The Thunderbirds are the six primary "miracle machines" of International Rescue. Each one (except Thunderbird 6) is specially designed to fill a certain requirement in the organisation's operations and has at least one dedicated pilot (see also below) from amongst the inhabitants of Tracy Island, including IR leader Jeff Tracy's five sons, inventor/engineer Brains and his assistant/deputy Tin-Tin Kyrano.
Thunderbird 1 is piloted by Scott Tracy. His younger brother Alan is also subject to call for this craft. TB1 is a hypersonic, atomic-powered rocket-plane with retractable wings for travel at slower speeds within the atmosphere. Its purpose is to carry its pilot to the danger zone in as little time as possible, to assess the situation and establish a control centre for directing the rescue.
Thunderbird 2 is piloted by Virgil Tracy. His younger brother Gordon is subject to call for this craft, both as co-pilot and mission specialist (see below). TB2 - a supersonic freight plane with a huge carrying capacity - is the workhorse of International Rescue, generally used to transport heavy equipment, and personnel, needed to carry out the rescue, in any of six differently-equipped cargo pods.
Thunderbird 3's piloting chores are shared by astronauts Alan Tracy (primary) and John Tracy - in alternating monthly shifts - usually joined by Scott (as Alan's co-pilot) and Tin-Tin. TB3 is a single-stage-to-orbit (SSTO) space rocket, providing transportation and overall support to Thunderbird 5 (see below) in Earth orbit, as well as responding to rescue situations out in space beyond Earth.
Thunderbird 4, piloted by aquanaut Gordon Tracy, is a compact, versatile mini-submarine possessing an impressive array of high-tech gadgetry suitable to any underwater-rescue scenario it might encounter - be it oceans, lakes or even rivers! It's usually transported to where it's needed by Thunderbird 2, in its own specially-equipped cargo pod: the aptly-designated Pod 4.
Thunderbird 5's monitoring chores are shared by astronauts/space monitors John Tracy (primary) and Alan Tracy, in alternating monthly shifts. Their older brother Scott is also subject to call for this craft. The largest of the Thunderbird machines, and the only one on duty 24/7, TB5 is a space station - in geosynchronous Earth orbit with Tracy Island - containing sensitive detection equipment that allows International Rescue to pick up requests for help transmitted from anywhere in the world.
Thunderbird 6, piloted by Brains, is unique amongst the International Rescue fleet: it's a meticulously-restored (by Alan) vintage Tiger Moth biplane! Originally improvised as a rescue vehicle, it's still used in rescue situations where the other IR craft are not suitable.
Thunderbird Shadow, piloted by Kayo Kyrano, is a stealth aircraft, used for missions concerning the security of International Rescue and the thwarting of extreme villainy, such as the dangerous plans of IR's recurring nemesis, the Hood.
- In the 1970's, Japanese company Imai marketed a model kit called Thunderbird 7. It was an amphibious mobile rocket launcher carried in Thunderbird 2.
- The Japanese anime Thunderbirds 2086 featured 17 different Thunderbirds.