Air Canada Flight 143 was a Boeing 767 flying from Montreal to Edmonton on 23 July 1983 when both engines stopped for lack of fuel over northern Ontario.
This three-minute Smithsonian Channel clip follows Germanwings Flight 9525 on 24 March 2015 from its takeoff in Barcelona to the moment it dropped off radar over the French Alps.
Four flights where a mistake made on the ground, or a part that was not what it should have been, surfaced in the air. Three crews got their aircraft down, but Helios Airways Flight 522 crashed north of Athens with the loss of all 121 people on board. Each investigation traced the problem to work on the ground and the checks that should have caught it.