Glider winch launch question
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Anybody ever in haste and tiredness forget to double the broken cable back before putting the broken ends in the hydraulic crimper? (forget what it was called: it was 50 years ago after all.)
Neatly fixes the crimper to the cable, that does.....
Neatly fixes the crimper to the cable, that does.....
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Watched some cadet air experience fly a chippie into a cable once. Glider hardly missed a beat, disengaged and landed. I wasn't sure if the shear link went or pilot pulled. The chippie slid nose first down the cable quite gently. It was a bit bent though. I'd love to know if it ever flew again. Old Sarum about 66-68 Anyone know?
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I was once amused and confused by the rule at Portmoak stating "The cable must be attached to the glider and the tug before the tug takes off" until I saw the performance during the D Day landings!Agree with wot Mary said, I have tried in vain to persuade power pilots to try gliding just to see what it's all about but lack of interest prevails. They have been known to fly up the winch line in oblivion.
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There was an incident at our club last year where someone connected the winch cable to the aerotow hook on the glider. The glider took off ok but didnt climb very well. At the top of the launch he couldnt release because of the cable angle. The winch driver cut the cable and the the glider did a 270 dragging the cable to land. Combined gliding experience in the glider was 70+ hears so it can catch out even the most experienced
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Cats five, sorry to hear your launches at Shenners were not so high as we manage these days, with the Skylaunch (like the nice one depicted earlier in this thread).
The farmer has permitted us to extend width of runways, and use the entire triangle midfield, but some runs are still shorter than others.
A nice headwind, say 15 knots, can help as well.
But if its a good day and I seriously want to go soaring X-country, I admit I would shell out for an airtow (we have a very good Chipmunk tow plane) and expect the tug pilot to deliver me to a 6 knot thermal under a nice fluffy cu.
The winch simply lobs you up and its partly luck if there is a decent thermal available nearby....but we locals know the sweet spots, just off our ridge.
I will be away now for 9 days helping with our Regional Competition, which will be all airtow as is the custom for comps. And will communicate again when it is over, so hoping for good weather with lots of bumpy air!
Mary
The farmer has permitted us to extend width of runways, and use the entire triangle midfield, but some runs are still shorter than others.
A nice headwind, say 15 knots, can help as well.
But if its a good day and I seriously want to go soaring X-country, I admit I would shell out for an airtow (we have a very good Chipmunk tow plane) and expect the tug pilot to deliver me to a 6 knot thermal under a nice fluffy cu.
The winch simply lobs you up and its partly luck if there is a decent thermal available nearby....but we locals know the sweet spots, just off our ridge.
I will be away now for 9 days helping with our Regional Competition, which will be all airtow as is the custom for comps. And will communicate again when it is over, so hoping for good weather with lots of bumpy air!
Mary
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I only ever saw the guillotine used in anger once.
I was on tow out duty and sitting in the cab of the winch with the driver during the launch.
The K21 launched and the pilot somehow managed to not release the cable, I have no idea how he managed it, but he started a turn with the cable still attached and as he had not overflown the winch the cable had not back released.
The glider actually pulled the winch sideways a few feet before the driver used the guillotine. Just as the he cut the cable it also released from the glider and it landed safely, but it was pretty interesting for a couple of seconds!
I dread to think what the loadings were through the hook, but I remember that the weak link didn't break.
I was on tow out duty and sitting in the cab of the winch with the driver during the launch.
The K21 launched and the pilot somehow managed to not release the cable, I have no idea how he managed it, but he started a turn with the cable still attached and as he had not overflown the winch the cable had not back released.
The glider actually pulled the winch sideways a few feet before the driver used the guillotine. Just as the he cut the cable it also released from the glider and it landed safely, but it was pretty interesting for a couple of seconds!
I dread to think what the loadings were through the hook, but I remember that the weak link didn't break.
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Hi Mary
It was the Skylaunch, and it was a club member driving which was the problem I suspect. Flew forwards and managed to get away (after some thermalling over the winch) & flew to Sacville & back.
The triangle wasn't crop when we were there.
It was the Skylaunch, and it was a club member driving which was the problem I suspect. Flew forwards and managed to get away (after some thermalling over the winch) & flew to Sacville & back.
The triangle wasn't crop when we were there.
Further to my definition of a glider club as a bunch of nice people who at any time might set you up to kill yourself (albeit with the best intentions), our winch arrived back from repair and the K-21 got launched with the nose hook
The guillotine did not have to be used this time
The guillotine did not have to be used this time
As others have said - a positive 'cut' of the throttle at the correct moment/angle would normally operate the back release due to the weight of the cable and this technique also prevented releasing under tension and ending up with a 'birds nest' on the winch drum.
I have seen a couple of winch drivers over the years keeping power on until the cable was vertical and then relying on the wind to clear the cable away from the cab
I have also seen one guy do it to the extreme and ended up with the cable wrapped aroung the cab - that was exciting to watch he was lucky not to get hurt by the flying splinters and flailing cable etc !
Of course a throttle cut would not help if the cable was attached to the wrong hook !
I have seen a couple of winch drivers over the years keeping power on until the cable was vertical and then relying on the wind to clear the cable away from the cab
I have also seen one guy do it to the extreme and ended up with the cable wrapped aroung the cab
- that was exciting to watch he was lucky not to get hurt by the flying splinters and flailing cable etc !Of course a throttle cut would not help if the cable was attached to the wrong hook !
