A mámtu ten samý problém zas a znovu. Opět odfláknutá práce při skládání kluzáku, opět odfláknutá práce při jeho denní prohlídce,opět odfláknutá práce při pozitiv checks těsně po složení stroje.
Co jsou positiv checks?
Pro neplachtaře, positiv cheks je způsob, jak se po složení stroje kontroluje připojení táhel k ovládaným plochám. Jeden pilot stoji u kokpitu, druhý pilot stojí u kontrolovaného kormidla – například výškovky, jejíž pohyblivou plochu pevně drží. Pilot se snaží přitáhnout a pokud to nejde, je vše v pořádku. Pokud to jde, není připojení táhlo. A tak se postupuje postupně pře křidýlka, a směrovku, brzdy a klapky. Tuto kontrolu by měl provádět jiný pilot než je ten kdo stroj skládal. Tím se eliminuje šance, že si pilot řekne, jo to jsem udělal to je OK není třeba to kontrolovat.
Problém je častý!
Tento problém se opakuje každou sezonu. Každou sezonu se na něj upozorňuje, každou sezonu máme rozbité plechy či lamináty a zraněné piloty.
To: BGA Club CFIs
Owners of Cirrus, Kestrel, Libelle, ASW15, ASW19, ASW20 & Pegase gliders.
Please would all CFIs bring this note to the attention of all pilots at your club, irrespective of the glider type that they fly.
One pilot among us is very lucky to be alive. Using his words, here is how a winch launch very quickly became the stuff of nightmares;
“I knew that the nose was rising and not responding to my attempts to control it with elevator. I had a sudden realization that I had not connected the elevator….Not wanting the nose to keep rising with the possibility of a back-release at a near-vertical attitude I decided to abandon the launch.
As the speed reduced the nose came down and we started to speed up…I have a memory of the angle of dive flattening giving me a moment of hope. Moments later the glider impacted the ground…I do remember seeing the ground and sky swap places…the glider slowed to a stop inverted”.
The club at which the winch launch took place is a popular expedition site. Based on experience prior to this accident, the club has for some time included a verbal challenge/confirmation at the launch point that positive checks have been carried out.
Despite the standard advice to pilots on rigging gliders and the additional safeguards at this club, how did the accident occur? The injured pilot, who unusually in this type of accident, is here to tell the tale, is very supportive of his experience being used to educate others and notes:
“Looking back, the rigging itself had been uneventful, but not quite a ‘standard’ rig. Initially the tail plane bolt was missing from the rigging kit, but was found, along with the related rigging kit, in a toolkit in the front of the trailer. The trailer itself was parked close to the main club entrance such that during rigging the glider port wing overhung the road, with my car parked close by to provide a visible barrier to motorists. This led to my moving the glider as soon as the wings were on rather than completing assembly before moving it. I find it hard to accept that these minor points could be sufficient distraction to cause the problem.
I am at a loss to understand why I did not connect the elevator when I fitted the tail plane, which is my usual method; why a DI failed to find it; and why positive control checks weren’t carried out. If I had set out with the intention of doing this, it would have been difficult to achieve. But I seem to have managed it accidentally”.
We are human. Shortcomings in glider integrity usually arise from the universal human failings of distraction, forgetfulness, and making unwarranted assumptions.
Shortcomings in preparing a glider for flight can be lethal and are completely avoidable. Please ensure:
* Rigging is directed by a person experienced on the type, in accordance with the flight manual, without interruption or distraction
* The DI is conducted by a person experienced on the type, without interruption or distraction
* You, the pilot, carry out proper pre-flight checks, again without interruption or distraction.
BGA statistics demonstrate that owners of certain types of gliders are particularly vulnerable to failing to connect a flying control during rigging. That is why in addition to all CFIs, a number of owners have been sent this note. We hope you find it helpful.
BGA Safety Committee
22 July 2014