Summary
This document proposes adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC120 helicopters. This proposal would require inspecting the tail rotor drive shaft (drive shaft) damper half-clamps (half-clamps) to determine if they are centered on the friction ring, and if not correctly positioned, centering the half-clamps on the friction ring. This proposal is prompted by the discovery of half-clamps that were incorrectly positioned. This condition, if not detected, could result in interference of the two half-clamps with the drive shaft, which could result in scoring on the drive shaft, failure of the drive shaft, and subsequent loss of control of the helicopter.