CS 25.445 Outboard fins

• ED Decision 2003/2/RM found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

CS 25.445 Outboard fins ED Decision 2003/2/RM (a) When significant, the aerodynamic influence between auxiliary aerodynamic surfaces, such as outboard fins and winglets, and their supporting aerodynamic surfaces must be taken into account for all loading conditions including pitch, roll and yaw manoeuvres, and gusts as specified in [CS 25.341(a)](#_DxCrossRefBm1709820927) acting at any orientation at right angles to the flight path. (b) To provide for unsymmetrical loading when outboard fins extend above and below the horizontal surface, the critical vertical surface loading (load per unit area) determined under [CS 25.391](#_DxCrossRefBm1709820946) must also be applied as follows: (1) 100% to the area of the vertical surfaces above (or below) the horizontal surface. (2) 80% to the area below (or above) the horizontal surface.