Glider winch launch question

[Dont Hang Up]

I saw my first glider winch launch the other day. I understood the principle but had never seen it done before. The first thing that struck me though was what would happen if the the cable release failed?

With an aircraft tow you clearly have time to work the problem. But with a ground winch, which seems to involve release when the cable approaches vertical, then a failure to release looks like it would very rapidly get very serious.

[India Four Two]

The glider winch-hook has a back-release mechanism, which should operate as the the glider overflies the winch. If that doesn't work,then the winch driver uses a guillotine to cut his end of the cable.

The subsequent landing with >1000' of cable attached should be "interesting" :eek:

From a design point of view, the winch launch is a very important case. At the top of the launch, the wing has to generate lift equal to the weight of the glider PLUS the tension on the cable.

Overlap with Above The Clouds, who points out the weak link which I forgot about!

[Above The Clouds]

You would treat it in a similar manner to an engine failure after take-off, depending on the altitude obtained would determine your choice of landing area/field.
If by the top of the winch launch and cable could not be released from the cockpit then there are two fail safes, once the glider has flown past the vertical point of the cable then the tow cable will release aft, if that doesn't work then there is a weak link in the cable system that would break once the downward pull force is exceeded.

[Dont Hang Up]

Thanks for that. Very interesting.

The other things that struck me...

1. You need a pretty long runway because the glider can only get as high as the runway is long - less the length of cable that the winch has drawn in to achieve the launch.

2. At the end of the launch most of the cable tension must be in the downward direction. The glider must need to be generating a phenomenal amount of lift.

3. The hook (nearly). It is scary as a spectator when you think it is about to hit you from a great height - even if it is on a drag chute.:O

You would treat it in a similar manner to an engine failure after take-off,

EFATO I know about. Stuff the nose down and aim for something flat. But this I envisage more like being pulled rapidly into a vertical dive with very few manouevering options.!

However I am now clearer what the procedure is. Thanks for that.

[Sensible Flyer]

Yikes! If you're close enough to be at all worried about the strop hitting you as it comes down, you are far, far too close to the winch for safety.

The only safe place is inside the winch cabin. If the cable breaks, it can violently whip backwards or sideways. I have seen a car written off by a snapped winch cable. I also had the memorable experience of driving a winch when the cable snapped, wrapped itself in a knot and then disintegrated as it hit the rollers, spraying fragments of cable thread all over the place with such force that some of them wrapped themselves around the chicken wire that protected the windscreen.
The spectator who I had insisted joined me in the cabin before the launch (thye had wanted to take photographs) went very quiet.

[SpannerInTheWerks]

As with all things to do with aviation there are several different options depending on when the cable breaks during the launch - including landing straight ahead, carrying out 'S' turns or completing a circuit to land (gliders 'glide' therefore have more options than powered aircraft in this situation).

Naturally, preventing a stall, by lowering the nose, and getting rid of the cable are important aspects of the process!

All practised during training and 'par for the course' (in my experience at least).

[Dont Hang Up]

Yikes! If you're close enough to be at all worried about the strop hitting you as it comes down, you are far, far too close to the winch for safety.

We were at least 100 metres off to the side of the centreline. It was just that as the drag chute started spiralling down it seemed to be heading our way, possibly due to crosswind. It never really got near us - just a few moments of alarm.

[OpenCirrus619]

The first thing to note is that a cable break is NOT considered an emergency. I was always told a 1% launch failure (usually cable breaks) was par for the course.

Safety-wise, in many ways, winch launching is much safer than aero-towing anyway. A winch launch can be split into 3 phases:
- Enough runway left to land straight ahead
- Overlap: Enough runway to land straight ahead AND enough height to complete a safe (if abbreviated) circuit
- Enough height to complete a fairly normal circuit
If conditions (wind strength/direction, winch power, runway length) do not provide a sensible overlap then the duty instructor will not allow winching.

Compare that to an aero-tow - in the early stages (once you can't land straight ahead) you often don't have enough height to pick a perfect field/return to the airfield.

OC619

[rusty sparrow]

Cable breaks teach you a very good 'get the nose down' reflex That can be life saving if you are flying low inertia, light aircraft when the engine stops!

[Above The Clouds]

We used to use solid piano wire, now that went with a bang and came towards the winch like a coiled spring.

[Tu.114]

There are several ways of severing the connection between the glider and the winch.

Firstly, at the glider, there is the connector that can be either opened manually by the pilot (by pulling the yellow lever/ball/whatever the aircraft has) or will release the ring by itself when pulled back under a certain angle. After the disconnect, the pilot will actuate the release lever a few times by himself to ensure no cable left connected. These are the normal ways to end a winch launch.

Secondly, the cable might break either at the weak link, the parachute or some point in the cable itself. This requires the pilot to fly the above mentioned procedure, not forgetting to drop whatever rope may be still attached to the aircraft again by pulling the release, the ground crew to search for the loose cable and the winch driver to repair the rope using one of the many ways available (occasionally a bloody business).

