AD/PC-12/47 Main Landing Gear Special Bolt Assembly (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.

Pilatus PC-12 Series Aeroplanes

AD/PC-12/47 Main Landing Gear Special Bolt Assembly 9/2005

Applicability:

Model PC-12 and PC-12/45 aircraft, manufacturer serial numbers MSN 101 through MSN 620; equipped with the following main landing gear (MLG) assemblies and special bolts:

MLG assemblies part number (P/N) 532.10.12.049 and P/N 532.10.12.050 delivered before 31 December 2004.

Special bolts P/N 532.10.12.077 delivered before 31 December 2004.

Requirement:

In accordance with Pilatus PC-12 Service Bulletin No. 32-018; perform an inspection of the left and right MLG assemblies to determine if there are bolts with P/N 532.10.12.077 installed that do not have white primed and painted heads.

If the inspection reveals any P/N 532.10.12.077 bolts without white primed and painted heads, before further flight, replace the affected bolts with new P/N 532.10.12.077F bolts in all MLG assemblies.

Note:  Switzerland FOCA AD HB-2005-288 refers.

Compliance:

Within 100 hours time in service or 3 calendar months after 1 September 2005, whichever occurs first.

This Airworthiness Directive becomes effective on 1 September 2005.

Background:

The separation of a part number 532.10.12.077 bolt head occurred in the main landing gear assembly of a specified manufacturer.  Investigation revealed the cause as corrosion of the bolt, which occurred because the bolt head was not primed and painted.  This condition can decrease the specified fatigue life and could lead to main landing gear collapse during operation with consequent loss of aircraft control.

David Villiers
Delegate of the Civil Aviation Safety Authority

20 July 2005