What happened
On September 30, 2016, an EMS aircraft, a Piaggio P180 Avanti I with registration SP-MXH, was undergoing a preflight inspection while on duty at Warsaw-Okęcie (EPWA). During the inspection, after the crew connected external power, the warning panel displayed an "L F/W V INTRAN" alert. This specific warning indicated that the valve regulating the fuel flow to the left engine had become stuck in a transitional position.
The pilot attempted to reset the system by toggling the left engine fuel valve (LF/W VALVE) from the OPEN to the CLOSE position multiple times, but the warning remained active and the valve failed to respond correctly.
The investigation
The investigation, conducted by the operator, focused on the mechanical failure of the fuel regulation component. Technical personnel performed a replacement of the faulty valve with a new unit (SN 1139) in accordance with the Aircraft Maintenance Manual (AMM 28-21-00). Following the replacement, the fuel system was tested and confirmed to be functioning correctly, allowing the aircraft to be returned to service.
Findings
- The primary cause of the malfunction was the mechanical jamming of the valve slide in a transitional position.
- This failure was attributed to the operational wear and tear of the valve component.