History of Flight
On October 14, 2015, at 1510 mountain daylight time, a Bucker Jungmeister BU 133/C, registration N1940J, crashed in a parking lot during the initial takeoff climb at Missoula International Airport (MSO), Missoula, Montana. The pilot was fatally injured, and the airplane was destroyed. The airplane was owned by the pilot and operated under 14 Code of Federal Regulations Part 91 as a personal cross-country flight destined for Alabama. Visual meteorological conditions prevailed, and no flight plan had been filed.
The pilot had purchased the World War II-era single-seat biplane the day before the accident. According to the former mechanic for the airplane, on the day of the accident, the previous owner contacted him about the pilot experiencing fuel running into the cockpit. The mechanic spoke with the pilot, who reported that after refueling at The Dalles, Oregon, and later in Coeur d'Alene, Idaho, he encountered fuel on the floor and down the cockpit tubing when lowering the nose. The pilot shut off all electrical power, and the problem subsided. The mechanic suggested the fuel tank might not be venting properly and advised against flying until the issue was fixed, but the pilot indicated he needed to proceed to Alabama. The pilot stated he would depart Missoula with all electrical power off. The mechanic learned of the crash about 20 minutes after their conversation.
Witnesses at the Northstar Jet fixed base operator reported that the pilot pumped his own fuel and spilled some during fueling, adding 14 gallons. No personnel reported helping inspect the fuel system.
Witness Observations
Several witnesses observed the takeoff. A mechanic at another FBO stated that during takeoff from runway 25, the airplane appeared to have plenty of power and sounded good. Once airborne, the airplane made a hard-right turn with increasing bank angle. Another witness described a steep right bank and descent. A third witness reported that after rotation, the airplane climbed quickly and made an immediate right turn; the rate of climb decreased, and the airplane began to sink as it continued turning. After about 180 degrees of turn, the airplane "suddenly rolled about 90° to the right as the wing stalled" and entered a spin, descending "almost straight down" into a rental car lot at the airline terminal. A fire erupted on impact. Another witness saw the airplane about 80 ft above ground level enter a hard-right turn, then descend and impact, noting the engine sounded like it was "powering up." A witness at the eastern end of the rental car lot stated the engine was running at impact.
Aircraft Information
The airplane was a Bucker Jungmeister BU 133/C, serial number not specified in the source. The last maintenance was an annual inspection completed on June 12, 2015, at an airplane total time of 2,038.9 hours. The engine was a radial piston Warner Aircraft Engines Scarab 165, serial number 2031A; at the annual inspection, the engine total time was 909.4 hours, with 32.7 hours since major overhaul.
Medical and Pathological Information
The Montana Department of Justice Forensic Science Division conducted a postmortem examination. The cause of death was listed as blunt force trauma with thermal injuries and smoke inhalation. The FAA Bioaeronautical Sciences Research Laboratory performed forensic toxicology on specimens from the pilot; results were negative for cyanide, ethanol, and drugs of abuse, but positive for carbon monoxide at 10% in heart blood.
Tests and Research
According to Northstar Jet personnel, two company airplanes had refueled before the accident airplane using the same fuel truck. The fuel was tested with no discrepancies noted. A visual engine examination revealed no obvious mechanical problems. The engine could not be manually rotated due to impact displacement. The number three cylinder had separated from the crankcase. Both magnetos remained attached; the left magneto produced spark when rotated, while the right magneto had fire and impact damage but no mechanical malfunctions upon disassembly. The fuel system was compromised by the postcrash fire. The fuel selector was removed and tested: initially, compressed air did not escape from any position, but after manually moving through positions, air exited each opening, indicating functionality.