The One With… the fashion show in the sky.
Under his alias "Mr Hackenbacker", Brains has designed the Skythrust, a new type of jetliner. While it is undergoing final tests over London, Lady Penelope is asked to visit her designer friend, François Lemaire, in Paris. This designer has developed a new, revolutionary fabric, which he has named "Penelon" after everyone's favourite London Agent. Taken aback by such an honour, Lady Penelope nevertheless maintains her wits enough to determine that Lemaire is under intense surveillance. Convinced of the threat to this new fabric, Lady Penelope arranges for the first fashion show to take place aboard the Skythrust.
However, the evil masterminds determined to steal Penelon don't let that stop them and hijackers take over Skythrust. The Thunderbirds respond instantly to Lady Penelope's distress call and, at Brains' urging, use a non-explosive rocket to disable Skythrust's landing gear. The pilots warn the hijackers of the explosive consequences of attempting a landing with nearly-full fuel tanks on a rough strip in the middle of the Sahara with no landing gear. The hijackers agree to return to London, where the Skythrust performs a no-gear crash-landing at London Airport. Fortunately, Brains' innovation - an ejectable fuel supply - prevents Skythrust from going off like a bomb, making it unique amongst aircraft in the Thunderbirds universe. The two men who were supposed to be meeting the hijacked Skythrust got an explosive surprise courtesy of international rescue.
- Always Camp: François Lemaire is a fashion designer. So naturally, he has glittery eyeshadow and speaks with an outrageous accent.
- Awesome, but Impractical: Ejecting excess fuel to reduce a crashing plane's explosiveness is a sound idea used even today. However, modern planes will simply dump the fuel rather than taking Skythrust's unnecessarily complicated approach of a separable rocket-propelled fuel tank.
- Badass in Distress: Lady Penelope is among the passengers aboard the hijacked Skythrust. There's not much she can do but call for International Rescue to come and save them.
- Being Watched: Nearly everything in Lemaire's penthouse is bugged: there are telescopes pointed at it, microphones in the sugarcubes and
his pen actually records and transmits what is being written with it. - Big "SHUT UP!": After Thunderbird 2 disables Skythrust's undercarriage, Mason (a hijacker) does this to Madeline (another hijacker) when she protests Mason's reluctant decision to allow the flight crew to return to London.
- Coming in Hot: Two for the price of one!
- The episode opens with an airliner crashing on landing and being consumed by flames before the fire crews can reach it. This turns out to be in-universe archival footage that is being used to demonstrate the danger of an emergency landing with full fuel tanks.
- Bookended in the episode's climax when Skythrust has to land without landing gear, but this landing is much safer thanks to "Mr Hackenbacker's" ejectable fuel tanks.
- Contrived Coincidence: Lady Penelope suddenly needs a secret place to hold a fashion show just as Brains is about to hold secret tests of his new airliner.
- Cool Plane: Skythrust, which seems like a regular old airliner until it launches its fuel tanks into the stratosphere.
- Episode on a Plane: The new Skythrust is one of the two main elements of the plot and a great part of the episode takes place on board the Skythrust.
- Fashion Show
- Impossibly-Compact Folding: Penelon has this ability; even a complete dress made of Penelon can be folded to fit into a matchbox.
- The Mole: Madeleine.
- Properly Paranoid: Lady Penelope suspects from the start that Francois's rivals might be spying on him, so she urges him not to say anything about this new invention untill she has thoroughly searched the room. Her suspicions are correct, as she discovers one spy tool after another.
- Secret Identity: Brains' alias Mr. Hackenbacker.
- Interestingly, both the 2004 movie and the 2015 revival series use Hiram Hackenbacker as Brains' real name.
- Secret Ingredient: Lemaire's invention Penelon and the Skythrust's innovation against explosions during crash landings.
- Stuff Blowing Up: Notably averted in the case of Skythrust. This may stand to be the only Thunderbirds episode where the Cool Plane Of The Week is not blown up.
- Virgil and Alan compensate by blowing up the outpost of the hijackers.
Virgil: Use a live missile this time, Alan. - Unspoken Plan Guarantee: Brains flat-out refuses to tell anyone why shooting out the landing gear of Skythrust is a reasonable plan. He may not have wanted the hijackers to know that the plane was still safe to land, but he won't say anything beyond "Trust me" to the men in the control tower or even his own teammates who have to do the actual shooting.
