Commonwealth legislation

AD/B747/299 - Yaw Damper Actuator

RepealedCTH

This Act has been repealed and is no longer in force. It is retained for historical reference.

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This is a safety order for airlines operating specific Boeing 747 models (the 747-400, 747-400D, and 747-400F). It requires an ultrasonic inspection (using high-frequency sound waves to detect internal cracks) of the "yaw damper" components in the upper and lower rudder power control modules.

What the problem is: Cracks in these parts could cause an "uncommanded left rudder hardover"—meaning the rudder could suddenly swing hard to the left without the pilot touching the controls. This could make the aircraft harder to control during landing and potentially cause it to run off the runway.

What must be done: Airlines must inspect these components following the technical instructions in an American aviation safety order (FAA AD 2003-23-01). The directive became effective on 22 January 2004.

Who is affected: Operators of Boeing 747-400 series aircraft listed in Boeing Alert Service Bulletin 747-27A2397.

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Current sections

Direct links to the current provisions in AD/B747/299 - Yaw Damper Actuator.

AIRWORTHINESS DIRECTIVE

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For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (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.

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Boeing 747 Series Aeroplanes

AD/B747/299 Yaw Damper Actuator 1/2004

Applicability: Model 747-400, -400D, and -400F series aircraft, as listed in Boeing Alert Service Bulletin 747-27A2397, dated 24 July 2003.

Requirement: Action in accordance with the technical requirements of FAA AD 2003-23-01 Amdt 39-13364.

Compliance: As specified in the Requirement document, with a revised effective date of 22 January 2004.

This Airworthiness Directive becomes effective on 22 January 2004.

Background: This Directive requires an ultrasonic inspection of the yaw damper portion of the upper and lower rudder power control modules main manifold for cracking. Such cracking, unless detected and corrected, could result in an uncommanded left rudder hardover, consequent increased pilot workload, and possible runway departure upon landing.

Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.

David Villiers

Delegate of the Civil Aviation Safety Authority 5 December 2003

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Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

AIRWORTHINESS DIRECTIVE AIRWORTHINESS DIRECTIVE

AIRWORTHINESS DIRECTIVE

Boeing 747 Series Aeroplanes