraction of a second while also considering all the other choices such as whether or not to release.  What mattered more than anything was a prompt ]reaction by the tow pilot. (Basically to level off or push the nose down and pick up speed).  Just saying the abbreviated three digit call sign takes an entire second and saying “X-Ray Yankee Zulu, 10 more knots” would have taken about two seconds which I didn’t really think I had.

What will you do differently going forward?

The main thing is to adjust my briefing to avoid such situations in the first place.  I don’t always know what the air speed units are in the specific tow plane ahead of me.  Therefore, I am now requesting a minimum tow speed in knots AND MPH.  E.g., I’m now saying “Towplane XYZ, behind you is glider Victor One, Fully Ballasted, Minimum Tow Speed 70 knots or 80 MPH.”

You can find a collection of my favorite soaring safety articles on this page.

There’s been a lot of interest in my recent accident analysis “Invisible Trap Kills Glider Pilot – How To Avoid Microbursts.”  Within days it has been read by more than 5000 people, a significant number for our relatively small community.  I also received a lot of feedback and questions, some public, some private.  Most were quite insightful and thought provoking and I’d like to thank everyone for the engaging discussion.  It certainly helps to internalize the lessons we can learn from this.

In this post I would like to emphasize and respond to some of the comments and questions.

Be observant, patient, and wait!  Cold downdrafts created by virga displace warmer air near the surface creating updrafts glider pilots can, and should, use to avoid landing in downburst conditions. The very existence of virga indicates a soarable sky. Most western pilots have patiently worked such lift for an hour or more while waiting for conditions to improve near their destination airport. They made the decision to loiter long before descending to pattern altitude and sometimes miles away from the airport. The secret is to always be observant, patient and to take action to avoid dangerous conditions as early as possible.

Very well said!  If we can wait for the threat to pass this is clearly the best approach; especially when the virga is fairly isolated and the clouds are cycling.

The only caveat I would add is that waiting may not not always be the best strategy.  I have tried to wait out a storm only to watch a bigger and badder one to move in and the overall weather situation getting worse.  Through careful observation we must learn to anticipate what is likely to happen and make the best decision given the uncertainties involved.

Are dry microbursts really invisible? They occur below virga and generate dust rings.  Both of these are readily visible to an observant pilot. 

I completely agree that we must be observant and look for all possible warning signs.  However, I  would not count on microbursts always being readily visible ahead of time.

1. • While microbursts probably occur mainly below virga there have been reported cases even when no virga was visible before the microburst occurred.  Also, while virga is visible, it is not readily apparent if there is a downdraft below.  In fact, having flown below virga many times, in most cases there was no major downdraft, or no downdraft at all.  Sometimes the air was even rising.  Unfortunately, such experiences can lead to complacency such that we underestimate the risk.
   • Dust rings only appear once the microburst has reached the ground.  Unfortunately, we can be unlucky with the timing and fly into a microburst in the landing pattern before any dust is visible.  This exact situation may have happened to Shmulik. The preliminary NTSB report states that at “about the time the glider [was] descending” [as filmed by the surveillance camera], “a dust cloud appears in the background travelling in the same direction as the glider.” The dust may not have been visible to Shmulik until he was on downwind and fully committed to landing.
   • A dust ring will also only be visible if the ground in the area is sufficiently dry.  That may not always be the case.

Dust isn’t the only indicator of microburst outflows.  We should also observe the ground for other markers such as the disturbed surface of lakes, wind rushing through crop fields, blowing smoke, etc.

Yes, great point!  We need to watch out for all markers of high surface winds.

We should make more pro-active use of our radios to warn other aviators of threatening weather.

Absolutely!  If you notice something, say something!

I don’t know when the pilots of the Challenger jet noticed the gust or whether they were even aware of the approaching glider (remember that Shmulik offered to delay his landing but did not get a response) but even if they were unaware it would have been prudent to immediately warn anyone who might be in the area of the gusting wind on the ground.

It’s impossible to say if such a warning would have alerted Shmulik in time to have the chance to take evasive action but we should all remember that we ought to warn other traffic immediately when we notice threatening conditions.

Considering the delay in the AWOS reporting,  it may also be helpful to proactively use the radio to ask anyone on the ground for the current winds (e.g. the local FBO).

Microbursts are not the only source of severe wind-shear close to the ground.

Yes!  This is another great point.  Sudden and very powerful surface winds can have various other causes.  They are also not limited to summer soaring weather.  Possible causes include:

• • Rotor turbulence, e.g. on wave days.  In Boulder, rotor, associated with wave aloft, is a frequent cause of severe ground level wind shear.  Sometimes the wind socks at both ends of the runway point in opposite directions!
  • Rapidly approaching cold fronts (or other fronts, e.g. sea breeze fronts). Here is an article and video of a pilot landing in cross winds set off by a cold front that arrived minutes earlier. In certain conditions blowing dust (a “haboob“) can make an approaching front easily visible.
  • Dust devils and other extreme lifting motions can also cause havoc near the surface.  Imagine being on final approach right when a  small-scale thermal breaks off the ground that can even send a 300 pound porta-potty flying high into the air.  (Btw – notice the blue sky in the video.) A more detailed assessment of such “rogue air currents” events can be found in this article in Soaring Magazine.

Shmulik was flying a motor-glider.  Why didn’t he start the engine?

There are wide-spread misconceptions about the capabilities of self-launching motor-gliders.  Once Shmulik was in the pattern the key thing that possibly could have helped him (besides a greater altitude) is a very high airspeed to get out of the sink and safeguard against the sudden tail wind.  This is not possible with an extended engine.  Extending the engine would have made the situation worse instead of better.

Here is why:

• • You actually have to slow down before you can extend the engine mast.  I don’t have a handbook for the Shark MS but similar gliders need to be flown well below 70 kt before the engine mast may be extended. (e.g. ASG 31Mi: 59 kts, Ventus 3M: 59kts)
  • The process of extending the mast and starting the engine is typically a multi-step process, not just the “flick of a switch”.  See the video below for an illustrative example.
  • With the engine running, the glider must be flown very slowly to generate a positive climb rate (usually around 55-65 kts).  Also, if you fly much faster, the engine will overspeed and may shut down.  If that happens, the propeller causes a lot of extra drag, comparable to half-extended airbrakes.
  • In still air, the climb rate under full power is likely in the range of 3-5 kts given the high density altitude environment at Rifle.  That does very little when you’re in 10-20 knot sink.

The engine could have been of help to sustain altitude at a safe distance from the airfield to wait until threatening weather has left the area.  However, had Shmulik wanted to wait 5-10 miles away he would not have needed the engine to do so because lift was readily available while he was on final glide.  But once he was in the pattern and experiencing the heavy sink it was already too late to try to deploy it.

The following video is a good illustration of a typical in-air engine start with a self-launching motor glider. (The procedure in Shmulik’s glider would probably have been a little (but not much) simpler than the one shown here given that his was a more modern design.)

As an aside, for anyone considering a motor glider, I highly recommend you review this article by Dave Nadler before you get carried away by your imagination. If you’d rather watch a YouTube video, here is one of Dave’s excellent presentations on this subject.

Why didn’t Shmulik fly straight ahead to a controlled-crash landing away from the airport instead of trying to make the runway?

It is definitely true that a controlled crash is statistically much more survivable than a “stall and spin” accident from about 200 ft.  That said, does anyone really think that this is the choice they would have made?  Here are some things to consider:

• • This option was only available before Shmulik attempted the turn to final, stalled, and spun in.  Once the glider stalled there was absolutely nothing he could have done to affect a different outcome.
  • Making such a radical decision would have required the foresight and conviction that reaching the runway is no longer possible and that a controlled crash is the only available option.
  • The possibility of a stall may not even have been on his mind: the ground speed of the glider before the stall was much higher than one normally experiences in the landing pattern – ADSB shows 92 knots.  This makes it unlikely that Shmulik even anticipated the possibility of a stall – let alone its imminent certainty – until it occurred.
  • Also consider the psychology: how do you rationally weigh – under extreme stress  and within very few seconds – the diminishing probability of a safe landing on a perfect runway against the probability of a certain crash with an uncertain outcome for your own survival?

Are you still confident that you would have instantly made the decision to fly a semi-controlled crash instead of trying to execute a safe landing on a 7000 ft runway?

Our energy is comprised of not just airspeed but airspeed and altitude together.  We need to manage both.

Yes, that is a critical insight.  That’s why I tried to lay out mitigation strategies for myself that account for both components if I must land in similar conditions (i.e., if I am unable to delay or divert).

• • Altitude:  I will enter the pattern high enough that I can be confident that I can complete the turn to final at about 1000 AGL even if I hit enormous sink. (In some situations this may require a pattern entry at 2000-3000 ft AGL).
  • Airspeed:  My baseline pattern speed in these situations will be 80 kt (20 kt above the yellow triangle speed) plus I will immediately add extra airspeed equivalent to any sink that I may encounter in the pattern.

It’s been a few weeks that our friend Shmulik Dimentstein died in a tragic crash of his HpH Shark just as he was about to land at his home airport Rifle in Garfield County, Colorado.

As I’ve written before, soaring is objectively dangerous.  Per activity hour, the risk of dying is about 40x greater than when driving a car.

However, we also know that it does not have to be so dangerous. About 90% of accidents could have been prevented by the pilot.  Most can be avoided by diligent pre-flight preparations; by paying attention to what’s happening around us; by staying disciplined and flying within one’s margins; and by avoiding basic piloting mistakes through regular practice.  The 10% of unavoidable accidents tend to be the result of particular mid-air collisions, medical problems, or – very rarely – equipment failure.

So when a pilot you personally knew to be all of these things – experienced, disciplined, diligent, observant, careful, as well as current – becomes the victim of a fatal crash while landing at their home airfield after a successful flight in typical summer soaring conditions, it gets your attention.

And when all signs point to a “stall and spin” during the final turn to land it really makes you wonder what happened.  “Stall and spin” accidents in the pattern, although quite common and often deadly, are usually easy to avoid.  Pilots just have to enter the pattern at a safe altitude and fly at a safe speed.  We all know about the yellow triangle and adding an extra margin for wind and gusts.  Could Shmulik have made such a basic mistake?  Having flown with Shmulik myself, I immediately found that implausible.

It turns out my instinct was right.  This accident was not the consequence of a simple mistake.  If you or I would have been in Shmulik’s position, I doubt we would have done anything different. If you find that disturbing you’re not alone.

As you will see, Shmulik was supremely unlucky.  He literally flew – or fell – into a microburst, an invisible, deadly, trap.  Which made me wonder: must we simply rely on luck to avoid the same outcome?

Well, after giving this a lot of thought, I don’t think so. Nor should we.  There are things we can and should do differently if we face similar conditions in the future.  As we probably will.

