Commonwealth legislation

AD/AL 250/77 - Third Stage Turbine Wheel P/N 23001977

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This Act has been repealed and is no longer in force. It is retained for historical reference.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

1/10 complexity

This is a safety order (called an Airworthiness Directive) issued by the aviation safety regulator. It requires owners or operators of specific aircraft engines to remove a faulty turbine component from service.

What is affected:

Allison 250-C28 series aircraft engines fitted with a specific part: third stage turbine wheel part number 23001977

What must be done:

Remove the identified turbine wheels from the engine
Follow the manufacturer's instructions in bulletin CEB A72-2176

Why this matters: The manufacturer reported three failures of blade shrouds on this specific part. If the shroud fails during flight, it could cause serious engine damage or failure, potentially leading to an accident.

When: The requirement took effect on 2 February 1996.

This type of directive is mandatory—aircraft cannot legally fly until the defective part is replaced or removed according to the specified instructions.

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Current sections

Direct links to the current provisions in AD/AL 250/77 - Third Stage Turbine Wheel P/N 23001977.

AD/AL 250/77 - Third Stage Turbine Wheel P/N 23001977

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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 250/77 Third Stage Turbine Wheel P/N 23001977 4/96 TX

Applicability: All 250-C28 series engines fitted with a P/N 23001977 third stage turbine wheel. Requirement: Remove applicable third stage turbine wheels from service in accordance with Allison

Alert Commercial Engine Bulletin CEB A72-2176.

Compliance: Effective 2 February 1996; as detailed in the requirement document.

Background: This Directive has been issued to require certain third stage turbine wheels to be removed from service. The requirement reflects advice from the manufacturer of three P/N 23001977 third stage blade shroud failures.

Source text

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