This is Throwback Thursday #323. In these, we look back into the past at ESCONI specifically and Earth Science in general. If you have any contributions, (science, pictures, stories, etc …), please send them to esconi.info@gmail.com. Thanks! email:esconi.info@gmail.com.

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Newspapers.com recently featured an interesting article about the tragic mid-air collision over the Grand Canyon on June 30, 1956. TWA Flight 2, a Lockheed Super Constellation en route to Kansas City, collided with United Flight 718, a DC-7 bound for Chicago. Both aircraft had departed from Los Angeles, and the collision is believed to have occurred at an altitude of about 21,000 feet.

Tragically, there were no survivors or eyewitnesses to the collision. Investigators also lacked the benefit of cockpit voice recorders and flight data recorders, which were not yet in widespread use, making it difficult to determine exactly what had happened.

During the investigation, however, a crucial piece of evidence emerged. Investigators discovered blue paint streaks on the fuselage of the TWA aircraft. The paint was matched to the blue paint used on the United DC-7, conclusively confirming that the two airliners had collided in mid-air, which was a theory already suspected because both aircraft disappeared from radar and crashed at nearly the same time.

On June 30, 1956, two commercial airliners flying at 21,000 feet collided over the Grand Canyon in Arizona. The crash killed 128 people and was the deadliest aviation disaster in U.S. history at the time. The tragedy led to major changes in aviation safety and the creation of what is now the Federal Aviation Administration.

In 1956, commercial airline travel was still a novelty for most Americans. Fewer than one in three people flew that year.

On Saturday morning, June 30, TWA Flight 2 departed Los Angeles International Airport at 9:01 am. The Lockheed Super Constellation carried 70 crew and passengers and was headed to Kansas City. Three minutes later, United Flight 718, a DC-7 headed for Chicago, also departed Los Angeles International Airport carrying 58 crew and passengers.

The TWA flight climbed to 19,000 feet, and the United flight climbed to 21,000 feet, giving both planes plenty of space between them. Still over California, the TWA pilot requested permission to climb to 21,000. His request was denied, as it would put both planes at the same altitude. When the TWA flight once again requested permission to fly above the weather, possibly to avoid thunderstorms, the request was granted. Air Traffic Control (ATC) assumed that clear skies would allow both pilots to see the other aircraft. Neither pilot was apprised of the other’s position.

Unbeknownst to both aircraft, they were on a collision course. Both pilots reported to ATC that they would reach the Painted Desert line at 10:31 am. The Painted Desert line ran between Bryce Canyon, Utah, and Winslow, AZ. It was between VORs, or navigational ground beacons, making the area uncontrolled and without active radar. Both planes were approaching the Grand Canyon at the same altitude and nearly the same speed.