08-22-20 | A Tale of Two Airmasses

It was the best of times, it was the worst of times, it was soarable in Pennsylvania, it was miserable in New Jersey, there were cloudstreets, there were 40 mile blue holes, an airmass with strong and high thermals, and another that produced a thunderstorm that nearly wiped out the airport; in short, a memorable day!

I arrived at the airport with no expectations. It was August; hot and humid with a southwesterly wind pumping in air expended from the swelled up swamps of South Carolina.  My sweat accumulated after assembling the glider, completely soaking my clothes, and refused to evaporate. The few clouds triggering over the ridge were hardly much above ridge top. Having not flown the DuckHawk in a little over a month, I was content to simply get airborne and do a couple takeoffs and landings. And if I managed a short soaring flight, heck that would be an accomplishment.

Glancing at the forecast, the Poconos looked promising. Perhaps it would be good enough to poke around in that wonderful high ground? I set a short task up to Lake Wallenpaupack to do a little bit of sightseeing.

Taking off a little after noon, there were still low, scrawny clouds over the ridge. The first climb off tow was a struggle; 10 minutes in a half knot thermal to claw my way up to cloudbase at 3200ft. A short thermal street lined up into the wind, along the ridge. The DuckHawk was much more content flying straight than circling in these weak bubbles.

The line promptly ended at the hang glider launch, hardly ten miles away from the airport. A slow climb took me up to 3800ft and I looked over at the high ground to the northwest. The clouds were slightly higher over East Stroudsburg and the lift was fairly reliable. And heck, with a 50-1 glider, the odds are good that I’ll find something.

Sure enough, there were a couple bubbles along the way to keep inching upwards. Off my right, there was a rain shower; the sucker looked like an enormous billowing cauliflower, with a dark ominous bottom, slowly moving toward the airport. I didn’t think much of it at the time.

Looking dead ahead toward the Poconos plateau though, the sky totally transformed. The clouds formed little cottonball puffs at 6500ft and you could see miles and miles away. Once over the edge of the plateau, I found solid lift and climbed right alongside the clouds!

My flight computer read out that the wind was 300 degree or so; quite different than the 220-250 degree wind in the valley. I discovered that this was a new airmass, bordered by a trough parked right at the very edge of the Poconos. Coupled with the heating of the high ground earlier in the day, it created a steep boundary where the clouds rose thousands of feet. This was going to be cool to explore!

Along the edge of the line, the lift was not all that continuous, although it worked nicely where the clouds hung down like a curtain. And there it was really fun climbing up on the edge of the wispies!

Abeam of Beltzville, the line made a hard left and seemed to lose definition. I suppose it would be fun to poke deeper into PA. Who knows, maybe I could even make it to the Susquehanna River?

Picking up the pace, I found reliable 2-3 knot thermals under honest clouds. Going toward Hazleton, the cloud base dropped off, but no worries; my nose was aimed squared at the Berwick Nuclear Powerplant.

My name for the thermal that comes off the plant is Ol’ Faithful. The steam plumes are often visible from Blairstown, beckoning the wayward glider pilot like a siren to come over and harness its energy. Positioned in the middle of a valley, right by a river, it’s often the only lift within a considerable distance. The resulting thermal is nearly always marked by a cumulus cloud hanging a little lower than the rest; laden with the moisture coming from the stacks, the thermal is always in a hurry to condense into a cloud. And sure enough, there was a solid 3-4 knotter that picked up to a turbulent 5-6 knots near the top. The thermal was so gusty that at one point it nearly spun me out! After a fun rodeo ride, I was back in business at cloudbase.

Heading across Scranton, the Alleghany plateau invited me with beautiful clouds ahead. While I had flown up before, I’ve never directly flown across these imposing mountains. The wind is often times a bit too strong and the thermals are disorganized for many miles. Going into unlandable terrain, higher terrain, and a headwind is a dubious proposition. Most of the time the edge of this plateau acts like a brick wall.

This time, I cleaved into the higher ground without any difficulty, climbing right up to 7000ft. Out yonder, it looked even better!

But as I drove along, I ended down at 4500ft and felt low. There was an airport in comfortable gliding distance ahead, but that piece of property was situated at a daunting 2000ft MSL. Best to tread carefully.

