AD/CESSNA 560/1 - Engine Flow Divider Start Valve Diaphragm

Overview

The Civil Aviation Regulations 1998, Part 39 - 105, is a legislative instrument enacted to ensure the safety of civil aviation operations within Australia. This particular legislative instrument, AD/CESSNA 560/1, was introduced to address the specific issue of uncommanded in-flight engine shut-downs in Cessna 560 series aircraft fitted with PWC JT15D-5A engines. The problem arose due to the deterioration of the engine flow divider start valve diaphragm, which led to two such incidents. The Civil Aviation Safety Authority, under the authority of the Australian Parliament, issued this directive to mandate changes to the Aircraft Flight Manual and to require a modification of the flow divider, aiming to prevent future occurrences and ensure the safe operation of the affected aircraft. This directive was designed to align with the policy objective of maintaining the highest safety standards in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the Cessna 560 (Citation V) series aeroplanes equipped with PWC JT15D-5A engines that do not have Pratt and Whitney Canada Service Bulletin No. 7372 incorporated. This legislation is intended to ensure the airworthiness of these aircraft by addressing potential risks associated with the engine flow divider start valve diaphragm. The regulation mandates amendments to the Aircraft Flight Manual to incorporate the requirements of Pratt and Whitney Canada Service Information Letter (SIL) No. 7060 Rev.1, and actions consistent with Pratt and Whitney Canada Service Bulletin No. 7371. The compliance requirement is to be met either before further flight or within 50 hours of time in service, whichever comes first, or before 1 December 1992. This directive responds to two uncommanded in-flight engine shut-down events due to the deterioration of the engine flow divider start valve diaphragm. While this regulation primarily affects aircraft operators and maintenance personnel, its overarching aim is to enhance safety standards within the civil aviation sector, ensuring the continued reliability and safety of the affected aircraft models.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 - 105, under the Civil Aviation Safety Authority's schedule of Airworthiness Directives, address the maintenance and operation of certain aircraft models, including the Cessna 560 series aeroplanes (section 1). This regulation targets Cessna 560 series aircraft fitted with PWC JT15D-5A engines that do not have the Pratt and Whitney Canada Service Bulletin No. 7372 incorporated (section 13/92DM). The primary requirement of this directive is to amend the Aircraft Flight Manual to reflect the updated procedures and recommendations outlined in Pratt and Whitney Canada Service Information Letter (SIL) No. 7060 Rev.1, specifically paragraph 1 (section 1). Additionally, it mandates that aircraft operators must take action in accordance with the requirements of Pratt and Whitney Canada Service Bulletin No. 7371 (section 2). The directive references Transport Canada Directive CF-92-19 for additional context and guidance (Note). Compliance with these requirements is crucial, as the directive mandates that the specified actions must be completed before further flight, with a strict timeline of within 50 hours of time in service or before 1 December 1992, whichever comes first (section Compliance). The obligations imposed by this directive on the aircraft operators and owners include ensuring that the Aircraft Flight Manual is updated to include the new procedures and recommendations from Pratt and Whitney Canada's SIL No. 7060 Rev.1, paragraph 1. This update is necessary to address the risk of in-flight start valve failure due to the deterioration of the engine flow divider start valve diaphragm. Furthermore, operators must implement the modifications specified in Pratt and Whitney Canada Service Bulletin No. 7371. These obligations aim to enhance the safety and reliability of the aircraft by mitigating the risk of engine shutdown events, which have been identified as a potential hazard. The directive underscores the importance of timely and accurate updates to flight manuals and adherence to specific maintenance protocols. Failure to comply with the requirements of this Airworthiness Directive may result in serious safety risks and potential legal consequences. While the Civil Aviation Regulations 1998 do not explicitly state specific penalties for non-compliance with this directive, non-compliance with airworthiness directives generally can lead to severe civil and criminal penalties. These may include fines, suspension or revocation of aircraft certificates, and potential criminal charges under the Civil Aviation Act 1988. The maximum penalties for such violations can be substantial, reflecting the critical nature of ensuring aircraft airworthiness and safety. Operators found in breach of these regulations may also face operational restrictions, impacting their ability to conduct flights until compliance is achieved.