Donald Keyhoe in True Magazine

The action began at 12:40 a.m. on the night of July 20. At midnight, eight air-traffic controllers, headed by Harry G. Barnes. took over the watch at the Washington Center. The night was clear, traffic was light, and the men settled down for a routine watch.

To understand the queer events that followed, you must first have a clear picture of the Center's operations. The Center is located entirely apart from the airport tower, which directs take-offs and landings and close-in traffic. The radar room of the Center is a long, dimly lit chamber, darkened so scopes can be easily read. Its radar equipment, by which controllers have guided thousands of airliners through fog and storms, is an M.E.W. (Microwave Early Warning) type similar to the sets used by the air-defense forces.

On a nearby hill, a huge parabolic antenna, rotating six times per minute, transmits a narrow radio beam which swings around the horizon. When the beam strikes a plane, an "echo" or "return" is reflected back. Amplified, this appears as a small spot or "blip" on the face of a cathode-ray scope. The Center's main scope, 24 inches in diameter, has a pale lavender glow. Traveling around the glass, like a glowing clock hand, is a purplish streak called the "sweep" which shows the direction of the moving radio beam.

As the echo comes back from a cruising airliner, a small round violet blip appears on the scope. At that spot, the phosphor coaling of the glass maintains a diminishing glow. Every ten seconds, a new blip appears, showing the plane's changed position. The glass retains seven blips before the first one fades out. From the position of the blips and the space between them, the plane's course and speed can be seen at a glance, also its location, distance and compass bearing.

Besides the main scope, which is adjusted to show traffic within a 34-mile radius-a (38-mile circle-the Center operates two smaller console scopes which show the transmitter's full range of 105 miles, or a circle 210 miles in diameter.
Radarscopes show other things than planes in the sky-irregular blobs are reflected from thunderstorms, thin spotty blips from flocks of birds, spreading blotches caused by rain or snow clouds.

Very-high-frequency radar sets can pick up even cobwebs or clouds of nearby insects. But these do not appear on the M.E.W. scope, nor would their echoes resemble the clear, sharp blip of a plane. There are two known things which can cause somewhat similar echoes-balloons especially equipped with large panels of metal for radar tracking, and "chaff" or "window," which are strips of aluminum coil dropped by military planes to jam radar sets. The presence of either is indicated by their drift at the speed of the wind. Strips of chaff, usually dumped by the hundreds, cause heavy returns which trained radar men can easily recognize. In addition, chaff falls to the ground, so that its blips soon disappear.

On the night of July 20. none of tbcse things were involved, as an Air Force check has proved. The scope was clear of any strange objects until 12:40. At that moment, seven round blips, like those of planes, suddenly appeared in the southwest quadrant. Since no group of planes-military or civilian-was due to arrive, the Control Center men were immediatelv concerned. Harry Barnes, the senior controller, tracked the unknown visitors at 100-130 m.p.h.- a speed oddly low compared with their swift appearance.

Barnes quickly checked the consoles; both scopes showed the strange blips. He called in radar technicians; they found no flaw in the set or antenna.

Worried, though the low speeds didn't indicate Soviet bombers, he called the Washington Airport tower. To handle local traffic, the tower has a separate set, an A.S.R. (Airport Surveillance Radar) with a 30-mile range.
Tower operators Howard Cocklin and Joe Zacko both reported the strange blips on their scope, and in the same position. So did Air Force radarmen at Andrews Air Force Base, which uses an A.S.R. set. Not only that, visual observers at both points could see mysterious lights moving in the sky.

Flashing word to Air Defense, Barnes turned back to the scope. The unknown visitors had separated, were now over Washington, two near the White House, one close to the Capitol.

A few minutes later, the controllers bending over the scope got a new jolt. One blip track showed an abrupt 90 degree turn, something no plane could do. As the sweep came around, another of the strange objects suddenly reversed -its new blip "blossoming" on top of the one it had previously made. The unknown craft, or whatever it was, had stopped dead from over 100 m.p.h., then completely reversed direction- all in about five seconds.

"Then we noticed another strange thing," Barnes told me later. "Some blips suddenly disappeared, between sweeps. I couldn't explain it, until Jim Ritchey
called- 'Casey' Pierman to check on one group of the things."

Captain Pierman, flying a Capital airliner, had just taken off from Washington. In a few moments he radioed that he saw a bright light where the scope showed one of the objects. At the very instant he called the Center, the object raced off at terrific speed.

"It was almost as if whatever controlled it had heard us, or had seen Pierman head toward it," said Barnes. "He said it vanished from sight in three to five seconds. But here's the important point: at that very moment, the blip disappeared from the scope.

''That means it must have raced out of our beam between ten-second sweeps, It could have done this in one or two ways. First, it could make a steep climb at terrific speed, so that in ten seconds it would be above the vertical area swept by our M.E.W. set. [The beam's average altitude, at its highest point, is from 35,000 to 40,000 feet, far out, but it is much less near the airport. At 30 miles, it is about 8,500 feet, sloping to 1,200 at three miles.] Second, it could race horizontally off our 34-mile scope within ten seconds."