As you probably know by now we have a second Skylaunch Winch at Middle Wallop. This has come to us on long term loan from our sister club Heron. This winch has some differences to our own, which some of you may not have encountered before, and I want to bring you all up to speed, as it were, in time for solo flying to re-commence this weekend.
⦁ The winch is loaded with Dyneema. This is a synthetic multiplat rope that has a much higher strength to weight ratio than our traditional steel cable. However this weight advantage comes with the need for some small disadvantages. The first and most important is that Dyneema is prone to abrasion damage. This means that for now it can only be used on the North/South run. We’re sourcing some matting for the track across the East/West run so it can be used there also. This means it cannot be pulled over tarmac, or driven over. Winch drivers, when preparing the cables for the retrieve please lay them out well apart. Retrieve drivers, when picking up the Dyneema from the winch please reverse back between cables rather than taking the shortcut of driving over them.
⦁ Dyneema differs from steel cable in another important respect. It creeps. If you watch it at the launch point after it has been dropped off you will see it pulling back towards the winch. This isn’t a problem during the normal flying day, but it is, when the winch is put to bed. The Dyneema will continue to creep and if it is left wound tight on the drums, as after a launch, it can tighten enough to distort them. Because of this it is vital that the cables are “relaxed” before the winch is put away at the end of each day’s flying. The procedure is to pull the cables back to the launch point, and a little beyond if possible, then wind them back in with the small tyre attached.
⦁ Due to it’s lighter weight the drogue chute used with Dyneema needs to be smaller than used with steel cable. Please do not swap the chutes from one winch to the other.
⦁ The Heron winch is fitted with an automatic tow out brake. This is on whenever the drum selector is in neutral. However it does not put as much drag on the drums as you may be used to so Retrieve drivers need to take more care when slowing down towards the launch point. If you’ve driven Retrieve at Middle Wallop you will know that there is a pronounced dip in the run. As a rough guide you should start a slow deceleration as you come out of the dip. The aim is to be at walking pace about 20 meters from the drop off, and taxi in from there. The auto brake and lighter cable do not give as much drag as the steel, therefore you will need to use the brakes during deceleration. Please do not wait until the last moment, then brake hard. The winch drums can’t stop as quickly as the Jeep, and all you will achieve is a birdsnest of tangled rope on the winch and a delay to launching. It’s much better to brake gently over a long distance to a stop a little way out from the launch point then creep in at a snail’s pace.
⦁ Because the Heron winch uses Dyneema it has a different roller set up. No big deal, except that the rollers are aluminium rather than steel. As they are softer, they are much more prone to damage if the metal work is allowed to go into them. In fact it could cause enough damage that the roller could then damage the Dyneema on the next launch, see my comment on abrasion above. With this in mind, please do not fly the cable all the way back to the winch. Please drop it to the ground at least 50m out, the nearest lip of the dip is a good guide point if you are unsure, and then bring it to no closer than 10m on idle. In fact I’ll give everyone a challenge, to take the winch out of gear and have the cable stop 10m in front of the winch without using the brake.
⦁ The Heron winch has the bigger engine, so better launches all round especially for the Duo in still air, but more care will be needed with single seaters to not overpower them.
⦁ You will find the throttle on the Heron winch feels “heavy” or “stiff”. This is because it has a damper on it to stop it being opened too aggressively for light gliders. From experience driving other Skylaunch winches with the damper system it also prevents accelerating heavy 2 seaters properly. It will take some getting used to, but for the 2 seaters you will need to push against the damper to get the 3 second “All Out” acceleration, much less so for the single seaters. Just take your time and get the feel for it, and for the first few times ask for feedback from the DI on the acceleration.
⦁ Splicing Dyneema is not as straightforward as splicing steel cable with ferrules. I will produce a guide with photos and a “knots” board, as well as making some off cuts available for everyone to practice with in the near future. The good news however is that when treated properly Dyneema has a life expectancy 4, or more, times that of steel. Many clubs report going years without the need to do any splicing at all.
⦁ There will be a new handbook in each of the winches which will be required to be read Once you have read them please sign the appropriate page ( these will be provided in the next few weeks.
If you are unsure about any of the above please speak to myself, Jamie or Richard Lovell-Butt, and we’ll happily go through things with you.
Can’t wait to see you all at the launch point. Here’s hoping for 2000ft+ launches straight into 10kts thermals.
Thanks for your time