The movie was inspired by a real-life event which occurred on December 21, 1978, and which involved Air New Zealand flight 103 (and not 308) on a DC-10 (and not a 767.) The airliner captain's name (Gordon Vette) was preserved, but Jay's last name was changed from Prochnow to Parkins. Most other names were changed for the movie.
Near the end of the movie, where Jay finally lands his airplane and everyone at the airport is cheering, the camera focuses on two men, one a bit taller than the other, hugging and slapping each other in celebration of Jay's landing. These are the real Jay and Gordon Vette, as this movie is based on a true story.
In real life, after Frank crashed on take-off from Pago Pago, Jay landed back in the airport to check on his friend and then resumed his journey. In the movie, Jay stays in the air even after the crash.
In the movie the light aircraft is first sighted by the passengers, after the search by the jet. In the actual event, the light aircraft eventually happened across an oil rig under tow, and was thus able to determine his position (the search happened as depicted, but was not actually successful.)
In the actual event, the light aircraft proceeded to Norfolk, under escort by the Air Force Rescue aircraft (which didn't turn back, as depicted in the film) and the DC-10 jet. The DC-10 then proceeded to Auckland, its original destination.
The Flight Engineer of the DC-10 jet, Jim Collins, later lost his life in an aircraft accident on a tourist sight-seeing flight in Antarctica. Captain Gordon Vette (the captain of this search flight) wrote a book about his colleague's death entitled "Impact Erebus", published in 1983.