Other mistake: As Virgil prepares to clear the wreckage of the tower from the rescue area using the Firefly, Scott tells him that he will go over to Thunderbird 2 to prepare the Mole for tunneling. The Tower Controller then says to Scott, "I've got a fast car ready for you outside" without moving his lips.
Other mistake: At the end of the episode in the space rocket Scott says "you can say that again" without moving his lips.
Other mistake: Just as the villains' car goes out of control in the opening sequence, a huge lump of greenery falls out of the sky in the background.
Other mistake: When Lady Penelope is counting her sheep, Parker had just told Jeff that she has 200,007 sheep. When we see her using the sheep-counter machine its display only has five digits instead of the necessary six. (00:14:35)
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.
The Perils of Penelope - S1-E3
Other mistake: When Virgil enters Thunderbird 2, there are no pods to the left of Pod 3.
Other mistake: When Scott and Virgil are putting Chip to bed towards the end of the episode, the globe in Chip's bedroom is upside down.
Terror in New York City - S1-E4
Other mistake: When Tin-Tin says "However" while typing Jeff's letter, her lips do not move.
Other mistake: Some scenes in this episode feature portraits of Jeff Tracy's sons in their civilian clothing. This is only done on "Operation Cover Up" to disguise all evidence of the International Rescue organisation when a visitor comes to Tracy Island, but there were no visitors to the island during the episode.
Other mistake: In one shot of Gordon in Thunderbird 4, the shot has been horizontally reversed.
Other mistake: Every time Thunderbird 3 is used during a mission, members of the Tracy family enter it by being lowered on the settee onto a mini rail system, which takes them to Thunderbird 3's hangar before a pole raises the settee into the ship. However, during the initial descent, there is usually an empty settee that passes behind the descending one carrying the impending Thunderbird 3 crew, to fill in the resulting hole in the floor. If the ascending one passes behind the descending one then there is no way that it could fill that hole as it would be too far back.
Suggested correction: As we see the replacement sofa correctly located, the fault is that we do not see the mechanism for doing this. For example, the poles might have been angled to achieve the effect or the start of the rail track might shift over a bit.
Terror in New York City - S1-E4
Other mistake: One of the puppets used in this episode is called "Joe" and is a TV Cameraman. As this particular puppet falls into the cavern, the back of his head can be seen to fall off.
Other mistake: When Lady Penelope is relaxing with Jeff and the other members of International Rescue on Tracy Island, you can see in the lounge the pictures of the Tracy sons are in "Operation Cover-Up" mode, even though there are no other visitors on the island.