Continuity mistake: When the Professor goes up to check on the solar reflector tower it collapses, and as it falls down the mountain the reflector's triangular center breaks off, but in the following shots it's perfectly intact for the episode's plot. (00:16:05)
Continuity mistake: When Elliot picks up the radio microphone to call Search Control, the radio headset on his shoulders turns round between shots.
Continuity mistake: When Thunderbird 2 launches Thunderbird 4, the number "4" on the puppet sized pod door in a close-up does not match that in the model scale long shot.
Visible crew/equipment: In a shot of the camera moving through the castle, the shadow of some studio equipment is moving down one of the pillars.
Continuity mistake: When Scott says goodbye to Goldheimer, you can that the cockpit window on Thunderbird 1 has bolts directly around it, but when Thunderbird 1 is pursuing the Hood a little later on, the cockpit window now has a metal border with bolts.
Continuity mistake: When Thunderbird 2 leaves its hangar, it has a small "Thunderbird 2", but when we see the craft in the air, the "2" has changed to a larger font.
Continuity mistake: When Scott arrives in Ireland in Thunderbird 1, he starts to land with the landing gear down and you can see wheels on the legs, but when Thunderbird 1 touches down, the wheels have changed to skis.
Character mistake: Scott flew to Ireland to look for the missing Fireflash airliner, but when Jeff asks where Scott is, Virgil replies, "His take-off from England was delayed for some reason."
Continuity mistake: When Thunderbird 2 leaves the hangar, the craft still has the old-style steering column. The column changes twice throughout the episode.
Continuity mistake: When we see The Hood inside Thunderbird 1, the cockpit is placed in its vertical position, as opposed to horizontal when the craft lands.
Other mistake: When Virgil says "That's better" when he and Scott are pushing the reactor rods back in place, his mouth does not move.
The Duchess Assignment - S1-E21
Other mistake: When the WAT Wombat lands on the runway, the jetex attached to the underside can be seen falling off.
Pit of Peril - S1-E2
Other mistake: When the atomic reactor goes down 20 points in the Sidewinder, look at Frank and you can see his left eyebrow is missing.
Revealing mistake: When we see the passengers in the departure lounge at London Airport, one of them is reading a newspaper. If you look carefully, the front page is on the wrong side; it is on the left instead of the right.
Continuity mistake: When Bob Meddings boards the Fireflash and grabs hold of the pipe, the pipe is red both in a long-shot and a shot of him grabbing hold of it. When we see Meddings moving his hands along the pipe, it is now silver.
Visible crew/equipment: When Hooper says "Sound the alarms!", you can see a hand moving Hooper's legs as he gets up from where he is sleeping.
Audio problem: When the first reporter asks Saville, "Have you found an answer with Skythrust?", he is voiced by Jeremy Wilkin. When he says "Yeah, captain, make a statement", he now has a completely different voice provided by Paul Maxwell.
Audio problem: When Professor Marshall says "Detonate", her lips don't move.
Move - And You're Dead - S1-E20
Continuity mistake: When we first see Alan in his racing car, a close-up shot shows the steering wheel on the left-hand side. However, the miniature model used for the distance shots shows the steering wheel on the right.
Move - And You're Dead - S1-E20
Continuity mistake: In a close-up of Victor Gomez' racing car, he has a very large number 7 behind the driver's position. But the miniature model used for the distant shot has only a small white number 7 on the door.
