Investigation Summary
Flight 845 was a multi-leg journey from Seattle to Sydney, with stops in Portland and Honolulu. Shortly after departing Portland, while climbing through 10,000 feet, the crew experienced a sudden, violent vibration. The number 3 engine and its propeller separated from the aircraft, causing significant aerodynamic damage and control difficulties. The captain, realizing the aircraft could not maintain altitude or reach land, opted for an emergency ditching. The impact with the water was severe but the fuselage remained intact long enough for the majority of those on board to evacuate into life rafts. The rescue was facilitated by the proximity of the USS Bayfield, a Navy attack transport, which reached the survivors within two hours. The investigation focused on the Hamilton Standard 24260 hollow steel propeller blades, which had a history of fatigue issues on the Stratocruiser fleet. While this 1955 event is often overshadowed in museum archives by a 1971 accident involving the same flight number and a Boeing 747, the 1955 ditching remains a landmark case in emergency water landing procedures.
Final Conclusions
The Civil Aeronautics Board determined the probable cause was the failure of the number 3 propeller, which resulted in the separation of the engine and subsequent loss of control. The failure was attributed to a blade fracture, a known vulnerability in the hollow steel propellers used on the Boeing 377. The successful ditching and evacuation provided critical safety data that influenced future emergency procedures, notably contributing to the survival of all passengers on Pan Am Flight 6 the following year.
Photographic Evidence (1)
Video Analysis
Pacific Ocean Ditching | Pan Am Flight 845/26 — A look at the 1955 ditching of a Pan Am Stratocruiser off the Oregon coast following a catastrophic engine separation.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Captain H. S. Miller
First Officer
First Officer P. E. Dixon
Second Officer
Second Officer J. N. Zerega
Flight Engineer
Flight Engineer G. M. Avery
Systems & Failure Modes
Hamilton Standard 24260 Propellers
Hollow steel propeller blades that were prone to fatigue cracking, which could lead to catastrophic blade failure and engine separation.
Pratt & Whitney R-4360 Wasp Major
The four 28-cylinder radial engines powering the Stratocruiser; the number 3 engine detached completely following the propeller failure.
Interesting Facts
- 01The aircraft was named 'Clipper United States'.
- 02The ditching occurred in water approximately 1,600 meters (5,200 feet) deep.
- 03The USS Bayfield, a Navy attack transport, performed the rescue approximately two hours after the ditching.
- 04Lessons learned from this evacuation were credited with saving lives during the ditching of Pan Am Flight 6 in 1956.
- 05The flight number 845 was later involved in another major accident in 1971 involving a Boeing 747 at San Francisco.
Safety Actions & Advisories
Propeller Inspection and Replacement
The industry accelerated the phase-out of hollow steel propeller blades in favor of solid aluminum blades to prevent similar fatigue-related separations.
Ditching Procedure Refinement
Pan Am updated its cabin crew training and emergency ditching protocols based on the evacuation challenges faced during this event.