The aircraft received instructions to taxi to Runway 31L at 9:54 am EST, and clearance to proceed to Los Angeles nonstop under instrument flight rules (IFR) at 10:02 am. Flight 1 became airborne at 10:07 am. Following American Airlines procedures and departure control instructions, the aircraft initiated a left turn to a heading of 290°. In the course of the turn, at 1,600 feet, the aircraft banked too sharply, flipped past 90°, and began an upside-down, nose-first descent in a nearly vertical dive.