After slowly climbing up and another tricky glide, I finally connected with a solid 2.5 knotter. A little stumbling around here and recentering there wound the averager up to eight knots. Woohoo!

I kept climbing, and climbing, and climbing. At 6000ft, the cloud above me didn’t feel any closer. Neither at 7000ft! Man, what’s going on here? At 8000ft, the thermal was still going and going, just like the energizer bunny.

That sucker topped out at 9,500ft! No wonder the sink was strong before; there were monster thermals around!

My watch inched toward 3:20pm. A pang of doubt crossed my mind; I better start thinking about heading home.

Around that time, the airport was experiencing an epic deluge. The shower I skirted earlier in the day turned into a massive, slow moving thunderstorm. The radar map showed all sorts of pretty colors and orange/red polygons. And then as you gaze at the legend, your eyes widen as you see a tornado warning in effect.

As the billowing cloud crept toward the airport, all the gliders airborne bolted toward the field. The pilots quickly landed, tied down and ran for cover. Those unlucky enough to be still outside when the rain swept in were caught in a torrential downpour. The wind was so strong that the rain came in sideways. This is the kind of the day when rusty stakes, frayed ropes, and creative knots are put to the test.

Meanwhile, I was oblivious to the mayhem back home. My thoughts drifted toward the ease and relaxation of being in the cool, dry air at 9500ft. My cloud was part of a cloudstreet extending ahead of me and it was just too good of an opportunity to pass up. I nosed over and flew up to the Buttonwood Ridge, 20 miles northwest of Williamsport, a good 108 miles from home. Figuring this would do for the day, I turned for home. It was 3:40pm.

Picking up the pace to 90 knots, it now was time to put the pedal to the metal. Better to run back home while the conditions were still working well! Sure enough, the lift remained totally solid over the plateau. Consistent 3-5 knot thermals to 9,000ft, good air in between and a tailwind for good measure too. This was glider pilot heaven!

Abeam of Scranton, 70 miles from home, the clouds ahead lost some of their definition. Off my left, the cloudbase dropped off precipitously.  I tanked up as high as I could; better to be thermalling up here, than down there! This climb took me to within 1000ft of a MC 3 final glide. This would comfortably get me across the whole Pocono plateau and might even do for squeaking it home in a pinch.

Over the next 45 miles, the air flattened out. The day was softening up; boy was I glad to have tanked up! I slowed up and floated in the good air, but there were no solid thermals for a long way.

Looking ahead, I could see Mount Pocono Airport beckoning in the distance, with many clouds still formed along a parallel line to the plateau. Sure enough, the trough line was still working! Beyond these clouds, the air was a hazy blue, devoid of all clouds. It looked like the streets at the edge of the Poconos were pushed into this invisible barrier, with the resultant cloud spewing in all directions; upwards, downwards, and sideways. The tendrils hanging down indicated solid lift was working ahead. I relaxed, knowing that I had it made.

Sure enough, approaching the line there was a good thermal and I easily climbed up for final glide with plenty of height to spare. But these peculiar clouds alongside me were just too tempting to simply bypass. Instead, I turned toward Lake Wallenpaupack and played with the line.

It was so much fun! When the glider sank a bit lower, I’d park my wing in the tendrils and thermalled right up the edge of the cloud. In between the streets, there was some mildly good air serving to extend the glides. This worked very nicely for a lap up and down the line, which was slowly inching its way northwestward. With my watch showing a little past 6pm, it was time to call it a day. After rounding the last cloud, the flight computer showing a MC-3 glide, I turned toward Blairstown Airport, heading into the blue, dead void.

Slowing down to best-glide speed, the air was dead smooth. I let go of the stick, turned the variometer down, and just watched the mass of trees under me, gliding toward the ridge off of my nose, the glider contentedly humming along. The upper reservoir was way off in the distance, slowly inching downwards in my canopy.

I looked down at the twists and turns of the terrain below, the setting sun off my right shoulder, and the clouds dissipating behind me. It was just so peaceful, so much so that it felt odd that the flight should ever end. It seemed like the sailplane will silently sail on forever.