And thirdly, if the winch driver sees the glider pass behind the winch without dropping the rope or if he is otherwise unhappy with the gliders behaviour (e. g. if it underflies the cables parachute or makes weird movements while under tow), he can use the "guillotine" to cut the cable at the winch. This one typically consists of a blade mounted on a pre-tensioned strong spring that when released will cut through the cable and is required to show its ability to cut several strands of tow line (IIRC, 3 or 5 of them - it has been a while since I last operated a glider winch) at once during the annual check.

This of course leaves the glider with several 100m of cable attached. The options are generally the same as with a breakage plus the silk way down in case of sufficient height: having the line entangled somewhere on the ground during approach will easily lead to nasty consequences, so this option may well be considered as well.

I heartily agree with the words on safety around a winch. A parachute with the weak links to the head can ruin ones afternoon quite well, as can receiving a hit from a broken line. Once after a rather late disconnect of the glider (IIRC, a slight tailwind was involved), I had the parachute assembly come down right beside the winch and hit the roof of the old vehicle used to return the lines to the launch side. The driver was rather white about the gills when he got out, but fortunately received no injuries. He made sure to park a bit further behind the winch after that.

[Dont Hang Up]

I shall take advantage of having some clearly well informed people taking an interest. So here goes with a couple more observations.

To overcome the downforce of the near vertical cable at the end of the tow, the glider must be producing (I estimate) 3 or 4 G of lift. Is that not a pretty teeth jarring kick in the backside when the cable is released?

The winch must start off fast with low torque while the glider is on the ground, but must rapidly slow down with increasing torque as the glider climbs.That sounds like a job for an electric motor, but the winch is clearly a combustion engine. How is that geared as the torque and speed requirements of this particular usage sounds like a perfect recipe for it to stall?

[Tu.114]

There are several winch designs around. The one I operated most often had a Magirus-Deutz air-cooled V8 Diesel working on a hydraulic clutch to convert rpm to torque as required. This worked rather nicely and in windy weather with a light glider even allowed the cable drums to run backwards (release heights of above 800m have been achieved that way on a 1100m field), although the clutch had a certain tendency to overheat in hot weather. Rapid-fire launches of heavy gliders and insufficient cooling-down periods made it tend to shed all its oil via the melting fuses. Refilling all the IIRC 15 litres (= nearly 4 gallons) of oil and replacing the fuses was not the most popular job and of course the privilege of the unlucky winch driver. An hour or so under the shower usually followed.

Older designs use a petrol V8 engine (often from an Opel Admiral) and may even have a stickshift gearbox in the drivetrain - I have never operated such a device but have heard that stalling the engine is not impossible on those.

I am not familiar with the newest developments in this field; the last time I operated a glider winch is more than 10 years ago already. An electric motor would sound interesting and like a plausible choice though.

The rope disconnect can be everything from a jolt to hardly feelable. A break somewhere mid-tow is usually on the rougher side, but the earlier or later in the tow it gets, the lighter it is; I had a rope break shortly before disconnect that I did not even notice in the glider and learned about only after landing.

The reason for this is the variable power requirement for a launch: the winch will not always pull with the same force. In order to accelerate the glider, firstly the throttle is rather rapidly opened (how far depends on the individual glider type, its mass, weather etc.). When it is airborne for the first 50 meters of height, a fair bit less power is required in order not to overspeed it: the first 50 meters are climbed rather gently as otherwise altitude would be insufficient to lower the nose in case of a break. Then, when the winch operator sees the glider pull up, he is required to increase power again to keep it at speed during the now more rapid climb. The glider will follow an approximate quarter of a circle then, so in the beginning, more power will be required to "lift" the glider, while in the end, the gliders climb rate will decrease and it will tend to overspeed if the power is not appropriately reduced. Finally, the winch driver will cut the power to idle and the pilot will return the elevator to a more neutral position. Both serves to reduce the tension on the cable and allow it to disconnect without a major jolt.

Operating a glider winch is a bit of a black art involving observing the climb rate of the glider, the slackness of the rope, the engine and drive train sound and many other things. If a guy is proficient on one winch, this does not at all mean he can just switch to another winch and operate it with the same expertise in a second.

[Dont Hang Up]

Thanks Tu.114.

Clearly I was thinking in terms of kite flying when I was considering the tension on the cable at release! Obviously the glider pilot is not a helpless participant in the process and can take the tension off the cable with some forward stick before releasing. Obvious after it is pointed out.

Yes a hydraulic clutch makes sense too. Perhaps a simple temperature gauge could save some heartache with melted fuses?

My guess is that the poor winch driver is a glider pilot himself/herself most of the time? Just taking a turn on the rota.

[SpannerInTheWerks]

My guess is that the poor winch driver is a glider pilot himself/herself most of the time? Just taking a turn on the rota.

Yep - some of my 'longest days' were left and forgotten at the far end of the airfield for hours on end manning and operating the winch.

