Skies reopen: civilian flights resume across the United States

For two days, American skies held roughly 4,000 grounded aircraft and not a single scheduled civilian flight. On September 13, 2001, the Federal Aviation Administration lifted the ground stop it had ordered the morning of the attacks, and airports began waking runway by runway. Airlines flew reduced schedules under new security rules, and passengers who had booked flights two days earlier went through metal detectors and new screening rules for the first time…