Aircraft catapult An aircraft catapult is a device used to launch aircraft from ships — in particular aircraft carrier s — as a form of assisted take off . It consists of a track built into the flight deck , below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft , or in some cases a wire rope called a catapult bridle is attached to the aircraft and the catapult shuttle . The ramps at the catapult ends on some aircraft carriers are used to catch the ropes so they can be reused ; bridles have not been used on U . S . aircraft since the end of the Cold War , and all U . S . Navy carriers commissioned since then have not had the ramps . The last U . S . carrier commissioned with a bridle catcher was USS " Carl Vinson " ; starting with USS " Theodore Roosevelt " the ramps were deleted . During Refueling and Complex Overhaul refits in the late 1990s – early 2000s , the bridle catchers were removed from the first three " Nimitz " - class aircraft carrier s . USS " Enterprise " was the last U . S . Navy operational carrier with the ramps still attached before her decommissioning in 2012 . At launch , a release bar holds the aircraft in place as steam pressure builds up , then breaks ( or " releases " ; older models used a pin that sheared ) , freeing the piston to pull the aircraft along the deck at high speed . Within about two to four seconds , aircraft velocity by the action of the catapult plus apparent wind speed ( ship ' s speed plus or minus " natural " wind ) is sufficient to allow an aircraft to fly away , even after losing one engine . History . First recorded flight using a catapult . Aviation pioneer and Smithsonian Secretary Samuel Langley used a spring - operated catapult to launch his successful flying models and his failed aerodrome of 1903 . Likewise the Wright Brothers beginning in 1904 used a weight and derrick styled catapult to assist their early aircraft with a takeoff in a limited space . On 31 July 1912 , Theodore Gordon Ellyson became the first person to be launched from the experimental catapult system . The U . S . Navy had been perfecting an air - compressed catapult system and mounted it on the Santee Dock in Annapolis , Maryland . The first attempt nearly killed Lt . Ellyson when the plane left the ramp with its nose pointing upward and it caught a crosswind , pushing the plane into the water . Ellyson was able to escape from the wreckage unhurt . On 12 November 1912 , Lt . Ellyson made history as the Navy ’ s first successful catapult launch , from a stationary coal barge . On 5 November 1915 , LCDR Henry C . Mustin made the first catapult launch from a ship underway . Interwar and World War II . In the late 1920s the passenger liners SS " Europa " and the SS " Bremen " of the Norddeutscher Lloyd line experimented with catapult - launched mailplanes . Up to and during World War II , most catapults were hydraulic . Some carriers were completed before and during World War II with catapults on the hangar deck that fired athwartships , but they were unpopular because of their short run , low clearance of the hangar decks , inability to add the ship ' s forward speed to the aircraft ' s airspeed for takeoff , and lower clearance from the water ( conditions which afforded pilots far less margin for error in the first moments of flight ) . They were mostly used for experimental purposes , and their use was entirely discontinued during the latter half of the war . In the 1920s and 1930s , many naval vessels apart from aircraft carriers carried float planes , seaplanes or amphibians for reconnaissance and spotting . They were catapult - launched and landed on the sea alongside for recovery by crane . There were submarine aircraft carriers , and some Japanese submarines used them for offensive operations also . The first launch off a Royal Navy battlecruiser was from HMAS " Australia " on 8 March 1918 . Subsequently many RN ships carried a catapult and from one to four aircraft ; battleships or battlecruisers like the HMS " Prince of Wales " carried four aircraft and HMS " Rodney " carried two , while smaller warships like the cruiser HMNZS " Leander " carried one . The aircraft carried were the Fairey Seafox or Supermarine Walrus . Some like " HMS Nelson " did not use a catapult , and the aircraft was lowered onto the sea for takeoff . Some had their aircraft and catapult removed during WWII e . g . HMS " Duke of York " , or before ( HMS " Ramillies " ) . During World War II a number of ships were fitted with rocket - driven catapults , first the Fighter catapult ship s of the Royal Navy , then armed merchantmen known as CAM ship s from " catapult armed merchantmen . " These were used for convoy escort duties to drive off enemy reconnaissance bombers . CAM ships carried a Hawker Sea Hurricane , dubbed a " Hurricat " or " Catafighter " , and the pilot bailed out unless he could fly to land . Steam catapult . Although Heinkel - manufactured seaplane catapults in use by the German Deutsche Luft Hansa ' s South Atlantic Air Mail service utilized , as early as 1929 , high - pressure air to launch their mail delivery aircraft from specially equipped vessels such as the SS " Westfalen " , the SS " Bremen " , and the SS " Europa " , the modern steam catapult as we know it was a British invention . The use of steam to launch aircraft was suggested by Commander Colin C . Mitchell RNVR , and trials on HMS " Perseus " , flown by pilots such as Eric " Winkle " Brown , from 1950 showed its effectiveness . Navies introduced steam catapults , capable of launching the heavier jet fighters , in the mid - 1950s . Powder - driven catapults were also contemplated , and would have been powerful enough , but would also have introduced far greater stresses on the airframes and might have been unsuitable for long use . Nations that have retained large aircraft carriers and high performance CATOBAR ( Catapult Assisted Take Off But Arrested Recovery ) ( the United States Navy , Brazilian Navy , and French Navy ) are still using catapults out of necessity . Other navies operate STOVL aircraft , such the Sea Harrier or AV - 8B Harrier II , which do not require catapult assistance , from smaller and less costly ships . The Russian Su - 33 " Flanker - D " can take off from aircraft carriers without a catapult , albeit at a reduced fuel and armament load . U . S . Navy tactical aircraft use catapults to launch with a heavier warload than would otherwise be possible . Larger planes , such as the E - 2 Hawkeye and S - 3 Viking , require a catapult shot , since their thrust - to - weight ratio is too low for a conventional rolling takeoff on a carrier deck . Future . The size and manpower requirements of steam catapults place limits on their capabilities . A newer approach is the Electromagnetic Aircraft Launch System ( EMALS ) . Electromagnetic catapults place less stress on the aircraft and offer more control during the launch by allowing gradual and continual acceleration . Electromagnetic catapults are also anticipated to require significantly less maintenance through the use of solid state components . Linear induction motors have been experimented with before , such as Westinghouse ' s Electropult system in 1945 . However at the beginning of the 21st century , navies again started experimenting with catapults powered by linear induction motor s and electromagnet s . EMALs would be more energy efficient on nuclear - powered aircraft carriers and would alleviate some of the dangers posed by using pressurized steam . On gas - turbine powered ships , an electromagnetic catapult would eliminate the need for a separate steam boiler for generating catapult steam . The U . S . Navy ' s upcoming " Gerald R . Ford " class carrier includes electromagnetic catapults in its design . Civilian use . From 1929 , the German Norddeutscher Lloyd - liners and were fitted with catapults to launch mail - planes . These ships served the route between Germany and the United States . The aircraft , carrying mail – bags , would be launched while the ship was still many hundreds of miles from its destination , thus speeding mail delivery by about a day . Initially , Heinkel HE 12 aircraft were used before they were replaced by Junkers Ju 46 , which were in turn replaced by the Vought V - 85G . The catapults were powered by compressed air . After World War II , Supermarine Walrus amphibian aircraft were briefly operated by a British whaling company , United Whalers . Operating in the Antarctic , they were launched from the factory ship FF " Balaena " , which had been equipped with an ex - navy aircraft catapult .