AD/A320/179 Main Landing Gear Axle Nut (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.

Airbus Industrie A319, A320 and A321 Series Aeroplanes

AD/A320/179 Main Landing Gear - Axle Nut 9/2005 TX

Applicability:

Airbus A320 aircraft, Manufacturers Serial Numbers (MSN) 2275 to 2486 inclusive except MSN 2441, 2447, 2449, 2451, 2453, 2455, 2459, 2475, 2479 and 2484.

Requirement:

1.    Inspect the locking bolts, nuts, washers and pins of each Main Landing Gear (MLG) wheel and apply corrective actions, if necessary, in accordance with Airbus All Operators Telex (AOT) A320-32A1303 dated 04 July 2005 or later approved revisions.

2.    Report the results of this inspection to the aircraft manufacturer.

Note:  DGAC Emergency Airworthiness Directive No. UF-2005-120 as approved under EASA reference no. 2005-6066 dated 08 July 2005 refers.

Compliance:

1.    Unless already accomplished, within 500 flight cycles from the effective date of this Directive.

2.    With in 7 days of inspection per Requirement 1 of this Airworthiness Directive.

This Airworthiness Directive becomes effective on 12 July 2005.

Background:

An A320 operator has reported a brake, wheel position 3, dragging and the relevant brake temperature rising during taxi out.  The inspection of the wheel position 3 showed that the axle nut had separated from the axle.

The investigation showed that the most probable cause is that locking bolts securing the axle nut were not installed on aircraft whilst on the final production assembly line.  The absence of locking bolts, associated nuts, washers and cotter pins can allow the loosening of axle nut and subsequently separation of the wheel from the axle with consequential damage to the gear.

The actions specified by this AD address the unsafe condition identified above through inspection for locking bolts, associated nuts, washers and cotter pins installation.

James Coyne
Delegate of the Civil Aviation Safety Authority

11 July 2005