Summary
This document proposes adopting a new airworthiness directive (AD) for the specified Eurocopter France (ECF) model helicopters. The AD would require cleaning the auxiliary system unit (ASU) board. Also, the AD would require modifying the wiring and wiring harness. If a temporary modification is done, the AD would require inserting a placard regarding on-ground operation of the emergency landing gear pump (pump). Also, the AD would revise the Limitations section of the Rotorcraft Flight Manual (RFM) to limit the operation of the pump. Permanently modifying the wiring and wiring harness and removing the placard and limitations from the RFM would be terminating action. This proposal is prompted by the report of an emergency landing with the landing gear retracted. The landing gear failed to extend in normal and emergency extension modes following failure of the ASU board 10 Alpha 2. The actions specified by the proposed AD are intended to prevent an electrical short circuit, failure of landing gear to extend, and a landing gear-up emergency landing.