I will present them after a detailed analysis of what I believe happened to Shmulik.

A First Hand Account by Rick Roelke

I’d like to start by re-printing a very insightful write-up of the accident by Rick Roelke who was one of four glider pilots flying that day from Rifle.  John Good published Rick’s report on RAS. I will come back to Rick’s account throughout my analysis as it is essential to understanding what happened.

“Four gliders flew out of Rifle on June 9th 2022. We all launched around 11:00 and moved to the north side of the valley. It was tough to find that first good climb, but Shmulik found one, leaving the rest of us floundering low. Eventually we did get away. Long story short we all ended up going in different directions, all having great flights. They were not without challenges but nothing spooky, just enough work to be rewarding. In a flight of about 600 km, Shmulik made his goal of Duchesne UT, and was happy about that. We made plans to be on the ground at 6:00 and all converged on the Rifle area in time for that.  

There was virga in the area, and it got my attention as Shmulik had warned me on a previous trip to be careful with local virga. I was listening intently to the ASOS for wind or gusts, letting it repeat 5 or 6 times with the exact same report: 9 kts straight down the runway; no gusts. Later, as we got ready to land, the same benign report. OK I thought – the virga is clearly a non-issue. As we will learn, it was the whole issue. 

There was virga over the airport (elevation 5537 ft) and to the north of the valley, and northeast as well. None of the wisps extended below 11,000 ft (cloud base was approximately 19,000). Cloud cover was scattered. The clouds producing virga were not towering – they were perhaps a bit bigger than non-producing clouds, but not much. It was a point of interest to me as we don’t see a lot of it in the eastern US – I was wondering what drove the difference. 

Shmulik and I discussed the landing order: as he was a bit lower we agreed he would go first. After we decided this, we heard a Challenger jet announce “Taxiing to 26 for takeoff”. That was the runway we would use to land. 

Rifle has a moderate amount of bizjet traffic; not constant but present. We always try to accommodate and be polite citizens. Shmulik called the Challenger and offered to delay but got no reply. I was still high so it was no problem for me. He tried again, with no reply. It’s worth noting that Shmulik had a close call in the past: a jet pulled onto the runway in front of him with no radio call. This near miss was avoided only by the jet taking off immediately in front of him. I am sure he did not want to repeat that. I speculate that the Challenger was on a different frequency temporarily, perhaps the ASOS. 

As he descended, he called that he was in heavy sink and was going to make left traffic for Runway 26 (for which the normal traffic pattern is right). Shortly after this a call came from the Challenger that there was a glider crash.  

I was not sure I’d heard it correctly so I asked for clarification. “There has been a glider crash and we see no movement.” They truly had a front-row seat, as moments before they were hit by a gust so strong that they had rotated their jet to avoid a compressor stall. 

I then asked if the runway was clear, was told yes, then landed uneventfully into the 9 mph headwinds. I am not sure of the time between our landings – I would guess it was 5 min. The other glider pilots landed without problems, though all could see the wreckage of our friend’s aircraft which left no doubt as to the outcome. 

The last moments of the crash were recorded by an airport security camera. We were allowed to view the footage (but not record it). It showed Shmulik in a moderately steep turn, apparently carrying a lot of speed. In the background you can see dust and gravel being blown by the gust. Then at 90 deg to the runway and 150 to 200 ft you can see the inside wing start to drop and the nose go down. There was no opportunity to recover and it hit the ground hard, thankfully just out of camera view.  

The Rifle ASOS recorded a gust of 43 mph from the south: a 100-degree shift in direction, putting it right on his tail. 

My analysis and proposed scenario are as follows: 

The virga produced a microburst directly over Shmulik as he was waiting for the jet. He expedited his landing trying to fly out of what was likely epic sink. While his base leg was low it looked high enough to make the runway with plenty of energy to flare and roll out. But he then got hit from behind or descended into winds in excess of 40 kts and perhaps as much as 50, stalling the aircraft and removing any opportunity for control. 

One of the most difficult aspects of this accident is that, given the information available to the pilot, it is hard to picture what anyone would have done differently. This truly seems like the hand of God. There is discussion in another thread about the yellow triangle. Here is a case that would require 60 over stall speed to maintain even a narrow margin. How many people do you know that would plan to come over the numbers at 100+ on a day that is blowing steady 9 straight down the runway? 

As has been noted, Shmulik was a very experienced and skilled pilot. He had more flights and time in gliders from Rifle than anyone. We all want to learn from accidents, especially what were the pilot errors we might avoid. This is a hard one to gain insight from other than this: Some atmospheric events are bigger than our plastic airplanes. 

RR”

The Pilot

As Rick pointed out, Shmuel Dimentstein was one of the most experienced, competent, current, and safety conscious pilots anywhere.  In the 2021 soaring season he flew more than 35,000 cross-country kilometers, a distance almost equivalent to the circumference of the earth.  That year, according to OLC, only six pilots worldwide had done more cross-country flying than Shmulik.  Even in the current season he had already flown more than 100 hours.

Rifle, the location of the accident, was Shmulik’s home airport. He was intimately familiar with it and the surrounding terrain.  He frequently hosted visiting pilots, providing them with detailed briefings of the area and the weather.  He had owned his HpH 304MS Shark for several years and was completely accustomed to the aircraft. Shmulik was also a very safety-minded pilot: if you examine his flight traces you will see many long cross-country flights but you will be hard pressed to find any signs of inappropriate risk taking.

June 9, 2022

By all indications and consistent with Rick’s report, June 9, the day of the accident, was a good and typical early summer soaring day in western Colorado and eastern Utah, the main task area around Rifle.

Skysight forecasted abundant cumulus clouds with bases rising from 16,000 to about 19,000 ft.  There was a modest chance for some overdevelopment and isolated showers in the afternoon but nothing that looked concerning.  The CAPE index, a measure of convective energy and instability, was below 100 joules, indicating a very low probability of severe weather or thunderstorms.

Boundary layer winds were moderate at 10-20 kt out of the WNW.  Surface winds were forecasted to be even lighter. The surface temperature in the afternoon was likely to reach 100 degrees F over the western desert generating strong thermals in the 6-10 kt range as is typical for the area at this time of year.  Moderate wind shear in some areas could make some thermals somewhat difficult to work but that, too, is typical.  Some passing high clouds were unlikely to be a factor.  500 km flights were easily doable with a good chance for even longer flights.

As Rick reported, four glider pilots launched from Rifle that morning.  The flight traces of Shmulik’s three visitors, including that of Rick Roelke, were uploaded to OLC here, here, and here.  These traces show good soaring conditions consistent with the forecast with pilots repeatedly climbing above 17,000 ft and achieving flight distances in the 400-600 km range.

Shmulik’s Flight

Shmulik’s flight was recorded via his ADSB-out system and can be viewed on Flightaware.

The trace shows that Shmulik launched exactly at noon.  44 minutes later he had climbed to an altitude of 16,000 ft and began heading west on a cross-country flight.  His flight path took him deep into Utah.

At about 3:30pm he was about 10 miles NNE of Carbon County Airport near the town of Price, UT.  That put him at about 160 miles to the WNW of Rifle, and he decided to turn back east.  Most of his flight was at altitudes between 12,000 and 17,500 ft – a typical and safe altitude range when flying in this area.

At 5:12 pm, 5 hours and 12 minutes into the flight, Shmulik was 10 miles north of the airport of Meeker, CO at an altitude of 14,300 ft, when he decided to turn south, back towards Rifle, ~45 miles away.

Less than 20 minutes later he was about 9 miles north of Rifle at an altitude of 10,000 ft, continuing south and preparing to land.

Approaching Rifle

The last six minutes of Shmulik’s flight are plotted on the following map.  The data is from the publicly available ADSB tracklog. For each data point you can see the time stamp, the altitude MSL, the Ground Speed in kt, and the Vertical Velocity in feet per minute (fpm).

The ground elevation at Rifle airport is 5536 ft MSL.  The first datapoint of the trace is at the top left.  At 5:31:34 pm, Shmulik had 9.4 miles to go.  He was at an elevation of 10,025 ft MSL, i.e. 4,489 ft above the airport.  He only needed a glide ratio of 14:1 to reach the airfield to arrive at a typical pattern altitude of 1,000 ft AGL.

The next few miles towards the airfield show nothing unusual.  There were some patches of moderate lift and sink as would be expected on a normal summer soaring day.  Shmulik flew quite fast at ground speeds between 100 and 130 kt, carrying a lot of extra energy. Unsurprisingly, the actual glide ratio of his 49:1 glider was much better than the required 14:1 and he approached the airport relatively high.

At 5:34:04 pm, Shmulik was over the town of Rifle, just 2.1 miles ENE from the center of the runway, getting ready to land.  At this point he still had an altitude of 8,275 ft MSL, i.e. 2,739 ft AGL.  This is much higher than what most pilots would consider an adequate safety margin.

Reported Winds on the Ground

Shmulik likely checked the winds on the ground by tuning to the frequency of the local AWOS (Automatic Weather Observing Service).  Between 5:10 and 5:34 PM, Rifle’s AWOS system reported light winds out of the west in the range of 4 to 9 kts (see chart below) with no wind gusts.  This is consistent with Rick’s report, which referenced 9 knots of wind.

With light westerly winds, Shmulik was likely planning to land on Runway 26, directly into the wind. He may have expected an easy and uneventful landing.

Pattern Entry and the Challenger Complication

The normal landing pattern for Runway 26 at Rifle is north of the airport with right turns to base and final.   At 5:35:22 Shmulik could have immediately entered the downwind leg of the pattern.  At this point he was just NW of the runway at an altitude of 8000 ft MSL (2464 AGL).

However, we see from his trace that he continued south past the west end of the runway to the southwest side of the airfield.  It is possible that he still considered himself to be too high for an immediate pattern entry. After all, a pattern entry altitude of approx. 1000 AGL is customary and Shmulik was still more than twice as high at this point.  He may have planned to remain on the south side until mid-field, cross the runway to the north, and then enter the normal right traffic pattern to runway 26. This would have slightly extended the flight path, helping him fly off the extra altitude.

However, Rick’s report suggests that there is likely a different – or at least an additional – explanation for why he continued to the south side of the airport.

“Shmulik and I discussed the landing order: as he was a bit lower we agreed he would go first. After we decided this, we heard a Challenger jet announce “Taxiing to 26 for takeoff”. That was the runway we would use to land. 

Rifle has a moderate amount of bizjet traffic; not constant but present. We always try to accommodate and be polite citizens. Shmulik called the Challenger and offered to delay but got no reply. I was still high so it was no problem for me. He tried again, with no reply. It’s worth noting that Shmulik had a close call in the past: a jet pulled onto the runway in front of him with no radio call. This near miss was avoided only by the jet taking off immediately in front of him. I am sure he did not want to repeat that. I speculate that the Challenger was on a different frequency temporarily, perhaps the ASOS.”

