Wormingford Airfield, Fordham Road, Wormingford, Colchester, Essex CO6 3AQ Tel: (01206) 242596 glide[at]esgc.co.uk  "essexandsuffolkglidingclub"
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Safety Briefing 7

from Andy Sanderson

10/11/01

Winter is upon us. Condensation, mud, rain, high winds, and low temperatures can affect our performance and that of our gliders markedly. Please be aware of any factors likely to affect your skill and your safety, and stay within your safety margins. If in doubt, ask an instructor for advice. Cloths and canopy de-mister are in the launch vehicle, but if you cannot rid the canopy of mist do not rely on it clearing during the launch - you must not launch.

Also, the usual annual plea to take care of parachutes. You may never need one, but if it's damp or mouldy inside because someone once let it get wet, would you be confident it will open? Likewise, why leave gliders out in the rain? If they are not required, put them back inside the hangar, especially if there is any risk of rain or heavy condensation.

Glider picketing: we are getting some new wingtip weights made up, but whether you use them or tyres instead the primary aim is to safeguard the glider in a wind. If you do not know how to properly park a glider, please ask. Each glider is different, but they all need to be parked with the wind coming from the side and slightly aft. Anyone who leaves a glider facing into a strong wind with the brakes closed and without a pilot inside must expect it to blow over, and as the wind direction changes parked gliders may well need re-parking. Canopies must at all times remain closed, and ideally locked, unless directly supervised and within reach.

Vehicles:

For many reasons (including legal, insurance, duty of care, etc.) the committee has decided that the following groups of people are permitted to drive vehicles on the site:

1. Those with a current and full UK driving licence may drive any vehicle but must be in current practice for that type.

2. Those 16 years of age or more without a driving licence may drive the tractor and buggies with express permission from the committee for each type of vehicle.

3. Those under 16 years of age may drive only the buggies with express permission from the committee.

The basic difference to what has been in force up to now is that now no-one under 16 is allowed to drive the tractor. If you are not sure whether you have permission then it is up to you to check with a committee member first. ALL driving on site must be slow, careful and responsible, and please drive the buggies very slowly over bumps.

Unconnected with this change, the general standard of tractor driving has been concerning the committee, as well as the BGA. The following represents the ideal sequence of a tow-out of the cables. Please adhere to these, if safe:

1. When hooking on at the winch have the tractor arms down for four cables. If towing two cables on the grass, towing with the arms half up is acceptable, but fully up is not acceptable as it increases the chance of cables crossing during the early part of the launch, and makes unhooking the cables at the launch point at eye level more hazardous. If you have the arms half up, hook on to the inner (lower) weak links. If towing on the grass ensure you drive in as straight a line as possible, from directly in front of the winch. From the very start of your tow-out, aim towards the side of the grid that will ensure that the cables cannot cross during the up slack.
2. Ensure that any broken weak links are cut off when new ones are added, so as to prevent injury to fingers.
3. DO NOT leave the parachutes connected to the cable and placed in the tractor rear box. If the wink link fails, at best the parachute will be wrenched over the edge of the box and reduced to shreds.
4. WAIT for positive confirmation from the winch driver that it is safe to set off and the brakes are set, and take up slack VERY gently for BOTH cables. Use full hand throttle in top gear for the majority of the tow-out.
5. About 100m short of the launch point reduce speed progressively (I have found that gently tapping the hand throttle up is a good way to achieve this smoothly), and ensure you are travelling slowly over the worn parts of the track. As you come to rest, steer the tractor away from the gliders, and take the tractor OUT OF GEAR.
6. Ensuring nobody is behind you, reverse a couple of feet. Set the engine to IDLE and take it out of gear again. Either remove the cables and parachutes yourself or wait for someone else to do it and then WAIT for their positive confirmation that the cables are unhooked, the parachutes have been removed, and it is safe to raise the arms. DO NOT MOVE OFF until you get this signal. ENSURE nobody is near the arms, raise the arms, CHECK THEY ARE FULLY UP, and then move off slowly.
7. If it is obvious that you will be able to get to the winch without delaying the next launch, then return to the winch. Otherwise, wait until after the next launch, or until after both cables have been used. If you are not sure of the state of readiness of the glider, then ask an instructor, the launch marshal, or the pilot (but do not rush the pilot).
8. If not returning to the winch immediately, turn the tractor engine (and electrics) OFF as the noise makes it more difficult to hear the launch signals.
9. If not returning to the winch immediately, WATCH THE ENTIRE LAUNCH, in case of launch failure, as it will then be much easier to find any broken cables or strops that fall in the fields. If the tractor is returning to the winch immediately, someone else at the launch point must always watch the entire launch.
10. At all times BE AWARE that you are driving a large, powerful, unstable vehicle with no suspension, relatively coarse steering and a high centre of gravity. Remember that, as a speed-governed diesel, if it escapes your control it will happily deliver enough power as required to maintain its speed setting, regardless of however many vehicles, gliders and people it decides to plough through.

