AD/A320/197 Landing Gear Gravity Free Fall Control Mechanism (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/A320/197 Landing Gear Gravity Free
Fall Control Mechanism 2/2007

Applicability:

Airbus Industrie A319 series aircraft manufacturer serial numbers (MSN) 578 through 625 inclusive; and

A321-100 series aircraft MSN 385 through 620 inclusive.

Requirement:

Carry out the following actions in accordance with Airbus Industrie All-Operator-Telex (AOT) 32-15 dated 1 July 1997 or later DGAC approved revisions.

i)     Adjust the landing gear unlocked-stop screw of the free fall control mechanism at 3 turns.

ii)    Replace the 2 shear pins in the reduction gear box as well as the 2 shear pins in the pulley assembly.

iii)    Inspect the cut-out valve.

Replace it if damaged and with aircraft on jacks, perform a functional test of the normal extension/retraction of the landing gear, and a functional test of the free fall extension system.

iv)   Perform an operational test of the gear uplock and door uplock mechanical control (aircraft on wheels).

Note:  French DGAC AD 97-177-101(B) dated 13 Aug 1997 refers.

Compliance:

Unless already accomplished, within 50 flight hours or one month after the effective date of this AD, whichever occurs earlier.

This Airworthiness Directive becomes effective on 15 February 2007.

Background:

An incorrect rigging of the landing gear free fall control mechanism became evident in production.

In case of landing gear extension by gravity, this incorrect rigging could damage the cut-out valve and the four shear pins installed on the landing gear free fall control mechanism and could result in non-extension of one or more landing gears.

James Coyne
Delegate of the Civil Aviation Safety Authority

5 January 2007