Investigation Summary
The accident occurred during a line check where the First Officer was flying from the left seat under the supervision of the Captain. As the aircraft reached approximately 100 feet in altitude, the crew reduced power, and a sharp yaw developed. A fire warning light for the number one engine illuminated, though the audible alarm did not sound. The First Officer throttled down the affected engine while the Captain, observing a loss of power on the BMEP gauge but not seeing the warning light, pulled the mixture to idle cutoff. When the First Officer attempted to manually feather the propeller, the Captain intervened, believing the automatic feathering system would handle the task. However, because the throttle had been retarded to a position aft of the arming switches, the auto-feather system did not activate. The resulting drag from the windmilling propeller caused the aircraft to lose altitude and crash into a valley beyond the runway.
Final Conclusions
The probable cause was determined to be uncoordinated emergency action in the very short time available to the crew, which produced an aircraft configuration with insurmountable drag. The initial mechanical trigger was the failure of an exhaust connector clamp, which allowed hot exhaust gases to blow directly onto an overheat detector, initiating the fire warning.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Raymond F. McQuade (Survived)
First Officer
Harlan V. Jesperson (Survived)
Systems & Failure Modes
Automatic Feathering System
A system designed to automatically feather a propeller in the event of engine failure to reduce drag; it requires the throttle to be above a specific position to remain armed.
BMEP Gauge
Brake Mean Effective Pressure gauge, used by the crew to monitor the power output of the engines.
Exhaust Connector Clamp
A mechanical component that failed, allowing high-temperature exhaust to leak and trigger the engine overheat/fire detectors.
Interesting Facts
- 01The flight was a multi-stop service to Newark with scheduled stops at Harrisburg, Reading, and Allentown.
- 02There were 33 passengers and 3 crew members on board.
- 03The First Officer was being line-checked by the Captain and was occupying the left seat.
- 04The aircraft (MSN 14103) was manufactured in 1951.
- 05The fire warning was a false alarm in terms of an active fire, caused by hot gases hitting a sensor.
- 06Both pilots survived the crash, but the flight hostess and 21 passengers were killed.
- 07The auto-feather system failed to activate because the throttle lever was moved too far back to keep the system armed.
- 08Rescue efforts were delayed by 20 minutes because fire trucks had to navigate narrow country lanes to reach the site.
Safety Actions & Advisories
Emergency Procedure Revision
Following the investigation, TWA revised its emergency procedures for powerplant fire or failure to prevent similar uncoordinated actions in the future.
Crew Coordination Review
The accident highlighted the dangers of uncoordinated cockpit actions during critical flight phases, reinforcing the need for standardized emergency procedures.