Full Size Slope Soaring?

[Carl]

I know some on this forum have flown or still do fly full size gliders. But any done slope soaring in full size gliders?

I ask this because I was watching a couple of YouTube videos which I found shockingly amazing

I remember living in Oxford (as a lad) my parents taking me to London, and on the M40 I'd see the gliders using the thermals. But I never knew about using lift along coastal cliffs.

This video has a camera mounted on a wing tip and one on the tail. About 2:20 another glider comes into view after they do a turn:



This video has a camera inside the cockpit. The pilot gets very excited about the experience :



Imagine walking on those cliffs and seeing these whistling by

[Martin]

I flew full size gliders at the Midland Gliding Club, on the top of Long Mynd. The Mynd has a long west-facing slope and provides reliable lift in westerlies.

In a strong westerly we used to bungee launch full size gliders off the side of the hill by hand! It was mainly done for historical interest and fun. When you were the pilot being launched you sat in the glider while the people on the bungee rope ran over the edge. You kept the airbrakes out, and engaged the wheel brake, if you had one. When you felt the glider being dragged forward despite the brake, you waggled the elevator (more on this later) slammed the brakes shut and... twang... you were flying.

When you were helping to launch another glider, you were either on the end of the bungee rope (three people on each end with the rope laid out in a V ahead of the glider), holding the wing tip in the usual way, or holding on to the fuselage right next to the tail. At the 'all out' signal from the pilot the guys on the ends of the rope would run over the edge of the hill and keep going for as long as the rope allowed. It was quite a steep hill and you wouldn't really want to run over the edge without a rope to hold on to! The rope would bring you to a standstill and then you'd see the glider ping overhead a second or so later.

If you were on the wing tip, you let go as the glider started to move, in the normal way.

If you were holding the tail, the waggled elevator was the signal to you to let go and get out of the way quick!

We only ever did it in really strong westerly winds - wind speeds that would ground light aircraft and gliders at flat field sites! The bungee rope wasn't really necessary though I'm sure it made things safer - but if you just pushed a glider over the edge in those conditions, it would roll down the hill a few yards and start flying even without the bungee.

I also saw a 'shoulder launch' carried out on a single seat glider - I think it was a K8 but it was a long time ago and I'm not sure now. Three guys got under each wing, lifted it up and just ran into the wind carrying it over the edge and into flight!

The normal method of launching in lighter winds at the Midland Club is a winch. When the winds are westerly, they don't run the winch at full power - you don't need much launch height as when you come off the winch you're only a few yards flying away from reliable hill lift where you can then gain height. The normal method of flying is to get as high as you reasonably can using the slope lift and then search out over the valley for thermals (if there are any) or sometimes a thermal blows through and adds to the slope lift: normal technique then is to do a couple of S turns (turning away from the hill) and then if the lift remains strong start circling and drift back with the thermal downwind of the slope. If you're out over the valley into wind and start to get down to launch height, you can always fly back to the slope for a 'top-up'.

[Carl]

Thanks Martin for sharing your crazy experience.

I can't find it again, but I watched an older bit of footage where there was this enormous winch on the top of the cliff and it didn't take much for the glider to be in the air (like what you described) and of it would then go up and down the coastline.

[Spike S]

Manned gliders are subject to the same Air Law as powered aircraft - I'll reserve comment on the heights they flew.
The first video appears to be the Jurassic Coast red cliffs between Seaton and Sidmouth. I soared a 1hr 15 min Bronze leg above those cliffs back in 1975 in an SFS31 motor glider (with the motor off of course). No portable video recorders in those days! Soaring that ridge as the evening lift dwindled, I was very conscious of the narrowness of the beach below, even at low water, and scarcity of sensibly level landing fields behind the cliffs ! After recording the necessary soaring time, I was only too glad that the motor restarted for my return to Yeovilton.
I watched the video to see where he landed but there must have been significant lift above the cliffs to enable recovery to a suitable field or to enable the 17 mile return to point of departure at North Hill (just North of Honiton).
I accept that low flying is fun but ...
Aviation Aphorism No. 578: You can only hope to gain a 'tie' for the lowest flypast !
It can go wrong very quickly, especially if you are concentrating on 'selfies':
https://www.ebaumsworld.com/videos/glid ... /85923644/

We also soared the Mendips hills at Cheddar. One of my co-owners failed to restart the engine so landed in a good field and took a hike to the nearby farm to phone base for a road recovery (mobile phones not yet invented). On his walk back to the aircraft he was passed by a convoy of Police cars and crash wagons from Bristol Airport going to the same field because someone had phoned 999, reporting "an aircraft has crashed!"

[Martin]

It looks like they've done away with the elevator waggling on the Mynd since I used to do it - at least with the two seater gliders - see video below. Maybe they still do it with an old-fashioned wood and fabric lighter glider where holding the tail up keeps the weight on the glider's skid and prevents it rolling forward.

Being on the tail was a pretty dangerous job though, and if you didn't release and get out of the way quickly you risked getting hurt and/or damaging the glider's tailplane.


You'll see the bungee guys at the point of launch - the Land Rover is only to tow the glider out to the launch point. Also you get a nice view of the 'valley' to the west of the Mynd when the glider launches.

[Carl]

Martin, can't believe how easily that glider was launched into the air. Good to hear the pilot under instruction was giggling and enjoying the experience even without flying lower than you should.

I was interested to hear the term the instructor used "ridge running" which is very appropriate.

SpikeS - not being a pilot I don't know the rules. I didn't choose the videos for the low flying, they were ones I saw and was struck by learning that there is such thing as full size cliff/slope soaring. I didn't appreciate so much lift would be possible to fly unpowered aircraft along the coastline. The video Martin posted really demonstrated this with flying along the ridge.

[Wayne_H]

In my part of the world, it's only thermal soaring - conditions are such that great flights can be had year round . The prevailing "hills" are little more than rocky outcrops, but they make great thermal trigger points

My one real slope soaring experiance was some years ago in the "Victorian alps". After a winch launch and working scratchy thermals, I was able to jump across to the real hills and enjoy some fabulous gentle ridge soaring in the prevailing 15 kt breeze. Cruising along just in front of the "mountain" crests (4-5 thousand feet AMSL), waving to the occassional hikers on the trails, was awesome! Landing back at base 2+ hours later, just before sunset, capped off a wonderful experience

[Carl]

My one real slope soaring experiance was some years ago in the "Victorian alps". After a winch launch and working scratchy thermals, I was able to jump across to the real hills and enjoy some fabulous gentle ridge soaring in the prevailing 15 kt breeze. Cruising along just in front of the "mountain" crests (4-5 thousand feet AMSL), waving to the occassional hikers on the trails, was awesome! Landing back at base 2+ hours later, just before sunset, capped off a wonderful experience

Wayne, it may have been your only 'real' slope soaring experience but sounds like it was an unforgettable one

[Wayne_H]

Wayne, it may have been your only 'real' slope soaring experience but sounds like it was an unforgettable one

Carl - absolutely!! I managed to dig out a few pictures on a back-up HD - my stupid grin says it all :

[Carl]

We only ever did it in really strong westerly winds - wind speeds that would ground light aircraft and gliders at flat field sites! The bungee rope wasn't really necessary though I'm sure it made things safer - but if you just pushed a glider over the edge in those conditions, it would roll down the hill a few yards and start flying even without the bungee.

Martin, what you described reminded me of this video of a large scale rc glider being launch by rolling it down the hill: