AD/BAe 146/122 Nose Landing Gear Axle Spacer (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.

British Aerospace BAe 146 Series Aeroplanes

AD/BAe 146/122 Nose Landing Gear Axle Spacer 8/2006

Applicability:

All Models BAe 146 and AVRO 146-RJ series aeroplanes.

Requirement:

Modify the nose landing gear per SB 32-174-70676A Initial issue or later EASA approved revision.

Note:  EASA AD 2006-0137 dated 23 May 2006 refers.

Compliance:

Prior to 31 May 2007.

This Airworthiness Directive becomes effective on 3 August 2006.

Background:

The BAe146 nose wheel assembly abutment ring is manufactured with an internal chamfer on one side, so when correctly installed, the wheel clamping loads are not applied to the machined radius at the root of the stub axle.  If installed incorrectly, i.e. the wrong way round, the abutment ring is displaced outboard from the correct position.  This configuration allows the wheel to be installed but the wheel nut locking bolts will not be fully engaged.  Normal operational forces can then cause the wheel nut to loosen and the wheel assembly to detach from the aircraft. In addition, the wheel clamping loads are applied to the stub axle radius, which may result in damage.

This AD requires the replacement of the existing nose wheel abutment rings with revised nose wheel abutment rings.  The ring ensures that if during a wheel change, the abutment ring is fitted the wrong way round, will prevent the nose wheel retaining nut from engaging with the axle threads.

James Coyne
Delegate of the Civil Aviation Safety Authority

20 June 2006