AMC 25.905(d) Release of Propeller Debris

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

AMC 25.905(d) Release of Propeller Debris ED Decision 2003/2/RM 1 *Propeller Installation*. Design features of the propeller installation, including its control system, which are considered to influence the occurrence of propeller debris release and/or mode of such a failure should be taken into account when assessing the aeroplane against [CS 25.905(d)](#_DxCrossRefBm1709821388). 2 *Aeroplane Design Conditions* 2.1 *Impact Damage Zone*. All practical precautions should be taken in the aeroplane design to minimise, on the basis of good engineering judgement, the risk of Catastrophic Effects due to the release of part of, or a complete propeller blade. These precautions should be taken within an impact zone defined by the region between the surfaces generated by lines passing through the centre of the propeller hub making angles of at least five degrees forward and aft of the plane of rotation of each propeller. Within this zone at least the following should be considered. a. The vulnerability of critical components and systems (e.g. location, duplication, separation, protection); and b. The fire risk in the event of flammable fluid release in association with potential ignition sources (e.g. location, protection, shut-off means). 2.2 *Other Considerations*. Consideration should be given to the effects on the aeroplane resulting from – a. The likely out of balance forces due to the release of part of, or a complete propeller blade; and b. Loss of a complete propeller.