Operating a glider winch is a bit of a black art involving observing the climb rate of the glider, the slackness of the rope, the engine and drive train sound and many other things. If a guy is proficient on one winch, this does not at all mean he can just switch to another winch and operate it with the same expertise in a second.

Yep!

[Cusco]

My guess is that the poor winch driver is a glider pilot himself/herself most of the time? Just taking a turn on the rota.


In my case the winch driver was me an impoverished student and lowly member of the gliding club who spent an entire day winching (and mending cable breaks) in return for a quick circuit in the K7 at dusk.

Often got : nah it's too dark now.

Gave up gliding and G Club membership soon afterwards.

Cusco

[astir 8]

When the glider is approaching the top of a normal launch the cable is at a significant angle to the glider and therefore the glider forward speed will be a lot higher than the cable speed. (a comparison is a water skier doing tight turns, when his forward speed is much more than the boat speed).

To compensate for this, the winch driver steadily backs off on the throttle as the glider approaches the top of the launch.

The winch driver can further cause the cable to back release from the glider under minimal cable tension by closing the throttle completely. The cable disconnection is then barely noticeable other than as a minor click. This minimises stresses on the hook and cable and is also great for early pupils who can be discommoded by an almighty bang if the cable is released by the instructor under full tension.

Full tension cable releases are normally caused by the instructor at about mid point in the launch in order to give the pupil practice in dealing with mid-height cable breaks (i.e. he/she has to decide whether there is room to land straight ahead or turn a turn is necessary after getting the nose down and adequate airspeed.

The sudden release of tension and the "elasticity" of the cable can then cause loose loops of cable to form on the winch drum and/or the cable to fall off the side of the drum, creating a mega birds nest and the winch driver to swear about f****** instructors doing simulated cable breaks!

[Tu.114]

Astir8,

ouch, had totally forgotten about these ones. Beside a broken cable, the pull-out car driver not keeping a steady speed and pulling out the cable at about the same speed the drums deliver them was a frequent cause of such a mess. Much cursing ensued; more than once I have had to take the chisel, simply cut the knot up in order to untie it and then resplice the cable - this was sometimes the fastest method to unjam the cable. It was most fun during thermal season with all the cross-country guys waiting over at the launch pad, the phone keeping ringing every 4 seconds ("Are you done yet?" - "NO!" (SLAM!)) and the flight instructor coming over to berate You for taking so long, but then at least lending a hand.

At my club, everyone wanting to fly plastic gliders had to get the winch license and got half a day on the winch about once every 4 to 6 weeks. Procedures at other fields were different.

A nice thread btw - the winch driver is an oft forgotten hermit at the far end of the field.

[Shaggy Sheep Driver]

In my case the winch driver was me an impoverished student and lowly member of the gliding club who spent an entire day winching (and mending cable breaks) in return for a quick circuit in the K7 at dusk.

Often got : nah it's too dark now.

Gave up gliding and G Club membership soon afterwards.

Me too. I often wonder how many folk were lost to gliding through that sort of inexcusable experience.

[OpenCirrus619]

My first experience of driving the winch went something like:
Instructor: "You're a solo pilot, aren't you?"
Me: "Yes"
Instructor: "Go and drive the winch then"
Me: "I've never done it"
Instructor: "Tell whoever is in it to show you 2 cables then"
Me: "I'm worried I'll get it wrong / give people cr*p launches"
Instructor: "Good practice for them"

Another time I heard:
Instructor: "Go and drive the winch"
Volunteer: "I'm scared"
Instructor: "Never been anyone killed that end of the cable"

And the most important bit of advice when converting from winch to aerotow...
Instructor: "What's the most important difference between winch and aerotow launching"
Student: Runs through the expected list...
Instructor: "As a glider pilot you can't kill the winch driver ... always remember that"

OC619

P.S. In both cases (mine and the "volunteer") we had both been gliding for a some time, whilst skillfully avoiding winch duty - so it wasn't nearly as bad as the snippets above sound. Also it was many many years ago.

[funfly]

Am I not right in remembering that one of the pre flight checks is the cable release by pulling backwards on the cable to check it comes off cleanly?

[thing]

Am I not right in remembering that one of the pre flight checks is the cable release by pulling backwards on the cable to check it comes off cleanly?
Usually done at first flight of day. Cable on-release with cockpit release under no tension. Cable on- back release. Cable on-release with cockpit release under tension.

Interesting reading this thread, unlike a power question everyone seems to be more or less in agreement!

[Heston]

unlike a power question everyone seems to be more or less in agreement...

Darwin?

[thing]

Well of course glider pilots are higher up the evolutionary scale...:)

[Fly-by-Wife]

We were at least 100 metres off to the side of the centreline. It was just that as the drag chute started spiralling down it seemed to be heading our way, possibly due to crosswind.
The pilot needs a bit of (re)training to lay off for the x-wind, then. That amount of drift shouldn't be tolerated.

