AD/S-Puma/78 Main Rotor Blade De-Icing System Clamps (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/78 Main Rotor Blade De-Icing System Clamps 8/2008 TX

Applicability:

EUROCOPTER AS332 C, C1, L and L1 helicopters, fitted with main rotor blade de-icing system distributor retaining clamps, P/N 225000-18454 or P/N D18454 with no batch number or letter “V” marked after the part number.

Requirement:

1.    Check the following:

-      The condition of the clamp; and

-      That the screw head does not interfere with the clamp; and

-      That there is no crack in the screw shank; and

-      That there is a lock-wiring hole in the screw head.

2.    If there is a risk of interference between the screw head and the clamp, rework the clamp.

If there is a crack in the screw shank, replace the screw.

If there is no lock-wiring hole in the screw head, produce a hole and lock the screw.

Action the above requirements in accordance with paragraph 2.B. of EUROCOPTER AS332 Emergency Alert Service Bulletin (EASB) No. 30.00.66 or later NAA approved revisions.

Note:  French DGAC AD UF-2008-008 dated 19 June 2008 refers.

Compliance:

For Requirement 1:

For parts installed in a helicopter - Within 50 flying hours but before exceeding 3 months after the effective date of this AD, unless previously accomplished.

For parts held as spares - Before installation of the parts on the helicopter.

For Requirement 2:

Before further flight after the effective date of this AD.

This Airworthiness Directive becomes effective on 25 June 2008.

Background:

This AD is issued in response to two cases of failure of the screw that secures the main rotor blade de-icing system distributor retaining clamp.  The examinations carried out on these screws have revealed that these failures were the result of assembly stress in the screw head.

In addition, in some cases, it was found that the lock-wiring hole was missing from the screw head, making it impossible to ensure additional security using lock-wiring between the screw head and the nut.

Failure of the clamp attachment screw can lead to damage to the main or tail rotor blades, and is a risk for persons on the ground.

James Coyne
Delegate of the Civil Aviation Safety Authority

20 June 2008