Investigation Summary
On the morning of June 30, 1956, TWA Flight 2 and United Flight 718 departed Los Angeles just three minutes apart. Both aircraft were flying toward the same waypoint, the Painted Desert, using a combination of Instrument Flight Rules (IFR) and Visual Flight Rules (VFR). At the time, vast stretches of the United States were 'uncontrolled airspace,' where pilots were responsible for their own separation. TWA Captain Jack Gandy had requested to climb to 21,000 feet to stay '1,000 feet on top' of a cloud layer, placing him at the same altitude as the United flight. Because they were off-airways, Air Traffic Control (ATC) was not required to provide separation. The two aircraft converged at an angle over the canyon. Post-crash analysis of the wreckage indicated that at the moment of impact, the United DC-7 was banking right and pitching down, suggesting a last-second evasive effort by the crew. The DC-7's left wing and propellers struck the Super Constellation's rear fuselage and tail, causing the TWA aircraft to disintegrate and fall into the gorge. The United aircraft, missing a wingtip and suffering engine damage, crashed into a cliff face on Chuar Butte.
Final Conclusions
The Civil Aeronautics Board (CAB) determined the probable cause was that the pilots did not see each other in time to avoid the collision. Contributing factors included intervening clouds reducing visibility, the limitations of cockpit visibility, and the inherent risks of the 'see and be seen' principle in an era of increasingly fast aircraft. The CAB also considered that the pilots may have been preoccupied with normal cockpit duties or matters unrelated to flight, such as providing passengers with a scenic view of the canyon. The investigation highlighted that the ATC system was fundamentally incapable of managing the growing volume of high-speed commercial traffic, leading to a complete overhaul of American airspace management.
Video Analysis
The 1956 Grand Canyon Mid-Air Collision | Mayday: Air Disaster — A detailed look at the collision between United 718 and TWA 2, exploring how the disaster led to the creation of the FAA and modern air traffic control.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
See and Be Seen
The primary method of aircraft separation in uncontrolled airspace, relying entirely on pilot visual acquisition of other traffic.
Air Traffic Control (ATC)
In 1956, ATC only provided separation for aircraft flying on designated airways under IFR; 'off-airway' flights were largely unmonitored.
Interesting Facts
- 01This was the first commercial aviation accident to result in more than 100 fatalities.
- 02The collision occurred at approximately 21,000 feet near the confluence of the Colorado and Little Colorado Rivers.
- 03Both aircraft were flying in uncontrolled airspace where 'see and be seen' was the only method of collision avoidance.
- 04The wreckage was discovered by a scenic tour pilot who spotted smoke rising from the canyon.
- 05The crash sites were designated a National Historic Landmark in 2014.
Safety Actions & Advisories
Federal Aviation Act of 1958
The disaster directly led to the passage of this act, which created the Federal Aviation Agency (later Federal Aviation Administration) to oversee all U.S. aviation safety.
Modernization of Air Traffic Control
The accident spurred a massive investment in radar technology and the requirement for all high-altitude flights to be under positive ATC control.
Known Controversies & Unanswered Questions
Weather and Visibility Conditions
Reference ↗While the official report cited clouds as a factor in reducing visibility, some researchers argue that the sky was clear and the collision was due to pilots being distracted by sightseeing or attempting to fly faster.