What happened
On 16 October 1999, a Pierre Robin HR100/210, registration G-BGTP, departed Blackbushe on a private flight destined for Calais. The aircraft was carrying one pilot and one passenger, both of whom were experienced in flight. During the pre-flight inspection, the pilot had topped up the engine oil to a level of 9 litres.
While crossing the English coast at an altitude of 3,500 feet, the engine RPM unexpectedly surged to its maximum of 2,800. Upon attempting to reduce the RPM, the pilot observed that the oil pressure had dropped to zero. The pilot notified Manston ATC of the emergency and attempted to glide toward Manston, which was approximately 15 miles away. However, as the aircraft passed abeam Deal, the engine ceased operation entirely, prompting a 'Mayday' declaration.
In selecting a landing site, the pilot evaluated several options, rejecting one field due to livestock and another due to overhead cables. The pilot eventually performed a forced landing in a third field. The impact was heavy, causing the wheels to sink into the soft earth and resulting in the noseleg detaching from the airframe. Both occupants sustained minor injuries and were able to exit the aircraft via the canopy.
The investigation
Investigators examined the wreckage and the circumstances leading to the engine failure. The aircraft sustained considerable damage to the cowling, the left wing, and the fuselage. An insurance assessor noted that while oil was present in the sump with no visible external leaks, the sudden loss of pressure was a critical factor. Because the aircraft was sold by insurers following the accident, a detailed teardown of the engine was not performed.