Oil Pressure Warning
The pilot of an amateur-built experimental airplane reported that while conducting clearing turns in preparation for slow flight testing, an oil pressure warning appeared on the engine monitor, with indicated oil pressure at zero. The pilot immediately turned toward the airport and reduced engine power to idle.
Engine Failure and Forced Landing
Approximately 60 seconds after the oil pressure warning, the engine lost power completely. The pilot established best glide airspeed and set up for a forced landing. He overshot his initial chosen field but selected a second field. During the approach, the airplane clipped two sets of trees, and during the landing rollout it struck a wire fence. The pilot estimated the airplane slid about 20 feet after touchdown.
Inspection Findings
A post-accident inspection revealed a failure of an oil hose: the return hose from the oil cooler had a one-inch longitudinal split at a bend in the line. The pilot, who was also the builder, commented that he might not have properly accounted for the compound S-bend at that location during installation. The airplane had accumulated approximately 5.4 hours of operation at the time of the accident.
The pilot reported that the purpose of the flight was to conduct flight testing of the amateur-built experimental airplane, and he was also the owner/builder of the aircraft.