Investigation Summary
The investigation into Flight 7 was hampered by the extreme depth of the Pacific Ocean, leaving investigators with only floating debris and 19 bodies to examine. A significant finding was the presence of 'possibly disabling' levels of carbon monoxide in 14 of the 19 recovered victims. This led to theories ranging from an engine failure that breached the fuselage to malicious intent. A key piece of evidence was a section of an engine cowl support ring found embedded in a floating pillow; the lack of fire damage on this specific non-fuselage part helped investigators rule out a pre-impact fire in that section of the aircraft. Furthermore, the aircraft had a history of maintenance issues, including two 'hard' landings earlier in the year where inspection protocols, such as checking wing spar webs, were reportedly bypassed. Investigators also considered hazardous cargo, including sodium sulfide and cellulose acetate film, but found no evidence they contributed to the crash. Contrary to initial assumptions of a high-speed dive, the CAB concluded the aircraft likely attempted a successful ocean landing that failed only when the starboard wing dragged in the water. A later analysis of a Dictaphone recording suggested a possible distress call, but this was never officially confirmed.
Final Conclusions
The Civil Aeronautics Board (CAB) officially stated that it had insufficient tangible evidence to determine the cause of the accident. While carbon monoxide was found in the victims, investigators could not rule out post-mortem decomposition as the source, nor could they confirm if an in-flight fire or mechanical failure had occurred. The board noted that the airline's maintenance and airworthiness practices could not be accepted as normal in all respects, but no direct link to the crash was established.
Video Analysis
The Most Horrific Airline Tragedy in History: Pam Am Number 7 — A detailed look at the mysterious disappearance of the Clipper Romance of the Skies and the subsequent investigation into the Boeing 377 Stratocruiser's safety record.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Gordon H. Brown
First Officer
William P. Wygant
Second Officer
William H. Fortenberry, acting as pilot-navigator
Flight Engineer
Albert F. Pinataro
Systems & Failure Modes
P&W R-4360-B6 Engines
The four radial engines were suspected of potential failure, specifically the possibility of a turbocharger disk or propeller blade failure breaching the fuselage.
Propeller Control
The Boeing 377 fleet had a history of propeller overspeed incidents, which had caused two previous Pan Am ditchings.
Interesting Facts
- 01The aircraft was 90 miles north of its intended track when the wreckage was discovered.
- 02Pathologists found carbon monoxide in 14 of the 19 recovered bodies.
- 03A section of an engine cowl support ring was found embedded in a floating pillow.
- 04The aircraft had experienced a runaway propeller incident five months prior to the crash.
- 05Investigators found no evidence of an in-flight explosion or fire on the recovered debris.
Safety Actions & Advisories
Maintenance Practice Reassessment
The CAB recommended a reassessment of Pan Am's maintenance practices after finding that mechanics were skipping mandatory inspection steps and failing to document 'hard' landing inspections.
Known Controversies & Unanswered Questions
Carbon Monoxide Origin
Reference ↗There was significant debate over whether the carbon monoxide found in victims was caused by an in-flight emergency (like a fire or engine failure) or was a result of post-mortem decomposition.
The William Payne Insurance Claim
Reference ↗Insurance companies initially refused to pay a claim for passenger William Payne, an explosives expert who was heavily in debt and whose body was not recovered, leading to suspicions of sabotage that were later dismissed by the CAB.