Mayday, known as Air Crash Investigation(s) outside of the United States and Canada and also known as Air Emergency or Air Disasters (Smithsonian Channel) in the United States, is a Canadian documentary television series produced by Cineflix that recounts air crashes, near-crashes, fires, hijackings, bombings, and other mainly flight-related disasters and crises.

It reveals the events that led to each crisis or disaster, their causes as determined by the official investigating body or bodies, and the measures they recommended to prevent a similar incident from happening again. The programs use re-enactments, interviews, eyewitness testimony, computer-generated imagery, cockpit voice recordings, and official reports to reconstruct the sequences of events.