What happened
On 17 March 2003, a Piper PA-2-235 Pawnee, registration G-BFSC, was conducting a familiarisation flight at North Weald Aerodrome, Essex. The pilot, part of a group of three tug pilots from a local gliding club, was performing a routine flight to gain experience on the aircraft, which had been recently delivered to the club.
During the initial climb to approximately 700 feet, the engine power abruptly ceased, and smoke began to enter the cockpit. The pilot immediately notified North Weald Radio and declared his intention to perform a downwind landing on the departure runway. During the approach, the pilot shut off the fuel and electrical systems. The aircraft completed a successful dead-stick landing, though significant smoke was observed emanating from the engine compartment. While the local fire service arrived, the fire had already been extinguished by airfield personnel within five minutes.
The investigation
Investigators examined the aircraft to determine the source of the smoke and the engine failure. The inspection revealed a large fracture in the muffler section of the engine exhaust, measuring approximately 10 cm in diameter. This opening allowed hot gases to escape into the engine bay, where they ignited combustible materials. This heat damage specifically affected the ignition harness, which led to the sudden and complete loss of engine power.
Findings
- The primary cause of the engine failure was the damage to the ignition harness caused by escaping hot gases.
- A significant hole in the engine muffler allowed high-temperature exhaust gases to enter the engine compartment.
- The aircraft, a 1976 model, had been in storage for much of its life and had accumulated fewer than 40 hours of total operation.
- Internal corrosion within the exhaust system, likely a result of prolonged storage, may have weakened the muffler and made it more susceptible to damage from an exhaust backfire.