Primary finding
Probable cause
The loss of engine power due to a malfunctioning fuel pump.
Investigator assessment
Analysis narrative
The pilot flew the airplane for about 30 minutes and then returned to the airport for landing. As the airplane approached the airport, the engine lost power, and the pilot conducted a forced landing short of the runway. Fuel was found onboard, and it was not contaminated. Testing of the engine's fuel pump revealed that the fuel pressure oscillated due to a malfunctioning relief valve in the fuel pump. It is likely that the engine lost fuel pressure and subsequent power during the accident flight as a result of the malfunctioning fuel pump.
Source record
Factual narrative
On October 31, 2013, about 1230 central daylight time, a Pitts S-1S, airplane, N67JC, impacted terrain after experiencing a loss of engine power near Wellington, Kansas. The commercial rated pilot, sole occupant, was not injured, and the airplane was substantially damaged. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from the Wellington Municipal Airport (KEGT), Wellington, Kansas about 1200. The pilot reported to the responding Federal Aviation Administration inspector, that he earlier had flown the airplane for about thirty minutes. As he approached the airport for landing, the engine lost power and was unable to make the runway. The pilot executed a forced landing short of the runway and impacted a berm, which resulted in substantial damage to the right rear wing spar. Additionally, fuel was available and appeared free of contaminants. An initial examination of the engine did not reveal a reason for the loss of power; however, additional testing of the fuel pump, by the owner, who is also an aircraft mechanic, revealed an issue with the fuel pump. The owner reported that during testing, the fuel pressure would oscillate, and during one test, went to zero, and the engine stopped. He added that he thought the low fuel pressure was the result of a malfunctioning relief valve in the fuel pump, and this was also the reason why the engine quit during the accident flight