Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede an existing airworthiness directive (AD) that applies to all Turbomeca S.A. Arrius Models 2B, 2B1, and 2F turboshaft engines. The existing AD currently requires replacement of injector manifolds and borescope-inspection of the flame tube and the high-pressure (HP) turbine area for possible damage. Since we issued that AD, we received a report that the corrective actions of the existing AD were insufficient to eliminate the unsafe condition. This proposed AD would require, depending on the engine model, repetitive replacements of fuel injection manifolds and the privilege injector, or, repetitive replacements of the privilege injector. We are proposing this AD to prevent an uncommanded in-flight shutdown of Arrius 2B1 and 2F turboshaft engines and damage to the helicopter.