Coming over the airport, the wind sock was dead limp. There was some mist forming off the runway and I lined up to land on 7. Since the original objective of the flight was to perfect my landings in this glider, it felt appropriate to oblige. I lined up over the trees, pushed over and landed short of the mid-field taxiway; a challenge completed!

Getting out of the glider, I was surprised to find the grass to be wet and squishy. Everything was soaked and the airport was totally deserted.

When young Kevin emerged out of the shack, it seemed like he was the sole survivor of an apocalypse. He greeted me with the harrowing tales of the afternoon and later helped me disassemble the glider. Later, a couple stragglers banded together to spend the rest of the evening trading tall tales of exploits in days and years past.

All in the adventure that we call a day at the airport!

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What a wonderful day! A day that started with no expectations, yet ended in a 270 mile flight! Blairstown offers such dynamic and wonderful soaring; no matter how long you fly here, there will always be new challenges. Thanks Tommy for towing and Bill Thar for crewing in the morning!

Find my flight log here.

Daniel’s Ridge Commandments

Violate these commandments at your own peril, for the Almighty Ridge will smite those who fail to respect it.

  1. Thou shalt be proficient and prepared to tow in windy conditions (eg: Checklists complete, no loose articles, belted in tight, emergency plan prepared, familiar with tow signals, etc.)
  2. Thou shalt test the ridge with a landing option in glide and your approach planned.
  3. Thou shalt not fly low and slow near a ridge (eg: < 150ft AGL AND < best glide speed).
  4. Thou shalt not drift downwind of the ridge band!
  5. Thou shalt not turn toward the ridge.
  6. Thou shalt s-turn until sufficiently above a ridge (min: 200ft AGL, 400ft better)
  7. Thou shalt turn nose low, coordinated, and with sufficient airspeed (eg: best glide speed).
  8. Thou shalt not fly into a box canyon.
  9. Thou shalt have a landing option in glide and approach planned at every moment when completing a transition to another ridge.
  10. When approaching an unlandable area, thou shalt reassess the conditions and establish your landing options/approaches ahead and behind you.
  11. Thou shalt not fly on the downwind (lee) side of the ridge!
  12. Thou shalt respect the right of way rules: Right wing to the ridge has the right of way.
  13. Thou shalt be proficient and prepared to land in windy conditions. Maintain extra altitude and airspeed during approach/landing. (eg: +200ft above IP, +15-20 knots in the pattern, turn final 100-200ft higher and land long down the runway if practicable.)

And if you’re flying at a site that requires soaring back to your airport:

Thou shalt establish and maintain a minimum margin to return to the airport (eg: Blairstown – 2400ft in a 1-26).

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Note that these margins are provided as ballparks and may need to be adjusted for a given ridge site, sailplane, conditions, and the experience of the ridge pilot.

Why Thermal in a Slip? | And the Hazards of Skidding

Experienced soaring pilots usually advise thermalling in a slip. Dick Johnson in the October 2004 issue of Soaring magazine provides an excellent technical explanation for how and why to use this technique.

The bottom line is that a turn requires a combination of pitch, bank, and yaw to maintain a stable configuration. And it requires some compromises to achieve the most efficient combination.

If you thermal fully coordinated, you will need to use top aileron to avoid “falling into the turn”. If you slip using top rudder, you will minimize or even eliminate the top aileron. You are compromising by dragging the fuselage through the air stream, while making the wing cleaner.

It seems like some combination of top rudder and top aileron is often most efficient.

Conversely, turning with ANY amount of skid is VERY inefficient. The MORE you skid, the MORE top aileron you need to avoid falling into the turn.

In this case, you are BOTH dragging the fuselage through the air stream AND using quite a bit of aileron to keep the turn stable. This is very bad!

I notice that many pilots thermal with a heavy inside foot, resulting in a skidding turn. Aside from being more spin prone, even a minor skid will be very draggy!

Next, skidding into a turn (leading with the rudder) makes the glider especially spin prone. Initially you rudder into the turn, followed by feeding in back stick and opposite aileron to stabilize the turn. This serves to load up the glider while putting in control inputs that aggravate stalling/entering a spin.

