A Fairchild Metroliner SSA26 flips upside down just before making an emergency landing. Propair Flight 420 has just taken off from Montreal but must turn back due to a warning message. The left wing is overheating and as the pilots try to figure out what's happening, the left engine catches on fire. Seconds before the crew touches down on the runway, the left wing fails and the airplane flips upsisde down. What happened to this airplane? Find out on this episode of Black Box Down.