AD/ALF/11 Amdt 1 - Third Stage Compressor Disc

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Legislation au F2006B02307 In force Legislative Instrument

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

 


AlliedSignal (Lycoming) Turbine Engines - ALF502 and LF507 Series

 

AD/ALF/11

Amdt 1


Third Stage Compressor Disc 8/91

 

Applicability: All ALF502 engines fitted with third stage compressor disc part number 2-101-630- 04/-05.

 

Requirement: Inspect third stage compressor discs part number 2-101-630-04/-05 for evidence of cracking and apply Sermetel W or ALSEAL 518 protective coating in accordance with;

 

(a)      Model ALF502R series engines: Lycoming SB ALF502R 72-203 R2, or

 

(b)     Model ALF502L series engines: Lycoming SB ALF502L 72-203 R2.

 

Note: For ALF 502R series engines, FAA AD 90-24-01 refers. FAA AD 90-24-01 supersedes FAA AD T89-13-52.

 

Compliance: As detailed in requirement documents.

 

Background: This Directive has been amended to include ALF502L series engines and to reflect a reduction in the inspection threshold. This amendment follows advice of cracking found in two discs at engine cycles below the 8,500 cycles since new inspection threshold detailed in FAA AD T89-13-52.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Overview

The Civil Aviation Regulations 1998, amended by AD/ALF/11Amdt 1, addresses the critical safety concerns associated with the third stage compressor discs of AlliedSignal (Lycoming) Turbine Engines, specifically the ALF502 and LF507 series. Enacted by the Commonwealth of Australia, this legislative instrument aims to mitigate risks related to potential cracking in these engine components, which can compromise the overall safety and reliability of aircraft operations. The policy objective of this amendment is to ensure that all relevant engines are inspected and maintained to the highest safety standards, thereby protecting both the passengers and crew aboard the aircraft. This directive was introduced following incidents where cracking was discovered in the compressor discs at lower than previously anticipated engine cycle thresholds, prompting the need for more stringent inspection and maintenance requirements.

Scope and Application

The Civil Aviation Safety Authority (CASA) Regulations 1998, specifically PART 39 - 106, encompasses Airworthiness Directives for ensuring the safety and airworthiness of aircraft engines. This particular legislative instrument pertains to AlliedSignal (Lycoming) Turbine Engines, specifically the ALF502 and LF507 series. It applies to all ALF502 engines that are fitted with a third stage compressor disc part number 2-101-630-04/-05. The directive mandates an inspection of these specific compressor discs for any evidence of cracking, with a requirement to apply either Sermetel W or ALSEAL 518 protective coating in compliance with specified Lycoming Service Bulletins. For ALF502R series engines, Lycoming SB ALF502R 72-203 R2 must be adhered to, while for ALF502L series engines, Lycoming SB ALF502L 72-203 R2 applies. Notably, for ALF 502R series engines, FAA AD 90-24-01 takes precedence over FAA AD T89-13-52. This amendment to the directive follows findings of cracking in two discs at engine cycles below the previously mandated 8,500 cycles since new inspection threshold, thus reflecting a more stringent and timely requirement for inspections. The directive is applicable across the Commonwealth of Australia and is enforced to ensure that the specified engines meet the necessary safety standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically under PART 39 - 106, mandate the compliance of AlliedSignal (Lycoming) Turbine Engines - ALF502 and LF507 Series as outlined in AD/ALF/11 (Amendment 1). This legislative instrument addresses the inspection and protective coating of the third stage compressor discs for certain ALF502 engines. The applicable engines are those fitted with the third stage compressor disc part number 2-101-630-04/-05. The requirement (section 8/91) is to inspect these discs for any evidence of cracking and to apply either Sermetel W or ALSEAL 518 protective coating as per the Lycoming Service Bulletins (SB). For ALF502R series engines, the applicable bulletin is Lycoming SB ALF502R 72-203 R2, and for ALF502L series engines, it is Lycoming SB ALF502L 72-203 R2. Additionally, it is noted that for ALF 502R series engines, FAA AD 90-24-01 supersedes FAA AD T89-13-52. Compliance with these directives is crucial for ensuring the airworthiness of the engines in question. Operators must adhere to the detailed instructions provided in the relevant Lycoming service bulletins for the inspection and application of protective coatings. This involves thorough checks for any signs of cracking on the specified compressor discs, followed by the application of the protective coating as per the manufacturer's guidelines. Such compliance is essential for maintaining the safety standards set by the Civil Aviation Safety Authority (CASA). Failure to comply with the provisions outlined in the AD/ALF/11 Amendment 1 may result in significant consequences. While the specific penalties are not detailed in the text, non-compliance with Civil Aviation Regulations can typically lead to a range of enforcement actions. These may include fines, grounding of the aircraft until compliance is achieved, and potential criminal charges for severe violations. The exact penalties would be determined based on the severity and impact of the non-compliance, as governed by the broader Civil Aviation Act 1988 and related regulations. Ensuring adherence to these airworthiness directives is therefore not only a legal obligation but also a critical safety measure to prevent in-flight failures and ensure the continued safe operation of the aircraft.

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Sourced from the Federal Register of Legislation at 26 August 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au.