4. LESSON 15 - WINCH LAUNCHING IN CROSSWIND
Check the wind speed and direction
Correct for the weathervane effect
Keep the wings level
Apply the proper drift correction into the wind
CHECK THE WIND SPEED AND DIRECTION
Before every winch launch, you should check the windsock to determine whether you will be launching with crosswind. During most take-offs, you will experience at least some crosswind, which makes every winch launch unique. If other gliders are departing before you, keep an eye on the amount of wind correction that they are applying to determine how much you will probably need to correct yourself. Without correcting for crosswind, you risk being drifted off course. Not only does this prevent you from following the ground track in the direction of the winch, it will also risk the cable being dropped outside the fence of the airfield.
During the initial acceleration you have to take account of the weathervane (or weathercock) effect. The weathercock atop a church tower is always facing the wind, because its tail is pushed back by the wind. A similar thing happens with the glider’s fin. If the wind is blowing sideways towards your fin, it will try to turn the glider’s nose into the wind. You can prevent the glider from turning sideways by using some opposite rudder. If, for example, the wind is coming from the left, you will need to apply the right rudder when rolling on the ground. It is very important to keep the wings level and react quickly to a dropping wing; the crosswind will make it a lot harder to get your wings level again after a disturbance.
LAYING OFF FOR DRIFT
After you have established a normal climb angle, you will need to start correcting for drift. Gradually apply some aileron and rudder in the direction of the wind until you reach the desired drift correction. The windward wing needs to be kept slightly lower, which allows the glider to side-slip a little bit towards the wind. Try to keep the yaw string in the middle with the rudder pedals.
If you let yourself be blown off course too much, the cable may drop outside the fence of the airfield