The CAA Safety Regulation Group has sent me a note asking if we continue to want a hard copy of GASIL, suggesting that it would keep down costs (ultimately paid by general aviation as a whole) if we could read it on the web. However, I told them it was useful to have a copy we could hang on the Safety Notice Board, so I hope you all do read it - glider stories are occasionally featured, and many of the comments apply to us anyway.

I have observed a number of "pole-bending" launches being executed by quite experienced pilots, who when questioned have sometimes said that they did not want the speed to become excessive, so pulled back early. THIS CAN BE A FATAL ERROR when the launch fails, especially on windy days with a significant wind gradient. If you do not understand why it is perfectly safe to allow the glider to exceed the placarded maximum launch speed by a wide margin during the early part of the launch, then you should ask an instructor to explain or even demonstrate it to you before flying solo again. During the early rotation, accept any speed above minimum winch launch speed (50 knots for a K13) up to maximum manoeuvring speed (approximately equal to maximum rough air speed - 80 knots for a K13) WITHOUT attempting to signal too fast. Only signal above 300 feet if the speed does not reduce to the placarded maximum as you rotate into the full climb. Pilots who waggle furiously below 300 feet are asking for a poor launch, a launch failure, or a crash. However, towards the top of the launch you must be careful not to overstress the glider by exceeding the maximum placarded speed with the stick fully back.

Speaking of which, what should you do if the launch remains "too fast"? DO NOT LOWER THE NOSE before signalling or releasing the cable. If you lower the nose whilst still connected, you may fly into the cable. Unlikely though it may sound, such events have happened and have always caused serious crashes, almost all of them FATAL. Make your too-fast signal, and if necessary release under full tension, as you would do if you launched into cloud. This is the current BGA instructional policy. The winch driver can sort out a cable tangle on the ground much more easily than you can sort out a cable over your wing whilst airborne. A second after releasing the cable, it should be far enough below for you to lower the nose to maintain a safe airspeed, if you need to.

Two things that are also generally only relevant in the winter, when two cables have been towed out to the very end of the track, and we are launching off the concrete in the middle of the east end of the runway. First, before bringing the first cable over to the launch point you MUST attach both cable parachutes, just as you ALWAYS should in any case, or there will be the mother of all birds nests of cable - again - if the cables touch during the launch. Secondly, when a glider is returning up the concrete track after a landing you MUST NOT launch a glider on the first cable unless the glider is also clear of the second cable - in practice this means waiting until the glider has turned onto the peri-track at the east end. Failure to observe this may cause a sawn-off wing or very much worse.

Finally, when launching a glider on the first cable quite close to the track, take the second cable and its attached parachute WELL CLEAR TO THE SIDE so that the launching glider's wing CANNOT DROP ONTO IT. If it does, the result will be a very nasty accident indeed. Ideally, drag the second cable to beyond the south edge of the track.

Andy

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