AD FAA-2009-1008

We are adopting a new airworthiness directive (AD) for the specified ECF helicopters. This AD results from a mandatory continuing airworthiness information (MCAI) AD issued by the European Aviation Safety Agency (EASA), the Technical Agent for the aviation authority of France. The MCAI AD states there have been two cases of failure of the screw that secures the main rotor blade (blade) deicing system distributor retaining clamp (clamp). Analysis revealed that these failures were the result of insufficient clearance of the screw and the clamp assembly causing the screw to bend and also by some screws having nonconforming material hardness. Also, some of the screw heads were missing a lock-wiring hole preventing the use of lock-wiring between the screw head and the nut. These actions are intended to detect failure of the clamp attachment screw leading to damage to the main or tail rotor blades and risk to persons on the ground by impact from a departed screw or clamp.