CS 22.1545  Air-speed indicator

CAA ORS9 Decision No. 1

Each air-speed indicator must show the following markings: 

(a) For V_NE, a radial red line. If V_NE varies with altitude, there must be a means to indicate to the pilot the appropriate limitations throughout the operating altitude range. (See AMC 22.1545(a)) 

(b) for the upper caution range a yellow arc extending from V_NE to the allowable rough-air speed

V_RA; 

(c) for the normal operating range, a green arc with the lower limit at 1.1 V_S1 with maximum weight and for wing-flaps neutral (see AMC 22.335) and landing gear retracted and the upper limit at the rough-air speed V_RA; 

(d) for the wing-flap operating range, a white arc with the lower limit at the stall speed 1.1 V_S0 for maximum weight and the upper limit at the allowable wing-flaps extended speed V_FE; 

(e) a yellow marking (triangle) for the lowest approach speed (at maximum weight without water ballast) recommended by the manufacturer; 

(f) for the best rate-of-climb speed V_Y a blue radial line (for powered sailplanes only).