It was ideal flying weather. The morning was dazzlingly clear, the ceiling and visibility unlimited, and a brisk, 20-mile-an-hour wind blew from the northwest. As New York waited to welcome Astronaut John Glenn, American Airlines' Flight One—nonstop to Los Angeles—screamed down the runway of International Airport at Idlewild, consuming a normal 5,000 feet of concrete before it left the ground in a perfect takeoff. Two minutes later, the flight...