Based on this account it is likely that Shmulik continued to the south side of the airport to get a better look at the runway and observe the Challenger jet taking off – or at least to establish two-way radio contact to rule out the risk of a conflict.

Under normal circumstances Shmulik would have had sufficient altitude to delay the landing by several minutes:  his glider’s minimum descent rate in still air was just 100 fpm.  Even a more typical descent rate of 200 fpm would have allowed Shmulik to hold for about 5-7 minutes before he would have had to proceed with the landing.

Downwind Leg and Turn To Final

If Shmulik’s plan was to delay the landing this soon turned out to be impossible because he was not in still air at all.  As he continued to the south side of the runway he found himself in very strong sink of 700 – 1200 fpm and rapidly lost his altitude reserves.  Within one minute he lost a full 1000 feet.

However, at 5:36:23 he still had an altitude of 7025 ft MSL, i.e. a normally very “safe” pattern altitude of almost 1500 ft, and prudently began to head toward the east end of the runway.  At this point his ground speed was 81 kts, which – in still air – would reflect a normal pattern speed of approx. 65 kts IAS given the high density altitude.

16 seconds later, at 5:36:39 the sink rate diminished to 273 fpm.  Shmulik was now directly south of the west end of the runway.  The reduced sink rate must have been a relief.

However, 17 seconds later, at 5:36:56, Shmulik found himself once again in very strong sink of almost 1000 fpm.  Roughly at this time he must have decided to stay on the south side of the runway and fly a left hand pattern instead of crossing back to the north.  This would have shortened his approach, a seemingly prudent decision.  His altitude was 1339 AGL and his ground speed was 92 kts.  Had it not been for the strong sink he would have still been in a very conservative position for a normal landing.  Here is Rick’s report:

“As he descended, he called that he was in heavy sink and was going to make left traffic for Runway 26 (for which the normal traffic pattern is right).”

Another 18 seconds later, at 5:37:14, the sink rate doubled yet again, becoming extreme. Shmulik was directly south of midfield.  The ground came rushing closer at a rate of 1900 fpm.  Shmulik’s altitude had dropped by 625 ft in less than 20 seconds and he was now down at 714 ft AGL.  All of a sudden this had become an emergency situation.  His ground speed had dropped to 75 kt so he also had less kinetic energy reserve.  (Without knowing the horizontal wind direction and speed at this point it is impossible to say what his indicated airspeed was. It is quite likely that the air at that specific point was only streaming downwards with very little horizontal component.)

16 seconds later, at 5:37:30, he was still in very heavy sink of more than 1200 fpm and his altitude had dropped to only 264 ft AGL.  His ground speed was back up to 92 kts. Seconds thereafter he attempted to make a 180 degree turn to the left to line up with Runway 26.   Tragically, he only made it half-way through this final turn.  The last datapoint was recorded at 5:37:48 at an altitude of 14 ft, probably just a split second before impact.  Rick’s report describes it as follows:

“Shortly after this a call came from the Challenger that there was a glider crash.  

I was not sure I’d heard it correctly so I asked for clarification. “There has been a glider crash and we see no movement.” They truly had a front-row seat, as moments before they were hit by a gust so strong that they had rotated their jet to avoid a compressor stall. 

The last moments of the crash were recorded by an airport security camera. We were allowed to view the footage (but not record it). It showed Shmulik in a moderately steep turn, apparently carrying a lot of speed. In the background you can see dust and gravel being blown by the gust. Then at 90 deg to the runway and 150 to 200 ft you can see the inside wing start to drop and the nose go down. There was no opportunity to recover and it hit the ground hard, thankfully just out of camera view.

The Rifle ASOS recorded a gust of 43 kt from the south: a 100-degree shift in direction, putting it right on his tail.”

The wind gust could of course only be reported after it had been measured.  However, reporting it took longer than one might expect.  It wasn’t until 5:53 PM, 16 minutes after the crash, that AWOS reported that a 43 kt gust had occurred at 5:39 PM (one minute after the crash; 14 minutes earlier than it was reported).

What Caused the Crash?

I believe Rick’s analysis is spot on. The deadly trap was a microburst.

“The virga produced a microburst directly over Shmulik as he was waiting for the jet. He expedited his landing trying to fly out of what was likely epic sink. While his base leg was low it looked high enough to make the runway with plenty of energy to flare and roll out. But he then got hit from behind or descended into winds in excess of 40 kts and perhaps as much as 50, stalling the aircraft and removing any opportunity for control.” 

As Shmulik began his final turn he faced two closely related problems that became impossible to overcome:

1. 1. Extreme sink of close to 2000 fpm, which had very quickly eroded his altitude reserves during the last part of his downwind leg.
   2. A sudden and very powerful wind gust from behind, which caused the airplane to stall and spin in just as he was in the midst of his final turn.

Just how quickly he lost altitude may be hard to imagine; especially for pilots from regions where 2000 fpm sink is very unusual.  Some basic math illustrates the magnitude:  a typical safe altitude at the end of the downwind leg (before turning base) is 500-600 ft AGL.  The typical time that it takes to turn from downwind to final is about 20-40 seconds (depending on how close the pilot flew the downwind leg parallel to the runway).   At a sink rate of 2000 fpm it only takes 15 seconds for the plane to lose 500 ft and reach the ground.  In other words: if you’re at 500 ft AGL and 20-30 seconds away from reaching the runway and you are in 2000 fpm sink it is mathematically and physically impossible to get there.

Now, you might say that the sink rate is likely to diminish as you get close to the ground.  This is of course true because the air cannot sink into the earth.  But that is where the second problem arises: the sudden tailwind.

Near the ground the rapidly down-streaming air is necessarily diverted into a very strong horizontal flow along the surface.  At the worst possible moment Shmulik descended into that strong horizontal outflow, which came directly from behind, at speeds exceeding 40 knots, maybe more.  The stall speed of Shmulik’s glider was approx. 40-43 kts in straight flight and 44-52 kts in the turn (depending on his bank angle).  A sudden gust of 50 knots would have caused a stall unless he had been flying at about 100 knots indicated.

The ADSB trace shows Shmulik’s ground speed of 92 kt as he began his final turn. At the high density altitude at Rifle a ground speed of 92 kt would have been equivalent to an indicated airspeed of less than 80 kt.  If this included a wind component of 50 kt from behind, his true airspeed would have suddenly dropped to 30 kt, i.e. well below stall speed.

Once the glider stalled (at an altitude of only 100-200 feet) there was nothing that Shmulik could have done to avert the crash.

As Rick pointed out, the root cause of the sink and of the subsequent tailwind was almost certainly a (dry) microburst.  To understand exactly what likely happened and what we may be able to do differently, we first have to learn more about microbursts.

What is a Microburst?

A microburst is defined as “a pattern of intense winds that descends from rain clouds, hits the ground, and fans out horizontally. Microbursts are short-lived, usually lasting from about 5 to 15 minutes, and they are relatively compact, usually affecting an area of 1 to 3 km (about 0.5 to 2 miles) in diameter. They are often but not always associated with thunderstorms or strong rains. By causing a sudden change in wind direction or speed—a condition known as wind shear—microbursts create a particular hazard for airplanes at takeoff and landing because the pilot is confronted with a rapid and unexpected shift from headwind to tailwind.”

Unlike tornadoes and other twisters, microbursts are straight-line winds. The air is streaming straight towards the earth.  Near the ground, it is deflected sideways in all directions. The following streamline diagram is from the November 2020 edition of Soaring Magazine which describes the Mayhem at Minden, NV when a powerful 56 kt microburst destroyed several gliders on the ground.

Wet vs Dry Microbursts

Meteorologists distinguish between wet and dry microbursts depending on whether they are associated with precipitation hitting the ground.  Wet microbursts can look very spectacular but this also makes them easy to see and avoid.  Dry microbursts are much more insidious because they tend to be invisible until the downburst reaches the ground.  And even then, the only visible sign may be blowing dust on the surface. This time-lapse video from the National Weather Service in Reno, NV captured a dry microburst with surface winds of 71 mph.  Note that you can’t see the downburst itself.  Only the blowing dust on the ground is visible.

The atmospheric conditions favoring dry microbursts are illustrated in the Skew-T chart below from the University Corporation for Atmospheric Research.  Note the very dry airmass near the surface and a more moist, sometimes saturated mid-level.  Cloud bases are high and precipitation evaporates in the dryer layer below.  This is visible as virga – streaks of rain or snow below the clouds.   This evaporation causes evaporative cooling, which accelerates the downward motion of the falling air.

Once the downdraft reaches the surface it spreads horizontally in all directions. The downdraft itself is invisible. Only a ring of dust on the ground below the virga may signify the presence of a dry microburst.

The Skew-T chart at Rifle at 5:30 pm on June 9 greatly resembles the Skew-T above.  Here, too, one can see the “inverted-V” shape at the bottom, signifying the very dry air near the surface and a more moist layer above.   Such conditions are of course very common during the summer soaring season in the western United States.

Evaporative Cooling

As mentioned, a key factor in the development of microbursts is evaporative cooling.

What is it and how does it contribute to a microburst?  Everyone’s familiar with evaporative cooling: dip your hands into water on a hot dry day and feel how cool they become as the water evaporates.  Evaporative cooling systems work according to the same principle.

As glider pilots we know that cool air is heavier than warmer air.  So if falling rain evaporates (or falling snow sublimates), the air becomes cooler and heavier, thereby accelerating its downward momentum.

This is the exact opposite of the “cloud suck” effect that we enjoy when latent heat energy is released below cloud base, making air warmer, lighter, and more buoyant.

Virga Is a Warning Indicator

Evaporative cooling is happening by definition when virga can be observed:  Virga is the visible indicator that rain evaporates (or snow sublimates).

From experience we know that sometimes there is massive sink below virga and sometimes there isn’t.  Sometimes you fly through virga and you can even find yourself in lift.  I cannot explain why this is the case; I can only speculate that sometimes the lifting motion is so strong that even rain and evaporative cooling cannot overcome it: in these cases the evaporative cooling may slow down the rate of ascent but it is not causing a downburst.  However, if air is already sinking, evaporative cooling will accelerate the decent.

None of the pilots I asked about these phenomena claimed that they are able to reliably predict when there will be strong sink under virga and when there won’t be.  And since we don’t know, I think we must take away from this accident that we have to be extremely careful when we fly below virga; especially so when we are relatively close to the ground.

Airflow Near the Surface

The following graph illustrates the airflow near the surface once the downdraft has reached the ground. You can see the air spreading out sideways in all directions.  

