Commonwealth legislation

AD/JT9D/20 - Diffuser Case Strut Inserts

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

Owners, operators and maintenance organisations of specified Pratt & Whitney JT9D engines must install strut insert assembly P/N 804698-01 into the No.4 and No.7 diffuser case struts per Pratt & Whitney Service Bulletin No. 5730. Compliance is required at the next K‑flange disassembly or by 31 August 1991.

The change—paid for by operators—aims to reduce No.3 bearing compartment fire risk by restraining strut collapse and providing an alternate airflow path.

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/JT9D/20 - Diffuser Case Strut Inserts.

AD/JT9D/20 - Diffuser Case Strut Inserts

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
Pratt and Whitney Turbine Engines - JT9D Series

AD/JT9D/20 Diffuser Case Strut Inserts 8/89

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

Requirement: Install strut insert assembly Part Number 804698-01 into both the number 4 and number 7 diffuser case struts, in accordance with the Accomplishment Instructions of Pratt and Whitney Service Bulletin No. 5730.

Note: FAA AD 89-10-07 refers.

Compliance: At the next disassembly of the high compressor case from the diffuser case at "K" flange, but no later than 31 August 1991.

Background: This Directive requires compliance with P & W SB No. 5730. The Requirement reflects concern regarding reported No. 3 bearing compartment fire events in certain JT9D models. The Requirement requires installation of strut insert assembly P/N 804698-01 to provide a physical restraint to strut collapse, and to provide an airflow path separate from 15th stage air.

Source text

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

1 AD/JT9D/20 - Diffuser Case Strut Inserts