Category: Theory

After we release over the ridge, the next crucial step is to test out the soaring conditions. We are primarily interested that the thermals are working and that the wind strength and direction should make the ridge work nicely.

We often try to find a thermal right off of tow. This works well as it gives more time to assess the conditions and gives us confidence that we can find a thermal later when we want to get back home. If we find that the conditions don’t look all that solid below us, we will often take this thermal up to cloudbase and fly the rest of the day in the thermal band! As we thermal, we note the wind strength and wind drift as the thermal takes us a couple turns downwind of where we started.

Next, we compare our drift to wind markers at ridge top. At Blairstown, the Upper Reservoir is an excellent wind indicator. You could also look at the steam plume rising off of powerplants, flags, and trees dancing at ridge top.

With some experience, you will be able to look at these wind markers and use them to accurately estimate wind strength.

You could also pay attention to your crab angle on the straightaways; the more you must crab, the stronger the wind.

Ideally, you want to see the wind strength above ridge top be somewhat greater than at the surface. If you don’t have that wind gradient, then the top of the ridge band might get cut off lower than you would expect.

Normally, you want to see winds 15-25 knots at ridge top, within 30 degrees of perpendicular for the section you intend to fly.

Once you are satisfied that the thermals are working well and that the wind looks reasonably solid at ridge top, you test out the “high” band. This entails settling down to 2,400ft, checking your variometer and feeling if there are gusts coming up underneath the glider. A 1-26 will sink at ~200fpm at best glide speed. If you are in “good air”, you will be settling down only at 100fpm. Even though you might not be sustaining, this suggests that the ridge is working underneath you.

As you are settling down, you should be positioned to leave at one of the two exit points (Doc’s Thumb or Upper Reservoir). Once reach a decision point at 2,400ft MSL. If you feel confident that the ridge is working underneath you. Otherwise, you will strongly consider leaving back to Blairstown Airport. If you elect to settle down lower, you will becommitted to the field at the base of the ridge should the ridge not work.

As you settle down lower yet, you will probably feel the lift strengthing and you have to speed up to maintain the same height above the ridge. Speed up to 65-70 mph in a 1-26 and settle down as low as the ridge lift will let you go. If you get down to 100 ft or so above ridge top, you are now “down on the trees”. Sometimes, the ridge lift is so strong that you can’t get down on the trees and will still be several hundred feet above the mountain!

At this point, you have successfully tested the ridge! Now you could go and stay low and fast, or you could transition back into the higher “float” band if you prefer to avoid the beating.

The whole process can take you an hour or more to build your confidence in the conditions. Experienced pilots can judge the conditions considerably quicker and go through the process much more rapidly if they want to. However, they are still doing all of these steps; we don’t simply drive down on the ridge on a hope and a prayer.

Ridge lift is awesome because it’s a nearly continuous lift source, so long as you have wind blowing and a mountain beneath you to push the wind up. When this happens, the lift sets up in a particular “lift band”. The best part of the band is called the “sweet spot”. This perfect position is very narrow; sometimes only one or two wingspans wide.

The sweet spot is simple to find down “on the crest”. The crest is defined abeam the top of the mountain and somewhat in front of the steep part. When you’re “down on the trees”, it’s fairly easy to find that sweet spot.

If you drift just a little bit downwind, the lift tapers off VERY rapidly. Drifting downwind is VERY bad.

Upwind of the ridge, the lift slowly weakens, but you still have good air quite a ways farther down the slope.

As a result, always err upwind rather than downwind. You can do little wrong being a little too far upwind. A little too far downwind, the lift goes away and you’re in a very bad place.

If you want to “float” higher up the ridge and get into the higher part of the lift band, you must push away from the mountain. This is because the sweet spot in the lift band moves further and further upwind as you get higher. If you get 1000ft above the mountain, the sweet spot may be as far as 1/2 mile upwind!

Common errors

1. Failing to crab correctly- We always fly with a crosswind on ridge days. This requires crabbing upwind to maintain our position. As you slow down, swing the nose further upwind. Maintain wings perfectly level with the horizon.
2. Holding steady pressure on rudder/ailerons- Pay attention to your controls. If you are consistently holding pressure to one side or another, the sweet spot is probably in that direction. Conversely, if you are unable to position the controls exactly neutral, you will have a much harder time finding the best part of the band.
3. Aiming the nose down along the mountain- This is very common; pilots have a tendency to aim their eyes down along the mountain and try to align the glider accordingly. But as they do this, they end up flying at a minimum in a continuous slip. Other times, they end up drifting out of position relative to the mountain immediately beneath them.
4. Drifting downwind- When you position yourself just a hair downwind of the lift band, the upwind wing gets pushed up because the lift is stronger upwind. This pushes you even further downwind. Pilots that get on the downwind side will then often “hunt” back and forth, tick tocking off the sweet spot and then bouncing back downwind. As we learned, the lift band is sharply defined on the downwind side and you really don’t want to be there. Instead, always err slightly to the upwind side.
5. Gusts pushing upwind wing up- Never, ever let your wing get pushed above level with the horizon. If a gust pushes your upwind wing up, immediately correct for it and push back upwind. Don’t drift downwind!!

