Mayday (also known as Air Emergency in the United States, Air Crash Investigation in the United Kingdom, Australia and other parts of the world, and Mayday: Catástrofes aéreas in Spanish Latin America) is a documentary television program produced by Cineflix in Canada. It is aired on Discovery Channel Canada and the National Geographic Channel. This documentary investigates many air crashes in modern history after the introduction of the black box flight recorders. It reveals events that led up to each disaster, the causes of the accidents and the measures recommended in the report by the NTSB or the investigating Commission to prevent a similar incident happening again. It features re-enactments, interviews, testimony, computer-generated imagery, and in some episodes, cockpit voice recordings to reconstruct the sequence of events to the audiences.