Summary
This document proposes adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC 130 B4 helicopters, with certain twist grip assemblies installed. This proposal would require inspecting the pilot and co-pilot collective levers for proper bonding between the twist grip drive tubes and the control pinions and if debonding is present, replacing the collective levers before further flight. This proposal is prompted by one incident in which the engine remained at idle speed although the twist grip had been turned to the flight position. The actions specified by this proposed AD are intended to detect debonding between the twist grip drive tubes and the control pinions on the pilot and co-pilot collective levers to prevent loss of cockpit throttle control of the engine, and subsequent loss of control of the helicopter.