AD/PA-31/86 Amdt 2 - Scott Fuel Selector Valve and Cable

Overview

The Civil Aviation Regulations 1998, amended by the Commonwealth of Australia's Civil Aviation Safety Authority, introduces specific Airworthiness Directives to address safety concerns with certain Piper PA-31 series aeroplanes. This legislation was enacted to mitigate risks associated with the Scott fuel selector valve and its associated cables, which have been identified as potential causes of inadvertent fuel shutoff. The primary objective is to ensure ongoing airworthiness and safety by mandating regular servicing, replacement of specific components, and thorough inspections of the fuel selector valve and its cables. Enacted by the Australian Government, this directive applies to particular Piper PA-31 models and serial numbers, aiming to prevent potential failures that could arise from sticking or binding of the spool "O" rings and subsequent cable fatigue. The directive requires compliance with specified maintenance intervals to ensure the continued safe operation of these aircraft, reflecting a commitment to stringent safety standards within the civil aviation sector.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses airworthiness directives for Piper PA-31 series aeroplanes, including models PA-31, PA-31-300, PA-31-325, PA-31-350, and PA-31P. This legislation applies to these aircraft models if they are equipped with Scott fuel selector valves and fall within specified serial numbers. The regulation mandates servicing, replacement of “O” rings, and inspection or replacement of fuel selector valve control cables to mitigate risks associated with potential sticking or binding of the spool “O” rings and subsequent cable failure. Compliance must be achieved within specified intervals post-January 31, 1981, and subsequently at intervals not exceeding 100 hours or 1000 hours, depending on the requirement. These regulations extend to the entire Commonwealth of Australia and apply to all relevant aircraft operating within this jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, mandate certain actions concerning the airworthiness of Piper PA-31 Series aeroplanes, as outlined in AD/PA-31/86 Amendment 2. This airworthiness directive applies to various models of Piper PA-31 aeroplanes that are fitted with Scott fuel selector valves, as identified by their serial numbers. The directive sets out three main requirements: the servicing of the fuel selector valve, the replacement of the valve’s “O” rings, and the inspection or modification of the valve control cables. These tasks must be carried out in accordance with specific sections of Piper Service Bulletin No. 648A. The obligations imposed by this directive include regular maintenance and inspection of the specified components. For instance, the fuel selector valve must be serviced within 100 hours of time in service after 31 January 1981 and then at intervals not exceeding 100 hours thereafter. Similarly, the fuel selector valve control cables need to be inspected within 100 hours after 31 January 1981 and then at intervals not exceeding 100 hours. If the control cables have been modified in accordance with Part III of Piper SB No. 648A, they are exempt from this inspection requirement. The “O” rings of the fuel selector valve must be replaced at intervals not exceeding 1000 hours time in service. Failure to comply with the requirements outlined in the AD/PA-31/86 Amendment 2 may result in civil or criminal consequences. While the specific penalties are not stated in this excerpt, non-compliance with airworthiness directives generally could lead to fines, imprisonment, or both, under Australian aviation law. It is essential for operators and maintenance personnel to adhere to these regulations to ensure the continued safety and airworthiness of the affected aircraft.