, on 1 February 1936. Robert Forbes Shirley died on 30 June 1956 in Arizona
On the morning of June 30, 1956, two airliners took off within minutes of each other from Los Angeles. United Flight 718 for Kansas City, a DC-7, climbed eastward above the great Mojave Desert to its requested cruise altitude of 21,000 feet. The other was a Lockheed Super Constellation, TWA Flight 2, also climbing toward the east. Destination: Chicago Midway. Both were on instrument flight plans under the control of the CAA (Civil Aeronautics Authority). TWA 2 was assigned 19,000 feet.
Over Arizona, both airliners obtained clearances to divert "off airways."
It was the custom of that time on commercial flights to give passengers a view of the Grand Canyon. There were towering clouds over much of Arizona, and the pilot of TWA 2 radioed a request for a higher altitude in order to fly above them. The request was denied by the CAA enroute controller in Salt Lake City.
According to the "hemispheric rule," eastbound instrument flights are assigned odd altitudes. The next such for TWA 2 would have been 21,000 feet, which was already occupied by United 718. The pilot of the Constellation elected to go "visual" and cancelled his instrument flight plan. Under the visual flight rules in effect at that time, a plane could legally fly at any altitude and in any direction so long as it remained clear of clouds. "See and avoid" then became the operative principle for separation. TWA 2 climbed to 21,000 feet.
Unknown to each other, the two airliners -- one a silver-winged cylinder with tall tail marked in red, white, and blue, the other having an inflected fuselage, gleaming white, and triple tail -- each with four perfect engines delivering rated power, each gently banking above the clouds, their passengers gaping at the natural wonders below -- two crafted marvels of performance and reliability took up momentary courses that converged in the sky.
All persons aboard both planes, a total of 128, died. Front pages around the world pictured only sooted rocks and aluminum shards glinting on the desert cliffs. Inaccessible silence. The worst such tragedy of its time. But not the last.
Bob Shirley was the pilot of the United flight.