Airworthiness Directive · Amendment 39-16227 · Eurocopter France Model AS355E, AS355F, AS355F1, AS355F2, and AS355N Helicopters
Eurocopter France Model AS355E, AS355F, AS355F1, AS355F2, and AS355N Helicopters
This AD applies to Model AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters with tail rotor drive shaft forward shaft section, part number 355A 34-1090-00, serial number 858 through 873 (inclusive) with a prefix “M,” certificated in any category. This AD does not apply to helicopters manufactured after January 1, 2005.
We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This 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 metallurgical non-conformity was discovered on a flange of the forward shaft section of the tail rotor drive shaft (drive shaft). The MCAI AD also states that stress analysis has shown that this non-conformity can significantly reduce the strength of the drive shaft and thereby its service life. The AD actions are intended to remove non-conforming drive shafts from service and prevent failure of the drive shaft and subsequent loss of control of the helicopter.
Unless already accomplished, do the following:
(1) For any drive shaft that has less than 2,400 hours time-in-service (TIS), on or before reaching 2,500 hours TIS, remove the drive shaft and replace it with an airworthy drive shaft that is not included in the applicability of this AD.
(2) For any drive shaft with 2,400 or more hours TIS, within the next 100 hours TIS, remove the drive shaft and replace it with an airworthy drive shaft that is not included in the applicability of this AD.
This AD differs from the MCAI AD as follows:
(1) We refer to the compliance time as “hours time-in-service” rather than “flying hours” and
(2) We do not require returning spares to the manufacturer.
Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, FAA, ATTN: Uday Garadi, Aviation Safety Engineer, Regulations and Policy Group, FAA, Rotorcraft Directorate, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5123, fax (817) 222-5961, has the authority to approve AMOCs for this AD, if requested, using the procedures found in 14 CFR 39.19.
