Boeing X - 32 The Boeing X - 32 was a multi - purpose jet fighter in the Joint Strike Fighter contest . It lost to the Lockheed Martin X - 35 demonstrator which was further developed into the Lockheed Martin F - 35 Lightning II . Development . Background . In 1993 , the Defense Advanced Research Projects Agency ( DARPA ) launched the Common Affordable Lightweight Fighter project ( CALF ) . The project ' s purpose was to develop a stealth - enabled design to replace all of United States Department of Defense lighter weight fighter and attack aircraft , including the F - 16 Fighting Falcon , McDonnell Douglas F / A - 18 Hornet , and vertical / short takeoff / vertical landing ( V / STOL ) AV - 8B Harrier II . Around the same time the Joint Advanced Strike Technology ( JAST ) project was started . In 1994 , the U . S . Congress ordered the two to be merged into the Joint Strike Fighter Program . Many companies took part in the first phase of this project , which involved drafting concept aircraft designs for submission to the Department of Defense . However on 16 November 1996 , only Boeing and Lockheed Martin were awarded contracts , allowing them to produce two of their concept aircraft each . Under the contract , these fighters were required to demonstrate Conventional Take Off and Landing ( CTOL ) , carrier take off and landing ( CV version ) , and short take off and vertical landing ( STOVL ) . They were also expected to include ground demonstrations of a production representative aircraft ' s systems , such as the Preferred Weapon System Concept ( PWSC ) . One major departure from previous projects was the prohibition of the companies from using their own money to finance development . Each was awarded $ 750 million to produce their two aircraft – including avionics , software and hardware . This limitation promoted the adoption of low cost manufacturing and assembly techniques , and also prevented either Boeing or Lockheed Martin from bankrupting themselves in an effort to win such an important contest . Designing the X - 32 . The X - 32 featured a large chin - mounted air intake akin to the Vought F - 8 Crusader and LTV A - 7 Corsair II , and a large one piece carbon fiber composite wing . The wing was trapezoidal , spanning 9 . 15 meters , with a 55 - degree leading edge sweep and could hold up to 20 , 000 pounds of fuel . The purpose of the high sweep angle was to allow for a thick wing section to be used while still providing limited transonic drag , and to provide a good angle for wing - installed antenna equipment . The wing would prove a challenge to fabricate . The engine is mounted directly behind the cockpit , which places it ahead of the center of gravity ( a very rare thing for a jet fighter ) , and also implies special hardware in the intake to prevent the blades from being directly visible to radar . Possibilities include a variable baffle designed to block incoming radar while not interfering with airflow . Boeing had proposed , in the 1960s , a similar supersonic fighter with a mid - center - of - gravity mounted engine with vectored thrust nozzles , but this never proceeded beyond pictures published in Aviation Week . By comparison , the Lockheed entry looked like , if anything , a smaller version of the F - 22 Raptor stealth fighter . The Boeing in - house nickname of the X - 32 was the " Monica . " Design changes . The two X - 32 prototypes featured a delta wing design , which was chosen to minimize production manufacturing costs . However , eight months into construction of the prototypes , the JSF ' s maneuverability and payload requirements were refined at the request of the Navy and Boeing ' s delta wing design fell short of the new targets . Engineers put together a new design with a conventional tail ( narrowly beating out a Pelikan tail ) with reduced weight and improved agility , but it was too late to change the prototypes . It was judged that they would be sufficient to demonstrate Boeing ' s technology . Flight testing . Due to the heavy delta wing design of the prototypes , Boeing demonstrated STOVL and supersonic flight in separate configurations , with the STOVL configuration requiring that some parts be removed from the fighter . The company promised that their conventional tail design for production models would not require separate configurations . By contrast , the Lockheed Martin X - 35 prototypes were capable of transitioning between their STOVL and supersonic configurations in mid - flight . The first flight of the X - 32A ( designed for CTOL and carrier trials ) took place on 18 September 2000 , from Boeing ' s Palmdale plant to Edwards Air Force Base . The X - 32B demonstrated STOVL flight , first flying in March 2001 . The X - 32 achieved STOVL flight in much the same way as the AV - 8B Harrier II with thrust vectoring of the jet and fan exhaust . The Lockheed Martin team used a riskier alternative , a shaft - driven lift fan powered by the main engine which was designed to generate more thrust than possible with only direct exhaust gases . A successful design would have greater payload , and thus longer range than a simple thrust vectored turbofan . Flight testing of both companies ' aircraft continued until July 2001 . JSF competition . On 26 October 2001 , the Department of Defense announced that the Lockheed Martin X - 35 won the JSF competition . One of the main reasons for this choice appears to have been the method of achieving STOVL flight , with the Department of Defense judging that the higher performance lift fan system was worth the extra risk . When near to the ground , the Boeing X - 32 suffers from the problem of hot air from the exhaust circulating back to the main engine , which causes the thrust to weaken and the engine to overheat . The X - 35 would be developed into the production F - 35 Lightning II . The loss of the JSF contract to Lockheed Martin in 2001 was a major blow to Boeing , as it represented the most important international fighter aircraft project since the Lightweight Fighter competition of the 1960s and 1970s , which had led to the F - 16 Fighting Falcon and F / A - 18 Hornet . At the time , the production run of the JSF was estimated at anywhere between 3 , 000 and 5 , 000 . Prior to the awarding of the contract , many lawmakers pushed the idea of retaining the losing competitor as a sub - contractor , however the " winner takes all " principle was not changed . Nonetheless , Boeing views its work on the X - 32 as a strategic investment , yielding important technologies which it has been able to adopt in the Boeing F / A - 18E / F Super Hornet and other studies . In 2005 , the Boeing X - 32A was transferred to the National Museum of the United States Air Force in Dayton , Ohio . Its condition had deteriorated due to sitting outside for several years following the end of the JSF competition . The X - 32B was transferred to the Patuxent River Naval Air Museum in St . Mary ' s County , Maryland in 2005 . It was undergoing restoration at the museum ' s restoration facility in June 2009 , and is now on display .