Commonwealth legislation

AD/JT9D/35 - HPT Disc Inspection

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

5/10 complexity

This Airworthiness Directive requires owners/operators of Pratt & Whitney JT9D‑7R4 engines to perform initial and recurring inspections of the high‑pressure turbine (HPT) stage‑1 disc firtrees, replace certain air seals, and complete a terminating action as specified in FAA AD 2001‑17‑30. It takes effect 18 April 2002.

The measure responds to reported contact between the HPT disc firtrees and an adjoining air seal that can cause disc failure and risk an uncontained engine failure.

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Current sections

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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.

Pratt and Whitney Turbine Engines - JT9D Series

AD/JT9D/35 HPT Disc Inspection 4/2002

Applicability: Pratt and Whitney JT9D-7R4 series engines.

Requirement: Initial action and repeat inspection in accordance with the requirements of FAA AD 2001-17-30.

Compliance: As detailed in the requirement document with a revised effective date of 18 April 2002.

This Airworthiness Directive becomes effective on 18 April 2002.

Background: HPT stage 1 disc firtrees are found to fail due to interaction with the adjoining air seal. This Directive requires replacement of some seals, and introduces an initial and repetitive inspection along with a terminating action to address a potential uncontained engine failure mode.

Signature of Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority

Eugene Paul Holzapfel

Delegate of the Civil Aviation Safety Authority 10 March 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.

Pratt and Whitney Turbine Engines - JT9D Series