CS 22.581 Aerotowing

• ED Decision 2003/13/RM found in: Sailplane Rule Book - Part-SAO Part-SFCL CS-22 (Nov 2022)

CS 22.581 Aerotowing ED Decision 2003/13/RM (a) The sailplane must be initially assumed to be in stabilized level flight at speed VT with a cable load acting at the launching hook in the following directions: (1) horizontally forwards; (2) in plane of symmetry forwards and upwards at an angle of 20° with the horizontal; (3) in plane of symmetry forwards and downwards at an angle of 40° with the horizontal; and (4) horizontally forwards and sidewards at an angle of 30° with the plane of symmetry. (b) With the sailplane initially assumed to be subjected to the same conditions as specified in [CS 22.581(a)](#_DxCrossRefBm2056272177), the cable load due to surging suddenly increases to Qnom, assuming the use of a textile rope. (1) The resulting cable load increment must be balanced by linear and rotational inertia forces. These additional loads must be superimposed on those arising from the conditions of [CS 22.581(a)](#_DxCrossRefBm2056272177). (2) Qnom is the rated ultimate strength of the towing cable (or weak link if employed). For the purpose of these requirements it must be assumed to be not less than 1.3 times the sailplane maximum weight and not less than 500 daN.