CS 25.233 Directional stability and control

(a)There may be no uncontrollable ground-looping tendency in 90° cross winds, up to a wind velocity of 37 km/h (20 kt) or 0·2 VSR0, whichever is greater, except that the wind velocity need not exceed 46 km/h (25 kt) at any speed at which the aeroplane may be expected to be operated on the ground. This may be shown while establishing the 90° cross component of wind velocity required by CS 25.237.

(b)Aeroplanes must be satisfactorily controllable, without exceptional piloting skill or alertness, in power-off landings at normal landing speed, without using brakes or engine power to maintain a straight path. This may be shown during power-off landings made in conjunction with other tests.

(c)The aeroplane must have adequate directional control during taxying. This may be shown during taxying prior to take-offs made in conjunction with other tests.