Catastrophic structural failure in flight
The Air Force accident investigation determined that B-47E 52-0470 suffered a catastrophic structural failure during high-stress training operations. The aircraft broke apart in mid-air with no crew survival. Investigators identified fatigue cracking in the fuselage center section, a problem that would later prompt corrective action under Project Milk Bottle.
Initial failure point
The fuselage longeron and center-section area experienced the first structural failure. This zone subsequently received reinforcement fleet-wide through Project Milk Bottle due to widespread cracking issues.
Wing separation
The right wing detached first, followed by rapid fuselage disintegration. The sequence aligned with eyewitness observations of the tanker crew and ground witnesses.
Stress loading
During a steep banking maneuver associated with the refueling approach, the airframe experienced extreme loads concentrated at the wing roots and fuselage frames.
No pre-breakup fire
The investigation found no evidence of onboard fire or explosion before structural failure. Fires observed by witnesses resulted from debris ignition after impact.
Structural fatigue confirmed
Metallurgical examination revealed fatigue cracking in recovered components, consistent with other B-47 losses and supporting the urgency of the reinforcement program described on the Project Milk Bottle page.
