What happened
On 11 April 1998, a Piper PA-23-250, registration EI-BYK, was conducting a private ferry flight from Waterford, Ireland, to Exeter, UK, for an annual inspection. The flight was being conducted under an Irish Ferry Permit, with a Cessna 182 flying in formation to assist with radio communications due to a faulty transmission switch on the Piper.
While cruising at Flight Level 60 near the Strumble VOR, the aircraft's right engine began running roughly. The pilot performed standard engine failure procedures, including adjusting fuel pumps, switching tanks, and adjusting the mixture, but the engine'_s power output continued to decline. Shortly thereafter, the left engine began to misfire as the aircraft approached Worms Head.
Recognizing the danger, the pilot initiated a shallow descent toward land and issued a 'Mayday' call. Due to the unsuitable terrain of the nearby undulating fields, the pilot opted to land on the firm sand of Rhossilli Beach, where the tide was out. The landing was successful, and the pilot escaped without injury.
The investigation
Following the incident, the aircraft was inspected by engineers from Exeter Airport. While the fuel flow to the right engine appeared sufficient, a grey, powdery substance was discovered in the right engine's fuel filter. Further examination of the right engine revealed that three fuel injector nozzles were completely blocked and one was partially obstructed. After cleaning these components, the engine's performance improved.
Regarding the left engine, investigators found no evidence of fuel contamination. While the engine's misfire could have been caused by a transient blockage, the investigation also considered that the pilot's attempts to manage the right engine's failure might have inadvertently introduced air into the left engine's fuel system from a low-level outboard tank.