Suppose you settled down lower and you felt that the ridge was not working. Or, it’s the end of the day and you want to go back home. At some point you will need to exit the ridge and make the 3.5 mile final glide back to Blairstown Airport.

The minimum altitude to leave is 2,400ft MSL at one of the ridge exit points (Upper Reservoir/Doc’s Thumb). There are several reasons the club selected this margin.

1. In a low performance ship, you will definitely not be high enough to make a full pattern if you leave lower. Leaving at 2,400ft is marginal for a full pattern as it is and you should be fully prepared to make a non-standard approach.
2. The lower you are, the stronger the sink. On the upwind side, the lower you get to the crest, the stronger the lift. The opposite is true on the lee side. So leaving 200ft lower may lead you to being 400 ft lower on the far side of the sink!
3. It is hard to find the landmarks and the airport if you are lower than 2,400ft. This makes it easier for you to get lost along the way.

If you are unable to get to 2,400ft, simply land at the field at the base of the ridge.

If you’re able to thermal up higher than 2,400ft, that’s certainly better! Ideally, you would leave in a thermal at 2,900ft or higher, drifting downwind in it. This is called “coming home like a gentleman”. You will ride over the top of all the sink and turbulence and get back with plenty of energy to spare.

Situational awareness for the final glide

1. Anticipate the sink. You may encounter severe sink on the back side of the ridge. Put the nose down and punch through it. It will eventually stop.
2. Once you get out of the sink, trust the performance of the glider. You will have a 15-20 knot tailwind. You will be high enough to get back to the airport.
3. Plan your approach early. Be willing to do a non-standard pattern if you’re a bit lower.

Execution

Once you decide to leave over the back of the northwest ridge, there is no turning back. You cannot change your mind 10 seconds later; you will very quickly not have enough energy to make it back to the ridge thanks to the strong tailwind pushing you along.

When you encounter the sink, put the nose down and ride it out. The sink is temporary and will go away. Even if it gets really bad, keep the nose down and drive through it.

When you get out of the sink, you will feel an acceleration as though as you hit a thermal. This is from going in strong sink to no sink. Some folks confuse this for a thermal, but don’t circle in it. Even if you’re low, keep going. You will have the airport made.

Once you get to Rt.94, plan out your approach. Are you going to do a non-standard pattern? Be prepared for a lot of sink and turbulence. Keep extra speed in the approach and follow the guidance in the Ridge Landing video.

Critical Errors

1. Leaving lower than 2,400ft- For reasons described above, this can get you into more severe sink and very low in a scary place.
2. Believing the sink will last forever and crashing in the Lower Reservoir- Several pilots have crashed their gliders in the Lower Reservoir when they thought they could not make it home. Even if you get flushed in the sink, it will eventually end. Ride it out and cross the hill; don’t turn.
3. Turning in the transition from sink to no-sink- Don’t get tempted by this transition. Keep the nose down and keep going; you will make it home.
4. Not trusting the performance of their glider- A pilot crashed a two-place ship in a field short of the airport when they thought they could not make it. Once you get out of the sink, you will have a 15-20 knot tailwind. Remember that the strong sink is temporary. Once you’re out of it, you will have the airport made.
5. Poor approach planning- Don’t aim for the middle, don’t make a low and slow pattern. Be prepared to make a non-standard approach.

Once you get off of tow, you should take stock of your situation. There are several things that can happen in the next several minutes:

1. Find a thermal and get higher.
2. Settle down to 2,400ft abeam one of the ridge exit points. Leave back to Blairstown Airport.
3. Commit to the field at the base of the ridge. Get below 2,400ft and the ridge works!
4. Settle down on the ridge. The ridge does not work and you land in the field at the base of the local ridge.

There are two ridge exit points. One is the Doc’s Thumb route, which goes over the Lower Reservoir, through a gully and lines you up with a right base for 25. The other route is abeam the Upper Reservoir, and is my preferred path. This lines you up with a left base for 7 and positions you directly with the Dairy Queen field along the way.

