What happened
On June 30, 1956, at 0901, Trans World Airlines Flight 2, a scheduled passenger service, departed from the Los Angeles International Airport. The aircraft, a Lockheed L-1049, was operating an instrument flight rules (IFR) route toward Kansas City via several waypoints including Daggett and Trinidad. After takeoff, the crew transitioned through overcast conditions and contacted the Los Angeles tower for departure. During the flight, the crew requested a routing change to Daggett via Victor Airway 210, which was granted.
As the aircraft approached Daggett, the crew used company radio communications to request an increase in altitude from 19,000 to 21,000 feet. The Los Angeles Air Route Traffic Control Center denied this specific request due to the presence of United Air Lines Flight 718. Consequently, the flight was cleared to fly at 21,000 feet provided they remained 1,000 feet above the cloud tops (1,000 on top). The aircraft proceeded through the area, reporting its position near Las Vegas at 0959 and estimating its arrival at the Painted Desert line of position at 1031.
At approximately 1031, while operating in visual flight rules (VFR) conditions at 21,000 feet, a mid-air collision occurred between the Lockheed L-1049 and a Douglas DC-7. The impact took place near the Grand Canyon area. At the moment of impact, the two aircraft were converging at an angle of approximately 25 degrees, with the Douglas DC-7 positioned to the right of the TWA aircraft.
Findings
Investigations into the collision determined that the pilots failed to see one another in time to take evasive action. Several contributing factors were identified, including the presence of intervening clouds and cumulus buildups that reduced the window for visual separation. Other potential factors included cockpit visibility limitations, crew preoccupation with flight duties or passenger service, and the lack of air traffic advisory services in uncontrolled airspace.
While the Salt Lake controller had position reports for both aircraft, the collision occurred in uncontrolled airspace where traffic information was not required to be issued by the controller. There was no evidence of mechanical failure or malfunction on either aircraft contributing to the accident.