What happened
On 30 March 2017, a Piper PA-28-140, registration G-ATVO, was conducting a training flight to convert a PPL(A) holder to the aircraft type. Following a normal takeoff from Shoreham Airport, the aircraft climbed through approximately 350 feet, at which point the flaps were retracted. As the aircraft continued its climb and crossed the coast heading southwest, it reached an altitude of 450 feet when the engine suddenly ceased producing power, though the propeller continued to windmill.
The pilot in command took control to maintain the best glide speed and turned the aircraft toward the shoreline. Despite attempts to troubleshoot the engine, including checking the fuel selection and using the carburettor accelerator pump, the engine failed to respond. Realising a ditching was unavoidable, the commander declared a MAYDAY and steered the aircraft parallel to the shore. The aircraft ditched in the sea approximately 10 metres from the beach. Both crew members successfully exited the aircraft and swam to shore. The aircraft was subsequently submerged in seawater.
The investigation
The AAIB examined the aircraft after it was recovered from the sea. The fuel system had been contaminated by seawater, preventing the collection of reliable fuel samples. While the engine showed significant wear on several camshaft lobes and tappet bodies, investigators found no mechanical failures that would explain a sudden and total loss of power. The engine had been running smoothly prior to the incident.
Testing conducted by the AAIB using a similar aircraft type revealed that if contaminated fuel were present in the right wing tank, there would be a delay of approximately one minute before the engine failed after the fuel selector was switched to that tank. This delay aligns with the timeline of the flight, as the crew had switched to the right tank during the engine run-up prior to takeoff.
Findings
- The engine experienced an abrupt loss of power during the initial climb.
- The cause of the power loss could not be definitively determined.
- Potential causes included the ingestion of contaminated fuel from the right tank or an unidentified obstruction within the fuel system.
- Significant wear was noted on the camshaft lobes and tappet bodies, though this was not found to be the cause of the sudden failure.