Size of Affected Area and Duration

Microbursts are usually short-lived events, lasting for only a few minutes.  They also tend to be confined to a relatively small area between 0.4 and 4 kilometers (2.5 miles) in diameter.

The following graph depicts a vertical cross-section of a microburst over time.  Note the scale in kilometers.  The microburst event begins a few minutes before the burst hits the ground and can last for about 10 minutes after the initial divergence begins at the surface.

Much more details about the structure, shape, and duration of microbursts can be found in this article by Mark R. Hjelmfelt from the National Center of Atmospheric Research in Boulder, CO.

How Common Are Microbursts?

On summer days with strong convection, microbursts are a frequent phenomenon, especially in the dry climate of the Western United States.

In the summer of 1982, the JAWS (Joint Airport Weather Studies) program was set up to detect and observe microbursts near Denver’s Stapleton International Airport.  Within 86 days a total of 186 microbursts were observed within a relatively small geographical area northeast of Denver.  Microbursts were detected on more than half of these days.  83% of the microbursts were dry.  (Source: Fujita/Wakimoto, JAWS Microbursts Revealed by Triple-Doppler Radar, Aircraft, and PAM Data)

99 of these microbursts were just within 10 nm of Stapleton International Airport. We can probably conclude from this that in the arid climate of the western United States microbursts are par for the course: They likely occur on almost every good summer soaring day.

How Does It Feel in the Cockpit When We Encounter A Microburst?

What we experience in the cockpit differs greatly depending on our altitude (and on the stage of the microburst’s development when we encounter it).

Microburst Encounters at Altitude

Imagine that you fly through the descending shaft of the microburst as illustrated below.

In this case, the only indication of a microburst may be very strong sink.  The onset of the sink could be quite sudden such that you bump your head on the canopy, or it can come about more gradually over a period of a few seconds.  In the western US, where we often fly 10,000 feet or more above the terrain we might not notice anything particularly unusual.  We have all have flown through patches of very strong sink lasting for about 30 to 90 seconds.  We might have been slightly annoyed that we just lost one or two thousand feet of altitude but that is likely all we noticed. Cruising at 80-100 kts we cover almost two miles per minute.  Normally, this is more than enough time to traverse through the confined area of most microbursts.

If we encounter the microburst a little earlier in its development, i.e. just when the air is beginning to drop past our flying altitude, we may also experience more turbulence and wind shear when entering and exiting the burst.  However, even then it seems rather unlikely that we would get in real trouble (provided that we are still at a safe altitude once we exit the sink).

Microburst Encounters Closer to the Ground

The encounter is quite different when we fly closer to the ground because we are now confronted with the horizontal outflows.  The lower we are, the more dangerous the situation. The above referenced study by Wilson, Roberts, Kessinger, and McCarthy suggest that the greatest danger is at altitudes below 1000 ft AGL.  The reason is that we first encounter a headwind followed by a tailwind as we fly through the outflow area near the surface.  The difference in speed between the headwind and the tailwind tends to be greatest at an altitude of about 200 ft AGL.  Consider the illustration below.

In this case we are likely to encounter a sudden headwind and therefore a surge in kinetic energy causing the glider to rise and accelerate, soon to be followed by a sudden tailwind and a rapid drop in airspeed that could force our glider to stall unless we were able to maintain a sufficient airspeed margin.

The Greatest Danger is Below 1000 ft

The lefthand side of the following chart illustrates the differential in wind speed between the headwind and the tailwind at different altitudes for 12 different microbursts.  The solid line is the average.

You can readily see that the greatest wind speed differential, i.e. the greatest wind-shear is at altitudes below 0.2 km (i.e. ~600 ft) with the peak of the average at less than 0.1 km (about 200 ft). With increasing altitude the wind speed differential (and therefore the danger) decreases.  In some cases it can be measured up to about 0.6 km (~2000 ft).

Reports in Soaring Magazine

Over the years, Soaring Magazine has reported on a number of such harrowing microburst encounters at low altitudes.  These were from pilots who were not quite as unlucky as Shmulik and lived to tell the tale.

Trish Durbin quotes Joe Carter in the September 1987 edition as he tells about his microburst encounter during a Region 9 contest in El Tiro near Tucson, AZ.

“There was an opening between [two storm cells]. I was doing about 80 knots and all of a sudden I hit this tremendous sink. I put the nose down 45 degrees to speed up and I was still doing about 80 knots. The controls became very sloppy, I just couldn’t figure out what was go­ing on. The ship wasn’t behaving the way it normally would. It was very sloppy as if it were ready to stall, but with 80 knots indicated air speed. The varios were pegged down; I finally got it to about 120 knots by putting it almost ver­tical and then started pulling out of the dive slowly because the ground was coming up fast. I was probably about 200 feet above the terrain.”  Joe got very lucky and landed safely in a field several miles away.

Bill Gawthrop writes about his crash in Truckee, CA in the September 2015 edition.

“I checked AWOS to get conditions prior to my landing approach, and heard winds 220 at 7 gusting to 15 knots. This was nearly straight down runway 20, the normal glider runway. I knew to be cautious because just north of runway 20 we often experience downdrafts as the runway drops off steeply, at about a 40-50% slope. I made a short pattern to minimize the time I spend in the down air. I turned final about 400 feet north of the runway about 180 feet above the runway.

Suddenly, I was dropping like a stone, being pushed into a left turn by the wind. I immediately pushed in the spoilers, hit hard right rudder, and hard right stick. The glider, after what felt like a freefall, started to respond to my inputs about the time I dropped below the runway. I could see I was too low to make it back up to the runway elevation.  … Witnesses said I had cartwheeled over the runway lip onto the taxiway, landing backwards but right side up. 

According to the weather records the winds had shifted suddenly to 260 gusting to over 20 knots about the time I arrived, lasting only a minute or two. The downdraft … struck at a much higher altitude than would be expected for a rotor off the trees and the descent was very rapid. I suspect that a small microburst that lasted only a short time forced the apparent downdraft that I experienced. 

The strong gust of wind was 60 degrees from my flight path.  My forward speed relative to the wind would have dropped significantly when I passed through the wind shear of this oncoming gust causing the wings to significantly lose lift. So rather than a down draft causing the violent drop it could have been caused by the wind shear. “

More insightful stories about powerful downdrafts as well as sudden updrafts can be found in the excellent article “Rogue Air Currents” by Bob Thompson in the October 2014 edition of Soaring.

Everything Fits

Now that we understand a lot more about microbursts we can readily see how all indicators fit together.

Shmulik was supremely unlucky because he flew directly through the center of the downdraft when he was on his downwind leg.  And then, just as he started to make the turn from base to final he was hit by the microburst outflow coming directly from behind.  At that point he had descended to an altitude of approx. 200 ft where the strength of the outflow is typically the strongest.

The following charts show radar images for 5:30 pm, 5:35 pm, and 5:40 pm. The purple circle shows the small cell from where the downburst most likely came from.

AWOS reported the strength of the gust on the ground at 43 kts.  Based on the data from the research study referenced earlier it is likely that at 200 ft AGL the outflow speed was about 10-20% greater than near the ground.  I.e., 50 kt or slightly higher.  Shmulik would have needed to fly at an IAS of around 100 kt to avert a stall and have a chance of maintaining control.

The time duration of the event was very limited, just as would be expected.  After the gust had come through, AWOS went back to reporting light winds out of the west.

That’s when the other three glider pilots returned to the airport, just minutes later. Based on their flight traces, all three landings appear completely normal and uneventful.

Rick Roelke followed Shmulik, touching down at 5:45:36, i.e. less than 8 minutes after Shmulik’s crash.  Bill Feiges was next, landing at 5:47:38, followed by Sean Franke who landed at 5:50:51.

It is worth noting that Shmulik had started his landing pattern significantly higher (!) than any of these three pilots: the altitudes of these three pilots on downwind at midfield were between 875 and 1148 ft AGL, i.e. typical and normal pattern altitudes.  Shmulik had been at 1339 ft AGL at an equivalent position in his pattern.  This means Shmulik had the greatest safety margin of all of them.  Also, none of these three pilots flew at a higher speed in the pattern than Shmulik did.

Could The Accident Have Been Averted?

This is very hard to say.  Perhaps the most important questions is whether the amount and location of the virga should have been so concerning as to prompt a reasonable pilot to delay their landing and wait at a safe distance for the virga to dissolve or move away.

Should the Landing Have Been Delayed?

Without being able to see the sky like Shmulik did, this is of course impossible to say.  However, by all accounts none of the pilots operating at Rifle at this time were overly concerned about the extent of the virga.  Everyone’s behavior suggests that many if not most pilots would have proceeded with the landing just like Shmulik did.

• • Rick’s report stated, “There was virga over the airport (elevation 5537 ft) and to the north of the valley, and northeast as well. None of the wisps extended below 11,000 ft (cloud base was approximately 19,000). Cloud cover was scattered. The clouds producing virga were not towering – they were perhaps a bit bigger than non-producing clouds, but not much. It was a point of interest to me as we don’t see a lot of it in the eastern US – I was wondering what drove the difference. 
  • Bill Feiges, one of the other pilots flying that day, wrote, “I did not think there was enough virga in the area to catch my immediate attention.” Bill is quite familiar with the weather in this area as he normally flies out of Steamboat Springs, CO, just 80 miles to the NW of Rifle.
  • The pilots of the Challenger jet were clearly not overly concerned either, otherwise they would not have been taxiing to the runway for takeoff.
  • Plus, none of the three glider pilots thought it necessary to delay their landing even after Shmulik had already crashed.

Bad Luck

Unfortunately there was a tremendous amount of bad luck involved:

• • The occurrence of a microburst with extreme sink in the pattern just as Shmulik returned from his flight;
  • The delay caused by the intended Challenger launch, which likely prompted Shmulik to fly to the south side of the airport exposing him to more sink and the sudden tail wind (instead of a head wind) on the turn to final;
  • The lack of a radio response from the Challenger which may have hampered Shmulik in his decision making (e.g. preventing him from landing straight in on runway 08 when getting low); and
  • Encountering the tremendous tail wind just as Shmulik was making his turn to final, i.e. at the worst possible moment, and at the worst possible altitude.

If only one of these factors would have been different it is quite possible – perhaps likely – that the outcome would have been different as well.

It is hard to argue that Shmulik did not have sufficient altitude when he returned to the airport at almost 3000 ft AGL with only 2 miles to go.  Or that he flew unusually slowly in the pattern.  The three pilots returning after Shmulik were aware that there had been an accident.  They would have been exceptionally careful.  And yet, none of them returned to the airport with more safety margin than Shmulik did.  None flew faster in the pattern.

