Joint Strike Fighter

How do the thinkers over at the Department of Defense decide that a fighter’s too old and needs to be replaced? Does it take a few decades before they start wondering about buying a bunch of shiny newer planes for the branches of service that require them? They actually make the call when the fighter’s in its initial stage of procurement, still having the finishing touches put on before they’re delivered for active duty. Take the F-16 for example. The Fighting Falcon went into service with the United States Air Force in August of 1978, but defense officials had already determined to open up a new fighter program in a decade or so that would see the birth of the F-16’s replacement yet another 10 to 15 years or so down the road, and then its entering into service not too long after.

The Joint Strike Fighter program traces its roots back to two parent programs of the late 1980s, early 1990s: the Common Affordable Lightweight Fighter and Joint Advanced Strike Technology projects, both of which came together to develop an SSF, a short take-off/vertical landing strike fighter aircraft as a replacement for the AV-8 Harrier in service with the Marine Corps, and as an eventual replacement for the F-16 of the Air Force. In 1992, the programs merged to design and build an all-new advanced fighter, capable of complimenting the F-22 Raptor in a similar way to how the F-16 complements the larger F-15 Eagle. Taking the common name of the JAST project in 1993, the Navy was included in the program allowing the Department of Defense to end a number of programs and intended acquisitions, freeing up money to be diverted towards the development of the Raptor and the Super Hornet. Adding on to JAST was the United Kingdom in 1995 and Canda in 1997, both interested in investing and possibly buying the resulting fighters for their air force fleets. The United Kingdom’s Ministry of Defence was especially interested in replacing their venerable-but-aging Sea Harriers/GR.7s, and so, they initiated Future Carrier Borne Aircraft project with a heavy focus on procuring the winner of this program for their naval aviation air arm. With all these developments in mind, a newer, all-encompassing project was formed. Thus began the Joint Strike Fighter competition which would eventually lead to the F-35 Lightning II.

The JSF competition commenced with the awarding of two contracts, one to Lockheed Martin and the other to Boeing. Their conceptual models beat out the bid from a combined team of McDonnell Douglas, BAE and Northrop Grumman, mostly due to the complexity and costs involved with MD/BAE/NG’s proposed design. The finished product of JSF was to fulfill the following primary roles:

– (Navy) Operate as a strike fighter aircraft, complementing the Boeing F/A-18E/F Super Hornets
– (Air Force) Operate as a multirole combat aircraft with the ability to perform air-to-ground missions, serving as a replacement for the F-16 and possibly A-10 Thunderbolt II while complementing the F-22 Raptor.
– (Marines) Replace the AV-8B Harrier as well as the F/A-18 Hornets in service in both attack and strike roles. The Marines would therefore buy both the B (STOVL) and C (CATOBAR) models.
-(Royal Navy/RAF) Replace Sea Harriers/GR.7 models with a strike fighter capable of supersonic speeds.

Both companies set about constructing flying prototypes, the Boeing X-32 and the LM X-35. The X-35 program developed faster than the X-32, and by the late 90s, thanks in part to the inclusion of 5th generation technology from the Raptor program, LM was able to have two flight-ready prototypes, one which was to be the carrier variant (X-35C) and the other the original which was then converted to the STOVL X-35B. Lockheed Martin’s design was somewhat conventional, looking like a scaled-down version of its bigger brother, the F-22. Its STOVL model had a large vertical-lift fan in the center of the plane, right in front of the engine. For a vertical landing, the large turbofan at the rear would vector downwards, adding to the power of the lift fan.  Boeing’s design was somewhat unsightly in appearance. It featured a massive delta wing constructed with composites, able to hold over 20,000 lbs of fuel. The engine was placed immediately behind the cockpit with a chin air intake underneath the nose, much like one you’d see on an old Vought F-8 Crusader. The intake was designed to limit the engine’s blades from being visible to enemy radar, increasing its stealth factor. The STOVL version used vector nozzles positioned on the wings and under the fuselage to achieve vertical flight. Both aircraft carried the majority of their missiles stores in bays within the fuselage to preserve stealth.

September of 2000 saw the first flight of the X-32; a month later, the X-35 took to the skies. Factors like maneuverability and RCS now came into play in the final evaluations. Of particular note to DoD overseers was the STOVL X-32’s issues with vertical flight, in that exhaust air managed to circulate into the engine, weakening the thrust and causing an overheat, especially in a hover near ground. The X-35, on the other hand, excelled, showcasing the prowess of LM’s engineers and designers. Perhaps the event that secured the X-35’s victory was its taking off in under 500 feet, transition to supersonic flight and then final vertical landing. The overseers were enamored and in October, 2001, Lockheed Martin officially won the contract for the JSF, one of the most vital and largest defense contracts in its history.

*Acronyms used:

CATOBAR- Catapult Takeoff But Arrested Recovery
STOVL- Short Takeoff Vertical Landing
RCS- Radar Cross Section
CALF- Common Affordable Lightweight Fighter program (precursor to JAST/JSF)
JSF- Joint Strike Fighter program
JAST- Joint Advanced Strike Technology program (precursor to JSF)
FCBA- Future Carrier Borne Aircraft project; British program (now known as Joint Combat Aircraft/JCA)