on June 15, 1960: the probable cause was changed to “deviation from the prescribed flight path for reasons unknown” given that malfunction of the fluxgate compass as a contributing factor could not be entirely ruled out. Pilots had complained of that particular aircraft's radio-magnetic indicator (RMI) malfunctioning under certain operational circumstances, but maintenance personnel had been unable to duplicate the complaint on the ground and returned the aircraft to service. After the fatal flight, the captain, Ivan Spong, and co-pilot, James Creason, were primarily blamed for navigational malfeasance by the CAB, resulting in many instances of Captain Spong's widow receiving "death-threat" phone calls, presumably from victims' surviving relatives or friends. On May 14 members of the New Mexico Mountain Club who had participated in the initial recovery effort returned to the site to recover and bury any human remains left at the site before the summer climbing season. They collected over 150 pounds of remains and also recovered a Fluxgate compass from the remains of the left wing tip where it had been left by the impact. Because of a design wiring defect both the pilot's and copilot's RMI gauges were driven by the same Fluxgate compass which was the one recovered. As a result, there was no opportunity for either pilot to be aware of the erroneous data displayed on their RMIs. While "in order to accept the theory offered, the Board must conclude that both crew members were completely oblivious to all these [countervailing] indications, that their attention was focused entirely on the RMI, and that they did not cross-check any other flight instruments", this evidence convinced the CAB to amend the accident report to include instrument error as a possible contributing factor. The CAB's third version of their Accident Report discussed their willingness to work cooperatively with experts from the airline and the pilots' association toward revising its previous report. References External links Civil Aeronautics Board Final accident report - June 9, 1960 - PDF Albuquerque Mountain Rescue Council Sandia Peak Airliner accidents and incidents caused by instrument failure 260 Accidents and incidents involving the Martin 4-0-4 Airliner accidents and incidents in New Mexico Aviation accidents and incidents in 1955 Aviation accidents and incidents involving controlled flight into terrain History of Bernalillo County, New Mexico 1955 in New Mexico February 1955 events in the United States Aviation accidents and incidents in the United States in 1955