Commonwealth legislation

AD/AL 250/62 Amdt 1 - Fourth Stage Nozzle Assembly - Replacement

RepealedCTH

This Act has been repealed and is no longer in force. It is retained for historical reference.

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

4/10 complexity

This mandatory CASA Airworthiness Directive requires owners/operators of Allison 250‑C30 series engines (including C30P/C30S variants with listed serials, or engines fitted with 4th‑stage nozzle P/N 23008470 or 6898694) to replace or rework the 4th‑stage nozzle assembly per Allison CEB‑A‑72‑3122 Rev 1. It prevents 3rd‑stage turbine rubbing that can damage the engine and cause in‑flight failure. Compliance is due by the next overhaul after 31 Dec 1984 or at the next power‑turbine disassembly.

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/AL 250/62 Amdt 1 - Fourth Stage Nozzle Assembly - Replacement.

AD/AL 250/62 Amdt 1 - Fourth Stage Nozzle Assembly - Replacement

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
Allison Turbine Engines - 250 Series

AD/AL 250/62

Amdt 1

Fourth Stage Nozzle Assembly - Replacement 7/85

Applicability: All model 250-C30, C30 (Hughes), C30P and C30S with serial numbers as listed in the requirement document and, turbine assemblies incorporating P/N 23008470 or 6898694 fourth stage nozzle assy.

Requirement: Allison 250-C30 series CEB-A-72-3122 Rev.1.

Compliance: Prior to completion of the next overhaul after 31 December 1984 or on the next occasion the power turbine is disassembled.

Background: This directive is amended to reflect the manufacturers CEB-72-3122 Rev 1 which revises affectivity, changes rework dimensions, and adds the latest nozzle part number and references.

There have been instances of rubbing contact between the third stage turbine wheel and the inner band of the fourth stage nozzle.

Source text

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

1 AD/AL 250/62 Amdt 1 - Fourth Stage Nozzle Assembly - Replacement