Commonwealth legislation

AD/JT9D/23 - First Stage High Pressure Turbine Airseal

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Commonwealth

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legislative instrument

Plain English Summary

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This AD requires replacement or inspection of specified first-stage high-pressure turbine airseals on Pratt & Whitney JT9D engines after cracking caused an uncontained engine failure.

engine owners/operators must arrange replacement at the next engine shop visit or inspection at next access, incurring maintenance and shop costs. It affects operators of listed JT9D variants fitted with those part numbers and requires compliance with the cited PWA service bulletin's serial-number replacement and inspection procedures.

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AD/JT9D/23 - First Stage High 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/23 First Stage High Pressure Turbine Airseal 2/91

Applicability: JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, -7R4H1, -7R4G2, engines fitted with P/N 797576, 797576P48, 793707, 793707P48 first stage turbine airseals.

Requirement: 1. Replace first stage high pressure turbine airseals as listed by serial number in PWA SB No JT9D-7R4-72-393 Rev 1, Para 2, Part A.

Inspect, first stage high pressure turbine airseals not listed by serial in PWA SB No JT9D-7R4-72-393 Rev 1, Para 2, Part A, in accordance with PWA SB No JT9D- 7R4-72-393 Rev 1, Para 2, Part B.

Note: FAA AD 90-23-19 refers.

Compliance: 1. At next engine shop visit regardless of planned maintenance action or reason for engine removal.

At next access to affected parts.

Background: This Directive reflects advice of an uncontained JT9D-7R4H1 engine failure event.

The failure was attributed to cracking of an Inconel-718 material airseal. Certain lower rated JT9D models may also be fitted with the same part number airseal. This Directive requires replacement or inspection of those airseals.

Source text

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

1 AD/JT9D/23 - First Stage High Pressure Turbine Airseal