Fog had closed in Frankfurt's Rhine-Main Airport one night last week; the administration building's lights could not be seen across the field. Near the runway, in a red and white checkered trailer, three G.I. technicians bent over their separate receivers—Search Scope, Middle Scope, Final Scope.
At 5,000 feet, 18 miles away, Search Scope picked up a moving white dot. It was a C-47 from the U.S. Air Force's Berlin airlift. Carefully watching the calibrations which told him the plane's altitude, speed and distance, the G.I. at Search Scope called over his microphone to the pilot: "Calling Easy Charlie three nine...