Operation Crash-Dive

"Operation Crash-Dive" is an episode of Thunderbirds, a British Supermarionation television series created by Gerry and Sylvia Anderson and filmed by their production company AP Films (APF) for ITC Entertainment. Written by Martin Crump and directed by Desmond Saunders, it was first broadcast on 16 December 1965 on ATV Midlands as the 12th episode of Series One. It is the eighth episode in the official running order.

Set in the 2060s, Thunderbirds follows the missions of International Rescue, a secret organisation which uses technologically advanced rescue vehicles to save human life. The lead characters are ex‑astronaut Jeff Tracy, founder of International Rescue, and his five adult sons, who pilot the organisation's primary vehicles: the Thunderbird machines. In "Operation Crash-Dive", International Rescue investigate the mysterious crashes of Fireflashes, a fleet of hypersonic airliners and discover it to be a case of sabotage.

In 1980, ITC's New York branch paired the episode with "Trapped in the Sky" to create the Thunderbirds compilation film Thunderbirds to the Rescue. "Operation Crash-Dive" had its first UK‑wide network broadcast on 8 November 1991 on BBC2.

While flying from London International Airport to San Francisco, Fireflash 3 is crippled by a technical fault and disappears over the Atlantic Ocean. Rescue teams find no trace of the airliner, which was carrying 600 passengers and crew. On Thunderbird 5, Alan Tracy determines that the Fireflash's last radioed position was out by 50 miles (80 km).

By order of the International Air Minister, all Fireflashes are grounded pending a full safety review. No design flaws are uncovered, so Commander Norman orders a transatlantic test flight to identify the fault. During the flight, the elevator power unit, locator and radio fail, and the Fireflash loses altitude and belly-flops into the ocean. The emergency exit jams, trapping the crew, and the aircraft sinks. An unidentified man, who parachuted from the undercarriage, is picked up in a helijet.

Alan alerts Tracy Island, reporting that the Fireflash went down 180 miles (290 km) from its last radioed position. Jeff orders an undersea search-and-rescue mission, dispatching Scott in Thunderbird 1 followed by Virgil with Gordon and Brains in Thunderbird 2 carrying Pod 4. Brains believes that the Fireflash sank intact and that the crew may still be alive, trapped on the seabed and running out of air.

Landing at a farm in Ireland, Scott performs an electromagnetic sweep and plots the Fireflash's position. Gordon launches in Thunderbird 4 and locates the airliner. Using Thunderbird 4's laser beam, he cuts off the Fireflash's heavy engine nacelles to enable it to float to the surface. As the cockpit instruments short-circuit and burst into flames, Gordon mounts the fuselage and cuts a hole in the window using a handheld laser, freeing the crew. Virgil airlifts the crew to safety, and Gordon escapes in Thunderbird 4, moments before the Fireflash is destroyed in a series of explosions.

Air chiefs agree that the source of the Fireflashes' trouble lies in their wing hydraulics. Realising that another test flight is needed, Jeff contacts Commander Norman and recommends that Thunderbird 2 accompany the aircraft so that if the fault reoccurs, International Rescue can respond.