Commonwealth legislation

AD/B747/273 - Thrust Reverser Flow Restrictor

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This Airworthiness Directive requires operators of Boeing 747-400 aeroplanes (line positions up to 1022) with Pratt & Whitney PW4000 engines to replace existing thrust reverser flow restrictors with one-way (check) valve restrictors, following Boeing Alert Service Bulletin 747-78A2128. CASA requires the work prior to further flight to address actuator piston seal leakage that could allow an uncommanded in‑flight thrust reverser deployment.

JSON API

Deep dive

Want the full deep dive?

Zoe can write the in-depth analysis on top of the summary above: how it works, who it affects and what each part actually does.

Current sections

Direct links to the current provisions in AD/B747/273 - Thrust Reverser Flow Restrictor.

AIRWORTHINESS DIRECTIVE

View image in the official source

View image in the official source
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 CAR 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 747 Series Aeroplanes

AD/B747/273 Thrust Reverser Flow Restric

AD/B747/273 Thrust Reverser Flow Restrictor 7/2002

Applicability: Model 747-400 series aeroplanes up to and including line position 1022, powered by Pratt and Whitney PW 4000 series engines.

Requirement: Replace the thrust reverser flow restrictor devices with one-way (check) valve restrictors in accordance with Boeing Alert Service Bulletin 747-78A2128, dated 10 March, 1994; or Revision 1, dated 26 May, 1994.

Note: FAA AD 94-20-11 Amdt 39-9040 refers.

Compliance: Prior to further flight.

This Amendment becomes effective on 11 July 2002.

Background: The manufacturer has reported several instances of thrust reverser sleeve actuator piston seal leakage during overhaul. Testing done by Boeing suggests that if there is sufficient seal leakage in two of the three actuators on a single sleeve, then a sleeve deployment could occur. This Directive introduces a modification to prevent the possibility of an uncommanded in- flight deployment of a thrust reverser.

Signature of James Coyne, Delegate of the Civil Aviation Safety Authority.

James Coyne

Delegate of the Civil Aviation Safety Authority 28 May 2002

View image in the official source

Source text

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

AIRWORTHINESS DIRECTIVE AIRWORTHINESS DIRECTIVE

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 39.1 (1) of CAR 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 747 Series Aeroplanes

AD/B747/273 Thrust Reverser Flow Restric AD/B747/273 Thrust Reverser Flow Restrictor 7/2002

AD/B747/273 Thrust Reverser Flow Restrictor 7/2002

Applicability: Model 747-400 series aeroplanes up to and including line position 1022, powered by Pratt and Whitney PW 4000 series engines.

Note: FAA AD 94-20-11 Amdt 39-9040 refers.

Compliance: Prior to further flight.

This Amendment becomes effective on 11 July 2002.

James Coyne

Delegate of the Civil Aviation Safety Authority 28 May 2002