CS 22.177  Lateral and directional stability

CAA ORS9 Decision No. 1

(a) With the sailplane in straight steady flight, and when the aileron and rudder controls are gradually applied in opposite direction, any increase in sideslip angle must correspond to an increased deflection of the lateral control. This behaviour need not follow a linear law. 

(b) In a sideslip any control force reversal must not be such as to require exceptional piloting skill to control the sailplane.