| X-32 JSF | |
|---|---|
 | |
| X-32 | |
| Role | Experimental stealth fighter aircraft |
| Manufacturer | Boeing |
| First flight | 18 September 2000 |
| Primary user | Defense Advanced Research Projects Agency (DARPA) |
The Boeing X-32 is a concept demonstrator aircraft that was designed for the Joint Strike Fighter competition. It lost to the Lockheed Martin X-35 demonstrator, which was further developed into the Lockheed Martin F-35 Lightning II.
 | This section needs additional citations for verification .(January 2019) |
In 1993, the Defense Advanced Research Projects Agency (DARPA) launched the Common Affordable Lightweight Fighter project (CALF). [1] 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. [2] Around the same time, the Joint Advanced Strike Technology (JAST) project was started. [3] In 1994, the U.S. Congress ordered the two to be merged into the Joint Strike Fighter (JSF) 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. On 16 November 1996, Boeing and Lockheed Martin were awarded contracts for them to produce two of their concept demonstrator aircraft (CDA) each. [4] 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.
Boeing's strategy for a competitive advantage was to offer substantially lower manufacturing and life-cycle costs by minimizing variations between the different JSF versions. The X-32 therefore was designed around a large one piece carbon fiber composite delta wing. The wing had a span of 9.15 meters, with a 55-degree leading edge sweep, and could hold up to 20,000 pounds (9,000 kg) 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 aerodynamic drag, and to provide a good angle for wing-installed conformal antenna equipment. [5] The wing would prove a challenge to fabricate. [6] [7]
The compete-on-cost strategy also led Boeing to pick a direct-lift thrust vectoring system, for the Marines' short take-off and vertical landing (STOVL) requirement, as this would only necessitate the addition of a thrust vectoring module around the main engine. [6] However, this choice required the engine to be mounted directly behind the cockpit, and moved the center of gravity forward from its usual position in jet fighters (towards the rear of the airplane) to enable a neutral-attitude hover. 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.[ citation needed ] By comparison, the Lockheed entry looked like, if anything, a smaller version of the F-22 Raptor stealth fighter. [8] Yet another effect of the selection of the direct-lift system was the large chin-mounted air intake. This was required to feed sufficient air to the main engine (to provide the thrust necessary to hover) during the zero horizontal velocity phase, when it could not exploit ram-air pressure. A knock-on effect of this large intake was the potential direct visibility of the compressor blades to radar (see radar cross-section). Mitigation possibilities included variable baffles designed to block incoming radio waves without adversely affecting airflow. [5]
The two X-32 aircraft featured a delta wing design. However, eight months into construction of the concept demonstrator aircraft, 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 altered the aircraft's design with a conventional canted twin tail that reduced weight and improved agility, but it was too late to change the aircraft. It was judged that they would be sufficient to demonstrate Boeing's technology. [6]
On 14 December 1999, Boeing unveiled both its concept demonstrators at its plant in Palmdale, California, in front of 5,500 attendees. While the X-32A was expected to make an appearance, the roll out of the X-32B was a surprise, as construction of the latter aircraft had started some three months after the former and was completed six weeks after the X-32A. [9] Boeing attributed the rapid construction of the STOVL version to the use of digital design and assembly methods. [10] After having the Pratt & Whitney F119 engine installed in April 2000, the X-32A commenced low- and medium-speed taxi tests, which had been completed by late May. [11] [12]
Due to the heavy delta wing design of the X-32, 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 concept demonstrator aircraft were capable of transitioning between their STOVL and supersonic configurations in mid-flight. [6]
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 aircraft, piloted by Boeing test pilot Fred Knox, took 2,200 feet (670 m) of runway before becoming airborne at 150 knots (280 km/h; 170 mph) at around 8:00 am. [13] Shortly after takeoff, a minor hydraulic leak was discovered and the flight was shortened to 20 minutes from the expected 30–40 minutes. [14] According to Knox, the F/A-18 chase plane required "a lot of afterburner" to keep up with the X-32 during the initial stages. During the flight, the aircraft reached 10,000 feet (3,000 m), attained a speed of 200 knots (370 km/h; 230 mph), and attained an angle of attack of 13°. Despite the shortened flight, about 80% of the planned test points were accomplished. [13] It was powered by a conventional derivative of the F-22 afterburning turbofan, designated F119-PW-614C.[ citation needed ]
