COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Lycoming Piston Engines
AD/LYC/83 Crankshaft Flange 11/88
Applicability: All AEIO-540-D series, IO-540 (250 & 260 horsepower) engines converted for aerobatic flight or any other 540 engines employing a 2-3/8 diameter main bearing seal used in unlimited category aerobatic manoeuvres.
Requirement: Visually inspect the crankshaft flange in accordance with Lycoming Service Bulletin No 482.
Compliance: For those engines which have been subjected to unlimited category manoeuvres - initially within 100 hours of engine operation after 3 November 1988 and thereafter at intervals not exceeding each 10 hours of aerobatic flight involving unlimited category manoeuvres.
Background: Lycoming SB 482 advises that cracked crankshafts have occurred on applicable engines which have been submitted to unlimited category aerobatic manoeuvres. These manoeuvres are more severe than contemplated when the engines were certificated for prolonged inverted flight and for normal aerobatic manoeuvres. Unlimited category manoeuvres such as multiple snap rolls, inverted flat spins, lomcevaks etc. produce severe bending loads on the propeller flange area. Exceeding engine maximum rated speed and/or using the aircraft in manoeuvres which produce rapid angular propeller centreline acceleration may result in crankshaft failure.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, include specific directives designed to ensure the safety of civil aviation. One such regulation, AD/LYC/83, was introduced to address the problem of cracked crankshafts in Lycoming Piston Engines, particularly those used in unlimited category aerobatic manoeuvres. The policy objective of this regulation is to prevent potential engine failures that could endanger flight safety. The regulation mandates a visual inspection of the crankshaft flange for AEIO-540-D series and other specified engines, following the guidelines provided in Lycoming Service Bulletin No 482. Compliance with these inspection intervals is critical for maintaining airworthiness, especially for engines exposed to unlimited category aerobatic manoeuvres, requiring inspections initially within 100 hours of engine operation post 3 November 1988 and subsequently every 10 hours of aerobatic flight involving such severe manoeuvres.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 106, pertain to airworthiness directives issued by the Civil Aviation Safety Authority, with AD/LYC/83 addressing the crankshaft flange of Lycoming piston engines. This regulation applies to all AEIO-540-D series, IO-540 engines rated at 250 and 260 horsepower, if converted for aerobatic flight, or any other 540 engines that use a 2-3/8 diameter main bearing seal and are used in unlimited category aerobatic manoeuvres. The directive is geographically applicable across the Commonwealth of Australia and mandates compliance with Lycoming Service Bulletin No 482, which advises on the visual inspection of the crankshaft flange. The inspection is required for engines subjected to unlimited category manoeuvres, initially within 100 hours of engine operation post 3 November 1988, and subsequently at intervals not exceeding every 10 hours of aerobatic flight involving such severe manoeuvres. The regulation does not explicitly mention exclusions or exemptions, but its scope is limited to specific engine types and operational conditions.
Key Provisions
The Civil Aviation Regulations 1998, under Part 39 - 106, include specific provisions for the airworthiness of Lycoming Piston Engines, particularly in relation to the crankshaft flange as outlined in AD/LYC/83 (1). This directive applies to all AEIO-540-D series, IO-540 (250 & 260 horsepower) engines converted for aerobatic flight or any other 540 engines that use a 2-3/8 diameter main bearing seal and are employed in unlimited category aerobatic manoeuvres (2). The key requirement is a visual inspection of the crankshaft flange in accordance with Lycoming Service Bulletin No 482 (3).
Compliance with these regulations is mandatory for engines subjected to unlimited category aerobatic manoeuvres. Specifically, the initial inspection must occur within 100 hours of engine operation after 3 November 1988, followed by inspections at intervals not exceeding each 10 hours of aerobatic flight involving unlimited category manoeuvres (4). This schedule is designed to ensure that the crankshaft flange remains in a safe condition, given the severe bending loads experienced during such manoeuvres. The background information provided indicates that cracked crankshafts have been observed in applicable engines subjected to these rigorous flight conditions, which exceed the engine’s original certification limits (5).
The Act imposes specific obligations on the parties responsible for the maintenance and operation of these engines. Owners and operators must ensure that the mandated inspections are conducted by qualified personnel following the detailed procedures outlined in Lycoming Service Bulletin No 482. Failure to adhere to these requirements can result in serious safety implications, potentially leading to engine failure during flight. Non-compliance with the airworthiness directives could lead to severe civil and criminal consequences. The regulations are clear that adherence to these provisions is not optional but mandatory to maintain the airworthiness of the aircraft and the safety of all persons on board.
In terms of penalties, the Civil Aviation Regulations do not explicitly detail penalties for non-compliance with AD/LYC/83 in the provided text. However, generally, under the Civil Aviation Act 1988, non-compliance with airworthiness directives can result in significant penalties, including fines and potential imprisonment for individuals. The severity of the penalty often depends on the extent of non-compliance and the impact on aviation safety. Operators found in breach of these regulations could face enforcement actions by the Civil Aviation Safety Authority, including potential grounding of the aircraft until the required inspections are satisfactorily completed.