“This Is Only a Test”
Fifty years ago, cold-war games halted all civilian air traffic—long before September 11 did the same.
- By Roger A. Mola
- Air & Space magazine, March 2002
National Archives and Records Administration
AT 8:53 A.M. ON SATURDAY, OCTOBER 14, 1961, Pacific Air Lines flight 715 from Sacramento rolled to its gate at Los Angeles International Airport and shut down its engines for 12 hours. At ticketing posts, a corps of temporary guides straightened their "World Way Blue" uniforms and accepted 50 cents for 20-minute tours of the new passenger terminal and the ramp. Inside the Pan Am 707 Jet Clipper Liberty Bell, stewardesses poured fresh Hawaiian fruit juice.
At every gate across the airport, airliners were receiving visitors but not passengers. United showed off its DC-8 and Boeing 720 jets, Convair 340, and Douglas DC-7A cargoliner. Bonanza opened its Fairchild F-27; Pacific Air Lines a Martin 4-0-4, and National Airlines a Lockheed Constellation. On the LAX ramp sat Western Airline’s tiny 1926 Douglas M-2 biplane.
LAX was only one of many airports to shut down. Nationwide, 50 civilian airports held open houses. But most passenger terminals just turned off the lights. Except for aircraft in Hawaii, the entire U.S. and Canadian commercial fleets and all civilian aircraft were grounded.
On that day, and on two others in the early 1960s, the airliners had to make way for waves of B-52 and B-47 bombers that were to cross from Canada into the United States and enter the continent from the coasts in a simulated Soviet nuclear attack. The three simulations, known as Sky Shield, were training exercises for the personnel, communications, and radar detection systems of North America. The plan was to make sure that the bombers were detected by radar and other early-warning systems, that interceptor and missile squadrons would be alerted and scrambled, and that the United States would remain able to strike back.
Operation Sky Shield II, which ran for 12 hours in October 1961, was the second time—and the longest—that U.S. civil air traffic had been grounded. The first was Sky Shield I, run on September 10, 1960, from 2 a.m. to 8 a.m. Eastern Daylight Time. The third and final time—until last September—was Sky Shield III: five and a half hours beginning at 3 p.m. EDT, September 2, 1962.
In 1951, 30 radars—the Pinetree Line—were constructed along the U.S.-Canada border. By 1954 Pinetree provided early warning of threats and control of friendly aircraft. In 1953, the first station of the more capable Distant Early Warning Line opened at Barter Island, Alaska. By 1957, nearly 60 DEW Line radars were installed 100 to 500 miles apart, within two degrees of the 69th parallel from Cape Lisburne, Alaska, to Cape Dyer, Baffin Island. The new Mid-Canada Line, which ran along the 55th parallel from British Columbia to the Labrador Sea, employed 90 unmanned stations consisting of an electronic "trip wire," an application of the Doppler effect, to detect aircraft.
Continental air defense seemed technically capable, but, untested by war, its true reliability was unclear. General Earle Partridge, commander-in-chief of North American Air Defense Command, hatched a plan for the first live test of the entire continental air defense force. Operation Sky Hawk was set for September 1959 but canceled days before, under the new NORAD commander, General Laurence S. Kuter. Would-be participants were advised to destroy all records. Representatives of the U.S. President, the Air Defense Commands of the United States and Canada, and the Canadian Chiefs of Staff Committee revisited the plan at Camp David, Maryland, on November 7, 1959, agreeing to the first (new and improved) joint exercise.
In October, the Ballistic Missile Early Warning System, which consisted of both detection and tracking radars, opened at Thule, Greenland. Detection radar was a fixed fan parabola, 165 feet high and 400 feet long—a football field on its side sending an invisible "V" 2,000 miles north toward the Soviet Union. The screen could withstand earthquakes and winds of 180 mph. Within the installation’s radomes were 55-ton tracking radars, which followed objects horizon to horizon.