This is especially dangerous in the pattern. Many pilots have a tendency to over-rudder their turns while on approach.

Here is a scenario that can easily result in a stall/spin. A low and slow base leg, followed by an over-ruddered, button-hooking turn.

As you start turning, you use too much rudder. This is followed by pulling back to get the turn established. And finally, feeding in opposite aileron to keep the glider from falling into the turn. This results in the glider departing into an unrecoverable spin.

Building Your Toolbox | Responsibly Developing Your Margins

Many accidents in soaring are while flying cross country, particularly during landouts. Most landout related accidents have little to do with unexpected occurrences in a good field. Instead, they have more to do with the situational awareness, judgment, and decision making of choosing an appropriate field at the right time and selecting the right time to quit soaring and land.

Most pilots get injured or killed in the stall/spin during low thermalling, or a poorly planned approach into the field. Or, neglecting the field selection process until it’s too late and the nearest field is unsuitable due to obstacles, slope, or wires.

I’d like to focus on low thermalling and approach planning. What is extremely disconcerting is that pilots do dangerous things near fields. Dangerous is a relative term; what is unsafe for one pilot is “safe” for someone else with more skill, experience, and practice.

However, what is scary is that pilots who are generally “conservative” near their home airport under the close eye of their fellow club members will often take “chances” while flying cross country.

An explanation for this behavior is that it is an example of loss aversion. Pilots confuse being risk-averse/conservative with simply finding losses being painful. Rather than being conservative with respect to landouts, they simply really really don’t want them to happen due to their inconvenience or feeling embarrassed. And if they find themselves getting lower near a field, they will be MORE tempted to take chances to avoid landing out!

If a pilot is conservative, they will select a good field EARLIER and quit at a HIGHER altitude, rather than taking chances near fields! Instead, a loss averse pilot accepts safety risks to minimize their likelihood of accepting a loss.

To stem this behavior, I suggest developing a toolbox of skills and margins. Think of this like an athlete. You practice at your home court, your gym, your own pool or your personal track. And when you go to a meet, now you put your skills to the test.

Just like you shouldn’t try out a novel swimming technique while competing against other swimmers, you shouldn’t be experimenting with anything you haven’t practiced before while flying cross country. Especially as it relates to safety!!!

The toolbox MUST be built up in controlled conditions. The idea here is that abbreviated patterns, landing techniques, low thermalling, ridge soaring, final glide planning, or anything else should be thought through and practiced beforehand. Here are the steps to building your toolbox:

Think Through the Theory

Especially as it relates to safety skills, there’s a lot of disagreement over what constitutes reasonable judgment and decision making. For the purposes of this discussion, I will discuss choosing margins related to low thermalling, although you can apply this process to all safety related skills.

If you go on RAS, some people will tell you that thermalling below 1000ft AGL is absolutely insane and you should be thrown out of a glider club should you attempt it. Others will tell you that thermalling at 200ft AGL is perfectly A-OK and no one has any business telling them otherwise.

I doubt that there is any sport that has a 500 percent disagreement over what is reasonable and safe!

I have my own thoughts about these margins, but my objective here is not to proselytize. Instead, you should think long and hard about your goals. The closer you get to the edge, the narrower your margins for error and the greater your risk. Come up with a set of approximate numbers and consider the various contexts that you might apply them.

Note that your margins should be built around less than ideal circumstances. In the case of low thermalling, assume that you will be hot, tired, dehydrated, distracted, on the last day of a competition while in contention for placing well, on a somewhat windy day, near a less than ideal landing option.

Don’t assume you will be 100 percent on your game! Give yourself some room for error.

Consult a Respected Mentor

After you have come up with your limits, discuss them with a pilot you trust. They will provide you feedback and give you a sense if you are in the ballpark given your experience level.

One word of caution is to be careful to whom you gravitate towards. If you look at people in a positive light, the spectrum goes from pilots who are more focused on the sporting side of soaring while others are on the recreational side. The alternate perspective is the spectrum goes from “crazy” to “safety conscious”.

The truth is usually more complicated, but the point is to be careful seeking out affirmation of more aggressive minimums from a pilot that has a reputation for being “crazy”. Regardless of your feelings toward your mentor, you should expect opprobrium from a good portion of your flying club should you apply aggressive minimums if you are a beginner.