On 29 March 2001, the X-32B STOVL version made its first flight. The flight lasted 50 minutes as the aircraft flew from Palmdale to Edwards AFB. The flight had originally been scheduled for the third quarter of 2000. [15] [16] A modified version of the -614C engine, known as the F119-PW-614S, powered the STOVL aircraft. [17] In normal flight, the -614S was configured as a conventional afterburning turbofan. However, in the STOVL mode a butterfly valve diverted the core stream exhaust gases to a pair of thrust vectoring nozzles located close to the aircraft's center-of-gravity. Forward of these nozzles, a jet screen nozzle provided a sheet of cool bypass air to minimise hot gas recirculation. There was also a pair of ducts leading to roll nozzles near the wing tips. Two pairs of ducts fed the aft-pitch yaw nozzles and the forward-pitch nozzles. [18] The afterburner was unlit, with no gas flow during lift. The X-32B achieved STOVL flight in much the same way as the AV-8B Harrier II with thrust vectoring of the jet exhaust. A smooth transition (between STOVL and normal modes) was obtained by maintaining a constant engine match, facilitated by the control system algorithm maintaining a fixed total nozzle effective area. Thus the engine was unaware of various nozzles being opened up and closed off to complete the transition.[ citation needed ]
The F119-PW-614S was a direct lift engine, whereas the Lockheed Martin STOVL team used a more complex and riskier alternative, known as the F119-PW-611, which comprised a remote shaft-driven lift fan powered by the main engine. However, this generated more lift 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. [19]
Flight testing of both companies' aircraft continued until July 2001.[ citation needed ]
On 26 October 2001, the Department of Defense announced that the Lockheed Martin X-35 had won the JSF competition. The X-35 would be developed into the production Lockheed Martin F-35 Lightning II. [6]
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 program 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. [20] 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. [21]
In 2005, the Boeing X-32A was transferred to the National Museum of the United States Air Force near Dayton, Ohio. Its condition deteriorated due to being outside for several years following the end of the JSF competition. [22] In December 2023, the museum completed a three-month-long restoration of the aircraft. [23]
The X-32B was transferred to the Patuxent River Naval Air Museum adjacent to NAS Patuxent River in St. Mary's County, Maryland in 2005. [24] It underwent restoration at the museum's restoration facility in June 2009, but has deteriorated since. The aircraft is on display.
Data from Frawley [25]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Related lists
The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, all-weather stealth multirole combat aircraft that is intended to perform both air superiority and strike missions. It is also able to provide electronic warfare and intelligence, surveillance, and reconnaissance capabilities. Lockheed Martin is the prime F-35 contractor, with principal partners Northrop Grumman and BAE Systems. The aircraft has three main variants: the conventional takeoff and landing (CTOL) F-35A, the short take-off and vertical-landing (STOVL) F-35B, and the carrier-based (CV/CATOBAR) F-35C.
A short take-off and vertical landing aircraft is a fixed-wing aircraft that is able to take off from a short runway and land vertically. The formal NATO definition is:
A Short Take-Off and Vertical Landing aircraft is a fixed-wing aircraft capable of clearing a 15 m obstacle within 450 m of commencing take-off run, and capable of landing vertically.
A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wing aircraft and other hybrid aircraft with powered rotors such as cyclogyros/cyclocopters and gyrodynes.
A vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) aircraft are a subset of V/STOL craft that do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover. Helicopters are not considered under the V/STOL classification as the classification is only used for aeroplanes, aircraft that achieve lift (force) in forward flight by planing the air, thereby achieving speed and fuel efficiency that is typically greater than the capability of helicopters.
The Northrop/McDonnell Douglas YF-23 is an American single-seat, twin-engine, supersonic stealth fighter aircraft technology demonstrator designed for the United States Air Force (USAF). The design was a finalist in the USAF's Advanced Tactical Fighter (ATF) competition, battling the Lockheed YF-22 for a production contract. Two YF-23 prototypes were built.
The Lockheed Martin X-35 is a concept demonstrator aircraft (CDA) developed by Lockheed Martin for the Joint Strike Fighter program. The X-35 was declared the winner over the competing Boeing X-32 and a developed, armed version went on to enter production in the early 21st century as the F-35 Lightning II.
The Lockheed Martin X-44 MANTA was an American conceptual aircraft design by Lockheed Martin that has been studied by NASA and the U.S. Air Force. It was intended to test the feasibility of full yaw, pitch and roll authority without tailplanes. Attitude control relies purely on 3D thrust vectoring. The aircraft design was derived from the F-22 Raptor and featured a stretched delta wing without tail surfaces.
The General Electric/Rolls-Royce F136 was an advanced turbofan engine being developed by General Electric and Rolls-Royce plc for the Lockheed Martin F-35 Lightning II. The two companies stopped work on the project in December 2011 after failing to gather Pentagon support for further development.
Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to control the attitude or angular velocity of the vehicle.
The Pratt & Whitney F119, company designation PW5000, is an afterburning turbofan engine developed by Pratt & Whitney for the Advanced Tactical Fighter (ATF) program, which resulted in the Lockheed Martin F-22 Raptor. The engine delivers thrust in the 35,000 lbf (156 kN) class and was designed for sustained supersonic flight without afterburners, or supercruise. Delivering almost 22% more thrust with 40% fewer parts than its F100 predecessor, the F119 allows the F-22 to achieve supercruise speeds of up to Mach 1.8. The F119's nozzles incorporate thrust vectoring that enable them to direct the engine thrust ±20° in the pitch axis to give the F-22 enhanced maneuverability.
The Pratt & Whitney F135 is an afterburning turbofan developed for the Lockheed Martin F-35 Lightning II, a single-engine strike fighter. It has two variants; a Conventional Take-Off and Landing (CTOL) variant used in the F-35A and F-35C, and a two-cycle Short Take-Off Vertical Landing (STOVL) variant used in the F-35B that includes a forward lift fan. The first production engines were delivered in 2009.
The Sukhoi Su-37 was a single-seat twin-engine aircraft designed by the Sukhoi Design Bureau which served as a technology demonstrator. It met the need to enhance pilot control of the Su-27M, a further development of the Su-27. The sole example built was originally the eleventh Su-27M (T10M-11) built by the Komsomolsk-on-Amur Aircraft Production Association before having thrust-vectoring nozzles installed. It also had updated flight- and weapons-control systems. The aircraft made its maiden flight in April 1996. Throughout the flight-test program, the Su-37 demonstrated its supermaneuverability at air shows, performing manoeuvres such as a 360-degree somersault. The aircraft crashed in December 2002 due to structural failure. The Su-37 did not enter production, despite a report in 1998 which claimed that Sukhoi had built a second Su-37 using the twelfth Su-27M airframe, T10M-11 remained the sole prototype. Sukhoi had instead applied the aircraft's systems to the design bureau's other fighter designs.
The Lockheed/Boeing/General Dynamics YF-22 is an American single-seat, twin-engine fighter aircraft technology demonstrator designed for the United States Air Force (USAF). The design was a finalist in the USAF's Advanced Tactical Fighter competition, and two prototypes were built for the demonstration/validation phase of the competition. The YF-22 won the contest against the Northrop YF-23, and the design was developed into the Lockheed Martin F-22 Raptor. The YF-22 has a similar aerodynamic layout and configuration as the F-22, but with differences in the position and design of the cockpit, tail fins and wings, and in internal structural layout.
The General Electric YF120, internally designated as GE37, was a variable cycle afterburning turbofan engine designed by General Electric Aircraft Engines in the late 1980s and early 1990s for the United States Air Force's Advanced Tactical Fighter (ATF) program. It was designed to produce maximum thrust in the 35,000 lbf (156 kN) class. Prototype engines were installed in the two competing technology demonstrator aircraft, the Lockheed YF-22 and Northrop YF-23.
Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Italy, Canada, Australia, the Netherlands, Denmark, Norway, and formerly Turkey. After a competition between the Boeing X-32 and the Lockheed Martin X-35, the latter aircraft was selected for a contract award and developed into the F-35 Lightning II, which will replace various tactical aircraft, including the US F-16, A-10, F/A-18A-D, AV-8B, EA-6B and British Harrier GR7, GR9s and Tornado GR4. The projected average annual cost of the program is $12.5 billion with an estimated program life-cycle cost of $1.1 trillion.
The Rolls-Royce LiftSystem, together with the F135 engine, is an aircraft propulsion system designed for use in the STOVL variant of the F-35 Lightning II. The complete system, known as the Integrated Lift Fan Propulsion System (ILFPS), was awarded the Collier Trophy in 2001.
Paul Michael Bevilaqua is an aeronautics engineer at Lockheed Martin in California. In 1990, he invented the lift fan for the Joint Strike Fighter F-35B along with fellow Skunk Works engineer, Paul Shumpert.
The British Aerospace P.125 was a British supersonic STOVL multirole combat aircraft being developed in the 1980s. The project was cancelled in the 1990s. The existence of the project was revealed by BAE Systems in 2006.
Shipborne rolling vertical landing (SRVL) is a method used to land a V/STOL aircraft that uses both the vertical thrust from the jet engine and lift from the wings.
| Authority control databases: National |
|---|