I believe that any of us – if put in Shmulik’s position – may have done exactly the same thing he did.  Any of us could have suffered the same outcome.  Indeed, it is tempting to conclude that this was indeed Shmulik’s fate.  That nothing could have been done differently; that none of us can do anything different.  Even, that nothing can be learned from this.

I sincerely hope that this is not true.  I am the first to admit that based on what I knew before doing this detailed analysis I would likely have acted just like Shmulik did.  But that is not the same as to say that I won’t change anything in my flying going forward.  I believe that there has to be, and that there is, something that I and others can learn from this.

Is There Anything To Learn?

I believe the answer is clearly “yes”.  The following summarizes my personal takeaways.  You may need to adjust these based on your flying environment, your experience and skills, and your glider.

Recognize the Potential for Microbursts

First, there are a few facts about microbursts that I will try to remember:

1. 1. Microbursts are a common  summer-day phenomenon. In the Western US they occur on practically any good summer soaring day.
   2. Microbursts do not just develop below towering cumulonimbus cells.  They can occur under any mature cumulus cloud that is starting to dissolve, especially if there are signs of precipitation below cloud base.
   3. Dry microbursts are invisible.  The only visible indicator may be a ring of dust on the ground emanating from the center of a downburst.  However, dust can obviously only be noticed after the microburst has already reached the ground. You may not be able to see it in time!
   4. Virga is an indicator that microbursts may be present because virga is a tell-tale sign of evaporative cooling, which accelerates any downward movement of the air.
   5. Microbursts can be extremely powerful and the sink alone can be overwhelming.
   6. Near the surface, strong sink from a microburst is typically followed by a sudden and powerful tailwind, no matter in which direction we’re heading.  This is a consequence of the fact that the down-streaming air is deflected outwards in all directions as it hits the ground.
   7. The greatest risk of sudden tailwinds exists below 1000 ft with a peak wind differential at around 200 ft AGL.  That’s why microbursts are so dangerous in the landing pattern.
   8. In addition, I will remember that AWOS reports are outdated.  Microbursts occur suddenly and the reported wind speed necessarily reflects what happened in the past, not what is currently happening. There can also be a substantial time delay in the reporting.

Anticipate and Avoid

Second, the best strategy to minimize the risk of getting caught in a microburst at low altitude is to anticipate and avoid it.  Practical strategies I will use going forward are:

1. 1. If there is any indication of overdevelopment or virga I will adjust my final glide approach such that I plan to arrive at the target airport with a minimum altitude of at least 3000 ft AGL. This will give me more time to assess the conditions and make alternative plans.
   2. If virga is present above or immediately next to my landing site I will attempt to delay my landing by staying in rising air at a safe distance and altitude and wait for the virga to move away or dissipate completely.  This usually only takes a few minutes.
   3. If this is not possible I will divert to a different airfield or landing site provided that the conditions look more favorable.

Modified Landing Pattern if Necessary

Third, as a last resort, if I must land despite the presence of virga above or next to the field I will modify my landing pattern as follows:

1. 1. I will enter the landing pattern much higher than usual.  This may be as high as 3000 ft AGL to allow for the possibility of massive sink on the downwind leg.  (I will also announce this unusual pattern on the radio so other traffic is not taken by surprise.)
   2. I will plan to maintain a substantial altitude safety margin throughout the pattern and complete my final turn while still at an altitude of approx. 1000 ft AGL, planning to fly a very steep final approach.  Completing the final turn around 1000ft will significantly reduce the risk of a sudden gust from behind, especially while turning.
   3. I will fly at a much higher pattern airspeed. This is especially important once I get below 1000 ft because that is where a gust from behind is most likely and also most dangerous.  If there is any virga in the vicinity I will fly at a minimum IAS of 80 kts (20kts above the yellow triangle speed).  If I encounter sink in the pattern I will immediately increase my airspeed further.  As a rule of thumb I will add extra airspeed equivalent to my sink rate.  E.g., if my sink rate is 10 kts (1000 fpm), I will add another 10 kts and fly at 90 kts IAS.  If my sink rate is 20 kts, I will fly at 100 kts IAS.  The stronger the downdraft, the stronger the potential tailwind once I get close to the ground.  I think this airspeed adjustment will better protect me against sudden tail gusts or descending into a sudden tail wind.

Communication and Training

1. I realize that flying such an unusual pattern can in itself be a risk.  There are two concerns in particular:

1. 1. Other traffic may not anticipate it and be taken by surprise.
   2. I could misjudge my altitude and overshoot the runway.

With respect to the first concern, I will mitigate it by clearly announcing my intentions.  I would also hope that such a pattern is rarely necessary because I intend to avoid to land in such conditions whenever possible. This pattern is a last resort.

With respect to the second concern, it is something that I will deliberately practice when there is no other traffic in the vicinity.  It is clearly helpful to get accustomed to the sight picture of finishing the turn to final at 1000 ft AGL and making a spot landing at the normal aim point.  I am fortunate that my glider has very powerful airbrakes, which allow for a very steep descent if necessary.  This approach may not work for gliders with less effective spoilers.

Learning From My Own Mistakes

I looked through my own inflight videos and found the following one from a flight on June 7, 2021 that illustrates a broadly similar weather situation to the one Shmulik was likely facing.

I’ve Been There Before

I recommend you begin to watch at 31:54.  The similarities include:

• • Virga directly above and in the vicinity of the airport.
  • I was at a similar altitude as Shmulik when I had 10 miles to go.
  • I encountered extreme sink of 20 kts in the vicinity of the airport, directly below virga.  In retrospect, this was also likely the result of a microburst.  (I did not encounter a sudden tailwind when exiting the sink because I was still a few thousand feet above the ground where sudden tailwinds are not likely because the down-streaming air has not yet been deflected.)
  • There were signs on the ground of an approaching gust front suggesting strong wind shear in the area.
  • The flight was during dynamic summer soaring conditions in Colorado at the same time of year (June 9 vs June 7), albeit at different airports.
  • The field elevation at Boulder is 5288 ft which is similar to the elevation at Rifle at 5536ft.

Compared to Shmulik, I was simply more lucky at the end.  Before I entered the pattern, the severe sink stopped.  I also didn’t get hit by a gust from behind on my final turn. Plus, I wasn’t distracted by another aircraft trying to take off from the same runway.  If it weren’t for these key differences, the outcome could have been the same.

Relying on Luck Is Not A Strategy

However, in the future I don’t want to leave the differences to luck.  Based on what I learned from Shmulik’s crash there are several things I will do differently from what I did in the video:

• • I will maintain more altitude on days like this before approaching the airport.  Note how – in the video – CX came back several thousand feet higher than I did.  In conditions like these, altitude can be lost very fast!  In the video you hear me joke at 32:52 that CX is too high.  No, he wasn’t! He made a smarter decision by climbing up while on final glide.  This put him into a safer position with a lot more options!
  • I will seek to avoid a landing while there is virga directly above or next to the airfield and a gust front is approaching.  You can see in the video that I considered diverting to Longmont but then the extreme sink over Boulder forced my hand.  CX had the additional altitude he needed to either wait the situation out (which he did) or divert to nearby airports.  CX landed 12 minutes after me when the gust front had passed through and the winds had calmed down.
  • I will accelerate immediately when I hit extreme sink.  You can see that my airspeed fluctuates between 70-80 kts as I hit 20 kt sink (starting around 37:00).  I should have pushed the nose down immediately, accelerating to at least 100 kts, if only to fly out of the sink faster (I was at an altitude of about 3000 AGL and a sudden gust from behind is not likely until closer to the ground).
  • I was not much above 1000 ft AGL when crossing midfield to enter a right pattern to Runway 26.  As explained above, in similar situations I will enter the pattern much higher in the future to guard against potential sink on the downwind leg.  (And I will not waste time by flying in circles listening to AWOS which may be outdated anyway.  I should just focus ob observing the wind socks and the surface of the lakes.)
  • My target airspeed in the pattern was 75 kts and my actual airspeed fluctuated between 70 and 80 kts.  I believe this was too slow, especially during the turn to final that I started at an altitude of about 700 ft AGL.  It would have been better to fly that last turn 300-500 ft higher and faster (and a little further east of the runway).  I should have never been below 80 kts in the pattern.  This also includes the last portion on short final.  It is important to maintain the extra speed until I get into ground effect where the risk of descending into a sudden tail wind no longer exists.

Final Thoughts

Writing this article has been difficult.  However, I sincerely hope that it was worth it. Unfortunately it won’t help Shmulik.  But I know that it will help me and hope that you, too, find it valuable.  I am not a fatalist and I like to avoid leaving things to chance. I know that our sport is objectively dangerous.  But I also know that if we are willing to do the hard work that it takes to learn from the accidents of others it does not have to remain quite as dangerous. I hope this analysis is another step in that direction.

Disclaimer: this analysis is not intended to preempt or substitute the official NTSB accident investigation.  It is solely based on information that I had ready access to.  More information may come to light (e.g. by analyzing the more detailed igc trace rather than the ADSB trace).  My analysis also includes interpretations that are necessarily subjective.

I often assert that Colorado is one of the best soaring locations in the world.  Powerful mountain thermals, long convergence lines, and 20k ft cloud bases are common and quasi par for the course.

Why then is it that no one has ever completed a declared 1000 km FAI triangle?*

*An earlier version of this article incorrectly stated that there had never been any declared 1000 km flight in Colorado (with up to 3 turnpoints).  While none were officially recorded as a state record, this is not true.  Dave Leonard completed a declared 1000 km flight from Kelly Airpark in 2001 in an LS6.  In 2005, he was followed by Tom Serkowski who flew a declared 1000 km out and return in his ASH26E also from Kelly.  There have also been numerous free six-leg OLC flights over 1000km, from Boulder, Kelly, and Owl Canyon.  But as far as I know there has not been a declared 1000km FAI Triangle.

This spreadsheet lists all 1000km flights per OLC rules (max of six legs) ever recorded in Colorado (37 flights by 11 pilots as of this writing, as far as I’m aware).  The list is in chronological order from the first to the most recent.  I also included a most remarkable downwind dash by Alvin Parker in 1964 who flew from Odessa, Texas in a straight line to Kimball, Nebraska in a Sisu 1A sailplane.  Although the flight neither originated nor ended Colorado, it crossed Colorado from south to north and is more than worthy of being listed here. It was a new world distance record at the time as is reported in detail in the September 1964 edition of Soaring Magazine.

As of this writing, only three of the 1000 km flights in Colorado were declared 1000+ km flights that were also completed. 1000km declared FAI triangles had been attempted a few times, most notably by Tom Serkowski, but for a variety of reasons none had been successfully completed.  Please email me if you see anything here that’s incorrect or if there is a flight that I may have have omitted.