Practice in Condor

Once you decide what is reasonable and appropriate, practice these skills in Condor. Put yourself in many different situations and see how your margins play out. Practice thermalling low near airports, fields, in windy and turbulent conditions, etc.

Practice breaking your margins. See what happens when you get a little too far away from your field. What happens when you thermal a bit lower than your minimums? What happens when you thermal too slow and enter a single full spin?

Are your margins robust to failure, or do they require perfection from you to work?

The point is to practice every kind of failure you can think of in the simulator before you attempt it in real life.

Build Your Margins Locally

As you soar in gliding distance of your airport, practice your thermalling techniques and slowly build up your margins. Suppose you decide that your thermal minimums are 800ft AGL. On a non-busy, calm day, maybe take that turn in that thermal near the airport.

Practice your techniques in the real world. These margins now form your toolbox for cross country flying.

Applying Your Margins Cross Country

Approach flying cross country like you are performing at an athletic meet. NEVER do anything that you hadn’t practiced before. When you find yourself in a tricky situation, open up your toolbox and responsibly apply your skills/margins.

If the lowest you are comfortable thermalling near the airport is 800ft AGL, then you should NOT thermal lower than that altitude near a field!

If you are uncomfortable making non-standard patterns at your home airport, you should NOT do anything less than a full pattern into a field!

If you are uncomfortable arriving lower than 1500ft AGL at MC 4 to your home airport on a final glide, you should NOT arrive at an unfamiliar airport with any less margin!

If you are uncomfortable flying a weak ridge locally, you should NOT attempt a save on a weak ridge far away from home!

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In summary, think through the skills you wish to develop, and practice them in controlled circumstances. Develop your toolbox. Practice, practice, and practice some more!

Note that these margins are elastic and depend on your proficiency. Just because you were comfortable doing something once, doesn’t mean that you can be comfortable doing it in the earlier part of a soaring season. Or ten years later after taking a hiatus from soaring. You must consistently assess and reassess your margins.

Think of cross country flying as going to an athletic meet. You are now performing, not practicing! And when you perform, don’t do anything you haven’t practiced before!

I believe if soaring pilots apply this approach to their soaring, they will be a lot safer.

Bringing It All Together | A Lap Along the Local Ridge

It’s a nice day with moderate wind, perpendicular wind direction, and decent thermals. We had towed over to the ridge, tested out the conditions and dropped down on the trees. We are finally ready to soar along the ridge, having trained all of the key ridge concepts and raring to go!

In this video, we do a simple lap from the Upper Reservoir, to the Delaware Water Gap, up to the Millbrook Powerline, and back to the Upper Reservoir. We discuss the local landmarks along the way and some of they key thoughts that come to mind in various stages of the flight.

If any of the concepts or landmarks are not familiar to you, refer back to their respective videos.

It’s worth noting that when the conditions are working well, ridge soaring *feels easy*. And in a way it is; when a pilot has the foresight and skill to choose the appropriate conditions and stays in the wonderful ridge band, there’s little that can go wrong.

But the training, coaching and the practice is to prepare you for that very reason. When you know the traps, have a plan and have the knowledge to extricate yourself from various situations, you will be able to fly the ridge safely.

And this is why there is about 3 hours worth of explanation and context that goes into a 20 minute video of showing how it works when everything goes right.

Introduction to Ridge Transitions | The Catfish Ridge Jump

The purple line is the flight path. We DO NOT fly in the “No fly zone” as this area is dangerous and the ridge works poorly. Instead, we make our transition from the local ridge to the catfish ridge. We often use the “gully line” to find a thermal and good air to make our crossing.

This segment is a crash course in how to do ridge transitions. We start out with the Catfish Ridge transition as it is the first one that many pilots will encounter in their ridge training. This little offset has all the features of a transition and gives our pilots a great way to practice their transition technique.

Ridge transitions often require a lot of attention in a ridge flight. These are areas where we have to cross from one ridge section to another, often due to the shape or current conditions making a section not work well enough to support the glider. These crossings are “hinge points”, as you are more likely to find sink, or a non-working section of ridge while completing a transition. Many ridge-related landouts are due to transitions going wrong.

