Summary
We propose to adopt a new airworthiness directive (AD) for the specified ECF model helicopters. This proposed AD results from a mandatory continuing airworthiness information (MCAI) AD issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community. The MCAI AD states that a dormant failure of one of the two contactors 53Ka or 53Kb can occur following certain modifications. Failure of a contactor can prevent switching from "IDLE'' mode to "FLIGHT'' mode during autorotation training making it impossible to execute a power recovery and compelling the pilot to continue the autorotation to the ground. This condition, if not corrected, can lead to an unintended touchdown to the ground during a practice autorotation at a flight-idle power setting, damage to the helicopter, and injury to the occupants.