The FAA is adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC225 helicopters with certain epicyclic modules installed. This AD requires inspecting the epicyclic module for the presence of a through-hole upstream of the magnetic plug.
This AD is prompted by a report of a missing through-hole between the integrated collector and the magnetic plug, which would prevent the flow of chips from the integrated collector to the magnetic plug. This could result in the chip-detector system failing to detect deterioration of the main rotor mast lift bearing (lift bearing).
These actions are intended to detect a missing through-hole and prevent lift bearing failure and subsequent loss of control of the helicopter.