Character mistake: After the first Fireflash crash, search and rescue tasks are unable to find the wreckage, and John in Thunderbird 5 comments that its position was way off what was reported. However, he never bothers to relay this vital information to the London airport overseeing the rescue effort, and IR never bothers to attempt a rescue of a passenger jet filled with civilians, despite showing on the second crash that they were completely capable to saving them. It's then stated that the crash had no survivors, which the viewer has to lay at IR's feet. Even if they were busy with another rescue at the time, notifying the conventional rescue effort of Fireflash's real position could have saved many lives and given the investigation more evidence to find the problem.
Continuity mistake: After Thunderbird 1 is shot down in the Sahara, Scott is hanging unconscious out of the craft's front door. When Scott and Lindsey spot Thunderbird 1, the door to the craft is closed.
Character mistake: When Gordon and Scott are playing chess at Tracy Island towards the end of the episode, the chess board is oriented incorrectly, as there is a white square in the bottom-left corner.
The Duchess Assignment - S1-E21
Character mistake: When the croupier at the Duchess' table calls out the phrase "Rien ne va plus" (French for "no more bets"), he pronounces "Rien" incorrectly - he pronounces it "RINE ne va plus" instead of "REE-en ne va plus".
Continuity mistake: When Jeff pushes the button next to his seat to do "Operation Cover Up" at the end of the episode, there's a closeup of his hand as he leans over to press the button while he is sitting down, but in the next shot he is suddenly standing up near the portraits of his sons.
Pit of Peril - S1-E2
Revealing mistake: When the four US Army members are talking outside the US Army helicopter discussing the Sidewinder situation, there is a man in the helicopter who is someone else and not Helijet Pilot Charlie.
Terror in New York City - S1-E4
Continuity mistake: When we see Virgil in his sick bed after crash landing on Tracy Island, he has a bandage around his head and there is a blood stain on the bandage above his left eye. But when Gordon comes into his room to watch the moving of the Empire State Building on television, the blood stain has disappeared.
Continuity mistake: When they are travelling the disused London Underground tunnels, Virgil is on the red hoverbike and Alan is on the blue hoverbike. In the next shot, they have swapped bikes, but when they arrive at the bank they have swapped back again.
Continuity mistake: When Joe Carter parks the car in the car park, there are several cars to the left of him. In the close up shot of the car several cars have disappeared.
Continuity mistake: When Sir Harry drives Lady Penelope down to FAB1 in his jeep, he is wearing a yellow helmet in the zoomed-out shot. When he is seen in close-up he is no longer wearing the helmet. Then, when the shot zooms out again, he is wearing the helmet.
Continuity mistake: Throughout series 2, the five pictures of Jeff Tracy's sons on the wall at Tracy Island are completely different to the ones seen in the first series. But when Scott prepares to launch Thunderbird 1, you can see the picture of John is the one seen in series 1.
Continuity mistake: When Thunderbird 3 takes off from Tracy Island, look at the "3" at the bottom of the rocket when it goes up from the hangar. It is a completely different "3" to the one that was seen in the previous shot.
