Site Of 1956 Collision Of Two Airlines Over Grand Canyon National Park Receives National Historic Landmark Status

This photo of the United Airline's Memorial in the Grand Canyon Cemetery was taken near the 50th Anniversary of the crash in 2006. NPS photo by Michael Quinn

Aviation safety has come a long way in the past half-century, including the development of nationwide radar coverage for air traffic control, a common military/civilian navigation system, new technologies such as collision avoidance systems and flight data recorders, and the establishment of the current Federal Aviation Administration (FAA). The impetus for those improvements can be traced to a tragic mid-air collision which occurred in 1956 over Grand Canyon National Park.

It's hard for us to grasp today just how rudimentary commercial air travel was in 1956 when compared to the state of the industry today. The two aircraft which were involved in what was to that date the worst civilian aviation accident in U. S. history were both propeller-driven...and considered state-of-the-art airliners. Neither aircraft had on-board radar or collision avoidance systems, and air traffic controllers had no ground-based radar to track the planes' current positions.

On the morning of June 30, 1956, Trans World Airlines Flight 2, a Lockheed L-1049 Super Constellation carrying 70 passengers and crew, departed Los Angeles International Airport, headed for Chicago. About three minutes later, United Flight 718, a DC-7 with 58 people aboard, took off from that same airport, en route to Chicago.

The initial flight paths of the two aircraft didn't coincide, but they merged over northern Arizona. Various histories of the crash indicate that both pilots were slightly off their designated routes, probably in order to provide an aerial view of the Grand Canyon for their passengers. Visibility at their assigned flight levels was probably hindered somewhat by clouds, and when the TWA captain requested a change in his assigned altitude to avoid some turbulence, air traffic controllers warned him that the United Flight was operating in the vicinity.

Some Details About the Accident Will Never be Known

Reconstruction of air accidents in the days before flight data recorders was an even bigger challenge than today, so some details will never be known, but the planes collided at about 10:31 a.m. over the park. The wreckage of both aircraft ended up in the depths of the Canyon, near the confluence of the Colorado River and the Little Colorado River. There were no survivors among the 128 people aboard both aircraft. A good summary of the incident is found here.

A history of the FAA notes, "The collision occurred while the transports were flying under visual flight rules (VFR) in uncongested airspace," and goes on to document the problems with aviation safety which were highlighted by the accident:

"The accident dramatiz[ed] the fact that, even though U.S. air traffic had more than doubled since the end of World War II, little had been done to expand the capacity of the air traffic control system or to increase safeguards against midair collisions. Sixty-five such collisions had occurred in the United States between 1950 and 1955."

"This was partly because the ATC system did not have the ability to segregate [visual flight rules] VFR traffic from instrument flight rules (IFR) traffic, or slow-moving flights from faster ones. Many experts recognized a need to institute positive control—requiring instrument flight over certain portions of the airspace irrespective of weather conditions."

"In the wake of the tragedy, Congress opened hearings to probe its relationship to the general problems of airspace and air traffic control management."

A Call to Action for Improved Air Travel Safety

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The severed tail section of TWA Flight 2 was one of the largest pieces of wreckage located in the Canyon. NPS photo

It's a sober bit of history that occurred somewhat by happenstance in a national park, but those hearings and the publicity about the crash helped spur numerous advances that make air travel much safer today. Air traffic controllers now have nationwide radar coverage, there's a common military/civilian navigation system, and collision avoidance systems and flight data recorders are now in wide use around the world.The establishment of an independent Federal Aviation Agency can be traced to the review of the accident over the Grand Canyon.

The collision site itself was in the air above the park, but the areas where both planes crashed were—and continue to be—very difficult to access. The remote location and rugged terrain made recovery operations extremely challenging; the combination of summer heat and the tricky wind currents that are always present in the Canyon tested the capabilities of both pilots and equipment in the 1950s era for helicopters. Initial work to recover victims and key parts of the wreckage in the weeks after the crash were followed by additional efforts over the next several decades. Due to the severity of the crash and subsequent fires, many of the victims could not be identified.

A large stone memorial at the Grand Canyon Pioneer Cemetery in the park marks the shared resting place for twenty-nine victims from the United Flight, and an equal number, who could be identified, are buried elsewhere. All but three of the 70 people aboard the TWA flight were interred in a mass grave in Flagstaff, Arizona.

National Historic Landmark Designation Announced In April

The aircraft accident site at Grand Canyon was one of four new National Historic Landmarks announced earlier this month during National Park Week by U.S. Secretary of the Interior Sally Jewell and National Park Service Director Jonathan B. Jarvis.

“This site really honors what we learned and how American society changed as a result of that accident,” said NPS spokesman Mike Litterst. Jon Proctor, a retired TWA flight service manager and an aviation journalist, told Cronkite News, "This accident woke up the industry, it really did."

Several media reports about this National Landmark designation have described it as the only such site that commemorates an aircraft crash site. To avoid any confusion, it should be noted that the Flight 93 National Memorial in Pennsylvia is an officially designated unit of the National Park System.

National Historic Landmarks designations, such as one the recently announced for the Grand Canyon accident site, are largely symbolic in nature, and the majority of such sites are owned by private individuals, universities, non-profit organizations, corporations, tribal entities, or local and state governments. Here's an explanation from the program's website:

"The National Historic Landmarks Program, established in 1935, is administered by the National Park Service on behalf of the Secretary of the Interior. The agency works with preservation officials, private property owners, and other partners interested in nominating properties for National Historic Landmark designation. Completed nominations are reviewed by the National Park System Advisory Board, which makes recommendations for designation to the Secretary of the Interior. If selected, property ownership remains intact but each site receives a designation letter and technical preservation advice."