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.

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.

The aircraft involved was a McDonnell Douglas DC-9-32, MSN 47196, originally registered as CF-TLU, that was manufactured in 1968 and was delivered to Air Canada on April 7.

The pilots heard a popping sound around 18:51 EDT (22:51 UTC), during dinner service, and discovered that the lavatory's circuit breakers had tripped.

[4]: 2 At about 19:00, a passenger seated in the last row informed flight attendant Judi Davidson of a strange odour in the rear of the airplane.

[4]: 3  Shortly after, the "master caution" light in the cockpit illuminated, indicating a loss of main bus electrical power.

The captain called the air traffic controller (ATC) in Indianapolis, Indiana, and notified them that Flight 797 had an "electrical problem."

Ouimet directed the flight attendants to keep the lavatory door closed, then returned to the cockpit, where he told Cameron, "I don't like what's happening, I think we better go down, okay?"

[4]: 4  This made controlling the plane's descent extremely difficult and required great physical exertion from the pilot and first officer.

[4] At 19:20 (23:20 UTC), Captain Cameron and First Officer Ouimet executed an extremely difficult landing at Cincinnati/Northern Kentucky International Airport.

Once the plane came to a stop, chief flight attendant Sergio Benetti opened the front door of the aircraft, through which he escaped.

Blood samples from the bodies revealed high levels of cyanide, fluoride and carbon monoxide, chemicals produced by the burning plane.

[4]: 57 This particular DC-9 had experienced a number of problems over the months leading up to the incident; 76 maintenance reports had been filed in the plane's logs in the previous year,[4] and the CVR recorded Captain Cameron telling First Officer Ouimet to "put [the tripping breakers] in the book there" when the breakers failed to respond to the first reset attempt at 18:52.

Cameron later noted that the Air Canada maintenance crew "did a heck of a job getting everything put back together" after the decompression incident.

In August 1984, the NTSB issued a final report that, while praising the captain for "exhibiting outstanding airmanship without which the airplane and everyone on board would certainly have perished", concluded that the probable causes were a fire of undetermined origin, the flight crew's underestimation of the fire's severity and conflicting fire-progress information given to the captain.

This report also found that the flight crew's "delayed decision to institute an emergency descent" contributed to the severity of the accident.

[1] In January 1986, after reviewing Ouimet's missive and reevaluating the available data, the NTSB issued a revised version of its accident report.

The NTSB also removed the word "delayed" from its description of the pilots' decision to descend, instead listing the "time taken to evaluate the nature of the fire and to decide to initiate an emergency descent" as a contributing factor.

[4]: 71 The crew of Flight 797 were later honoured by multiple Canadian aviation organizations for their heroic actions in landing the plane safely.

[8][9] As a result of this accident[4] and other incidents of in-flight fires on passenger aircraft, the NTSB issued several recommendations to the Federal Aviation Administration (FAA), including: Canadian folk singer Stan Rogers, 33, was killed by smoke inhalation.

[13] After the incident, Air Canada sold the right wing of the DC-9 to Ozark Air Lines to repair an airplane damaged on 20 December 1983, when Ozark Flight 650, tail number N994Z,[14] collided with a snowplow in Sioux Falls, South Dakota, killing the snowplow operator and separating the right wing from the aircraft.