Investigation Summary
The flight departed Salt Lake City at 14:00 local time amidst a regional storm that had deposited significant snow in the lowlands and even more in the mountain passes. Approximately 20 minutes into the flight, Pilot Lloyd Anderson radioed an 'All Okay' signal, which was the last communication received from the aircraft. When the plane failed to arrive in Cheyenne, a massive search effort was launched involving both air and ground teams, despite what operations managers described as the worst flying weather in the region's history. The wreckage was eventually spotted from the air on February 25, located about 35 miles east of Salt Lake City. The aircraft had crossed the summit of the pass and proceeded approximately three-quarters of a mile before impacting the terrain at high speed. The impact was so severe that the nose was buried in the earth and the tail was broken off, standing nearly vertical. All occupants were believed to have died instantly, with the pilots' watches stopped at 15:05.
Final Conclusions
The Department of Commerce and United Air Lines conducted separate investigations, both concluding that unfavorable weather was a contributing factor. Due to the extent of the demolition of the aircraft, investigators stated that a precise determination of the cause was impossible. However, the United Air Lines chief pilot theorized that the pilot may have been flying east and, upon suddenly seeing trees through the storm, attempted a 'chandelle' (a steep climbing turn) to avoid them. This maneuver likely caused the aircraft to stall and nose into the ground at high speed.
Video Analysis
No video analysis linked for this case file yet.
Crew Experience
Captain
Lloyd Anderson, age 32. Born in Canada. Licensed in 1926; extensive experience flying in Mexico (Mexicali, Mazatlan, Mexico City) and surveying mail routes. Joined United June 15, 1931. Survived a similar crash in the Wasatch Mountains in 1933.
Systems & Failure Modes
Boeing 247 Airframe
A pioneering all-metal, twin-engine transport aircraft. The accident aircraft was nearly demolished upon impact, leaving only the wings relatively intact but cracked.
Radio Communication
The crew utilized two-way radio to report status; the last successful transmission occurred 20 minutes after takeoff.
Interesting Facts
- 01The aircraft was a Boeing 247, serial number 1739, registered as NC13357.
- 02All eight occupants, including three crew members and five passengers, were killed.
- 03The wreckage was found wedged between two giant pine trees in a nearly vertical position.
- 04The pilot, Lloyd Anderson, was highly experienced with over 7,000 hours of flight time.
- 05One of the passengers was John J. Sterling, the Mayor of Benton Harbor, Michigan.
- 06Pilot Lloyd Anderson had survived a similar crash in the Wasatch Mountains (Rock Canyon) in 1933 after mistaking it for Provo Canyon.
- 07The crash site was located only a mile north of the airway beacon, which was invisible during the storm.
Safety Actions & Advisories
Stewardess Employment Policies
Source ↗At the time of the accident, United Air Lines required stewardesses to be unmarried. The death of Mary Carter revealed she had secretly married, highlighting the restrictive labor practices of the era which often forced crew members to conceal their personal status to maintain employment.