CS 22.331  Symmetrical flight conditions

CAA ORS9 Decision No. 1

(a) The appropriate balancing horizontal tail load must be accounted for in a rational or conservative manner when determining the wing loads and linear inertia loads corresponding to any of the symmetrical flight conditions specified in CS 22.333 through 22.345.

(b) The incremental horizontal tail loads due to manoeuvring and gusts must be reacted by the angular inertia of the sailplane in a rational or conservative manner. 

(c) In computing the loads arising in the prescribed conditions, the angle of attack is assumed to be changed suddenly without loss of flight speed until the prescribed load factor is attained. Angular accelerations may be disregarded. 

(d) Aerodynamic data required for the establishment of the loading conditions must be verified by tests, calculations or by conservative estimation. 

(1) In the absence of better information the maximum negative lift coefficient in the normal configuration may be taken as –0.8 

(2) If the pitching moment coefficient C_mo is less than ±0.025, a coefficient of at least –0.025 must be used for the wing and horizontal tail.