The Hood places a bomb aboard an airliner in order to be able to photograph the Thunderbird craft as they attempt to rescue it. International Rescue must simultaneously save Tin-Tin, who is aboard the airliner, and thwart the Hood's devious plans.
- Main article: Trapped In The Sky/Episode Guide
- Jeff Tracy - Peter Dyneley
- Scott Tracy - Shane Rimmer
- Lady Penelope Creighton-Ward - Sylvia Anderson
- Virgil Tracy - David Holliday
- Alan Tracy - Ray Barrett
- Brains - David Graham
- Aloysius Parker - David Graham
- Tin-Tin Kyrano - Christine Finn
- Gordon Tracy - David Graham
- John Tracy - Ray Barrett
- Kyrano - David Graham
- The Hood - Ray Barrett
- Commander Norman - Peter Dyneley
- Captain Hanson - David Graham
- Fireflash Co-Pilot - Ray Barrett
- Assistant Controller - Ray Barrett
- Flight Lieutenant Bob Meddings - David Graham
- Operator Harris - Ray Barrett
- TX-204 Pilot - Ray Barrett
- TX-204 Co-Pilot - Shane Rimmer
- Interceptor One Pilot - Peter Dyneley
- Air Terrainean Guide - Sylvia Anderson
- Kyrano's Doctor - David Graham
- Fireflash Passenger - David Graham
- Airport Mobile Police -David Graham (voice only - not seen on screen)
- Crash Tenders Chief - David Graham (voice only - not seen on screen)
- London Airport Tannoy - Christine Finn (voice only - not seen on screen)
- Departure Lounge - London Airport
- Cocktail Waiter Aboard Fireflash (1)
- Passenger Onboard Fireflash (Unnamed)
- Fireflash Passengers
International Rescue Equipment UsedEdit
Non-International Rescue Equipment UsedEdit
- Main article: Trapped In The Sky/Gallery
- Main article: Trapped In The Sky/Transcript
- This is the first appearance of The Hood, who becomes a recurring villain in a total of six episodes. Apart from this episode, he also appears in Edge Of Impact, Desperate Intruder, The Mighty Atom, Cry Wolf and Martian Invasion, as well as the movies Thunderbirds Are Go and Thunderbird 6.
- The Fireflash reappears in Operation Crash-Dive and has a small role in The Duchess Assignment, The Man From MI.5, and The Impostors.
- Alan is voiced by Ray Barrett in this episode alone. In future episodes, he would be voiced by Matt Zimmerman.
- Air Terrainean's Lieutenant "Bob Meddings" is named after Thunderbirds art director Bob Bell and visual effects supervisor Derek Meddings.
- The end credits music for this episode is Thunderbird 1's launch music. The reason for this is the original ending theme, a vocal piece sung by singer Gary Miller, was deemed unsatisfactory and removed weeks before its airing. In all other episodes, a dedicated arrangement of the Thunderbirds main theme is used.
- This is the only appearance of the Elevator Cars.
- This episode was originally 25 minutes long. After having been screened for Lew Grade, then ITC's financier, it was so critically acclaimed that Grade ordered it (and the series as a whole) to be brought up to 50 minutes for a full hour airing.
- Footage from this episode was reused in the clip show Security Hazard.
- The episode originally didn't come with an on-screen title card, until Carlton International added one, it's however only featured on BBC2/Boomerang/Cartoon Network transmissions and on Carlton's VHS/DVD releases.
- On 15th September 1965, AVRO aired a Dutch-dubbed, black-and-white version of "Trapped in the Sky" in The Netherlands, 15 days before it first aired in the UK.
- The TX-204 Pilot was previously seen as Lieutenant John Fisher in Stingray.
- The unnamed Doctor who visits Tracy Island at the episode's end can be seen earlier in the departure lounge at London Airport.
- According to the Gerry Anderson Story in Volume 5 of Gerry Anderson: The Vintage Comic Collection, inspiration for this episode came from Anderson's National Service at RAF Manston. Whilst up in the control tower, he watched a plane make an emergency landing with its undercarriage still retracted, and amazingly none of the crew were seriously injured despite the tricky landing.
- Main article: Trapped In The Sky/Goofs
- Main article: Trapped in the Sky (Fox Kids Series)
- Main article: Trapped In The Sky (TCTB)
- Main article: Fireflash (TB2015)
The Thunderbirds Are Go! series featured a remake of Trapped in the Sky, simply titled Fireflash.
- French: Pris au Piège (VHS)
- German: Gefährliche Landung (TV), Das fliegende Gefängnis (DVD)
- Spanish: Atrapados en el Espacio (DVD)
- Italian: Insidia nel cielo (8mm); Prigionieri del cielo (TV); Intrappolati nel cielo
- Dutch: Gevangen in de lucht
- Japanese: SOS原子旅客機