When a transition goes wrong, you have to execute a landing very quickly in sporty conditions. A couple seconds here or there could make a big difference in the outcome.

Having extra altitude and margin goes a long way to mitigating the risk.

Situational Awareness

While flying the ridge, you should be completely aware of all the transitions on the ridge you intend to fly. You should recognize that you are approaching a transition point as you are flying the ridge. Next, you should have scouted the landing options at the base of the ridge, should the transition go wrong. You should find them and plan out your approach before you begin the jump.

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There are five steps a transition:

Gain altitude (Float up in the ridge band or thermal)

As you approach a transition, it usually pays to slow down early and gain altitude. By working your way up into the higher lift band, you can make the ridge do the work of giving you sufficient altitude, rather than struggling to climb later.

The amount of height you will need depends on the conditions, your experience, and your glider. We often give some numbers for pilots to start out with, such as ~2100ft MSL for the Catfish Ridge transition. When we provide these values, we are giving pilots “the highest common denominator” with respect to altitude. The height that you would make it across assuming you run a bad line with a less favorable wind direction. But with more experience, you can judge the conditions on a day-by-day basis.

Pick your line

A big decision is deciding where you are going to jump off from. The simplest way to do it is to simply find the shortest line; get as high and as close as you can to where you want to go and make a beeline across to the other side. However, this neglects the effect of the air in between. Often transitions will have thermals or energy lines that line up consistently due to local terrain features. It often pays to run “a good line” upwind and maintain higher altitude rather than simply taking the shortest path. Conversely, making a transition in strong sink into a strong headwind will make your altitude evaporate very quickly and you may not make it across.

Probe the air

When you start a transition, you are not immediately committed to going all the way across; you can test out the waters. If the transition is working out well and you are generally maintaining your altitude, that’s good. If you start hitting sink and dropping out, you can still turn around and try again.

Point of no return

There is a point when you can no longer get back to the ridge you started from. You must recognize and acknowledge this point as you do your transitions. Once you have gotten beyond the point of no return, you will either make it across, or land in a field that you have scouted out in case the transition does not work out.

If you have extra altitude and you are going upwind, your point of no return can be delayed quite a while. Downwind jumps will reach this point a lot earlier as you get blown too far downwind to make it back very quickly.

Commit to the transition

This is less the case in small jumps like to the Catfish ridge, but there are instances in large transitions that you get beyond the point of no return and may or may not be able to make it across. This is the case such as if you are trying to do big upwind transition and you are in the middle of the valley, considering whether you have enough energy to safely go over the top of the mountain. During this stage, you are considering your landing options along the way. As you get closer, you decide whether you will want to commit to the transition and continue over the top of the mountain.

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Doing Transitions Low

In the videos, we explored how to do transitions by the book and what happens when you do them marginally. As you get lower, factors such as the wind direction can play a significant role as to whether you will make it across or not. If the wind angle is off and you have a significant headwind component, you may have to go a long way into lee sink, headwind and around a corner to find a working section of ridge. You will lose a lot of altitude along the way.

Next, we see how the stages shift based on your margins. If you’re low, you will reach the point of no return sooner. This commits you much earlier and you are taking a greater chance of coming up short and landing in a field.

In sum, a couple hundred feet here or there makes a BIG difference in ridge transitions. Stay ahead of the steps, know your outs, and maintain your margins.

Off-Angle Wind

When the wind angle shifts more than 30 degrees off from perpendicular, the ridge lift becomes less reliable. As a result, we strongly recommend that beginners “stick to the formula”; wind speed 15-25 knots at ridge top, within 30 degrees of perpendicular for the section you are flying. In these conditions, you can generally expect the well-flown ridges to have “robust” ridge lift. This is to say that the ridge lift should be consistent and reliable; few factors can suppress or significantly affect the ridge band.

However, when the wind is outside the formula, this is not to say that the lift shuts off. Instead, there are many more complications that can affect how the ridge band works. Certain sections may work very nicely, while other sections are completely flat. The high part of the band may allow you to float at a moderate speed, whereas the low band may not be working.

