Killer downwind turn.
This one came about because of slow-speed aircraft turning downwind shortly after takeoff, while simultaneously climbing through a stiff wind gradient. Obviously the climbing into a tailwind will decrease your airspeed, resulting in a possible stall (and the turn itself will further degrade your speed).
Likewise, another glider hazard is the 'clutching hand' effect of descending to land and transiting from a stiff headwind into a nil headwind area (over the top of trees, for instance, into the calm region in front of the trees). As soon as you lose your headwind, you lose your airspeed and drop rather rapidly (feels like a hand dragging you downwards).
But obviously if there is no wind gradient, the windspeed and direction is irellevant to your flight control.
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