Commonwealth legislation

AD/JT9D/18 - Low Pressure Turbine Airseal

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Commonwealth

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legislative instrument

Plain English Summary

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This Airworthiness Directive requires inspection and/or modification of the sixth-stage low-pressure turbine (LPT) airseals on specified Pratt & Whitney JT9D engine models, by adopting the actions in FAA AD 88-24-05. It applies to JT9D-3A, -7, -7A, -7AH, -7H, -7F, -7J and -20 engines.

The Directive aims to prevent airseal rub that could rupture seals and cause uncontained engine failure. Engine operators must schedule inspections or modifications within the stated time limits (next 500 cycles or at next LPT disassembly); operators pay the maintenance cost and decide timing within those bounds. Compliance can be achieved by installing parts per PWA SB 4835 rev 4.

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Current sections

Direct links to the current provisions in AD/JT9D/18 - Low Pressure Turbine Airseal.

AD/JT9D/18 - Low Pressure Turbine Airseal

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Pratt and Whitney Turbine Engines - JT9D Series

AD/JT9D/18 Low Pressure Turbine Airseal 3/89

Applicability: JT9D-3A,-7,-7A,-7AH, -7H, -7F, -7J, -20 engines.

Requirement: Action in accordance with FAA AD 88-24-05 amdt 39-6018, items (a)(1)(2), (b), (c).

Note: Subject airseals modified in accordance with the requirements of PWA SB 4835 revision 4 are considered to be in compliance with the requirements of this Directive.

Compliance: 1. Airseals conforming to FAA AD 88-24-05 amdt 39-6018 item (a)(1) - Within the next 500 cycles in service after 1 March 1989.

2. Airseals conforming to FAA AD 88-24-05 amdt 39-6018 item (a)(2) \- At next disassembly of the low pressure turbine module.

3. FAA AD 88-24-05 amdt 39-6018 items (b), (c) \- At next disassembly of the low pressure turbine module.

Background: This Directive has been issued to require modification and/or inspection of certain sixth stage low pressure turbine airseals. The Requirement follows advice that airseal rub could result in seal rupture and uncontained engine failure.

Source text

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

1 AD/JT9D/18 - Low Pressure Turbine Airseal