Splashdown is the 9th broadcast episode and 3rd produced episode of British television series Joe 90.
The World Intelligence network discovers a sinister death plot after two electronics experts are kidnapped and killed. While Professor Ian McClaine is presented as bait, Joe 90 must save the passengers of a crashing plane and his father, before they are both killed.
Two major air crashes are complete mysteries, but they have one thing in common: in each case, an electronics expert has disappeared, and it is suspected that they were kidnapped before the crashes. The World Intelligence Network plan a trap to foil a third attempt by persuading Professor McClaine and Joe to fly to Istanbul. As a world electronics authority, the Professor will be the bait, and Joe is given the brain pattern of a U.S. Army Air Force test pilot. Sure enough, Mac and Joe are tailed on their way to the airport, and the flight is well under way and not far from Athens when a man named Kramer, with the help of the stewardess, makes an appearance and drugs both the pilot and co-pilot. Beneath them in the sea a launch waits to transfer the Professor to a submarine. Mac is forced at gun-point to escape by way of a parachuted cylinder, together with the stewardess and Kramer, but Joe is left in the plane, which is now pilotless. Joe dons his special glasses and takes over the controls. Returning to the spot where his father was abducted and where the launch is preparing to contact the submarine, he produces some spectacular flying to prevent their joining up. The sub is forced to submerge, Mac is saved, and a sinister death plot is revealed.
- The AV21 and CV9 airliners seen here are revamped from the Spectrum Passenger Jet from Captain Scarlet and the Mysterons. They appear again in Three's A Crowd and Double Agent.
- The London International Airport entrance is the same one that appeared in Captain Scarlet and the Mysterons episode Winged Assassin.
- When the co-pilot is stunned, the pilot refers to him as Bill, but the co-pilot’s name is later revealed to be Frank, while the pilot’s name is Bill.