Sequence of Events
Three aircraft—a United Airlines DC-10 (Flight 99 Heavy) and two US Air DC-9s (Flight 25 and Flight 199)—taxied for takeoff at approximately the same time. Due to delays, the crew of Flight 199 shut down the No. 2 engine in accordance with fuel conservation procedures. After Flight 99 was cleared for takeoff, the Flight 199 crew started their engine, but it torched, emitting flames from the tail cone.
The captain of Flight 25 observed the flames and transmitted on the tower frequency, "99, you're right engine's on fire." At about that time, United Flight 99 was lifting off. Believing his aircraft had an engine fire, the captain of Flight 99 aborted the takeoff above V1/VR rather than continuing into a low ceiling with fog and rain. The captain thought the aircraft could stop on the hard surface but was unable to do so, and the plane came to rest on muddy terrain.
Injuries and Visibility
One passenger was injured during the subsequent evacuation. During the sequence, the tower controller was unable to see the runway due to low visibility (3/8 mile).