With experience, it becomes possible to anticipate these factors. That said, it requires flying on many days, progressively exploring the ridge, and building up your margins. Intermediates may explore these days in the comfort and safety of the local ridge and experts may take advantage of these days going cross country.

While I do not advise beginners to fly on an off-angle ridge, beginners should nonetheless have a sense of what to expect if the wind angle shifts, for instance if the conditions unexpectedly change over the course of the day.

The more off-angle the wind is, the higher off the ridge you have to be.

As the angle shifts, the air becomes violent down on the treetops. There will be a turbulent wash as the wind angles over the mountain. By the time the angle is 45 degrees off, you typically have to be at least 300ft-400ft above the trees for the band to work well. Aside from being turbulent, the lift will typically be disorganized and weaker lower.

The more the angle shifts, the higher you must float along the ridge.

If the wind is on the weaker end of the spectrum (<20 knots) and/or the thermal activity is limited (think overcast above), the high band will get weaker.

If the wind is weak and/or the thermal activity is suppressed, watch out. This will weaken the high/float band. This is a really big problem! The lift band becomes compressed; it becomes only possible to float at best glide speed at 2000ft MSL or so and you cannot get higher or lower. It takes very little for this lift band to weaken to the point where it will no longer sustain you.

If the wind is weak/moderate and/or the thermals are not working well, do not count on an off-angle ridge.

Expect substantial sink when encountering thermals on the ridge.

Watch out for thermal suppression, especially when heading into a quartering headwind. Recognize that you will be approaching the thermals on a cross angle. This means you will need to traverse a long band of sink before you encounter the lift.

If the ridge band is not working well and the thermals are strong, you can easily get flushed down to ridge top. Moreover, this effect worsens as the wind angle increases. For example, if the wind angle on ridge top is 45 degrees off, but the thermal street above angles 55 degrees off at cloudbase, you may traverse 5-10 knot down sink over the course of a half mile! This amount of sink could be enough to knock a glider off a ridge, especially a low performance ship.

Watch your airspeed while down at ridge top.

When going upwind, your ground speed will be very low. However, when you turn downwind, your ground speed will be very high. When heading downwind, it is easy to let yourself get dangerously slow if you are not paying attention. The trees will be flashing by very quickly, giving you the illusion of flying a lot faster than you really are.

Certain ridges are tolerant of an off-angle wind; others are not.

Generally, ridges that are fairly high, straight, have few upwind obstructions, and few issues like gaps, bowls and spurs are more tolerant of an off-angle wind. Conversely, any of these issues will cause a ridge not to work in a given section if the angle is sufficiently off. A ridge with many issues may not work with a wind angle greater than 30 degrees off.


In summary, when the angle shifts beyond suggested tolerances (+- 30 degrees), the conditions become marginal. This makes flying in these conditions an expert endeavor. However, the lift does not necessarily go away. With practice and experience, you may still find a solid working ridge band. And if the conditions unexpectedly shift, you will know what to expect.

The Downhill Trap

As you fly the ridge, you must pay attention to how the mountain is changing ahead of you. One important change is if the elevation of the mountain is increasing or decreasing. If the mountain is getting lower ahead, be careful!

The solution is to maintain a constant altitude over a low section of ridge. If you’re able to maintain a selected altitude, then you’re doing well. If you start settling down, be ready to turn back on a moment’s notice.

The downhill trap occurs when you drive along the ridge while maintaining constant altitude in relation to the crest, but you are in fact sinking down along a descending mountain. The lift could be pretty weak, but yet you could maintain high speed down on the tree tops.

When you run out of mountain ahead of you and turn around, you will instantly find yourself low and slow. You will see the mountain extending way above you. At best, you will limp along in weak lift trying to climb along in the increasing elevation, scared out of your wits. At worst, you will promptly fall off the ridge.

The Blairstown ridge extending from Sunfish Pond to the Delaware Water Gap is an example of a section that has this trap. As you build experience and prepare to fly the local ridge, pay special attention to this area and don’t make this mistake!

Falling Off the Ridge

What happens when the wind is too weak to sustain a glider at ridge top? You will settle down lower and lower, until you almost get down to ridge top. Then, you will immediately have to leave the ridge and head toward a landing option.

