AD/F100/53 Amdt 2 Main Landing Gear Sliding Member (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/F100/53 Amdt 1 and issues the following 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/F100/53 Amdt 2 Main Landing Gear Sliding Member 1/2006

Applicability:

All Model F.28 Mk. 0100 and Mk. 070 aircraft, equipped with Dowty or Messier-Dowty Main Landing Gear Part number 201072011, 201072012, 201072013, 201072014, 201072015, or 201072016, which include sliding member part numbers 201072301 or 201072305.

Requirement:

1.    For aircraft that are not compliant with the requirements of Netherlands CAA ADs 2002-060 and/or 2004-046 (AD/F100/53 Amdt 1), inspect the Main Landing Gear (MLG) sliding members for cracks in accordance with the Accomplishment Instructions of Messier-Dowty Service Bulletin (SB)
F100-32-110 original issue, or later UK CAA approved revision;

2.    For all other aircraft, inspect the MLG sliding members for cracks in accordance with the Accomplishment Instructions of Messier-Dowty SB F100-32-110 original issue, or later UK CAA approved revision.

Note 1:  Fokker Service Bulletin SBF100-32-144 pertains to this subject.

3.    After compliance with either Requirement 1 or 2 of this Directive, repeat the inspection of the MLG sliding members in accordance with the Accomplishment Instructions of Messier-Dowty SB F100-32-110 original issue, or later UK CAA approved revision.

4.    Each time after a High Drag Load landing, magnetically inspect the MLG sliding members for cracks in accordance with Fokker 70/100 Aircraft Maintenance Manual (AMM), Task 05-51-01-220-826-A.

5.    Each time the aircraft brakes have been applied during backward movement of the aircraft, inspect the MLG sliding members in accordance with Fokker 70/100 AMM, Task 05-51-01-220-876-A.

Note 2:  Fokker Manual Change Notification - Maintenance Documentation (MCNM) F100-083 Rev.1 contains the procedures related to Requirements 4 and 5.

When any crack indication is found, before further flight, replace the affected MLG sliding member with a serviceable part in accordance with Fokker 70/100 AMM, Chapter 32-11-08.

Whatever the results of the inspections as required by this Directive, report all findings to the Type Certificate Holder of the aircraft and the MLG manufacturer.

Note 3:  CAA-NL AD NL-2005-012 refers.

Compliance:

1.    Before the next flight after 19 January 2006.

2.    Within 2,000 flight cycles after the accomplishment of Messier-Dowty SB F100-32-103 (Ref. Fokker SBF100-32-133) or Messier-Dowty SB F100-32-105 (Ref. Fokker SBF100-32-139), or within the next 4 calendar months, whichever occurs later after 19 January 2006.

3.    At intervals not to exceed 2,000 flight cycles.

4.    Before further flight.

5.    Within the next 50 flight cycles thereafter.

This Amendment becomes effective on 19 January 2006.

Background:

A failure of the sliding member of a main landing gear occurred during a terminal departure push-back, following inadvertent brake application.  Investigation of the fractured surface revealed overload, initiated by a fatigue crack.  Inspection of other aircraft revealed cracking in the same area.

Amendment 1 required a second one-time inspection in response to the results of the previous inspection required by this Directive; in order to establish fleet safety.

Amendment 2 is issued in response to a new CAA-NL AD, which was prompted by the results of further inspections that have identified the need for a repetitive inspection on the MLG Sliding Member to establish fleet safety.  For this reason, this Directive requires repetitive magnetic particle inspections of all aircraft equipped with Dowty/Messier-Dowty Main Landing Gear units and replacement of cracked parts.

David Villiers
Delegate of the Civil Aviation Safety Authority

28 November 2005