AD/PORSCHE/2 - Engine - Output Shaft Bearing

Overview

The Civil Aviation Regulations 1998, specifically PART 39 - 106, address the critical issue of ensuring the airworthiness of civil aircraft, including their engines. Enacted by the Parliament of Australia, the Regulations aim to maintain the highest safety standards in civil aviation. The legislative instrument F2006B06305, pertaining to Porsche Piston Engines, illustrates a focused effort to resolve specific technical issues that could compromise the safety and reliability of certain aircraft components. In this instance, the problem addressed by Airworthiness Directive AD/PORSCHE/2 is the recurring failure of output shaft bearings in Porsche 930/67 and 930/01 engines used in Skyship 600 and Skyship 500 aircraft. The policy objective of this directive is to ensure the safe operation of these aircraft by mandating the replacement of defective engine components with improved parts that meet higher safety standards. The directive was issued by the Civil Aviation Safety Authority (CASA) following detailed investigations into bearing failures, which were traced to the use of heat-stabilised polyamide bearing cages with insufficient speed limits. The directive requires the replacement of these bearings with improved versions capable of operating at higher speeds, ensuring the longevity and reliability of the engine components. Compliance with this directive is mandatory for engines that have not yet been modified, with specific timelines provided for both installed and uninstalled engines. This regulatory measure underscores CASA's commitment to continuous improvement in aviation safety through targeted airworthiness directives.

Scope and Application

The Civil Aviation Regulations 1998, as part of the Australian legislative framework, apply to various entities and individuals involved in civil aviation within Australia. Specifically, the regulation pertains to Porsche 930/67 (Skyship 600) and 930/01 (Skyship 500) engines, requiring the replacement of certain components to ensure airworthiness. This requirement applies to both installed and uninstalled engines, with the mandate that such replacements must be completed within 75 operating hours for installed engines and prior to installation for uninstalled engines. The directive came into effect on 17 February 1989 and references compliance with specific modifications and manufacturer bulletins, notably those issued by Airship Industries and the UK's Civil Aviation Authority. This regulation underscores the Civil Aviation Safety Authority's commitment to maintaining stringent safety standards in aviation, ensuring that all relevant engines meet the specified safety criteria to mitigate risks associated with bearing failure.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 106, impose specific requirements for maintaining the airworthiness of Porsche piston engines in certain airship models. Section (4/89 DM) mandates that for Porsche 930/67 (Skyship 600) and 930/01 (Skyship 500) engines, the bell housing, complete with output shaft, bearing, bearing housing, sealing ring, and retaining nut must be replaced. This replacement must comply with Airship Industries SB 500-72-A297 for Skyship 500 and Airship Industries SB 600-72-A297 for Skyship 600. The directive references the CAA(UK) Airworthiness Directive 057-12-88, indicating a cross-jurisdictional requirement for compliance. It is crucial that these modifications are completed unless they have already been accomplished. Specifically, for engines already installed, this replacement must occur within 75 operating hours of the directive's issue date, while uninstalled engines must adhere to these specifications before installation. Entities and individuals governed by these regulations are required to ensure that the specified modifications are carried out promptly and correctly. This involves sourcing the correct components, performing the necessary replacements, and ensuring that all work is documented and compliant with the referenced service bulletins. The Civil Aviation Safety Authority (CASA) may require verification that these changes have been made, and failure to comply could result in the aircraft being deemed unairworthy. Failure to comply with these airworthiness directives can lead to severe consequences. The regulations outline potential civil and criminal penalties for non-compliance. Although specific penalties are not detailed in the excerpt, general aviation regulations often include fines, suspension or revocation of aircraft certificates, and possible imprisonment. The severity of the penalty may depend on the nature and extent of the non-compliance, as well as any resultant risk to aviation safety. The directive’s implementation date of 17 February 1989 provides a clear timeline for compliance, underscoring the urgency and importance of adhering to these safety measures.