It was ideal flying weather. The twilight skies were clear, with only a few small clouds, and winds were a negligible 7 m.p.h. USAir Flight 427 was nearing Pittsburgh, Pennsylvania, after an uneventful flight from O'Hare Airport in Chicago. Right around 7 p.m. the pilot radioed approach control at Pittsburgh International Airport, set in heavily wooded, lightly populated hills 12 miles northwest of the Golden Triangle, that he was "in range," about to ask for landing clearance.
What happened next came so swiftly that people watching from the ground disagreed on the exact sequence. But as best their stories could be...