Accident Overview
A private pilot/mechanic and the airplane's owner, also a private pilot, were conducting a personal maintenance test flight under 14 CFR Part 91 when the airplane lost engine power and subsequently collided with two residences. Both occupants of the airplane received fatal injuries. No injuries occurred on the ground.
Witness Accounts
Multiple witnesses observed the accident sequence. The airplane had just departed a local non-tower airport and was in the initial climb phase when it turned right, then left, as if attempting to return to the airport. Witnesses reported seeing the wings rock from side to side before the airplane entered a steep, nose-down attitude. A student pilot witness described seeing the airplane flying low and slow overhead; he saw the nose go up, then down, into what he characterized as a "classic stall-spin."
Another witness, who spoke with the owner prior to takeoff, was told there was a problem with the fuel system and they were conducting a maintenance test flight. The owner stated that the pilot/mechanic had "blown out the fuel system" earlier that day. Additional witnesses observed the airplane taxi to the run-up area, where it ran at high power for several minutes. After departure, everything appeared normal until the airplane initiated a left turn toward the airport, a maneuver they considered unusual. Numerous witnesses reported hearing the engine "cutting in and out," as if it were "running out of gas," before it eventually lost power.
Fuel and Postcrash Findings
The airport's fuel truck operator stated he had not fueled the airplane on the day of the accident. At the accident site, the NTSB investigator-in-charge (IIC) was informed by a firefighter that there was no postcrash fire and that no significant amount of aviation fuel was found at the site. Inspection revealed that the airplane's four fuel tanks were breached during impact, but there were no signs of fuel leaks, pooling of fuel on the ground, fuel blight on surrounding vegetation, and only a slight odor of fuel around the wreckage.
Engine Examination
The IIC, along with a representative of the engine manufacturer, conducted an examination of the engine. The intact fuel injection manifold valve and associated fuel lines were disassembled, and no fuel was present. Further examination of the airframe and engine revealed no evidence of any preimpact mechanical problems.
Registration and Parties
[Note: The source did not provide the aircraft registration number, so it is omitted.]