Two giant Fireflash airliners have crashed into the Atlantic under mysterious circumstances. Although International Rescue manage to save the pilot of the second crash, they can find no explanation for it. On a third flight, Thunderbird 2 follows the Fireflash, and the cause of the trouble is located, a saboteur hidden in the wing. At the last moment, Gordon repairs the sabotage and the Fireflash is saved.
- Main article: Operation Crash-Dive/Episode Guide
- Main article: Operation Crash Dive/Transcript
Regular Voice CastEdit
- Jeff Tracy - Peter Dyneley
- Scott Tracy - Shane Rimmer
- Virgil Tracy - David Holliday
- Alan Tracy - Matt Zimmerman
- Brains - David Graham
- Tin-Tin Kyrano - Christine Finn
- Gordon Tracy - David Graham
- John Tracy - Ray Barrett
- Grandma Tracy - Christine Finn
- Commander Norman - Peter Dyneley
- Captain Hanson - David Graham
- TV Reporter - Matt Zimmerman
Guest Voice CastEdit
- Lieutenant Burroughs - Ray Barrett
- International Air Minister - Peter Dyneley
- Chief Engineer Patterson - David Graham
- Pilot of Fireflash 4 - David Graham
- Co-Pilot of Fireflash 4 (Bob) - Ray Barrett
- Fireflash 3 Pilot - David Graham
- Irish Farmer - David Graham
- Seahawk Pilot (Air Sea Rescue) - Matt Zimmerman
- Radar Operator - Shane Rimmer
- Saboteur - Ray Barrett
- Television Newsreader - David Holliday
International Rescue Equipment UsedEdit
Non-International Rescue Equipment UsedEdit
- The original title for this episode was The Test Crew.
- The saboteur's pick-up aircraft would later be repainted and reused as the fake Thunderbird 2 in The Impostors.
- This episode marks the second and final major appearance of the Fireflash airliners in the series.
- The International Air Minister reveals that the Fireflash airliners cost £5 million.
- Several guns from Stingray are visible on the wall in the Tracy Villa shooting range..
- A pile of newspapers and magazines shows that The Daily Telegraph, Daily News, Life International and Mad are still being published in 2065.
- The particular issue of Mad that is seen is readily identifiable as the "Special Summer Travel Issue" from 1961.
- Main article: Operation Crash-Dive/Goofs
- French: Le passager clandistin
- German: Operation Fireflash
- Spanish: Operación Impacto Profundo; Operación aterrizaje forzoso (DVD)
- Italian: May Day! May Day!
- Dutch: Operatie "noodlanding" (TV 1966), Operatie duikvlucht (TV 1991), Operatie Noodlanding (VHS, DVD)
- Japanese: 原子力機ファイアーフラッシュ号の危機