What happened
On January 31, 2008, a privately operated Piper PA 32-260 (registration G-OCTI) departed Dinard aerodrome for a flight to Jersey. Shortly after takeoff, while performing a left-hand turn at an altitude of approximately 1,000 feet, the pilot experienced engine roughness.
In response to the engine instability, the pilot activated the carburetor heat, engaged the electric fuel pump, and reduced engine power while broadcasting a distress call on the aerodrome frequency. Despite these corrective actions, the engine misfires continued. The pilot completed the turn and performed an emergency landing on runway 30. During the landing roll, the propeller came to a stop. Following the incident, a mechanic recovered several liters of water, primarily from the fuel collector located beneath the fuselage.
The investigation
The investigation focused on the source of the water found in the fuel system. During the pre-flight inspection, the pilot had noted and drained water from the wing tanks. However, the pilot admitted to omitting the drainage of the fuel collector, noting that the procedure was cumbersome. The aircraft's flight manual requires both the wing tanks and the collector to be drained daily before the first flight of the day.
Investigators also examined the aircraft's storage conditions and maintenance state. The aircraft had been parked outdoors for three years. Inspection of the fuel system revealed that the fuel tank filler caps were heavily corroded. Specifically, one filler orifice was found to be pierced around the gasket seat, allowing rainwater to enter the fuel system.
Findings
- The engine power loss was caused by fuel contamination from water.
- The pilot failed to complete the required fuel drainage procedures, specifically neglecting to drain the fuel collector.
- The fuel system was compromised by heavy corrosion on the filler orifices, including a puncture that allowed rainwater to penetrate the tanks.
- The aircraft had been stored outdoors for an extended period, contributing to the degradation of the fuel caps.