What happened
The incident involved the first prototype of the Boeing 299, which was later designated as the Boeing B-17 Flying Fortress. The aircraft carried the registration NX13372 and was conducting a local test flight out of Wilbur Wright Field, located near Dayton. Shortly after lifting off, the plane lost control and stalled. It subsequently crashed into an open field situated just beyond the end of the runway. Upon impact, the airframe burst into flames.
The pilot was killed in the accident. Three other occupants sustained serious injuries during the crash. One of these survivors, who served as the flight engineer on board, succumbed to their injuries a few days later. This event marked a significant loss for the test team, as the aircraft represented an early development stage of what would become a major military transport and bomber platform.
Findings
Investigations into the accident determined that the loss of control immediately following takeoff was caused by locked ailerons. This mechanical failure prevented the crew from maintaining proper lateral stability during the critical climb-out phase, leading directly to the stall and subsequent crash.