What happened
On 4 August 2017, a Europa aircraft, registration G-BZTH, was conducting a private cross-country flight from Enstone toward an airstrip near Gloucester. The flight was operating in good visibility with a westerly breeze. While at an altitude of approximately 1,900 feet AGL, roughly eight miles northwest of Enstone, the engine failed and could not be restarted.
The pilot identified a suitable field near Parsons Barn, Long Compton, for an emergency landing. Although the pilot successfully touched down at the intended location, the aircraft continued to travel along the ground for a short distance before experiencing a violent deceleration. The pilot sustained minor injuries during the event. Upon exiting the aircraft, the pilot observed that the aircraft had struck ground ridges that were not identifiable from the air, which resulted in significant damage to the forward fuselage.
The investigation
Investigators examined the aircraft following its recovery to determine the cause of the engine failure and the subsequent impact. The inspection of the Rotax 912-UL piston engine revealed that the engine had seized because of a total lack of lubrication.
Further examination of the engine components showed that the oil drain plug was missing. The investigation established that the engine oil had been changed prior to the flight with the assistance of another individual. During this process, the engine was drained and left unattended before being refilled. While an initial engine run-up showed no signs of leakage, it was determined that the oil plug had not been properly secured. This likely led to the plug becoming detached during flight, resulting in the rapid loss of oil.