Glider winching

or "How to give the pilots their monies worth!"

Up Slack

Once the up slack singnal is observed make sure you select the correct drum for launching and engage inot gear smoothly and without "gratting". This is best achieved by applying the transmission brake and moving the gear select lever to the appropriate side. As you start to feel some resistance take of the over-run brake. As you release the over-run brake the tension in the cable pulls the drum round slightly and thus allowing the winch to "drop" into gear as the cogs line up. This takes a bit of practice but worth the effort and avaids those exensive sounding noises as the gearings's teath grind across each other.

There will of course be times when the avove desn't work, so best practice is to then ease off the transmission brake very slightly to allow the drive shaft to rotate a small amount whilst applying a gentle amount of pressure to select the gear. NB emphasis hire is on slighty and gently again whith practice gear selection should be painless, (for the winch that is)

Once in gear take up slack slowly and gently with only the minimum amount of power. Too fast and you run the risk of the glider over-running the cable with the associated risks. Snatching can also cause damage to the glider. There should b a definite stop/pause between up-slack and all-out i.e. once the slack has been taen out of the cable the drum should be stopped before all-out is actioned.

NB The amount of power equired to take up slack can very depending on the grass being dry, wit, long frosty etc...... and also what sort of mod the winch is in. It may be neccessary to keep things under control during this phase by using the appropriate drum brake - never the transmission brake.

Do not try to rush the up-slack phase- if it takes a while to wind the slack so what! It is far more preferable to have people at the launch point grumble at ethe slack being taken in slowly than to have an over-run.

All Out

Ensure your "free" hand is placed on your knee in readiness to select the correct drum if and when required.

Apply a small amount of extra power at firs to take out any residule slack that is usually still prescent in the cable.

Accelerate smoothly and gently to the second stop i.e. full throttle. DO NOT bang the throttle to this point as thiscauses rapid acceleration, which is unpleasant and potentially very dangerous for the pilot, *there has been instances where pilots have been stunned by hitting teir heads on the canopy frame due to this sudden acceleration. Fortuately they "came round" before anything else dramatic happerned - be warned. I find counting to 3 of 4 elephants to full trottle a good guide.

Keep watching the all-out signal untill the glider rotates and can be observed from the winch, then it should be simple case (providing the pilot is flying the lauch correctly) of keeping the throttle where it is untill the top of the launch. However you should still watch the glider and respond accordingly to his/her commands.

Aim to keep the enging note contant practice will tell yu when this is ok.

Top Of the Lunch.

You shold have noticed that there is a blind spot in the winch where the glider disappears behind the top frame of the winch cab. This is the point where you need to start to think about reducing the power. As the glider re-appears from this blind spot start to reduce the power gently but positiverly in order to allow the pilot to lower the nose to reduce tension in the cable and release. Reduce the power too quickly and the cable will back release, too slow and the pilot may "hang on" a bit too long. The exact point of this power reduction comes with practice and depends on the weater conditionas at the time.

It is at this point where you should place your free hand on the appropriate frum brake.

If you find when you are laucheding that gliders are always back releasing then this could be a sign of , taking the glider too hight, reducing the power too quickly or, of the pilot being slow to react to the reduction in power. Consider which of these may be the case and react accordingly - the aim is to always allow the pilot to release the cable. Back releasing is a safety mechanism and should not be treated as the norm.

Once the cable has been observed to drop away from the glider them power can be reapplied to pull the cable back in. Aim to use a half to two thirds power of just enough to get the parachute infated and to allow the cable to feed into the drum smothly without coiling up on the ground in front of the winch. Initially you may have to apply up to full throttle to get "things" moving, bus once going back off accordingly. Only use full power is absolutely necassary.

At about 200 to 150 ft from the ground ease off the trottle competely and gently apply the drum brake so the paracute drops to the ground dead or at worst case at a slow waling pace. The reason for this are:-

• It forms a habit. at some stage you may find the parachute or cable is about to drop on some one or something. If this is the case then it is far better that the cable / chute is "dead", as it causes less damage than if is under power. If you are already in this habit then at times of crisis you won't be under extra pressure to do something different.
• It cust down on wear and tear of the parachute and associated bits and pieces as well as damage to the grass, runway, crops etc.

If you do not think the parachute is not going to clear an obstruction of it's marginal then best option is to cut the power and brake the drum in plenty of time.

Wind In

Once the parachute is on the ground, double check that you have your hand on the correct drum brake and wind the cable in on tick-over only because:-

• If you have to brake quickly you can without the risk of throwing a loop.
• It allows the feeder pulley to slow down gradually thus reducing wear on both pully and cable. This is not so much of an issue though since we have changed to plastic pulleys.

As the cable approches the point where you wish to stop the parachute apply the drum brake gently and in good time. Once stopped, apply the transmission brake, then release the drum brake and dis-engage from gear. Now re-apply the drum over-run brake.

Prior to the cables being taken back to the launch point it is usually a good idear t check both drums first to ensure you havent't trown a loop which could cause problems on the pull-out.

As already stated the above is the method best used for a K21. Some gliders however require a slightly different technique. To describe each technique for each type of glider we have on site would take aproximately forever to write so, the next method is for single seat woodern gliders such as the K8.

Up slack is as for the K21, only you may need to use a bit less power. all-out is generally to the first stop or just bejond dependat on conditions. Once the glider has rotated then to avoid the sudden pitching up of the nose that can occur on these types, reduce the throttle setting slightly. Note the aim here is not to reduce the power as such, but to keep the acceleration in check. Once you start to here the engin start to take the strain of the glider then gently re-apply the power to the first stop, (or bejond dependat upon conditions), and keep it there untill the top of the launch. The rest should then be a La K21.

Pilots please note:-

1. Decide which type of launch you are comfortable with bearing in mind the type of glider you are flying for example if flying the junior then I normally request a K8 style launch, the discus then slightly faster than a K8. Decide what you want and ensure the winch driver is made aware.
2. A good or dad aunch isn't always down to the winch driver. A good launch is a team effort between both pilot and winch driver so think about your own possible failings before blaming it on the poor old winch drivers. If in doubt how to launch a particular glider then ask. Also it is a good idear for anew winch drivers to get feedback from pilots about their launches. This can be satisfying when all is well but also depressing when not. Either way it's a good learning tool.

Cable Breaks

A cable break simulated or otherwise should be ovious. You can usually feel the cable break and at the same time the engine speed increases as it looses its load at the other end of the cable.

Action- Let go of the throttle and gently but firmly apply the relevant drum brake. Allow the parachute to drop to the ground and disengage gear. Then wate to see what action the glider takes and awate further instructions. DO NOT attemt to pull in the cable untill you are absolutely certain the glider and cable will be or are clear of each other. Safest option is to let the parachute drop dead as already described and wait for the glider to land and react accordingly from there.

Generally

When operating the winch, be smooth and sympathetic to the machinery, do not bang and crash about, It's not a race.

Whilst winching, ensure both cab doors are closed and locked. The cab is your safety cage and will protect from loose ends of wire that thrash about during cable breaks.

To speed things up, if practical and safe to do, put the "used" cable on back of the appropriate side of the tractor in-between launches.

Be aware of what is going on around you, there may be instances where it is un-safe to launch despite the request/instructions from the launch point e.g. walers, gliders sneeking in from a different direction.

If in doubt do nowt!

Andy (Mr. Winch) Butler

from the Wolds gliding club