AD/B737/271 Aileron Control Transfer 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.

Boeing 737 Series Aeroplanes

AD/B737/271 Aileron Control Transfer Mechanism 1/2006

Applicability:

Model 737-100 and -200 series aeroplanes; as listed in Boeing 737 Service Bulletin 27-1033 dated 13 February 1970.

Requirement:

1.    Unless previously accomplished:

Replace the aileron control transfer mechanism, part number (P/N) 65-54200-4 or -5, with a new modified mechanism in accordance with Procedure 1 of the Accomplishment Instructions of Boeing 737 Service Bulletin 27-1033; Or

Rework the existing aileron control transfer mechanism, P/N 65-54200-4 or -5, in accordance with Procedure II of the Accomplishment Instructions of Boeing 737 Service Bulletin 27-1033.

2.    Do not install an aileron control transfer mechanism having P/N 65-54200-4 or -5 unless it has been reworked in accordance with Procedure II of the Accomplishment Instructions of Boeing 737 Service Bulletin 27-1033.

Note:  FAA AD 97-01-10 Amendment 39-9881 refers.

Compliance:

1.    Within 30 days after the effective date of this AD.

2.    After the effective date of this AD.

This Airworthiness Directive becomes effective on 19 January 2006.

Background:

This AD is issued to prevent an unexpected, significant control upset due to mechanical interference within the lateral control system transfer mechanism.  This could result in reduced travel of a control wheel and above normal control wheel forces during a jam override.

James Coyne
Delegate of the Civil Aviation Safety Authority

29 November 2005