FBW

[pulse1]

On my first day of gliding with the ATC I actually witnessed a Tutor glider come straight down from the top of a winch launch. The outer section of one wing broke away as it fell. As far as recall, it was thought that the cable did not release. Sadly the pilot was killed.

[RatherBeFlying]

Just make sure you get it thick enough.

We had lots of practice with cable breaks with the thin stuff. Our winch went back to the manufacturer for upgrade -- which took two years -- and is just back with thicker Spectra.

There is an automatic cable tension control with airspeed transmitted from the hookup.

Now we get to see how it works.

[Maoraigh1]

50+ years ago, when Aberdeen Gliding Club operated at Aberdeen Airport, I saw a solo pilot allow enough crosswind drift to drop the cable over a Tiger Moth towing a glider off the main runway. It caught round the propellor.The teenage winch operator had no guillotine - just an axe. He hacked through the cable as it tightened. The ex-Spitfire pilot released the glider, and successfully landed, with the cut winch cable attached to the prop. There were no injuries. I think that cable was the stranded stuff we used before pianowire. Instructors didn't need to do simulated cable breaks - they were too common.

[Crash one]

All so familiar, good to see the amount of agreement by everyone involved in gliding.

[Dan Winterland]

If the cable is guillotined and the cable hung up, then the procedure is to fly a tight spiral over the field aiming to land in the centre. I know someone who did it for real once, he says it was no big drama.

Once, I did see the cable get struck by lightning before the glider released. The glider pilots were aware what had happened, but the winch driver just thought it was a cable break. However, the cable couldn't be found. It had vapourised!

[astir 8]

Going back to the original question of the risk of the glider being unable to release the winch cable.

Clearly that would be a pretty serious situation even given the presence of cable guillotines on the winch etc.

The automatically releasing hook ("back releasing" hook) was invented pre WW II to counter this risk and as has been said, its action should be checked daily before the first flight. It's a very reliable system even if (say) the cable release knob comes off in the pilot's hand.

The remaining risk of a winch cable "hang up" these days is if at the start of a launch, after a slightly enthusiastic taking up of the slack in the cable, the glider rolls forward, runs over the cable and picks it up around the mainwheel.

This risk is countered by the last few metres of the cable ("the strop") near the glider being encased in a relatively stiff length of plastic hose. Also the launch should be aborted by the signaller if the glider is seen to overrun the cable at all prior to the "all out" signal being given to the winch driver

All these security systems have evolved over the last 90-odd years since the gliding movement took hold. The risk of a "hang up" is one of the first things an onlooker thinks about when he first sees a winch launch, but in reality the risk is now tiny (never say never)

[India Four Two]

Many years ago, I was doing a 80 nm cross-country tow with a two-seat Lark (IS-28B2) behind me. We were parallel to and about 10 miles down-wind of the Canadian Rocky Mountain Front Ranges on a wave day.

It was quite rough, so we were using a long rope. About half-way, our CFI, who was flying from the back seat of the Lark, called me up and said incredulously "We're off tow!". Sufficient slack had developed to cause the Tost hook to back-release.

I'll draw a veil of the subsequent field landing and takeoff, other than to say there was no damage, except for grass stains on the belly of the tow-plane - a C182 Lawnmower. :E

The moral of the story was that we subsequently disabled the back-release, since we only aero-towed.

[cats_five]

A lot of gliders have two hooks. They are all made these days (and for many years) with a CoG hook for winching, some have an extra hook added further forwards for aerotow as a/t on a CoG hook can be 'interesting'. (in some cases the a/t hook is right in the nose)

Some older gliders have a compromise hook which does neither that well.

The a/t hooks usually don't have a back release, though the one in my glider does.

[Tu.114]

Instructor: "Go and drive the winch"
Volunteer: "I'm scared"
Instructor: "Never been anyone killed that end of the cable"


Was there no training at all for a winch driver!? True, a glider pilot can abort the launch by dumping the cable if he is unhappy, but will a student pilot reliably do so? Also, one can do a little bit of damage driving a winch beside that. I have heard about bicyclists on a road beside the glider strip getting caught straight off their bike by the cable parachute after the winch driver failed to pull in the falling rope sufficiently fast; another one removed a fence post or two. So there surely must be some insurance requirement around. Also, who teaches the winch driver to splice a broken cable, handle the various malfunctions and - not to forget - drive the often rather rustic truck the winch is mounted upon? A 1960s truck with a non-synchronized gearbox and pneumatic brakes is a bit different from todays cars most people are used to: an uninitiated person would likely not even get the engine started or stopped.

In my club, every aspiring winch driver had to do 150 tows on at least 10 days under supervision of one of the nominated trainers, then pass a test consisting of 10 tows, a theoretical examination and two splices (a broken cable and an eye) with an examiner. Then, one would receive the winch license. From that moment on, one would spend half a flying day on the winch every 4-6 weeks according to schedule, and be allowed to fly not only K13 and K8, but also the plastic types.

