AMC 25.109(a) and (b) Accelerate-stop distance

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

AMC 25.109(a) and (b) Accelerate-stop distance ED Decision 2003/2/RM *Propeller pitch position*. For the one-engine-inoperative accelerate-stop distance, the critical engine’s propeller should be in the position it would normally assume when an engine fails and the power levers are closed. For dry runway one-engine-inoperative accelerate-stop distances, the high drag ground idle position of the operating engines’ propellers (defined by a pitch setting that results in not less than zero total thrust, i.e. propeller plus jet thrust, at zero airspeed) may be used provided adequate directional control is available on a wet runway and the related operational procedures comply with [CS 25.109(f) and (h)](#_DxCrossRefBm1709820677). Wet runway controllability may either be demonstrated by using the guidance available in [AMC 25.109(f)](#_DxCrossRefBm1709820757) at the appropriate power level, or adequate control can be assumed to be available at ground idle power if reverse thrust credit is approved for determining the wet runway accelerate-stop distances. For the all-engines-operating accelerate-stop distances on a dry runway, the high drag ground idle propeller position may be used for all engines (subject to CS 25.109(f) and (h)). For criteria relating to reverse thrust credit for wet runway accelerate-stop distances, see AMC 25.109(f).