Investigation Summary
The flight was a multi-leg journey from Bombay to New York. After a crew change and refueling in Cairo, the aircraft departed for Rome. Approximately 20 minutes into the flight, while climbing through 10,000 feet, the rear master rod bearing in the Wright R-3350 Duplex-Cyclone engine failed. This mechanical failure caused the rear crankpin to overheat, leading to the failure of all rear connecting rods. The rods punctured the cylinder walls and crankcase, severing oil lines and igniting a massive fire. Despite the crew's attempt to feather the propeller and return to Cairo, the intensity of the fire caused the entire engine assembly to burn through its mounts and fall off the aircraft. Faced with a continuing wing fire and the loss of an engine, the crew attempted a forced landing in the dark over the Western Desert. The aircraft struck the ground near a narrow-gauge railway, plowing through the tracks and scattering wreckage over 500 yards.
Final Conclusions
The Civil Aeronautics Board (CAB) determined the probable cause was the failure of the rear row master rod bearing, which precipitated an uncontrolled fire and subsequent crash landing. Investigators identified sludge buildup in the crankpins as the root cause, which had restricted the flow of lubricating oil to the bearings. This finding led to industry-wide improvements in oil screen designs, the implementation of crankpin plugs to prevent sludge accumulation, and revised oil change intervals for the Constellation's engines.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Walton Webb, 45. Employed by TWA since July 1, 1940.
First Officer
Halden Hammitt, 34. Employed by TWA since September 12, 1945.
Systems & Failure Modes
Rear Master Rod Bearing
A critical internal engine component that failed due to oil starvation, leading to total engine destruction.
Crankpin Oil Passages
Internal channels that became blocked by sludge, preventing lubrication from reaching the master rod bearing.
Propeller Feathering System
Used by the crew to stop the rotation of the damaged engine, though it could not stop the fire already fueled by severed oil lines.
Interesting Facts
- 01The aircraft was named 'Star of Maryland' and was only a few months old with 1,100 total flight hours.
- 02The aircraft's manufacturer serial number (MSN) was 2636.
- 03Among the victims were Egyptian actress Camelia, Polish architect Maciej Nowicki, and Indian mathematician S. S. Pillai.
- 04The wreckage was located 65 miles north-northwest of Cairo after searchers trekked 15 miles across the desert.
- 05The impact occurred near a narrow-gauge railway, destroying a section of the track.
- 06The fire was so intense that the engine fell completely free of the airframe before the final impact.
Safety Actions & Advisories
Engine Lubrication Modification
Implementation of improved oil screens and crankpin plugs to prevent the accumulation of sludge in engine oil passages.
Maintenance Procedure Revision
Revised oil change intervals were established to ensure cleaner oil circulation in high-performance radial engines.