What happened
On 16 June 2002, at approximately 17:00 hrs, an Evans VP-1, registration G-BIFO, was conducting a private flight from Bagby towards Eddsfield. The flight was expected to last roughly 35 minutes.
During the transit, the pilot observed a progressive reduction in airspeed. The maximum speed achievable while maintaining altitude dropped to between 50 and 55 knots. Upon applying full throttle in an attempt to maintain performance, a spark plug was ejected from one of the engine cylinders. Following this engine malfunction, the pilot was forced to land the aircraft in a cornfield located approximately two miles from the intended destination at Eddsfield. During the touchdown, the aircraft's landing gear collapsed. The pilot sustained no injuries.
The investigation
Investigators examined the circumstances surrounding the engine failure and the condition of the engine components. It was established that the spark plug in question had been installed into a helicoil insert. Evidence indicated that this plug had become loose within the insert prior to being blown out of the cylinder. Notably, the aircraft had been operated earlier on the same day by a flight instructor, who had completed a flight without encountering any mechanical issues.