to fabricate.[8][9]
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.[8] 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.[10] 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.[7]
Design changes
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 demonstrator aircraft. It was judged that they would be sufficient to demonstrate Boeing’s technology.[8]
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.[11] Boeing attributed the rapid construction of the STOVL version to the use of digital design and assembly methods.[12] 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.[13][14]
Crew: 1
Length: 45 ft 0.1 in (13.72 m)
Wingspan: 36 ft 0 in (10.97 m)
Height: 17 ft 3.8 in (5.28 m)
Wing area: 590 sq ft (54.8 m2)
Empty weight: 24,030 lb (10,900 kg)
Max takeoff weight: 38,000 lb (17,200 kg)
Powerplant: 1 × Pratt & Whitney YF119-PW-614 afterburning turbofan, 28,000 lbf (120 kN) thrust dry, 43,000[29] lbf (190 kN) with afterburner
Performance
Maximum speed: 1,200 mph (1,931 km/h, 1,000 kn) at altitude
Maximum speed: Mach 1.6
Range on USAF mission profile: 850 nmi (1,574 km)
Range on USN mission profile: 750 nmi (1,389 km)
Range on USMC/RN mission profile: 600 nmi (1,112 km)
Armament
20 mm M61A2 cannon, or 27 mm Mauser BK-27 cannon
Internal: 4 AMRAAM air-air missiles or 2 AMRAAM air-air missiles and 2 x 2,000 lb (900 kg) class guided bombs
External: Approx. 15,000 lb (6,800 kg) of full range of external stores including guided weapons, anti-radiation missile, air-to-surface weapons, auxiliary fuel tanks
