AD/F100/64 Main Landing Gear Main Fitting 3 (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.

Fokker F100 (F28 Mk 100) Series Aeroplanes

AD/F100/64 Main Landing Gear Main Fitting - 3 6/2005

Applicability:

Model F.28 Mk 0100 and Mk 0070 aircraft, all serial numbers, if equipped with Messier-Dowty (formerly Dowty Aerospace Gloucester) MLG units.

Requirement:

Inspect and, as necessary, repair both MLG Main Fittings in accordance with the Accomplishment Instructions of Messier-Dowty Service Bulletin (SB) F100-32-106 dated 18 February 2005, or later UK CAA approved revision.

Whenever cracks are found, determine whether (and for how many) flights may be continued, prior to repair or replacement, in accordance with the crack size and location thresholds as specified in Fokker Services SB F100-32-141 dated 18 February 2005, or later CAA-NL approved revision.

Irrespective of the inspection results, within 7 days after accomplishment of the inspection, report all findings to Fokker Services.

Note:  CAA-NL AD NL-2005-002 refers.

Compliance:

Within 2,000 flight cycles since the last inspection in accordance with Messier-Dowty SB F100-32-104 Revision 2, and Fokker Services SB F100-32-137 (as required by  AD/F100/55 Amdt 1; CAA-NL AD 2002-115/2 refers), or within 3 months after 9 June 2005, whichever occurs later.

This Airworthiness Directive becomes effective on 9 June 2005.

Background:

Recently, an empty Fokker 100, which was being moved for maintenance, suffered a failure of the left hand MLG Main Fitting.  The MLG Main Fitting broke into two pieces, whereby the lower part including the Sliding Member, Wheels and Brakes separated from the upper Main Fitting part.  Preliminary findings indicate failure due to a fatigue crack in the Main Fitting.  AD/F100/55 Amdt 1 (CAA-NL AD
2002-115/2) still applies, and although this Directive requires a second one-time inspection for cracks, the CAA-NL still consider this to be an interim action.

David Villiers
Delegate of the Civil Aviation Safety Authority

29 April 2005