Commonwealth legislation

AD/ALF/12 - Introduction of Improved Third Stage Turbine Rotor Assembly

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

The directive mandates that operators/owners of AlliedSignal (Lycoming) ALF502 L and R engines fitted with certain third‑stage rotor assemblies must install an “improved” or reworked third‑stage turbine rotor per Textron‑Lycoming service bulletins, to address reported cracking in blade retention slots.

Issued and enforced by CASA (effective 1 Jan 1994) the rule prescribes the engineering method via the manufacturer’s bulletins and places compliance scheduling and costs on the affected engine operators.

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Current sections

Direct links to the current provisions in AD/ALF/12 - Introduction of Improved Third Stage Turbine Rotor Assembly.

AD/ALF/12 - Introduction of Improved Third Stage Turbine Rotor Assembly

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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AlliedSignal (Lycoming) Turbine Engines - ALF502 and LF507 Series

AD/ALF/12 Introduction of Improved Third Stage

Turbine Rotor Assembly

13/93

Applicability: All ALF502 L and R series engines with third stage rotor assemblies listed in the Requirement Documents.

Requirement: Install improved or reworked third stage turbine rotor assemblies in accordance with Textron-Lycoming Service Bulletins ALF502L 72-270 or ALF502R 72-270 as applicable.

Note: FAA AD 93-14-13 also refers.

Compliance: Effective 1 January 1994. As detailed in the Requirement Documents.

Background: This Directive is issued to address reports of cracking in the third stage turbine disc blade retention slots and requires either fitment of an improved disc or rework of existing discs to provide a revised blade retention slot profile.

Source text

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

1 AD/ALF/12 - Introduction of Improved Third Stage Turbine Rotor Assembly