CS 22.151  Aerotowing

CAA ORS9 Decision No. 1

(a) If the sailplane is equipped for aerotowing, aerotows must be demonstrated at speeds up to V_T without: 

(1) excessive control forces and displacements for maintaining the wings at zero bank angle and in keeping a steady flight path; 

(2) control forces exceeding those given in CS 22.143 at speeds up to V_T; 

(3) difficulty being experienced in regaining normal towing position after the sailplane has been displaced laterally or vertically; and 

(4) any possibility, at the release, of the cable end or ends catching onto any part of the sailplane. 

(b) Tests must be carried out with crosswind components not less than 0.2 V_S0 or 15 km/h, whichever is the greater. 

(c) Compliance with the following requirements must be shown: 

(1) With the sailplane on tow in the normal towing position it must be displaced laterally relative to the towing aircraft by the use of rudder and aileron, to give an initial disturbance in bank of 30°. The pilot must then be able to regain the normal towing position without exceptional piloting skill. 

(2) The sailplane must be flown in a high towing position (approximately 15° above the flight path of the towing aircraft), and also in a low towing position (below the wake of the towing aircraft). In each case the pilot must be able to regain the normal towing position without exceptional piloting skill. 

(3) In conditions associated with the early stages of the aerotow, any pitching tendency of the sailplane must be immediately controllable, without exceptional piloting skill, under any combinations of allowable towing conditions.

(d) A suitable range of cable lengths must be determined. 

(e) Tests must be repeated for each location of the towing release mechanism and each configuration for which certification for aerotowing is requested.