Eurocopter AS 350/355/EC130 - Astar/Twinstar/Ecureuil
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Situational Awareness; Confusion
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Chart Or Publication; Human Factors; Manuals; Aircraft
During the build-up of the Aft Flex coupling on the Main Rotor Drive System (MRDS); there was some question on what the correct orientation of the beveled washer. Reference Aerospatiale AS350 Eurocopter Aircraft Maintenance Manual (AMM) 63-11-00; Paragraph 4-2. The Maintenance note states: 'NOTE: The face of the washers that makes a curve must point to the flexible coupling'. The curved face of the washer is easily mistaken for the flat side. Previous revisions of the AMM showed a very clear illustration that helped avoid this confusion. It would help if it was reinstated to the newer manuals.
A Maintenance Supervisor reports their new Aerospatiale/Eurocopter AS350 Aircraft Maintenance Manuals (AMM) do not have a clear Maintenance illustration reference to help determine the correct orientation of a beveled washer during build-up of the Aft Flex coupling; compared to the old manuals for the Main Rotor Drive System (MRDS).