Text in force at CS25-28: from CS25-0, effective 17 Oct 2003.
(a) There may be no uncontrollable ground-looping tendency in 90º 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 90º 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.
ED Decision 2003/002/RM · Source