At Lasham in the uk we use powerful winchea(450hp). A couple of makes of glider
have problems if the acceleration is too fierce initially.Typically they have a
Cof G hook mounted well aft, a high glider Cof G, high mounted wing (or the
main drag being relatively high), nose wheel or skid,and light weight.
If you watch them as the cable tighten the tail will bang down (sometimes
harder than you would like) This gives the wings a high angle of attack and the
glider will lift off with the tail skid still on the ground, straight into a
full climb. Quite often the pilot is just a passenger whilst this happens. Once
in the air and sufficient flying speed is reached the elevator will start to
become effective and he can regain control. The two makes that I have flown
that have this problem are the K8 and PW5.
We now teach pilots in the K8 to start the winch with full forward stick until
flying speed has been reached.
A couple of other factor that can make the problem worse. Strong headwind and
my pet hate, soft cushions. If a soft cushion is being used as a backrest in
these circumstances the acceleration and attitude will thow you back
compressing the cushion and not allowing full forward movement of the stick.
Also in the report it mentions a type of tow hook that sometimes jams under
tension, lethal in my opinion, change it.