Piper PA-34 Seneca III — Service Bulletins

This Airworthiness Bulletin addresses critical issues related to the fuel shutoff and selector valves in the Piper PA-34 Seneca and other aircraft equipped with similar valves. It highlights the potential for undetected internal leaks that could lead to fuel control loss and imbalance. The bulletin is intended for operators and maintainers, emphasizing the importance of regular checks on the fuel selector valve function. The document outlines findings from an investigation into a fatal accident involving the PA-34, where valve failures were identified as a significant airworthiness concern. Recommendations for maintenance and inspection procedures are provided to ensure safety and compliance with airworthiness standards.

• Regular checks of fuel selector valves are crucial to prevent fuel control loss.
• Functional checks should be performed every 100 flight hours or annually.
• Any valve that fails functional checks must be replaced before flight.
• The bulletin addresses issues identified in a fatal accident involving the PA-34.
• Operators should report any defects related to fuel selector valves to CASA.