Investigation Summary
The aircraft (MSN 13759) was conducting a secret electronics test flight for the 3150th Electronics Squadron as part of Project Banshee. Shortly after departure from Robins Air Force Base, a fire broke out in the number 1 engine. Investigators later determined the fire likely originated from breaks in the right exhaust collector ring. The situation was compounded by the inadvertent feathering of the number 4 propeller, which the crew could not restart or unfeather. Additionally, two other engines lost power due to a combination of maintenance failures and pilot errors. Human factors played a significant role; the pilot, copilot, and flight engineer had never flown together before, and in violation of standard procedure, the civilian engineers on board had not been briefed on emergency procedures. This lack of preparation contributed to the chaos during the emergency, as civilians struggled to don parachutes while the aircraft spiraled. The Air Force's internal investigation found that the aircraft had not been in compliance with specific Technical Orders (01-20EJ-117 and 01-20EJ-178), leading to the conclusion that the bomber was not considered safe for flight at the time of departure. The resulting legal battle by the widows of the civilian engineers reached the Supreme Court after the government refused to release the accident report, citing national security. The court ruled in favor of the government, establishing the state secrets privilege.
Final Conclusions
The declassified accident report attributed the crash to a fire in the number 1 engine and the failure to unfeather the number 4 engine. The fire was likely caused by a failure in the exhaust collector ring. The report explicitly noted that the aircraft was not safe for flight due to non-compliance with Technical Orders 01-20EJ-117 and 01-20EJ-178, which may have aggravated the fire.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Exhaust Collector Ring
A component of the engine exhaust system; breaks in this ring were identified as the likely source of the fire in the number 1 engine.
Propeller Feathering System
A system used to turn propeller blades parallel to the airflow to reduce drag after an engine failure; an inadvertent feathering and subsequent failure to unfeather the number 4 engine contributed to the loss of thrust.
Sunseeker
An experimental infrared heat-seeking device being tested for use in missiles; its presence led to the classification of the flight.
Interesting Facts
- 01The crash killed three civilian RCA engineers who were on board to monitor the 'sunseeker' device.
- 02The aircraft was not in compliance with Technical Orders 01-20EJ-117 and 01-20EJ-178.
- 03The government asserted the state secrets privilege to withhold the accident report from the victims' families.
- 04The declassified report eventually revealed the 'secret' device was not mentioned in the accident findings and played no role in the crash.
Safety Actions & Advisories
Technical Order Compliance
The investigation emphasized the necessity of complying with Technical Orders 01-20EJ-117 and 01-20EJ-178 to ensure the fire safety of B-29 exhaust systems.
Known Controversies & Unanswered Questions
United States v. Reynolds State Secrets Privilege
Reference ↗The government claimed the accident report contained vital national security secrets to avoid liability. When declassified decades later, the report contained no information about the secret project, leading to allegations that the privilege was used to cover up maintenance negligence.