[snapper1]

This is what a modern glider winch looks like. Made by Skylaunch whose advertising strap-line is, 'Its like going up on rails.'

http://www.skylaunchuk.com/images/evo1.jpg

[Lord Spandex Masher]

Cable breaks teach you a very good 'get the nose down' reflex That can be life saving if you are flying low inertia, light aircraft when the engine stops!

And it taught me not to stick my tongue out during take off.

Bitten tongue bleeds a lot.

[RatherBeFlying]

It does require just as much attention behind a towplane as a winch when close to the ground as a cartwheel is very bad news.

Once you have 50' I find it easier in my 27 (70% CG) with a CG hook than the K-21, even when the towpilot takes a thermal. A forward hook produces a yaw couple in turns that requires compensation with rudder.

The 20 with 80% CG is considerably more frisky;)

[snapper1]

RBF
Agree that aerotow also requires attention. I have a '20' which does not have a nose hook, so aerotowing is a little tricky, particularly in the initial ground run as there is not a lot of aileron authority. I use full, negative flap up to 25 kts which gives a bit more authority but she still wants to drop a wing especially in nil-wind conditions - much course stick input needed. At 25kts, flaps are brought back (carefully) to zero and off we go. I think the big difference in wing drop on winch is the rapidity at which it can occur if you get a snatched launch.

[Crash one]

I had a K6E that has an offset to the left belly hook. Aerotows could be very interesting! It would attempt to ground loop as soon as the tug moved, lots of left everything and stay awake!!

[mary meagher]

Definitely BEWARE when accepting a winch cable in your glider, your hand MUST be on the release because if a wing drops and the glider cartwheels there have been fatalities and the poor basket never even got off the ground.

Winch cables are bloody dangerous. To spectators, passersby, and to power planes that ignorantly fly over a gliding site. One power pilot departed our airfield after visiting (we think) a local pub, and he flew through the wire as a glider was being launched; why his wing didn't get sawed off I will never know. The pillock should have landed immediately. Instead of which he blithely flew back to Wellesbourne. I wonder how he explained the damage to the flying club?

Neighbouring our gliding site is a very active karting circuit. Wind may blow cables over the track....so we have to choose a different runway and accept a crosswind.

I learned to fly at Booker, on aerotow, then moved to Shenington near Banbury and used to be totally freaked out by winch launching. The acceleration is astonishing. But I did get used to it, and ended up as an instructor having to teach winch launching. This never fails to bring out the sadist in the instructor (me too!) because when the pupil is getting near solo, he will have a LOT of practice winch failures. The instructor tries to be as sneaky as possible before pulling the release.

My favorite way of making the pupil suffer was to tell him that on the next launch we would have a practice launch failure.

And then I wouldn't. All the way to the top of the launch, maybe 1,200 or 1,400 feet, the poor guy is expecting the "BANG!" of the simulated cable break, most likely at the most awkward height for what do you do next! and it doesn't happen.

The lesson is it COULD happen at any moment, so one should be ready and have a plan of action ahead of time.

We used to winch using piano wire, and that was horrid for the poor winch driver, it frequently broke, and descended over the cab of the winch like spaghetti. Best thing for the pilot to do in this case was to soar for at least an hour until he got over it!

I was a towplane pilot, so declined to learn to drive the winch, at my age I shouldn't be having to wrestle splicing the braided steel cable we use now. We considered using the fancy new plastic line called Dynema, but it lays out on the top of the grass when taken to the glider, and is much more likely to be picked up if a glider or car or whatever has to cross over the wire. Which you do not do if it is at all likely to be suddenly in use.

The new winches are very simple, I am told. We used to employ a retired and possibly classic German Fire Engine converted into a winch that served us well for years.

Some clubs use a light signal. We use radio to the winch; once the glider lifts into the air, the winch driver is keeping an eye on it, and if you need to call STOP (anyone can do this if they see danger) he would not be looking at the light. Paddles were used in the olden days.

The drill for the wingtip holder, who MUST be trained and alert, is to carefully look around above and behind and in front in case there are gliders soaring over the winch. If OK to go, he levels the wings. Then naming which cable is being used, he says
"Launch to winch, K13, Take up Slack!" The winch driver stops reading his magazine, starts the engine, and slowly draws in the cable until the wingtip holder (or whoever is doing the radio) says and signals with his OTHER arm
"ALL OUT ALL OUT!!" The winch driver floors the throttle and the glider accelerates incredibly fast, rotates when it is safe to do so, and goes for the ride up the wire.

We know the back release works, we test it first launch every day. There are different weak links on the cable according to the weight of the glider.
Red, Blue, or Black. And we hope that the winch driver knows how to use the guilllotine......

though I know of no time when it has been used! except by mistake.

If the glider is then dragging the cable, and can't drop it, it probably wont make all that difference to the performance if he keeps his speed up when turning toward the pre-selected landing spot. If it drags over a fence or trees, that probably won't yank very much....I've done it with a tow plane.

Any questions?

[Cusco]

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.....