This process happens very quickly. If you’re 400 ft above the mountain and the ridge is not working, you will be down at ridge top in as little as two minutes. The trees will be filling in your canopy very rapidly.

Note that you will NOT settle into an “equilibrium point”. No matter how low and slow you get, you will NOT sustain at ridge top.

Maintain your airspeed at least at Best Glide Speed with the ridge coming up at you, it will be tempting to pull back to keep the nose level with the mountain. Watch your airspeed like a hawk and don’t be tempted to pull that stick back and get any slower.

Plan on leaving the ridge at 150ft above the trees. Settling down lower and slower will rarely help you and yet the risk of doing so is very high.

Once you leave the ridge, transition immediately into a landing mindset. You will be down on the ground in the next 2-4 minutes. Take a deep breath. Do your landing checklist. Focus on making a nice landing.

Recovering From Below Ridge Top

You should not put yourself below ridge top. Should you attempt recovering below ridge top, you will be forced to fly low and slow in weak lift while in gusty conditions. This is dangerous. If you are a beginner, you must maintain good situational awareness and judgment to avoid these situations.

However, the Aero Club Albatross ridge training syllabus demonstrates a below ridge top recovery so that pilots: A) Understand how the ridge band works below ridge top, B) Are equipped with the knowledge to safely recover should they choose to.

1. How do we find ourselves below ridge top?

There are two ways to fall below ridge top. One way is because the ridge is too weak to sustain you above. In such a case, you should immediately leave the ridge and head for a field in the valley below. If the ridge is not working above ridge top, it will certainly be no better further below. A good minimum for a weak ridge is 150ft above the trees at Best Glide speed. Note that this is a minimum. Mentors and coaches would be wise to advise beginners to fly in considerably stronger conditions.

Also, a pilot can fly lower and faster if they would like to, but the ridge needs to be commensurately stronger allow them to go 10+ knots faster 50-100ft above ridge top.

If you settle down to ridge top, then expect to leave in short order.

The second reason we can find ourselves below ridge top is if we are transitioning low from elsewhere to a working ridge. For example, if we are crossing a gap and encounter sink in the middle of the transition.

Beginners should be doing transitions with ample energy so that they don’t end up below ridge top on the other side.

2. Does a ridge work below ridge top?

Sometimes yes, sometimes no. It depends on the wind speed, direction, and shape of the mountain. If the angle is off, you will often find the wind funnels parallel below ridge top and the lift works very poorly. If the angle is closer to perpendicular, there is a better chance that it will work. The next factor is wind speed. Sometimes the wind at ridge top is sufficient for the ridge to work well, but when you get 100ft or more below, the wind weakens to the point that the lift can no longer sustain a glider. The final factor is ridge shape. Usually a ridge flattens out toward its base. If the slope becomes sufficiently flat, even a strong wind will not deflect sufficiently upwards to sustain a glider.

However, if the slope is sufficiently steep, the angle sufficiently good and the wind sufficiently strong, it can be possible to recover 1/3 to 1/2 of the way below ridge top.

3. What is the technique for recovering below ridge top?

The first step is to select an appropriate airspeed. Usually best glide speed is a sufficient minimum airspeed. Next, slide into the ridge band at a flat angle. You will need to be right up against the trees as the lift band below ridge top is usually very narrow. Expect the lift to be weak; it can take a long time to work your way up. As you fly in the weak lift, avoid the temptation to turn in little gusts as you are more likely to lose more altitude than you will gain in the turn.

At any time, be prepared to turn away from the ridge. If you hit sink or turbulence, be on a hair trigger to turn away from the ridge and give yourself more room underneath you.

If you do decide to turn, recognize that you probably have only one shot. If you can complete the turn in lift, you will do well, but if you lose 50-100ft by misjudging the turn, you will likely fall into weaker lift below you.

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If this discussion sounds scary and risky, that’s because it is. Recovering from below ridge top is an expert maneuver and is not recommended for beginners. However, we emphasize these techniques for general knowledge and safety. At some point you may encounter a situation that requires applying these techniques. As a result, we train pilots such that they are familiar with what to do in these situations.