An Exceptional Flight Requires Exceptional Conditions

As I explained in my recent article about the Colorado 14er Challenge, a key reason for why we have not seen any completed 1000km FAI triangles in Colorado before, is the complex soaring terrain:  the many tall mountain ranges tend to divide the state into different air masses and weather systems.  It is exceptionally rare to find a day that works all across Colorado.  But that is what you need to plan and execute such a flight.

Another factor is the length of the available thermal day.  If the air is unstable enough for the day to develop early, there’s often overdevelopment and thunderstorms by early afternoon. If the air is a bit more stable, the day doesn’t really get going until noon and by then it is likely too late to finish such a long flight.  So what you need is a day that kicks off early but doesn’t blow up, at least not everywhere.  Some localized overdevelopment is ok, provided that the clouds cycle and thermals start up again.

Wind is also an important consideration.  E.g., if the jet stream dips south into Colorado, the wind often gets so strong that thermals are broken and it’s hard to achieve good speeds; especially if you must deviate from energy lines that the wind helps create (i.e., wave, convergence, and ridge lift). Really big flights, especially triangles, require relatively mellow wind conditions.

Forecast Conditions for June 4

The Skysight forecast for June 4 promised the potential for such an exceptional day.

The PFD Chart was dark red all across the Colorado Rocky Mountains.  That’s a promising indicator that very long flights are attainable.  However, Skysight can be a bit optimistic at times, e.g. when the cloud bases are too low to fly fast and safe, so it’s important to look at the specific parameters.  You want to know what it is that makes the day so good, and what pitfalls, if any, may exist.

Cumulus clouds would start to pop as early as 10 am and bases would immediately be around 17,000 ft.  That’s excellent to get an early start.

At the same time (around 10:30am) 5 to 7 kt thermals could already be expected.

By 3:30 PM, cumulus clouds with bases of 19,000 – 20,000 feet would extend across the entire task area.

The OD Chart suggested that the southern Front Range and South Park might overdevelop early.  If this is the case, it can be tricky to come back to Boulder from the south late in the day.

This was also confirmed by the Significant Weather Chart for 4PM, which suggested that South Park would be overcast under spread-out cumulus by late afternoon.  Fortunately, there was no indication of thunderstorms on this chart.

The CAPE (Convective Available Potential Energy) Chart did also not indicate a significant risk of thunderstorms, except for a few blue spots along the Front Range.  In our mountainous area you want this chart to be completely blank as any CAPE index values above 100 Joule suggest a potential for storms.  My interpretation from this chart was that there would be a likelihood of isolated storms that it would be possible to navigate around.

The winds in the boundary layer were forecast to be modest, especially on my second leg into the wind.  They would increase a little later in the day but by then I hoped to be on my third leg and benefit from a tail wind.

Thermal strength would peak at 1PM and begin to weaken by 3:30PM.  That seemed a bit early. and I did not give it too much thought.  I should have examined the reasons for this more closely (we’ll get to that later).  3:30PM is often the very best part of the day.

My main conclusions from this forecast were:

• • An early start would be possible.  I booked at tow for 10AM – about one hour earlier than usual for Boulder.
  • There would be nice cumulus clouds across the entire task area when I needed them.  Cloud bases would start high and remain high, allowing climbs to the legal maximum below 18,000 ft.
  • There would likely be overdevelopment with virga and isolated storms in parts of the task area.  The biggest concern was to the south of Boulder.  It would therefore be good to go south first and then avoid that area later in the day.
  • Thermal strengths would be good, although diminishing somewhat early, which seemed a bit surprising. The day was forecast to remain soarable until 6PM. By then it would be good to be on final glide.

Task Planning Considerations

When I pre-declare a task I try to design a route that makes the best use of the forecast soaring weather.

Initially I considered declaring a 1000 km border-to-border task (from Boulder to New Mexico, then to Wyoming, and back to Boulder via a third turnpoint south of Boulder). However, the forecast early over-development to the south hinted at potential problems on the northbound leg.

I was particularly intrigued by the projected cumulus conditions to the west up to the Utah border. This area is often too dry for cumulus clouds to develop.  I have never flown that far west and don’t like to fly in blue conditions so far from home, especially in an area where I have no experience.  The forecast presence of cumulus in that area in early to mid afternoon made me consider a big triangle.

Having set my sights onto a 1000 km FAI triangle I had to make some key decisions.

• • First, I wanted my start and finish point to be on one of the legs of the triangle, and not on a corner.  This makes it easier to return home if you run out of time before getting to the last turn point.
  • Second, I knew I wanted to go south first, because that area was projected to over-develop early.  I expected soaring conditions there to be quite good before the over-development would set in.
  • Third, I wanted to select a western turnpoint in an area with reliable cumulus clouds.  I also wanted to construct it so that my flight path could remain over high terrain as much as possible, minimizing any stretch over potentially blue areas (such as when crossing the Colorado River Valley). Furthermore, I wanted to ensure that my third leg would be as unproblematic as possible, e.g. avoiding areas of significant forecast overdevelopment.
  • Fourth, I wanted my last turnpoint to the north of Boulder in an area along the typical late-afternoon energy line over the Poudre.  It would have to be in glide range of good landing places, and ideally within glide range of Boulder. Plus it needed to be selected such that there would be a more or less straight line between that last turnpoint and the first turnpoint (to make the task a nice triangle and minimize any unnecessary detours).

The Task

With these considerations in mind I declared a task with the following turnpoints:

• • Start/Finish: Lee Hill. Lee Hill was likely a little further east than the first morning thermals but I did not want to pick a finish deep into the foothills that I may have difficulty to reach on final glide. Finishing just at the top of Lee Hill gives me appropriate altitude for a save arrival and landing in Boulder.
  • TP1: Greenhorn Mountain.  I picked this point at the southern tip of the Wet Mountains as my first turnpoint because it was the furthest point to the SSE that I thought could be reached below cumulus clouds early in the day.  Often there is a big blue gap between South Park and the Wet Mountains and the forecast suggested that this area would not be an issue. Greenhorn Mountain is also ideal because a straight line drawn from there via Lee Hill is optimally aligned with the energy line over the Poudre late in the day – so the last turnpoint can be placed directly on that line.
  • TP3: Comanche Meadow. Next, I picked my third turnpoint (rather than the second turnpoint) and placed it near Red Feather Lakes on the line mentioned in the bullet above.
  • TP2: North of Grand Junction. Finally, I selected a western turnpoint  as TP2 that would make my triangle just a bit bigger than 1000km.  It was important to pick a point where cumulus clouds were forecast at my projected time of rounding it.

Timing

Skysight’s route planning tool has better pilots in mind than I am.  I am almost always 15-25% slower than Skysight projects possible.  E.g., for June 4, Skysight projected an average task speed of 157 kph (99 mph).  There may be pilots that can fly that fast but I am not one of them.  I thought an average speed of 125 kph would be more realistic for me. (My average speed on OLC for the current year to date is 122 kph).

I had booked my tow at 10:00AM and expected my start at 10:30AM. This would give me the following expected times at each of my turnpoints:

• • TP1 Greenhorn Mountain (KM 246) : approx. 12:30PM
  • TP2 North of Grand Junction (KM 616): approx. 3:30PM
  • TP3 Near Red Feather Lakes (KM915): approx. 5:50PM
  • Finish: Lee Hill (KM 1002): approx. 6:30PM

The exercise of estimating the average task speed and turn point times is important.  It allows me to determine if my task is realistically achievable.  It also enables me to compare my actual speed against the forecast and helps me decide during the flight if I should give up on the task early to reduce the risk of a land-out late in the day, possibly still far away from home.

Cut Off Time: I also resolved that I would turn back early if I would not be able to reach my westerns turn-point before 4:00PM.

Probabilities and Beliefs

When attempting these challenges you have to believe that it can be done.  And I did.  However, I am also realistic.  No-one had ever completed a declared 1000 km FAI triangle.  And I’m told it’s not for a lack of trying.

Also, I recalled that it had taken me 6 attempts to finish Diamond Distance, and it had taken me 8 attempts to finish my 750km Diplome.  What were the odds that I would finish a 1000 km FAI triangle on my first attempt?

The evening before the flight I talked to one of Boulder’s most experienced XC pilots about my plans.  He pointed to the recent rains in Colorado and thought the ground was too wet and Skysight was far too optimistic.  His advice was, “wait until it has dried up.”  “Skysight doesn’t take the recent rains into account.”

I wasn’t so sure. How could he know what Skysight does or doesn’t take into account?  Of course Skysight isn’t always right. But if the day was as good as projected and I hadn’t tried, I would surely regret it.  There are probably only a few days each year when such a flight can be achieved.  So I made the calculated decision to ignore the advice I was given.

When fellow club members asked me in the morning what I thought the odds of completion were, I said, “about 20%”.  “But that’s no reason not to try.  If I don’t make the attempt, the odds are exactly zero.”

Execution

Reality never matches one’s plan exactly and at the end it all comes down to execution.  In this, soaring is not very different from business or other aspect of life where the best laid plan fall by the wayside when the first curve ball is thrown your way.   However, we can always learn from comparing plans and reality and figure out what we can do to improve; in planning as well as in execution. So here is my review.

The Start

I launched at 9:53am, a few minutes earlier than planned.  It would have been better to take off even earlier, around 9:30am, perhaps even sooner.

The valley was inverted and I towed all the way to the first clouds.  The tow was probably higher than necessary but I didn’t want to risk wasting time, or worse, falling out.

I crossed the Start Line at Lee Hill at 10:15AM, 15 minutes ahead of schedule, at an altitude of 11,400 ft.  The start altitude was a strategic decision: Lee Hill is at about 7800 ft MSL.  The FAI task rules say that the finish cannot be more than 1000m (3,280 ft) below the start altitude.  A start at 11,400 meant I had to arrive above Lee Hill at a minimum altitude of ~8,100 MSL, i.e. ~300 AGL, for a valid finish.

Had I climbed up high before crossing the start, I would also have to finish higher and that can be a problem at the end of the day when the thermals are dying.  It’s therefore best to start relatively low so this won’t be an issue later on.  However, I also didn’t want to take any risk of falling out after crossing the start line.  It’s a tricky equation but I think I got it about right.

First Leg to Greenhorn Mountain – 246 km

After crossing the start I was in search of a strong climb that could take me up toward cloud base.

I did not want to settle for 4-5 kts because it would take well over 10 minutes to climb up to cloud base.   As a result, I stayed lower for much longer than I wanted as I struggled to connect.

I joined TR in a great 10kt climb over Black Mountain (ESE of Mt Evans). Finally I got up to 17,500 ft in no time.

