Tragedy On Potosi Mountain
The accident was investigated by the Civil Aeronautics Board. Eyewitness and other evidence suggested Flight 3 proceeded from its departure in Las Vegas along essentially a straight line, 10° right of the designated airway, into high terrain that rose above their flight altitude of 8,000 ft (2,400 m).
Upon the basis of the foregoing findings and of the entire record available at this time, we find that the probable cause of the accident to aircraft NC 1946 on January 16, 1942, was the failure of the captain after departure from Las Vegas to follow the proper course by making use of the navigational facilities available to him.
1.) The use of an erroneous compass course
2.) Blackout of most of the beacons in the neighborhood of the accident made necessary by the war emergency
3.) Failure of the pilot to comply with TWA’s directive of July 17, 1941, issued in accordance with a suggestion from the Administrator of Civil Aeronautics requesting pilots to confine their flight movements to the actual on-course signals.