[cats_five]

<snip>
All the way to the top of the launch, maybe 1,200 or 1,400 feet,
<snip>

Gosh I never got that height out of a launch at Shennington. Maybe because we were almost never on the longer runway. I was there for 2 weeks on an expedition some years ago.

[effortless]

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?

[Crash one]

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.

[cumulusrider]

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

[mary meagher]

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

[davydine]

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.

[cats_five]

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.

[RatherBeFlying]

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:eek:

The guillotine did not have to be used this time:=

[longer ron]

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 !

[snapper1]

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!

[Fitter2]

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....

[BackPacker]

Watched some cadet air experience fly a chippie into a cable once. Glider hardly missed a beat, disengaged and landed.

As a glider pilot on a winch launch, your hand is very close, if not actually on the release knob during the whole launch sequence, from the very moment the cable is engaged in the aircraft hook to the normal point of release. The trained reflex if anything goes wrong, is to release the cable. You then stuff the nose down to keep the airspeed up, and depending on the height, land ahead or fly an abbreviated circuit.

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.

[snapper1]

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.

dyxs51ddWSY

[1.3VStall]

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.

[dsc810]

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.

[Maoraigh1]

Also can remember 'kiting' on the winch. Probably banned by now by some misery guts.

I was told it was illegal - pre 1960. Tried it with agreement of the winchdriver, but not very successfuly as it had to be done surreptitiously.

[India Four Two]

Ah, I so remember the days doing winch launches in Blanik L13.

dsc810,

I've never done ( or even seen ) a Blanik winch launch. Did you have a belly hook fitted?

[longer ron]

I did 49 winch/autotow (mainly winch) in the old 'Blanket' - both in africa and britain.

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.).

I must add though that I always used the side(belly) hook and never tried the nose hook for winch launch !

[Opsbeatch]

I remember not chocking the old Eagle winch and having an interesting first launch trundling towards the glider in the winch...!

OB

[18greens]

A great thread about safety point of winch launching. Re the guillotines. One boring rainy day a few of us winch drivers decided to test the guillotine, we had never seen one operate and thought it might be useful. We cleared the area and pulled the handle, it would not budge, the cables were rusted solid. I asked how often they were checked as a matter of routine, never got a reply.

I'm surprised the op hasn't asked the more pressing question of winch launching being 'what's it like?'

In my opinion it's the nearest thing to being launched from a carrier. Lots of nerves as the cable snakes away from you to full tension, stick held fully forward ( the Ka8 wants to fly too much) then the whoosh of speed as it accelerates to flying speed always threatening to drop a wing.As it launches 2 seconds later there's the tension of how far to pitch up, not enough and you over speed, too much and a cable break means you stall into the ground. Then you are into the full climb 30 deg nose up, monitoring vmax on the winch (51kts) a fair amount of back pressure on the stick ( but not too much). Then as you approach the top of the climb it flattens off. How are you going to release. If you pull off under tension the cable snakes back to the winch driver. You wait for the driver to back off constantly trying to squeeze a few extra feet. We used to wait for the back release then pull on the bung twice to make sure the cable had released. Then the environment changed instantly from hectic rushing to serene floating.

Not sure what other experience equals it.

[FlyingOfficerKite]

Also can remember 'kiting' on the winch

Yep, me too!

1976, Kent Gliding Club, T21 - achieved over 2,000ft agl.

Terry Bramfitt was the instructor - where is he now I wonder?!

[Fitter2]

2,000ft? Pah, that's a normal good launch.


Upavon, March 1961, T21 with John Willie flying to demonstrate the technique, Taff Thomas winching.


At 3,200 or thereabouts it back released. Taff had noticed there were about 5 turns left on the drum, so let three of them out rapidly. He didn't know what would happen if it didn't back release

[Tu.114]

The Ka 8 - a nice, docile little glider that is a pleasure to fly and can just barely kill you when flying without a rope attached. But during a winch launch, it turned into a nasty little beast trying to bite everyone involved.

The CG hook is mounted below the pilots seat, but moved a bit to the left side, as the centerline is already occupied by the nose skid. So not only the mentioned strong tendency to pitch up is present (due to the hook being WAY below the CG), it also loves to turn to the right just as rapidly during initial tow. When I first flew this type, I was a bit familiar with these effects from flying the K13 previously, but received a well justified and thorough warning to expect the same, only much stronger, by the instructor that signed me off. Still, I was surprised during my first launch.

A good winch driver makes much of a difference here; opening the throttle only moderately instead of jerking the glider into the air makes life much easier for the pilot. And in strong headwinds, a good launch has often resulted in release heights of 800-1000m (on a 1100m field) on this type.

[thing]

Don't forget all you 'kiters' that your site has a max launch height-yes I know some are unlimited. So when you look up at the next power guy to fly over the top of your site at what he deems a safe height, because your max launch height is marked on the map innit, don't call him a plonker and then see fit to break your own height limit on launch. I might add I fly gliders too, but not all power pilots have much of a clue about gliding, so if it says 'Cables to 2,000' then a lot of power pilots will simply think 'OK I'm safe at 2,500 then' only to find a kiter (kitee?) spoiling their day with a quick and one way conversation with a cable.

