Ad/S-Puma/79 - Main Rotor - Main Rotor Head (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Eurocopter AS 332 (Super Puma) Series Helicopters

AD/S-PUMA/79 Main Rotor - Main Rotor Head 11/2008 DM

Applicability:

Eurocopter AS 332 C, AS 332 C1, AS 332 L and AS 332 L1 helicopters, if a main rotor head (MRH) Part Number (P/N) 332A31-0001-05 or P/N 332A31-0001-06 is installed, having serial number (s/n) M172, M216, M261, M308, M547, M677, M811 or M936, and having logged less than 275 flight hours since its last overhaul or repair.

Note:  The additional s/n MRH units identified in Eurocopter Alert service Bulletin (ASB) AS 332 N° 62.00.73 have already been checked as required by this AD.

Requirement:

Action in accordance with the technical requirements of EASA AD 2008-0172-E.

Note:  Eurocopter Alert service bulletin AS 332 ASB 62.00.73 or later approved document refers.

Compliance:

As specified in the requirement document with an amended effective date of 10 September 2008.

This Airworthiness Directive becomes effective on 10 September 2008.

Background:

Eurocopter has recently received a report of deterioration of the swash-plate assembly upper bearing on a MRH, installed on an AS 332 L1 helicopter, after having logged only 72 flight hours since last overhaul.  The occurrence report states an onset of vibrations which compelled the pilot to land as soon as practicable.  These vibrations were found to be due to premature deterioration of the upper bearing of the swash-plates.  The degradation of this bearing generates a load increase on the scissors links.  This condition, if not corrected, could lead to the failure of the scissors links and consequently loss of control of the helicopter.

David Villiers
Delegate of the Civil Aviation Safety Authority

10 September 2008