CS-VLA 201  Wings level stall

ED Decision 2003/18/RM

(a)                            For an aeroplane with independently controlled roll and directional controls, it must be possible to produce and to correct roll by unreversed use of the rolling control and to produce and to correct yaw by unreversed use of the directional control, up to the time the aeroplane stalls.

(b)                            For an aeroplane with interconnected lateral and directional controls (2 controls) and for an aeroplane with only one of these controls, it must be possible to produce and correct roll by unreversed use of the rolling control without producing excessive yaw, up to the time the aeroplane stalls.

(c)                            The wing level stall characteristics of the aeroplane must be demonstrated in flight as follows: The aeroplane speed must be reduced with the elevator control until the speed is slightly above the stalling speed, then the elevator control must be pulled back so that the rate of speed reduction will not exceed 1,9 km/h (one knot) per second until a stall is produced, as shown by an uncontrollable downward pitching motion of the aeroplane, or until the control reaches the stop. Normal use of the elevator control for recovery is allowed after the aeroplane has stalled.

(d)                            Except where made inapplicable by the special features of a particular type of aeroplane, the following apply to the measurement of loss of altitude during a stall

(1)                            The loss of altitude encountered in the stall (power on or power off) is the change in altitude (as observed on the sensitive altimeter testing installation) between the altitude at which the aeroplane pitches and the altitude at which horizontal fight is regained.

(2)                            If power or thrust is required during stall recovery the power or thrust used must be that which would be used under the normal operating procedures selected by the applicant for this manoeuvre. However, the power used to regain level flight may not be applied until flying control is regained.

(e)                            During the recovery part of the manoeuvre, it must be possible to prevent more than 15 degrees of roll Or yaw by the normal use of controls.

(f)                             Compliance with the requirements of this paragraph must be shown under the following conditions:

(1)                            Wing Flaps: Full up, full down and intermediate, if appropriate.

(2)                            Landing Gear: Retracted and extended.

(3)                            Cowl Flaps: Appropriate to configuration.

(4)                            Power: Power or thrust off, and 75% maximum continuous power or thrust.

(5)                            Trim: 1.5 V_S1 or at the minimum trim speed, whichever is higher.

(6)                            Propeller: Full increase rpm position for the power off condition.