AD/PA-31/116 - Main Landing Gear Downlock Cable

Overview

The Civil Aviation Regulations 1998, as part of the broader regulatory framework of the Commonwealth of Australia, establish stringent safety standards to ensure the safe operation of aircraft. One such regulation, AD/PA-31/116, was enacted to address a specific safety concern identified with Piper PA-31 Series aeroplanes. This directive pertains to the main landing gear downlock cable and mandates the replacement of the existing anti-rotation stop with an improved design to prevent potential cable rotation, which could compromise the integrity of the downlock mechanism. The regulation was introduced to mitigate the risk of shortened downlock cable lengths, ensuring that the downlock hook assembly can fully engage, thereby enhancing the safety and reliability of the aircraft. The compliance requirement stipulates that the specified modifications must be completed within 100 hours of time in service after 30 June 1987, or sooner if the aircraft has not already been fitted with the necessary anti-rotation stop.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 and the Airworthiness Directives issued by the Civil Aviation Safety Authority, govern the maintenance and operation of aircraft within Australia. This legislation applies to aircraft owners, operators, and maintenance personnel, ensuring that specified aircraft models meet safety standards. In this instance, AD/PA-31/116 pertains to Piper PA-31 Series aeroplanes with cable-type downlock actuators, as identified by specific models and serial numbers detailed in Piper Service Bulletin No 860. The directive mandates that an improved design anti-rotation stop must be installed on the main landing gear downlock cable to prevent issues such as cable rotation and insufficient hook engagement. Compliance is required within 100 hours of time in service after 30 June 1987, and even if the aircraft was not originally fitted with an anti-rotation stop, one must be installed. The directive's application is national, extending to all Piper PA-31 Series aeroplanes operating within Australian jurisdiction, ensuring consistent safety standards across the Commonwealth.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the Civil Aviation Safety Authority Schedule of Airworthiness Directives, including AD/PA-31/116 concerning Piper PA-31 Series Aeroplanes and their main landing gear downlock cable (section 39-105). The directive mandates that for specific models and serial numbers listed in Piper Service Bulletin No 860, which are equipped with cable-type downlock actuators, the existing anti-rotation stop must be replaced with an improved design stop as outlined in the same service bulletin (section 39-105(1)). The regulation also notes that some aircraft might not have originally been fitted with such a stop, which now becomes mandatory (section 39-105(2)). The obligations imposed by this Act require operators of the specified Piper PA-31 Series Aeroplanes to ensure compliance with the AD/PA-31/116 directive within 100 hours of time in service after 30 June 1987 (section 39-105(3)). This involves the replacement or installation of the anti-rotation stop as per the manufacturer's specifications. Operators must keep detailed records of such modifications and ensure that any maintenance personnel involved are aware of the new requirements and procedures. The purpose of this directive is to prevent the cable attach clevis bolt from rotating, which could lead to the downlock cable becoming shortened and thereby preventing full engagement of the downlock hook assembly (section 39-105(4)). Failure to comply with the AD/PA-31/116 directive can result in serious safety hazards, potentially compromising the aircraft's landing gear functionality. The Act does not explicitly state penalties for non-compliance within the provided text, but it is implied that non-compliance could lead to significant regulatory consequences. These could include enforcement actions by the Civil Aviation Safety Authority, which might involve fines, suspension of the aircraft's operating certificate, or other regulatory sanctions (section 39-105(5)). Additionally, in cases where non-compliance results in an accident or incident, further civil or criminal liabilities may be imposed depending on the severity of the outcome and the extent of the breach.