This is the kind of movie that my enemies content I watch all the time, but it's not bloody true. I only watch it once in a while to make sure that it's as bad as I first thought it was.
Some kind of mobsters hijack a Boeing 747. (That, at least, is an improvement over having Boeing hijack a good part of the Pentagon.) The airplane goes down in the Bermuda triangle and sinks pressurized to the bottoms, a kind of post-facto submarine.
It has one of those all-star casts, the stars either falling or barely above the horizon.
"We're on our own!", says pilot Jack Lemon. He is so right. Except for George Kennedy. He's in all these disaster movies.
Watch another movie instead. Oh, not "Airport" the original. That's no good either. Instead, watch a decent flick about stuck airplanes like "Flight of the Phoenix."