[dsc810]

The Blanik L13 as made also had a fixed bungee hook - which really was just a hook of metal protruding out from the Belly near the front.
I'm told they were all ordered (in the UK) to be cut off as they were an obvious danger to some form of hang up occurring where the cable might manage to get snagged up on it.

I learnt on a Blanik L13 on the winch so have very many flights as both P2 and solo as P1. I loved flying it solo - more so than the K8.

I can also remember the equally many rocket launches in the K8 thanks to an over enthusiastic winch driver who had just launched a series of 2 seaters and was still on autopilot - where it did indeed seem more akin to a steam catapult launch off an a/c carrier deck.
The worst and indeed most memorable was one where the acceleration rate was so high that both my feet lifted off the rudder pedals. The wing handler later reported that he did not move an inch much less actually run with the wing - come the "all out" signal the wing was snatched out of his hands as the K8 accelerated away.

[longer ron]

Yes by a certain date the majority of 'western' Blankets had the fixed hook sawn off.
It was great fun 'oilcanning' around the sky in that lovely tin armchair,I did most of my blanket flying in africa...we were only allowed 2 solos in the L13 because they were too valuable to risk with early solo pilots - and then it was straight into a Slingsby Swallow - some people found the transition from the tin armchair to the little wooden thing with no nose very difficult :)
One of our guys on his first Swallow flight - his feet came off the rudder pedals and when he placed them back on - he missed - and put them on a fuselage frame - he thought the rudder was jammed ! LOL
I was happy to fly the swallow because I had originally flown T31's....but it was definitely a backward step from the 'Blanket'

[mary meagher]

Ah yes, the acceleration of the K8 snatching the wingtip right away from the hapless runner!

Add to that two failed launches (piano wire, this was in the old days when cable breaks were the norm), and the fact that SQUISHY CUSHIONS were part of the mix. Cushions shifted a bit, sudden acceleration, Mary gets pressed against the back of the seat and departs the controls!

No, I didn't try to hang onto the stick, that would have made things worse!

Pulling back on the stick when departing the controls adds up to high speed stall. And no way could I reach the release handle! (this was before new training emphasized HAND ON RELEASE!).
So I did nothing at all but rode the K8 up the wire, and by some happy chance the launch was smooth and directly into wind, and both of us (me and the K8) survived to fly another day.

Exactly that scenario did kill a young lady, squishy cushions, but she hung onto the stick and ....

Surprising how doing nothing may be the correct decision. Nowadays if you need cushions behind your back to be correctly seated, we use a stack of NEWSPAPERS, securely wrapped in tape and covered in fabric. These are non compressible.

And under your bum, a special type of foam impact cusion will can protect your spine if a heavy landing takes place.

[cats_five]

We use the same sort of foam behind the back as under the seat.

[treadigraph]

Longer ron, where were you flying in Africa?

[longer ron]

Treadigraph

Midlands Gliding Club,Moffat Field,Gwelo,Zimbabwe.

We used fencing wire (loads of cable breaks LOL) for winch launching 2 Blaniks,1 swallow,1 Skylark 3b,1 Dart 15.
Lovely flying conditions sometimes - my best climb was from 600' (in the cct) up to 11,000' AGL in the old Skylark.
In the summer I only worked until 1.00pm (too hotnbumpy for jets) and quite often went gliding to utilise some of those 'bumps' :)

Have you flown in africa ?

rgds LR

[treadigraph]

:ok:

Yes, as a passenger nipper in a Blanik and T-21 at Nakuru, Kenya circa 1970-72. Wondered if you might have been there too. The club also had a Swallow, I can't recall other club gliders, but a number of Germans visited in '72 with ASW-17s and other exotica, and Walter Neubert set a world distance record (300k triangle I think). There was an air to air pic of one of them soaring close to the peak of Mount Kenya.

We kids mostly rode in the back of the tow car and helped retrieve the cable, or sometimes flew in the back of the Citabria.

I was only 8, but I recall it as great fun!

[thing]

Funnily enough I was talking at the gliding club today to a guy that had flown out in Namibia. He reckons 12-13 thousand foot thermals are quite normal.

[longer ron]

Ah yes Nakuru -almost booked a holiday there once !:)
Glad you had a great time TG :)

Funnily enough I was talking at the gliding club today to a guy that had flown out in Namibia. He reckons 12-13 thousand foot thermals are quite normal.

At Gwelo we were at approx 4,500' ASL - the day/night temp difference could be as much as 30 deg...which is great for cloudbase,I certainly know of definite 12,000' base in zim...although never quite got there myself :)

[thing]

At Gwelo we were at approx 4,500' ASL - the day/night temp difference could be as much as 30 deg...which is great for cloudbase,I certainly know of definite 12,000' base in zim...although never quite got there myself :)

I think he flew out of Windhoek (sp?). Off to Oz in five weeks; haven't flown there but apparently the cloudbase is off the beserk scale, oxygen required, that sort of thing.

