AD/PA-42/23 - Aileron Hinge

Overview

The Civil Aviation Regulations 1998, as amended, encompass a range of safety directives to ensure the integrity and safety of aircraft within Australia. One such directive, issued under Part 39 - 105, pertains specifically to the Piper PA-42 (Cheyenne III) series aeroplanes, aiming to address issues identified with the aileron hinge. The directive was enacted by the Civil Aviation Safety Authority and became effective on 9 October 1997. The primary problem it seeks to resolve is the risk of structural failure of the aileron due to cracks found in the vicinity of the inboard aileron hinge bracket, aileron spar, and aileron rib. These failures could potentially lead to loss of control of the aircraft. The directive mandates inspections and specific actions to ensure the continued airworthiness of affected aircraft, aiming to prevent such critical failures.

Scope and Application

The Civil Aviation Safety Authority's Airworthiness Directive (AD) AD/PA-42/23 applies specifically to Piper PA-42 series aeroplanes, including models PA-42, PA-42-720, PA-42-720R, and PA-42-1000, identified by the serial numbers listed in Piper Service Bulletin (SB) 967. This AD mandates that the area beneath and around the inboard aileron hinge bracket on the aileron spar must be inspected for cracks using dye penetrant methods, in accordance with the instructions outlined in Piper SB 967. If cracks are detected, the corresponding aileron rib must also be inspected, and any cracked spar assembly and aileron rib must be replaced following the maintenance manual's guidelines. Additionally, the inboard aileron hinge brackets must be replaced with improved design parts, P/N 74461-02 (left) and P/N 74461-03 (right), unless this has already been done, again in accordance with the instructions in Piper SB 967. Compliance with these requirements is necessary upon the aircraft reaching 3,000 hours of total time in service, or within 200 hours after 9 October 1997, whichever is later, unless the actions have already been completed. This AD was made effective from 9 October 1997, responding to reports of structural cracks in the aileron area that could lead to loss of control.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105 (subsection 105.123), pertain to the Piper PA-42 (Cheyenne III) Series Aeroplanes and outline the airworthiness directives that must be followed. The key provisions in this directive (AD/PA-42/23) concern the inspection and possible replacement of certain components in the aileron system of specified Piper PA-42 aircraft models. For instance, the regulation requires an inspection using dye penetrant methods to check for cracks in the area beneath and around the inboard aileron hinge bracket on the aileron spar (subsection 105.123(1)). If any cracks are detected, further inspections and replacements are mandated (subsection 105.123(2)). Operators and owners of the Piper PA-42, PA-42-720, PA-42-720R, and PA-42-1000 models with specific serial numbers must comply with these directives. The obligations include conducting the required inspections and making any necessary replacements within stipulated timeframes. Specifically, the inspections and any resultant replacements must be carried out upon the accumulation of 3,000 hours of total time in service or within 200 hours of service after 9 October 1997, whichever occurs later (subsection 105.123(3)). The directive became effective on 9 October 1997, and compliance is mandatory for all applicable aircraft. Failure to adhere to the airworthiness directives stipulated in these regulations can lead to serious consequences. The primary risk addressed by these provisions is the potential for structural failure of the aileron, which could result in the loss of control of the aircraft. While the specific penalties for non-compliance are not detailed in the text, general civil aviation regulations imply that violations can result in significant fines, suspension or revocation of aircraft operating certificates, and potential criminal charges depending on the severity and intent behind the non-compliance. The overarching aim is to ensure the safety and airworthiness of the aircraft, thereby protecting passengers and crew.