Investigation Summary
Pan Am Flight 6 was a round-the-world service that began in Philadelphia on October 12 using a Douglas DC-6B. At Honolulu, the service switched to a Boeing 377 Stratocruiser, registration N90943, for the final leg to San Francisco. After departing Honolulu and reaching its assigned altitude of 21,000 feet, the number 1 engine began to overspeed. The crew attempted to feather the propeller, but the mechanism failed. To prevent further damage, the oil supply was cut, causing the engine to seize, but the propeller continued to windmill, creating significant aerodynamic drag. This drag necessitated high power settings on the remaining engines and a descent to lower altitudes. Approximately two hours later, the number 4 engine began to lose power and backfire, eventually failing completely. With only two engines remaining and the drag from the windmilling number 1 propeller, the Stratocruiser could not maintain enough speed to reach San Francisco or return to Honolulu. Captain Ogg navigated to Ocean Station November, where the USCGC Pontchartrain was stationed. The aircraft circled the ship for several hours to burn off fuel, reducing weight and fire risk, while waiting for dawn to ensure better visibility for the ditching. The ditching was executed at 06:15 local time; the aircraft's tail section broke off upon impact, but all 31 occupants successfully evacuated into life rafts and were picked up by the Coast Guard within minutes.
Final Conclusions
The Civil Aeronautics Board (CAB) investigation concluded that the accident was caused by a double mechanical failure. The initial failure involved the number 1 propeller's feathering mechanism, which prevented the crew from stopping the windmilling propeller and its associated drag. The subsequent failure of the number 4 engine left the aircraft with insufficient power to overcome the drag and reach a landing strip, necessitating the ditching. The successful outcome was attributed to the crew's decision to wait for daylight and the immediate proximity of the U.S. Coast Guard rescue vessel.
Photographic Evidence (1)
Video Analysis
"Ready On Ocean Station November" Pan Am Flight 6 Ditching — Official U.S. Coast Guard film documenting the emergency circling, ditching, and rescue of Pan Am Flight 6 near the USCGC Pontchartrain in October 1956.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Richard N. Ogg
First Officer
George L. Haaker
Navigator
Richard L. Brown
Flight Engineer
Frank Garcia Jr.
Systems & Failure Modes
Propeller Feathering System
A system designed to turn propeller blades parallel to the airflow to stop rotation and minimize drag after an engine failure. The failure of this system on engine number 1 caused the propeller to windmill, creating the drag that led to the ditching.
Pratt & Whitney R-4360 Wasp Major
The aircraft was powered by four of these 28-cylinder radial engines. Two of these engines failed during the flight.
Interesting Facts
- 01All 31 people on board survived without fatalities.
- 02The aircraft was a Boeing 377 Stratocruiser named 'Clipper Sovereign of the Skies', MSN 15959/36, manufactured in 1949.
- 03The ditching occurred near 'Ocean Station November', a fixed Coast Guard weather ship position.
- 04The tail section of the aircraft broke off during the water landing, a known vulnerability of the Boeing 377.
- 05The event was filmed by the U.S. Coast Guard, providing rare contemporary footage of a commercial ditching.
Safety Actions & Advisories
Ditching Procedures Refinement
The success of the rescue reinforced the value of Ocean Station vessels and led to improved coordination between commercial airlines and the Coast Guard for mid-ocean emergencies.