What happened
While positioned near the end of the runway with engines shut down due to an air traffic control delay, the flightcrew received instructions from ground control to begin engine starts in anticipation of takeoff. The captain reported that the right engine failed to start. After performing a clearing procedure, the crew successfully started the left engine and attempted to restart the right engine.
During this second attempt, Airport Rescue and Firefighting (ARFF) personnel observed smoke and flames emanating from the right engine, although no fire warning indications were present in the cockpit. The flightcrew executed the engine fire checklist and discharged both fire suppressant bottles into the engine. Following the shutdown of both engines, ARFF requested an evacuation of the aircraft.
During the evacuation via the 1L and 1R doors, a passenger suffered a broken wrist. A witness reported that as the passenger stepped onto the slide, they bounced and went over the side of the slide approximately four to five feet above the ground. There were no fatalities associated with this event.
The investigation
The investigation into the engine fire revealed that the engine start fuel scheduling for the Fuel Control Unit was high. Additionally, testing of the ignition system components was conducted. The investigation found that the ignition exciter box operated intermittently when powered by the D.C. circuit used during engine starts.