Investigation Summary
The investigation highlighted a critical failure in emergency preparedness and mechanical maintenance. The No. 1 engine had exceeded its 1,500 hour overhaul limit by 225 hours due to a clerical error at Northwest Airlines. During the flight, this engine suffered a rapid loss of oil pressure, forcing a feathering of the propeller. The diversion to Sandspit was necessitated by weather at Annette Island being below minima. A key technical factor was the Douglas DC-4's nose gear design, which was known to struggle with retraction in cold weather or during crosswind/three-engine operations requiring nose wheel steering. Investigators believe the nose gear failed to retract fully during the go-around, creating excessive drag that, combined with ice accretion on the airframe, prevented the aircraft from maintaining altitude.
Final Conclusions
The Civil Aeronautics Board concluded the probable cause was a nose gear retraction difficulty coupled with icing conditions or power loss, rendering the aircraft incapable of flight. A significant contributing factor to the high death toll was the lack of passenger preparation for a ditching and the failure to deploy life rafts, despite the aircraft remaining intact long enough for evacuation.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
John J. Pfaffinger, age 38. Fatality.
First Officer
Kenneth H. Kuhn, age 32. Fatality.
Systems & Failure Modes
No. 1 Engine Oil Cooler
A failure in this component led to a rapid loss of oil pressure, necessitating the shutdown of the engine.
Nose Landing Gear
Suspected failure to fully retract during the go-around, creating drag that prevented the aircraft from climbing.
Life Rafts
Stowed at the rear of the cabin but not successfully launched or utilized during the evacuation.
Interesting Facts
- 01The aircraft was leased to Northwest Orient Airlines by Trans World Airlines (TWA).
- 02The No. 1 engine had been operated 225 hours past its scheduled overhaul due to a clerical error.
- 03All 36 fatalities were attributed to drowning or hypothermia rather than the impact itself.
- 04The nose gear on the DC-4 was known to have retraction difficulties in cold weather when nose wheel steering was utilized.
- 05No emergency instructions were given to passengers regarding ditching or life raft usage prior to the impact.
Safety Actions & Advisories
Maintenance Record Audit
The investigation identified a clerical error in tracking engine hours, leading to a review of Northwest Airlines' maintenance scheduling procedures.