Air Canada Flight 797 was an international passenger flight operating from Dallas/Fort Worth International Airport to Montréal–Dorval International Airport, with an intermediate stop at Toronto Pearson International Airport. On 2 June 1983, the McDonnell Douglas DC-9-32 operating the service developed an in-flight fire in air around the rear lavatory that spread between the outer skin and the inner decor panels, filling the plane with toxic smoke. The spreading fire also burned through crucial electrical cables that disabled most of the instrumentation in the cockpit, forcing the plane to divert to Cincinnati/Northern Kentucky International Airport. Ninety seconds after the plane landed and the doors were opened, the heat of the fire and fresh oxygen from the open exit doors created flashover conditions, and the plane's interior immediately became engulfed in flames, killing 23 passengers who were unable to evacuate the aircraft. The accident became a watershed for global aviation regulations, which were changed in the aftermath of the accident to make aircraft safer. New requirements to install smoke detectors in lavatories, strip lights marking paths to exit doors, and increased firefighting training and equipment for crew became standard across the industry, while regulations regarding evacuation were also updated. Since the accident, it has become mandatory for aircraft manufacturers to prove their aircraft could be evacuated within 90 seconds of the commencement of an evacuation, and passengers seated in overwing exits are now instructed to assist in an emergency situation. Flight and crew At 16:25 Eastern Daylight Time on 2 June 1983, Flight 797 took off from Dallas/Fort Worth International Airport. The flight was a regularly scheduled passenger flight operated by Air Canada using a McDonnell Douglas DC-9-32 (aircraft registration ). The flight was scheduled to make a stop at Toronto International Airport, ultimately bound for Montreal's Dorval Airport. The flight's captain, Donald Cameron (age 51), had been employed by Air Canada since March 1966, and had qualified as a DC-9 captain in November 1974. At the time of the accident, Cameron had approximately 13,000 flight hours, of which 4,939 were in the DC-9. First Officer Claude Ouimet (age 34) had flown for Air Canada since November 1973. He had about 5,650 hours of flight experience, including 2,499 hours in the DC-9, and had qualified as a DC-9 first officer in February 1979. Incident Fire While the flight was over Louisville, Kentucky, a fire started in or around the rear lavatory of