What happened
The Boeing B-17 departed Great Falls, Montana, bound for Ainsworth Field in Nebraska. During the flight, weather conditions deteriorated significantly, bringing clouds and icing to the aircraft's operating environment. While flying over Melstone, the plane entered an uncontrolled descent. Maintaining a relatively flat attitude during this phase, the aircraft impacted the slope of Mt Bull, located south of Musselshell.
Upon striking the ground, the airframe slid along the terrain. It passed between two pine trees, which tore off the wings before the wreckage came to rest. The impact caused the fuel system to rupture, and the aircraft immediately burst into flames. The fire destroyed the airplane completely. All 12 occupants were killed in the accident. The crew consisted of ten military personnel from the 2nd Bomb Group, including the pilot, co-pilot, flight engineer, navigator, radio operator, bombardier, and four air gunners. Two additional passengers were also on board.
Findings
Investigations into similar incidents involving this aircraft type revealed that elevator fabric had torn loose from the supporting metal trailing edge structure. Boeing accident investigators determined that this separation was caused by a specific attachment method used on the elevators. Unlike traditional hand lacing, which passed needles between fabric threads, the pronged clips used in this instance created small tears in the material. These minor defects escalated into full attachment separation under aerodynamic pressure.
An engineering fix had been designed and implemented on production models, with follow-on Army Technical Orders issued to retrofit in-service aircraft. However, the specific aircraft involved in this crash had not received the necessary modification, leaving it vulnerable to the structural failure that contributed to the loss of control.