What happened
During the takeoff roll of ValuJet Flight 597, occupants heard a loud bang, followed by the illumination of the right engine fire warning light. The crew of a following aircraft alerted the ValuJet crew that the right engine was on fire, prompting the pilot to reject the takeoff.
Shrapnel from the failure penetrated the fuselage and the main fuel line of the right engine, causing a cabin fire to erupt. Once the aircraft stopped on the runway, the captain ordered an evacuation. The incident resulted in 1 flight attendant receiving serious puncture wounds and thermal injuries, while another flight attendant and 5 passengers sustained minor injuries.
The investigation
The investigation determined that the event was caused by an uncontained failure of the right engine. This failure was attributed to a fatigue failure of the 7th stage high compressor disc, which originated at a stress redistribution hole within the disc.
Analysis of fatigue striation measurements indicated that the fatigue crack had formed prior to the last overhaul of the disc at the Turk Hava Yollari repair station in 1991; however, the crack went undetected during that process. Furthermore, the investigation of the repair station uncovered inadequate recordkeeping practices and a failure to utilize process sheets to document step-by-step overhaul and inspection procedures.