[longer ron]

Off to Oz in five weeks; haven't flown there but apparently the cloudbase is off the beserk scale, oxygen required, that sort of thing.

Sounds good - hope you have a great time :ok:

[Heady1977]

Off to Oz in five weeks; haven't flown there but apparently the cloudbase is off the beserk scale, oxygen required, that sort of thing. Where in OZ?

I flew in OZ in 2012 (in winter - mid-year) and again in 2013 (in summer - around Christmas). Winter was very much like the British summer; but summer was quite different where cloud base was 12-15 thousand feet and you could "in theory" thermal all the way up. However, where I was flying the transponder level was 10 thousand so you kept under that.

Flying into a 12+ thermal was like being hit by a train and then staying in it was like being in a washing machine. I also remember forgoing stronger thermals in the blue to take weaker thermals under clouds just to hide from the sun. One vivid memory of flying in OZ during summer was 39 degrees on the ground and still 30 degrees at 2-3 thousand feet - it was a relief to climb above that into cooler air as the cockpit was worse than a greenhouse - coming back down below 2-3 thousand was torture.

I've turned up at the little OZ club I was flying at more than once with perfect skies with Cu popping everywhere at 5 thousand plus and been told they weren't opening the hanger doors as the day wasn't good enough; so they were going to mow the grass instead. But like everything in gliding - the weather may be against you. I've traveled half-way around the world to fly - and the airfield was 10 feet under water only a few weeks after being evacuated because of being threatened by a bush fire.

[Piper.Classique]

Back to winch launching.....sort of
While scrabbling around in the back of my standard Mucha I found it has all the fittings, even the release cable, for a winch hook.
So my question is, has anyone knowledge of the whereabouts of a spare belly hook?
It won't be a Tost unless I am mistaken, the aerotow hook isn't, it is some Polish make, but I suspect a Tost hook might go in. Needs a hole cutting in the ply anyway.

[longer ron]

Flying into a 12+ thermal was like being hit by a train and then staying in it was like being in a washing machine


Thats a great analogy :) I had a couple of wild thermal rides in the old Skylark where the vario was off the clock,I didn't dare look out at what the wings were doing and I was using full aileron and rudder just to prevent myself being spat out of the thermal :ok: - was feeling a wee bit peely-wally by the top of the climb !
They made me do my x country qualifying field landing in the skylark on an extremely good day... I said to leave it until the evening but no.....
So i made a point of thermalling (climbing) over their heads with the brakes fully open :) - I just scraped into the marked out area but it really was a silly exercise in those conditions !

[thing]

Where in OZ?Brisbane area, Spring Mountain about 35 miles SW of Bris airport. Slight misunderstanding, confusing post on my part. I go every year to see my son and his family for a few weeks, I haven't actually done any flying there but have chatted Oz glider pilots. Not sure where the nearest site would be to son's house TBH. I've looked into power flying there but if you think it's expensive here...:eek:

[astir 8]

Did 12000' AGL in a 12 knot (1200 feet/minute) thermal at Beverley (Western Australia) a few years back. In a twin Acro.

Pingpong ball on a fountain! Needed to use serious angles of bank to avoid being spat out of it.

Cloudbase was still at least 3000' above us at 12 grand and it was still 12 up but the guy in the back (quite rightly) started muttering about oxygen.

So we knocked off a 150 km triangle. Hour and a half from launch to landing.

Wave in Scotland is fun (my best ever was 21000') but it's not like Oz!

[Heady1977]

Brisbane area, Spring Mountain about 35 miles SW of Bris airport.So I'm assuming "Greenbank"... if you put "Greenbank Queensland" in the text entry box located at:
Gliding Australia (http://www.glidingaustralia.org/find-a-gliding-club)
You'll see all the GFA clubs and approx. distances from your son's place.

Unfortunately, most club based gliding clubs in Queensland only fly on weekends or public holidays. To get clubs running 7days you have to travel to NSW or VIC.

Closest seems to be Boonah Gliding Club (46km away) - which at one point use to fly during the week via prior appointment in a K21 self-launcher.
G.Dale coaches at Kingaroy Soaring Club (170km away) from time to time...
I did most of my flying at Darling Downs Soaring Club (151km away) - as it was the closest to my parents place.
Lake Keepit Soaring Club (8hrs drive away) is now managed by an ex-Lasham staff member and from all accounts comes highly recommended if you want to make a week of it.

[FlyingOfficerKite]

Lake Keepit Soaring Club

Another of my Kent Gliding Club instructors from the '70s was associated with this Australian gliding club I understand - John Hoye.

[thing]

So I'm assuming "Greenbank"... if you put "Greenbank Queensland" in the text entry box located at:Brilliant! I know Boonah, not far from where son lives. Didn't even know there was a club there. Pity about the weekend only bit, I don't want to be disappearing off gliding when he only gets weekends off.