The sole “sequel” episode, ‘Operation Crash-Dive’ once again puts the Fireflash in harms way due to a renewed bout of sabotage. When flights start disappearing without trace over the Atlantic Ocean, the aircraft is grounded until both a cause and solution are found. A test flight quickly suffers the same fate, though this time International Rescue is able to intervene as Gordon takes Thunderbird 4 down to the seabed and pulls off the sort of engineering feat that would blow minds around the world if such a “rescue” occurred today.
The second half of the episode sees Scott co-pilot a second Fireflash test flight, as for some reason International Rescue feels the need to get directly involved in the process of helping a privately owned, clearly dangerous and already grounded for-profit commercial airliner get back in the air. Makes you wonder what their game is? Of course, the damn thing goes down regardless, only for Gordon to pull off yet another feat of engineering lunacy to once again save the day.