CS 22.1323  Air-speed indicating system

CAA ORS9 Decision No. 1

(a) The air-speed indicating system must be calibrated to indicate true air-speed at sea-level in standard atmosphere with a maximum pitot-static error not exceeding ± 8 km/h or ± 5% whichever is greater, throughout the following speed range 1.2 V_S to V_NE, and with wing-flaps neutral and air brakes closed.

(b) Calibration must be made in flight. 

(c) The air-speed indicating system must be suitable for speeds between V_S0 and at least 1.05 times V_NE.