A few minutes later I caught up with TR, a club Discus piloted by Jason Ely who was finding great lift lines.  I was quite impressed by his route choices.

Convergence-enhanced thermals over the foothills of the southern Front Range.  Good lift along the western edge of these clouds.

Reliable clouds make for fun, uneventful, flying.

I tanked up over the 39 Mile Volcanic Field west of Victor before heading out across a blue hole towards the Wet Mountains in the center ahead. It’s a significant gap but not a big deal for my 18m Ventus 2 cxT.

Nice clouds over the Wet Mountains propelled me towards my first turn point at Greenhorn Mountain.

I’m taking a powerful climb before turning Greenhorn Mountain.

I rounded Greenhorn Mountain at 12:22 PM.  246 km, about 1/4 of the total distance, is done.  My average speed on the first leg was a little slower than the overall estimate of 125 kph but I was still 8 minutes ahead of my estimated schedule.  I hoped the second leg would go a bit faster given that I was getting to the strongest part of the day.

Second Leg: Greenhorn Mountain to North of Grand Junction – 370 km

Soon after turning Greenhorn Mountain, and heading north-west, I crossed paths with BC and XR who were aiming for the Colorado – New Mexico border. (Unfortunately both got caught in OD on their return leg to the north.  They made it back to Boulder but were not able to get to Wyoming.)

The clouds over the Wet Valley were not working nearly as well as those over the mountains .

I got much lower than I would have liked.  These situations can become a big time drain unless one is able to find a good climb.

I had to take a little detour and finally found a reasonable climb in the lee of the Sangre de Cristos.

At 1:15 PM I am above Salida.  I know this area well from SSB soaring camps.

There is a big blue hole west of Salida towards Monarch Pass.  The wind has shifted and is now blowing pretty hard out of the north-west, directly where I need to go.  This means I have to approach Monarch Pass from the lee side and the transition into the Gunnison Valley is likely to be tricky.  I am taking a climb to 15,700 ft – as high as I get get – before pushing on.

The transition ahead is the trickiest part on the second leg.  I anticipate significant sink before getting to Monarch Pass and will need to find another climb to get across.  The sky is not overly promising.

I arrive below a rotor cloud on the flank of Mount Shavano at 12,600 ft, about 1,600 ft below the peak. I’m hoping the rotor works.  If not, I have to turn back several miles where I should find a climb over the Arkansas Valley north of the Salida airport.

The rotor is quite rough.  It wants to roll the glider this way and that way and I have to use full control deflections to keep myself centered.  I work hard for 8 minutes to regain 3,500 ft, enough to press on.

Things look better at 16,000 feet. There are good looking clouds on the other side of these mountains.

It is 1:45PM when the first virga of the day appear.  But there is no significant vertical development in any of the clouds and I am confident the clouds will just cycle.  This likely means some virga dodging but hopefully continued good thermal conditions.  Also, as I get further west, and closer to the Utah desert, the air should become dryer.  And for now it’s too early to worry about the third leg.  I still have more than 200 km to go before TP2…

It’s typical for overdevelopment and virga to concentrate over the mountains while the wider valleys – such as the Gunnison Valley to the left – remain much dryer.  The lift is quite good here on the southern side of the clouds, often up to the edge of the virga.

In a few minutes I will get to an area where I have never flown before.  I take out my map to better visualize my landing opportunities beyond Crested Butte.  There are a number of good choices but it’s important to know where they are relative to the terrain.  And it’s always good to visualize this while you’re so high that you’re relaxed and the stress level is very low.

Crested Butte is a magical place.  A few years ago I ran one of the prettiest ultramarathons in this area.  Seeing the valley from the cockpit is even more magnificent.

The West Elk Mountains will be the last big mountains for a while.  The clouds ahead look quite promising.  Also, as expected, the air does look a bit dryer as I continue northwest.

I make good progress in this area and continue to enjoy the scenery.  The clouds work well and are reliable. There are also plenty of landing options in the valley to the left.

As I leave the tall peaks behind, mountains give way to rolling hills.  The sky keeps getting dryer but there is no shortage of nice cumulus clouds.  I continue my flight with confidence.

The clouds in this area are cycling and conditions are a little soft for a while.  But there’s no doubt – for now – that there is good lift ahead.  I have the airports of Glenwood Springs and Garfield County in glide.

The Colorado River Valley comes in sight as I approach Haystack Mountain.  I am relieved to see that there are clouds on the north side of the valley.  I will have to cross the valley and then continue to head west to get to TP2.

I am tanking up above Haystack Mountain before the Colorado River crossing.

It is now apparent that the clouds are much sparser on the north side of the Colorado River Valley. The air is also more hazy, indicative of a different and potentially weaker, airmass.  I have 70 km to go to get to my second turnpoint straight ahead.  Can it be done?  I’m not sure but I’m definitely willing to try.

There are still clouds ahead as I get to the north of the Colorado River.  But I also start to notice the cirrus layer in the distance and wonder if my turnpoint may be in the shade.

I am excited that my first climb after the valley crossing averages 8 knots to 17,500 ft.  When you’re flying into a different airmass there is always some uncertainty how things will go.  Well, this climb is promising.

It is 3:15 PM and I have another 36 km to go to my second turnpoint.  The clouds don’t look great but I anticipate that they will work: when the air is so dry, even small wisps can indicate powerful climbs.  In particular, I am on the lookout for any indication of new clouds that may be emerging.  That’s where the best lift is usually found.

As I approach TP2 it has become obvious that the cirrus layer overhead is rapidly moving eastwards.  The ground below is already shaded and I have not found a good climb in more than 10 minutes. I am now down to 14,000 feet and eager to get the turn behind me and back into the sun.

I turn TP2 at 3:27 PM, 3 minutes ahead of my schedule.  I find that quite remarkable.  My second leg of 370 km took me just 5 minutes longer than my estimate.  If commercial airlines would deliver that level of precision, I would be quite pleased. 🙂

Third Leg: North of Grand Junction to Comanche Meadow (NE of Red Feather Lakes) – 299 km

Starting out on my third leg I have two goals: find a good climb to get back to altitude; and get back into the sun and out from the cirrus overcast.

There are beautiful clouds below a beautiful blue sky in the distance. Lets get there!

I found some mediocre climbs under some wisps below the cirrus layer and I’m now considering two routing alternatives.  I had planned to follow the Colorado river along the north rim but there are good-looking clouds 20 degrees to the left in the direction of Meeker.  Since I am not familiar with that area I review it again on the map to ensure I have good landing options along the way.

I decide to head for the promising looking clouds toward Meeker. The labyrinth of canyons below is fascinating. It would also be a sure way to get lost. So let’s stay high…

The problem: once I get to the promising clouds, the cirrus layer has moved east as well and the clouds are decaying – promising no more.  I had expected an 8-10 kt climb.  Instead I only find three knots.  I only make three turns, then push on towards the sun.

There are more great looking clouds ahead under a pretty blue sky. The airport of Meeker is in the White River Valley to the left and in easy glide range.

As I approach the clouds, they have started to fall apart.  The cirrus layer has advanced as well and is shading the ground below.

I spend 6 minutes in a mediocre climb. Not because I want to but because I have to.  I gain only 1700 ft – a rate of less than 300 fpm – then I press on to outrace the cirrus!

After all: there are very appealing clouds ahead, under a gorgeous blue sky towards the Flat Tops.

But when I get there… same story: the cirrus layer has caught up once again.  I am still determined to win this race though.  I can feel that my entire task is hanging in the balance.  If I can’t outrace the overcast I will be too slow. Or worse, the lift may die altogether and I may be forced to land – far away from home.  It takes 4 1/2 hours to drive from Boulder to Meeker.  I really don’t want to land here!

Aren’t there great looking clouds over the Flat Tops Mountains to the east? And the sky is blue!

But when I get there … oh my this is frustrating!

OK, I have to get to THAT cloud.  It is very pretty indeed.  And the sky is so blue!

But when I get there?  You guessed it – the cirrus layer has just moved in. But: the cloud is still working!!!  I climb 4,300 feet in 7 minutes, an average of 615 fpm, and I get back to 17,700 ft.

There is still hope!  So let’s use the height and outrace that cirrus for good!

Doesn’t the sky look great!  But I cannot allow myself to make any mistakes.  The cirrus is moving fast.  I have to stay ahead of it but I also can’t afford to get low.  I can’t recall a glider race that felt so intense.  In a glider race your opponent may overtake you but that is it.  This opponent is different: if you don’t stay ahead you get taken out of the race altogether!

I made it across the Flat Tops and am heading towards Toponas.  This was my most westerly turn point during my Diamond Distance flight three years ago. This is the point where the Continental Divide comes back into view on the horizon.  And if the sky ahead looks like this then getting back to Boulder definitely seems doable. Maybe even the completion of the task?  I briefly wonder but then decide to ignore this unhelpful thought.  Don’t count the chicken until they hatch… I still have to focus on outracing the cirrus.  I know it’s not far behind.

Here’s proof: as I circle below a dark cloud east of Toponas I can see how much the cirrus has advanced as well.  The Flat Tops that had just been in the sun 10 minutes ago are already in shade and the clouds above look like they are falling apart.  Every minute does still count! For now there is still sun on the ground directly below.  Let’s concentrate on climbing well so I can keep it that way!

I stay north of Kremmling above the high ground and head towards the Rabbit Ears Range.  There are some pretty clouds along the north side, most likely the result of a typical convergence line in this area, virga to the south.

As I arrive over the Rabbit Ears, the sky has become more complicated.  The clouds ahead are dissolving, there is virga to my right, and I have to be careful not to be caught in a down-cycle.  Plus, with the cirrus not far behind, I really can’t afford to get stuck!

There is a tricky decision to be made here.  My third turnpoint is 85 km to the NE.  The direct route to get there is to the left of the nose via North Park, flying under the dark clouds in-between the virga lines.  It is works, that would be the shortest path. If it doesn’t work I would get stuck in North Park.  I might be able to make it to Walden or have to land in a field.  The alternative is to veer to the right and detour around the virga on the south side.  This route is more familiar to me, gets me closer to Boulder, and probably makes it easier to cross the Continental Divide.  If it doesn’t work I would land at the airport in Granby.

I opt for the detour and to go around the clouds on the sunny side.  The probability of finding lift here seems higher to me and the risk of getting caught in virga and rain much lower.  It’s also the closest route across the divide and I still worry about the cirrus catching up with me from behind.

Some snow falls outside as I work my way around the cloud into the sun. I quickly close my vents – otherwise snow makes it into the cockpit.

The Continental Divide is along the horizon, 40 km ahead.  Getting over these mountains is my next challenge.  If successful, I will have Boulder in glide and can assess the odds of making it to my last turn point. There are some clouds ahead, so I am hopeful that it will work.

