What happened
On 28 July 2020, a Europa aircraft, registration G-BXTD, was conducting a private flight at Enstone Airfield, Oxfordshire. The flight was intended as a training session to familiarise the owner with the aircraft's operation. After a successful takeoff from the grass runway, the aircraft began a climb and a right turn to comply with local noise abatement procedures.
While at approximately 520 feet, the engine RPM dropped rapidly over a five-second period before the engine stopped completely. The instructor took control of the aircraft and identified a suitable field for an emergency landing. To maintain sufficient airspeed, the instructor pitched the nose down aggressively. Despite attempts by the owner to restart the engine, the propeller remained stationary. The aircraft touched down in a field of crops, and while the landing speed was higher than intended, the crew managed to avoid a nearby hedgerman. The aircraft sustained damage to the right wing, undercarriage, flaps, and the rear fuselage, but both occupants were uninjured.
The investigation
The investigation examined the engine and the aircraft's history. It was noted that the aircraft had been in storage for an extended period prior to the owner's purchase in 2019. Upon inspection of the engine, the propeller could not be rotated beyond 15 degrees, indicating the crankshaft was jammed.
Investigators found that the oil pipe connecting to the oil pump had a narrowed cross-section due to the bend radius. Additionally, the engine showed signs of internal damage. Dents were found on the piston crowns, consistent with contact from the inlet valves. Furthermore, the investigation revealed surface pitting on the pistons, suggesting a corrosive environment had existed within the crankcase. The investigation also identified that the No 4 piston connecting rod and bearing had failed at the crankshaft attachment.
Findings
- The exact cause of the engine stoppage could not be definitively established.
- The narrowed cross-section of the oil pipe likely restricted oil flow, though this was not considered the primary factor as the engine had operated previously without issue.
- Corrosion-initiated fatigue in the No 4 connecting rod, likely resulting from an extended period of inactivity, was a probable cause of the failure.
- Evidence of prior mechanical damage, likely from a previous propeller strike and subsequent engine overspeed, was present within the engine components.