AD/PA-44/4 - Throttle Cable Installation - Modification

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, were introduced to ensure safety standards in civil aviation, addressing the need for a cohesive and comprehensive regulatory framework. The regulations, administered by the Civil Aviation Safety Authority, aim to maintain and enhance aviation safety through detailed directives, including specific requirements for aircraft airworthiness. One such directive is AD/PA-44/4, which pertains to the modification of the throttle cable installation in Piper PA-44 (Seminole) series aeroplanes. This directive was introduced in response to reports of engine throttle cable breakages caused by excessive spring-back, highlighting the authority's commitment to addressing specific safety concerns and ensuring the reliability of aircraft components. The policy objective of AD/PA-44/4 is to rectify the issue of throttle cable breakages in specified Piper PA-44 Seminole models by mandating the relocation of the throttle cable support bracket. This modification is required to be completed within 25 hours of the aircraft being in service after 5 April 1979, as outlined in Piper Service Bulletin No. 639 or FAA AD 79-05-11, Amendment 39-3433. This directive underscores the regulatory body's proactive approach to mitigating potential safety hazards and maintaining the highest standards of aviation safety.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, focusing on the Piper PA-44 (Seminole) series aeroplanes. This legislation applies to specific model numbers of the PA44-180 series, with serial numbers falling within the range 44-7995001 to 44-7995144, 44-7995146 to 44-7995180, 44-7995182 to 44-7995186, 44-7995190, 44-7995192, 44-7995193, 44-7995195, and 44-7995197. The directive mandates compliance within 25 hours of time in service following the directive's effective date of 5 April 1979, requiring the relocation of the throttle cable support bracket to address issues of engine throttle cable breakage due to excessive spring-back. The directive references Piper Service Bulletin No. 639 and FAA AD 79-05-11, Amendment 39-3433, to ensure compliance with safety standards. The scope of the legislation is confined to the specified models and serial numbers, and it applies nationally within Australia, encompassing the civil aviation industry and all relevant operators or owners of the specified aircraft models.

Key Provisions

The main operative sections of this legislation pertain to specific Piper PA-44 (Seminole) Series aeroplanes with particular serial numbers. Section 5 of AD/PA-44/4 mandates a modification to the throttle cable installation for these aircraft to address reported instances of engine throttle cable breakage. This requirement is to be fulfilled within 25 hours of time in service after the directive's effective date of 5 April 1979. Compliance can be demonstrated by referencing Piper Service Bulletin No. 639 or FAA AD 79-05-11, Amendment 39-3433. The obligations imposed by the Civil Aviation Regulations 1998 on the parties involved are clear and specific. Aircraft operators and owners of the affected Piper PA-44 models must ensure that the throttle cable support bracket is relocated as per the requirements set forth in the directive. This involves either implementing the modifications as described in Piper SB No. 639 or adhering to the specifications detailed in FAA AD 79-05-11, Amendment 39-3433. The directive leaves no ambiguity regarding the need for compliance within the stipulated timeframe. Failure to comply with the provisions of this directive can result in serious consequences. The Civil Aviation Safety Authority (CASA) has the authority to enforce penalties against non-compliance. While the specific penalties are not detailed in the legislative instrument provided, it is well understood within the aviation regulatory framework that breaches of such safety directives can lead to significant civil or criminal penalties. These may include fines, suspension of airworthiness certificates, or other enforcement actions deemed necessary to ensure compliance with safety regulations. The gravity of the potential consequences underscores the importance of adhering to the directive without delay.