UFO (TV series)
A single season of 26 episodes (including the pilot) was filmed over the course of more than a year; a five-month production break was caused by the closure of MGM-British Studios in Borehamwood, where the show was initially made. Production then moved to Pinewood Studios in Buckinghamshire. "UFO" was first broadcast in the UK and Canada in 1970, and in US syndication over the next two years.
UFO (TV series)
The North American DVD release of the series usually follows the production order, with a few diversions; a website ufoseries.com for the show offers seven possibilities of viewing sequence. According to "The Complete Gerry Anderson", the episode "Exposed" was intended to be aired second, but it was produced fifth and appears as the fifth episode in the American DVD release. It was only when the entire series was repeated by BBC Two in 1996–1997 that the series was shown in chronological production order in the UK for the first time.