Summary
This document proposes superseding an existing airworthiness directive (AD) for the specified Eurocopter France (ECF) model helicopters. That AD currently requires a onetime inspection for end play in the pitch control rod assembly double bearing (bearing) using the tail rotor (T/R) hub control plate, and before further flight, replacing the bearing if end play is present. This action would require checking the T/R gearbox (TGB) oil level before the first flight of the day and maintaining the oil at the maximum level for certain helicopters. Also, this action would require, during each required inspection or at certain specified intervals, ensuring the oil is at the maximum level for certain other model helicopters. Also, this action would require inspecting the magnetic plug for chips at specified intervals. Depending on the quantity of chips found, this action would require either replacing the TGB before further flight or further inspecting for axial play in the T/R hub pitch change control spider (spider). If axial play is found in the spider, before further flight, this AD would require replacing the bearing. This proposal is prompted by the finding that metal chips were not detected on the magnetic plug due to insufficient oil flow because the oil in the TGB was being maintained at the minimum level. The actions specified by the proposed AD are intended to detect metal chips on the magnetic plug, to prevent damage to the bearing resulting in end play, loss of T/R pitch control, and subsequent loss of control of the helicopter.