CS 22.375 Winglets

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

CS 22.375 Winglets ED Decision 2003/13/RM (a) When winglets are installed the sailplane must be designed for - (1) The side loads due to maximum sideslip angle of the winglet at VA; (2) Loads resulting from gusts acting perpendicularly to the surface of the winglet at VB and VD; (3) Mutual interaction effects of winglets and wing on aerodynamic loads; (4) Hand forces on the winglets; and (5) Loads due to wingtip landing as specified in [CS 22.501](#_DxCrossRefBm2056272129), if the winglet can touch the ground. (See [AMC 22.375(a)](#_DxCrossRefBm2056272128)) (b) In the absence of more rational analysis the loads must be computed as follows: (1) The lift at the winglets due to sideslip at VA –  where:  = maximum lift coefficient of winglet profile  = area of winglet (2) The lift at the winglets due to lateral gust at VB and VD –  where: U = lateral gust velocity at the values as described in [CS 22.333(c)](#_DxCrossRefBm2056272107)  = slope of winglet lift curve per radian  = Gust alleviation factor as defined in [CS 22.443(b)](#_DxCrossRefBm2056272121) The above-described load  need not exceed the value  (3) Hand forces of 15 daN must be assumed to act at the tip of the winglet - (i) In horizontal inboard and outboard direction parallel to the spanwise axis of the wing; and (ii) In horizontal forward and backward direction parallel to the longitudinal axis of the fuselage. In addition, the rigging loads as specified in [CS 22.591](#_DxCrossRefBm2056272127) must be applied if the winglet plane is not normal to the plane of the wing.