The clouds that just looked so nice 3 minutes ago have started to fall apart.  But there is still sun on the ground so there ought to be a climb somewhere.  I will need to gain two or three thousand feet to make it safely across the Divide.

I try every climb I can find.  The wind is favorable, drifting me in the direction I need to go.  So even a slow climb is ok.  I can’t be too choosey now.  Provided that I stay ahead of the cirrus!

Looking back to the west where I came from it is apparent that my return from turn point 2 has truly been “just in time”.  Had I turned TP2 only 10 minutes later I very much doubt that I would have made it.

I didn’t get much of a climb.  14,700 ft with 25 km to go to cross a 12,200 ft pass is not a recipe for success.  I will need another climb.  The clouds don’t look great but I still believe that it will work.

I am at 14,100 ft. The ridge ahead is at about 12,200 ft. Not a lot of margin, but I find myself in good air with a tailwind and I am pretty confident that I can make it safely across.  Parallax is the best way to gauge the likelihood of success: if more terrain beyond the ridge becomes visible I should be high enough.  If that isn’t the case I will have to find another climb first.  The good thing here is that I can always turn around and have a save glide to the Granby airport if necessary.

I am directly over the divide and trying to find a climb.  I now have Boulder in glide (although somewhat marginal) but I am looking for more altitude to see if I can make it to TP3.

Near Longs Peak I manage to climb to 14,000 ft and decide to start heading towards TP3, 62 km ahead.  The sky is not looking great but I am not ready to give up.  There is often an energy line in this direction and the western edge of the clouds should mark its location.  There are also often good climbs late in the day above the ridges ahead.  I definitely have to give it a try!

Indeed.  I find a climb north of Estes Park above the ridge leading to Mt. Dickinson.  As I climb through 15,000 feet I notice the absence of the familiar pulses from the oxygen system.   I started the day with 1300 PSI in my oxygen tank but more than 8 hours at altitude must have depleted it.  Oh no!  This is really unfortunate because late in the day it is often critical to stay in close connection with the clouds. I am not one to risk hypoxia and decide to leave the climb early.  It means I will have to bounce along well below cloud base and find evening climbs that still emanate from the ground.

The clouds ahead look pretty good and I’m hoping to find good air along the way as I continue towards TP3.  There is often a convergence line in this area.  A glance on my flight computer shows that Skysight is predicting such a line some 15km further east.  But looking at the clouds I think it is more aligned with the course I’m following.

The line did work reasonably well.  I am now approaching the final turnpoint.  There is some virga ahead and I wonder if I have to fly into it to get my turn.  There is always some uncertainty when approaching virga.  Sometimes there can be strong sink but that is not a given.  It’s even possible to find strong lift and rapidly climb while flying through rain or snow.  As I look ahead it’s hard to tell what I will find.  But even if I find strong sink, I have enough altitude to escape towards Christman Field at the base of the hills to my right.  With a good plan B in place I head into the turn.

There’s neither lift nor significant sink as I turn TP3 at 6:07 PM, now 17 minutes behind schedule.  The last leg took 20 minutes longer than I had anticipated, the consequence of weak thermals while I tried to outrace the overcast, plus the significant detour around the virga over the Rabbit Ears Range.  But at this point the schedule is irrelevant.  Getting to the finish and safely landing before sunset is all that matters.

Final Leg: Comanche Meadow to Lee Hill – 88 km

When I planned the flight I had hoped to be above 17,000 feet and within Final Glide upon my last turn.  But as things stand, I still have some climbing to do.

Looking ahead after turning TP3 I have 88 km to go to the finish.  There is still sun on the ground over the Poudre Canyon ahead to my left.  However, I decide not to take the most direct line.  Instead, I retrace my flight path to get back to the west side of the clouds ahead.  I expect to find the best air along that line.  It is quite beneficial for the last leg to be in an area that I know well.

I am delighted that there is still sun over the Poudre Canyon ahead.  I have often found late afternoon thermals in this area.  However, more often than not I am flying much higher in this area than today.  I have 80 km to go to the Finish Line and my flight computer shows that I am about 3,500 ft below final glide for my task at MC4.  Beyond the Poudre the sky looks completely overcast so I HAVE to find some lift in this area.

Lucky again!  I find my last climb of the day directly over the Poudre Canyon with 59km to go.  My flight computer shows that I just made Final Glide altitude! That’s a big moment!

The sky is completely overcast but I am now 900 ft above Final Glide at MC4 and I am confident that I have made it.  Wow!  I’d like to let that sink in, but I am also aware that I still have an airplane to fly to a finish and a safe landing. So let’s stay focused on that!

8 hours and 30 minutes after I flew across the Start Line above Lee Hill setting out on a flight across mountainous Colorado, I have returned to the same spot.  It is hard to believe.  I have completed my 1000 km FAI triangle.  The first ever in Colorado.  The time is 6:46PM, 16 minutes later than I had planned. My average task speed was 118 km per hour instead of my estimated 125. But all of that is largely irrelevant.  What matters is that I got it done. Now all that’s left to do is a safe landing.  I deliberately go through my checklist.  Dump the water, put the gear down, check the spoilers, check the wind, look for traffic, flaps in position 2, and bring it home.

Winds are calm on the ground as I bring a successful flight to completion with a smooth landing a little over an hour before sunset.

Flight Trace and Key Stats

You can find the full .igc flight trace with all details on WeGlide and on OLC.

• • Declared FAI Triangle Distance: 1001.5 km
  • Declared Flight Distance: 1001.5 km
  • OLC Flight Distance (optimized for 6 legs): 1071 km
  • Task Duration: 8:30:52 hours
  • Average Task Speed: 117.62 kph
  • Flight Duration: 9:06:30 hours
  • Circling Time: 2:08 hours (24%) – 52 Thermals, Average Climb Rate 4.4 kts
  • Average Glide Ratio 67:1, Average Netto: 1.4 kts,
  • Average Ground Speed in Cruise Flight: 184 km per hour

Lessons Learned

Reflecting back on the flight there are a bunch of things that I got right and also several opportunities for improvement.

Let’s start with what worked well.

• • Relying on Skysight as my main forecasting tool worked well and the forecast was quite accurate with respect to thermal heights, presence of cumulus clouds, cloud bases, wind direction and strength, etc.  There were a bit more virga cells than forecast and Boulder did see a local thunderstorm although none was predicted.  I had also checked local weather forecasts for key locations along the route, largely to assess the risk of storms.  But this was mostly helpful to boost my confidence. I did not learn anything that was new or different from Skysight.
  • I was well prepared for the geography of the flight.  I even carried a list of all airports along each leg with local radio frequencies. Having my physical soaring map in the cockpit was also very helpful.  I knew the overall terrain quite well but it was super useful to better visualize the location of airports within those sections of the task area that were new to me. There was no point during the entire flight when I did not have a suitable airport within easy glide range.
  • My estimated speed of 125 kph and the estimated times at each turn point were quite realistic even though I ended up flying a little bit slower.   I did not trust Skysight’s attainable speed of over 150 kph and I don’t know if anyone could have flown this fast.  I think 135-140 kph may have been possible for a better pilot than me but I doubt 150 or more was really achievable in an 18m glider.
  • Crew for a potential landout.  I had talked to ABC, one of SSB’s flight instructors and my Official Observer, and he assured me that he would be prepared to come and get me if I were to land out.  I also know there are many other great members at the SSB who would do the same.  Having made such arrangements in advance was not only very comforting.  It ultimately proved to be essential because it allowed me to take the sporting risk of a potential landout (not a safety risk!), especially when I had to push to my westernmost turnpoint even though I could see the cirrus layer moving in.

Things I would do differently if I could do it all over again:

• • I would launch even earlier.  The first little clouds appeared by 9:15 am and I did not get off the ground until 9:53 am.  Every minute counts if you have to be concerned about making it before the end of the soaring day.  I left more than half an hour on the table at the beginning.
  • I missed the predicted Cirrus forecast.  In fact, I did not look at the high clouds forecast at all.  That was clearly a mistake.  I even remember that I was puzzled about the declining lift strength by 3:30PM but did not think to examine the possible reasons for it.  Next time I will look.  However, somehow I am glad that I didn’t because the forecasted cirrus layer might have dissuaded me from attempting the western turnpoint.  And in that case, a 1000 km FAI triangle task would probably not have been possible.
  • I need to add more oxygen for such long flights.  I never ran out of oxygen before and I thought 1300 PSI would easily suffice. It is entirely possible that forcing myself to fly below 14,000 ft towards the end could have caused me to fall out of the working band and land out just before the end. Luckily I kept finding new climbs and eventually got on final glide.   Next time I will look for a completely full bottle to fill my tank to the max.

Luck comes into play to!

• • I did not anticipate that the cirrus layer would move so fast.  Ultimately it was sheer luck that I was able to outrace it.  Only after the fact did it sink in how narrowly I won that race.  Had I arrived at my second turn point only 10 minutes later I am fairly certain that I would not have made it back to the Front Range.

Finally, I would like to thank Armand Charbonneau, my official observer  and potential retrieve crew. I could not have done it without you.  In addition, I’d like to thank everyone at SSB, in Austria, and in France who has been instrumental in coaching and mentoring me over the years.  There are too many to name.  You know who you are.  Your advice and counsel has played a key role helping me get to the point where I was able to complete such a flight. Thank you!

Concluding Thoughts

At the beginning of this article I explained that declared 1000 km triangle flights in Colorado might not have been done before because they require exceptional days.  However, exceptional days have existed before and they will continue to exist. They are probably more frequent than we might think. I am convinced that there are several days each year when such flights can be achieved.

But one thing has changed over the years:  in the past, it was usually impossible to know which days were truly exceptional.  The weather forecasting just wasn’t good enough.  Now we’re seeing many more record breaking soaring flights in Europe, in New Zealand, in Africa, and all over the world, and it’s not (primarily) because the sailplanes have gotten better.  It is also not that the pilots have become better or more ambitious.  What really has become better is the weather forecasting.

Historically you could not know which parts of a task area would OD first.  You could not reliably predict whether there would be cumulus clouds hundreds of miles away from home at a specific time of day. It was practically impossible to forecast how the wind speed and wind direction would evolve in different parts of a task area at different times of the day. And the position of convergence lines somewhere in the blue? Only a few years ago there was no chance of knowing.

But now we can predict all these things.  Don’t get me wrong.  The forecast is still only a forecast.  Reality can – and is – different.  There still are inaccuracies.  However, these inaccuracies have drastically diminished and they will continue to diminish.

We can now plan much better that we ever could.  My flight will not be the longest flight in Colorado for long.  I believe we will see many more.  I wish everyone attempting them the best of success.

Have fun and fly safe!