When you’re at 3,400ft, you should find the airport and the landmarks around it (Dairy Queen Field, Lake Susquehanna, Ball Fields) and scope out your return back home. When you get lower, it will be harder to spot these landmarks.

We also pointed out a number of important landmarks along the ridge.

• Corn Field- Large field at the base of the ridge which is your alternate landing option.
• Upper Reservoir- The middle of the local ridge and an excellent landmark. Also a good wind indicator; keep an eye on the waves. If there are white caps, that indicates the wind is nice and strong. Pay attention to the streaks to get a sense of the wind direction.
• Sunfish Pond
• Tock’s Island Golf Course- An emergency landing option
• Delaware Water Gap- Southwest limit of the local ridge
• Catfish Pond
• Millbrook Powerlines- Northeast limit of the local ridge.

Note that you don’t want to fly the “high ridge” all the way to Catfish pond. Instead, you would transition to the lower “Catfish Ridge” if you were heading up to the Millbrook powerline. Beginners would normally stay on the “strict” local ridge, which goes from Sunfish Pond to the “saddle” before the upwind jump to the Catfish Ridge. We will demonstrate this in future videos.

Ridge days are often windy and turbulent, leading to sporty approaches and landings. You should be 100 percent on your game to deal with sink, rotor, and a strong crosswind during the approach.

As you leave the ridge, position yourself in such a way to give yourself the most options. At Blairstown we often consider making a non-standard approach (base to final for 25 or 7 instead of a full pattern) when we are returning from the ridge. Aim at the numbers instead of the middle to leave yourself this option; if you end up over the middle of the airport, you are completely committed to making a full pattern.

Do your checklist early, especially if you have a strong tailwind. The landing is going to happen quickly and will require all your attention.

When entering the pattern, maintain extra energy in both airspeed and altitude. Crab to account for the crosswind on downwind; don’t drift downwind! Keep your downwind and base legs tight up against the airport property.

Make your base to final turn with extra altitude. Account for the wind in the turn; if you have a headwind on base leg, extend a bit farther and let the wind drift you back on final.

On final, aim for the middle of the airport; don’t aim for the fence! You want to make absolutely sure you will make it on the airport property despite possible sink and wind shear along the way.

Once on final, transition into a slip for the crosswind correction. Maintain your speed all the way down to ground effect.

After you land, make an effort to clear the runway by taxiing off.

Ridge days are windy and require dealing with a gusty, direct crosswind. This can make the tow very sporty and sometimes the most challenging part of a ridge day.

In order to manage the ridge tow effectively, you must be 100 percent ahead of the glider before the tow begins. You’re completely ready for the challenge ahead.

This means the glider was perfectly prepared during pre-flight. Everything loose was stowed. When you get strapped in, you cannot be rushed. And before you give the go-ahead to the wingrunner, you should have completed your checklists and completely thought through your emergency plan. You should be in the zone as the wingrunner lifts your wingtip.

When you begin the tow, you should be ready to input crosswind corrections. In the case of a crosswind from right to left, this means left rudder and right stick. You should also keep your right wing a bit lower than level.

Once you get airborne, you will then adjust a bit upwind and transition into a crab to remain in position somewhat upwind of the towplane.

Be ready for significant turbulence and shear. Often times when you get above a tree line, the towplane will accelerate and the glider will then hit a massive gust. This will likely cause you to hit your head on the canopy.

Hitting your head on the canopy is dangerous and will cause you to momentarily lose control of the glider, while in an awkward position to deal with a rope-break. Instead, you should be prepared for the gust beforehand.

The best solution for slack line recovery is to never let it happen in the first place. By being vigilant and actively maintaining position and adding tension to the line BEFORE the big gust throws you out of position, you can avoid almost all slack line situations.

To avoid getting flung out of position, you must maintain good position behind the towplane and some tension on the rope. First, this is by remaining just above the wake (which is a bit lower than “normal” tows.) Secondly, this is by strategically opening up the divebrakes when appropriate. If you see the towplane get flung up, open the brakes 1/4 of the way. The added drag and tension will keep the glider in position.

If you do get out of position, deploy some spoiler and correct accordingly. But be ready to release if your situation is not recoverable.

Always be ready for a rope break. You’re much more likely to experience a rope break in turbulent conditions. When it occurs, treat it like an emergency that it is, rather than an inconvenience. Be willing to go straight ahead for an alternate field well up to 400ft AGL rather than attempting a marginal turn, at or a little bit above 200ft.