AD/F100/76 Main Landing Gear Outboard Door (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/F100/76 Main Landing Gear Outboard Door 3/2006

Applicability:

Model F28 Mark 0070 and Mark 0100 aircraft, all serial numbers, if equipped with Carbon-Fibre Reinforced Plastic (CFRP) Main Landing Gear Doors, Part Number D13312-401 through -410, including units held as spares.

Requirement:

1.    Inspect the main landing gear (MLG) outboard doors for cracks in the CFRP outer skin at the countersunk heads of the operating rod bracket attachment bolts in accordance with Part 1 of Section 3, Accomplishment Instructions, of Fokker Service Bulletin SBF100-52-080, dated 12 December 2005, or later CAA-NL approved revision.

2.    If cracks are found, modify the MLG outboard door operating rod bracket attachment by the installation of reinforcement plates in accordance with Part 2 of Section 3, Accomplishment Instructions, of Fokker SBF100-52-080, or later CAA-NL approved revision.

3.    If no cracks are found, modify the MLG outboard door operating rod bracket attachment by the installation of reinforcement plates in accordance with Part 2 of Section 3, Accomplishment Instructions, of Fokker SBF100-52-080, or later CAA-NL approved revision.

4.    For CFRP MLG Outboard Door units held as spares, part number D13312-401 through -410, all serial numbers, modify the MLG outboard door operating rod bracket attachment by the installation of reinforcement plates in accordance with Section 3, Accomplishment Instructions, of Fokker Component Service Bulletin D13312-52-09, dated 12 December 2005, or later CAA-NL approved revision.

Note:  CAA-NL AD NL-2006-001 refers.

Compliance:

1.    Within 9 months after 16 March 2006.

2.    Before further flight.

3.    Within 12 months after 16 March 2006.

4.    Within 12 months after 16 March 2006.

This Airworthiness Directive becomes effective on 16 March 2006.

Background: The manufacturer received a recent report of a Fokker 100 MLG outboard door rod bracket in-flight detachment.  Investigation revealed that the operating rod between the MLG outboard door and the MLG fitting was broken and the rod’s bracket was detached from the outboard door.  The affected parts subsequently became jammed between the MLG and the outboard door hinge.  As a result, two of three adjacent hydraulic lines were damaged.  Several more operators have reported finding partly detached operating rod brackets.  This condition, if not corrected, could result in further events of MLG operating rod brackets breaking loose from the CFRP MLG outboard door, including the possibility of blocking the proper functioning of the main landing gear.

David Villiers
Delegate of the Civil Aviation Safety Authority

2 February 2006