Bungee launching
We could always go back to the good old days and use the bungee method. Now that's a nice, civilised way to get airborne - and in these environmentally conscious days, 'green' as well!
Bungee launching
Ah, the only type of launch you do for the pleasure of the launch itself. I once, in a rather strong wind at the Long Mynd, exceed the rough air speed of the glider while still attached to the bungee....
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Watched some cadet air experience fly a chippie into a cable once. Glider hardly missed a beat, disengaged and landed.
The winch launch sequence, including attitudes and speeds, is designed so that at any point during the sequence, you can disengage and land safely. Cables, weak links and other parts of the winch cable arrangement may (and will) break at any inconvenient moment.
Bungee launching.
OK, I know its thread drift, I but thought it worth putting this link on here. Its a bit of edited video taken at the Camphill Vintage Rally last year.
Backpacker,
It's a bit more scientific than "stuffing the nose down" after a launch failure and, indeed we make strenuous efforts to ensure that students do not get this as a message.
The words we actually use are "lower the nose to the appropriate recovery attitude". This could be the attitude for normal circuit cruising speed if the launch failure occurs at a height to permit an abbreviated circuit, or it could be the attitude for approach speed if the failure occurs nearer the ground.
Of course if the launch failure occurs just after lift off, stuffing the nose down could literally stuff the nose into the ground. For this reason we demonstrate to students an ultra-low-level launch failure during the training syllabus.
And we train students to have their hand on (not close to) the release during the launch.
It's a bit more scientific than "stuffing the nose down" after a launch failure and, indeed we make strenuous efforts to ensure that students do not get this as a message.
The words we actually use are "lower the nose to the appropriate recovery attitude". This could be the attitude for normal circuit cruising speed if the launch failure occurs at a height to permit an abbreviated circuit, or it could be the attitude for approach speed if the failure occurs nearer the ground.
Of course if the launch failure occurs just after lift off, stuffing the nose down could literally stuff the nose into the ground. For this reason we demonstrate to students an ultra-low-level launch failure during the training syllabus.
And we train students to have their hand on (not close to) the release during the launch.
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Ah, I so remember the days doing winch launches in Blanik L13.....with my left hand holding the flaps at half setting - there was no detent......and nowhere near the cable release at all which was in the middle of the instrument panel.
Used to get exciting if you got a cable break.
Also can remember 'kiting' on the winch. Probably banned by now by some misery guts.
In strong wind days the winch driver could stop the winch drum rotation mid way up and the glider would still kite up the launch.
If the winch driver (& the winch) could do it they could actually let the drum run slowly in reverse by paying out under braking control, hence paying OUT the cable while the glider was still on the cable maintaining altitude, then apply a bit of forward power rotation to power the glider further up in altitude - then start the process again.
Got some amazing altitude launches that way......my record was something like 2700ft.
Used to get exciting if you got a cable break.
Also can remember 'kiting' on the winch. Probably banned by now by some misery guts.
In strong wind days the winch driver could stop the winch drum rotation mid way up and the glider would still kite up the launch.
If the winch driver (& the winch) could do it they could actually let the drum run slowly in reverse by paying out under braking control, hence paying OUT the cable while the glider was still on the cable maintaining altitude, then apply a bit of forward power rotation to power the glider further up in altitude - then start the process again.
Got some amazing altitude launches that way......my record was something like 2700ft.
Also can remember 'kiting' on the winch. Probably banned by now by some misery guts.
Ah, I so remember the days doing winch launches in Blanik L13.
I've never done ( or even seen ) a Blanik winch launch. Did you have a belly hook fitted?
I did 49 winch/autotow (mainly winch) in the old 'Blanket' - both in africa and britain.
From the L13 Pilots Notes
I must add though that I always used the side(belly) hook and never tried the nose hook for winch launch !
From the L13 Pilots Notes
WINCH LAUNCHING
If original towing-bridle is used, the maximum weak link strength is 2,000 1b. (910 kp).
For maximum launch height, the side-towing bridle should be used. To reduce the possibility of
"whipping", the towing-bridle should be laid out in front of the sail- plane before launching. During take
off, as the control loads are very light, care should be taken not to climb too steeply at a low airspeed, and it
is important when releasing the cable to pull the release handle fully so as to allow the cable hooks to fall
off.
The nose hook, which embodies a back release mechanism, also may be used for winch launching.
Partial flap may be used during winch launching, if desired, in order to reduce the take-off run. A speed of
54 knots (100 km/hr.) should not be exceeded if the flaps are extended, or 65 knots (120 km/hr.) with the
flaps retracted.
The recommended speed for winch launching is 43-54 knots (80-100 km/hr.).
If original towing-bridle is used, the maximum weak link strength is 2,000 1b. (910 kp).
For maximum launch height, the side-towing bridle should be used. To reduce the possibility of
"whipping", the towing-bridle should be laid out in front of the sail- plane before launching. During take
off, as the control loads are very light, care should be taken not to climb too steeply at a low airspeed, and it
is important when releasing the cable to pull the release handle fully so as to allow the cable hooks to fall
off.
The nose hook, which embodies a back release mechanism, also may be used for winch launching.
Partial flap may be used during winch launching, if desired, in order to reduce the take-off run. A speed of
54 knots (100 km/hr.) should not be exceeded if the flaps are extended, or 65 knots (120 km/hr.) with the
flaps retracted.
The recommended speed for winch launching is 43-54 knots (80-100 km/hr.).