Amateur-built LANCAIR IV P accident near Fallbrook, California, April 2, 2016

The NTSB's narrative final · quoted from the NTSB record

About 15 minutes after departing on the cross-country flight, the experimental, amateur-built airplane experienced a loss of engine power, and the private pilot considered landing on a 550-ft-long airstrip for remote-controlled aircraft. After observing numerous people on and near the runway, he subsequently decided to land on an interstate highway. Upon touching down with the landing gear retracted, the airplane slid into a car parked on the paved shoulder of the highway, fatally injuring one of the car's occupants. Video footage captured by a cell phone inside the airplane showed normal engine indications before the accident. A video taken shortly thereafter did not capture the instrument panel or engine indications; however, the engine could be heard surging. The airplane was equipped with fuel tanks in the left and right wings, as well as a fuselage tank. The right and left wing tanks each had a capacity of 52 gallons, and the capacity of the fuselage tank was 33 gallons. The fuel system was configured so that the left wing tank connected to the fuselage tank, and the engine would draw from the fuselage tank. The fuselage tank did not have a dedicated fuel quantity gauge; the pilot stated that he knew it was full when the wing tank gauge began to indicate above zero. The pilot stated that before departing on the accident flight, the left fuel tank quantity gauge indicated 1 gallon, which corresponded to 34 gallons available. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A test run of the engine at low, intermediate, and high power settings was successful. The fuselage tank was breached during the accident, and an undetermined quantity of fuel leaked out. The gascolator did not contain any fuel, and the line from the gascolator to the engine-driven fuel pump, as well as the fuel inlet line to the fuel manifold, contained no fuel. The lack of fuel in these areas, coupled with the engine surging heard on video, may be an indication of fuel starvation; however, since the investigation was unable to determine the total quantity of fuel on board the airplane, the reason for the loss of power and engine surging could not be determined.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.