The Joint Strike Fighter (JSF) program was born out of a 1993 requirement by Defense Advanced Research Projects Agency (DARPA). The requirement established the launch of Common Affordable Lightweight Fighter (CALF) program that put forth a proposition for DoD aircraft to unify airframes across all branches. This was hardly unprecedented, as it was a similar program that birthed the F-4 Phantom II, and subsequent platforms that did not retain their mission objective (such as the F-15 and the F-16). But what happens when you try to make the best of your multi-role designs? What happens when you try to merge other key concepts such as S/VOTL into your concept? This was all uncharted territory, despite the existence of the AV-8B Harrier.
The JSF program was the result of the merger of two DoD requirements: the CALF program, and the Joint Advanced Strike Technology (JAST) Demonstrator program. The results of the program however, both have had their share of shortcomings. The X-35 was selected for large scale production, but what about the aircraft that didn't make the cut? Let's take at least a brief look at the Boeing X-32 "Monica."
A Brief Background
The JSF program, while primarily serving to function to replace American aircraft, also was to introduce and streamline aircraft across multiple NATO nations and Western Allies. It also marked the first time an American stealth design would be cleared for export to foreign nations. RDE for the JSF had begun in 1993 with the CALF and JAST programs, thus ultimately the JSF program itself finds it's origin date in 1993 as well. Much like the preceding ATF, by the time the first prototypes flew, seven years had passed from the beginning of the project. Due to the recent nature of the program however, much of the research history is still classified or is otherwise missing from most directorates.
By 2000, it was determined that the two primary contenders for the program would be Lockheed and Boeing, with the former pitting their X-35 up against Boeing's X-32. The ultimate goal of the project was to introduce a sweeping replacement for a multitude of aircraft in the U.S. inventory. This included eventual replacement for the F-16, F/A-18, the AV-8B, and even the A-10. International customers were interested in replacing their aging F-16's, AV-8's, Tornado's, and even MiG-29's. By the time the first prototypes flew, twelve nations had signed on with interest in an exported model of the winner of the JSF program, with another eight tentatively committed to purchase.
The Boeing X-32
|Dimensions:||45'0" L, 36'0" W, 17'4" H|
|Weight:||38,000 lbs (maximum)|
|Speed:||~1,200 mph (cruise)|
|Range:||850 miles (A), 750 miles (C), 600 miles (B)|
|First Flight:||18 September 2000|
The Happiest Plane In the Skies
Cost overruns were the biggest challenge wrapped up within the JSF program. Even today, problems continue to plague the winner in the form of manufacturing issues, fielding issues, market fluidity, and supply & demand fluctuations - especially in the export market. Boeing attempted early to mitigate these risks by using a single uniform blended wing body to make up the foundation of the X-32. The frame was designed with carbon fiber which also made it cost-effective for additive manufacturing. The nature of the wings however, was extremely challenging during the design phase. Creating a wing that was heavy enough to maintain structural integrity while housing all necessary control surfaces and to limit drag.
Like the Lockheed program, the X-32 was tasked of having three variants to serve three separate branches of the military. The would uniformly be powered by Pratt & Whitney's F119 turbofan. The powerplant for the X-32 was mounted immediately behind the cockpit, which unfortunately not only changed where the center of mass of the aircraft sat, but also increased cockpit noise. This was to stabilize the aircraft for STOL purposes. This is because the engine utilized direct life thrust vectoring for STOL functions. The requirement of ample air required to cool and stabilize the engine resulted in the distinctive chin feature on the front of the aircraft for the intake. This feature has led to much criticism of the design of the aircraft, with some dubbing it "the happiest plane in the skies." (It's led to a good number of memes, too!)
The original Boeing concept had a single vertical stabilizer, but popup requirements pushed by the U.S. Navy resulted in a weight reduction which changed the tail configuration to the two canted stabilizers. It is highly unlikely that the production F-32 would have looked the same as the prototype X-32, as a result of this. By the time of the third prototypes completion, most modifications could have been added, but Boeing had already determined that further modifications to the weight or dimensions would not impact performance of the demonstrators.
The first X-32 was completed by the end of 1999. By September of 2000, it had flown for the first time and the X-32B was already well underway in production - with the B model entering design/built phases ahead of schedule.
For lack of a better way of putting it; Boeing failed to present the X-32 in a favorable light. When it came to engine configurations, the X-32 was unable to demonstrate it's transition between STOL and supersonic flight, a major setback despite Boeing's assertation that it could be done in production models. In addition, the prototypes were plagued with problems ranging from hydraulic complications, to engine issues. Most testing points were met, however the failures revealed fundamental problems in aircraft design and engineering.
In VTOL flight, the X-32 underperformed mostly due to Boeing's inability to take risk on new design and technology. The X-32 utilized straight-forward thrust vectoring which was akin to how the AV-8 had achieved it's VTOL flights. However, while the AV-8's technology with VTOL had been proven, it was also no longer considered efficient. Loss of thrust power also reduced the flexibility of the aircraft and reduced it's readiness, both key factors in the selection of the JSF winner.
Flight testing on the prototypes continued until late 2001 when the winner was selected. However, unlike previous competition aircraft, the X-32 was almost immediately pulled from testing and put into storage or on display. The X-32A that remains is pending restoration at the USAF Museum in Dayton, Ohio.
Unfortunately due to the number of failures in the X-32 program, Lockheed's X-35 went on to win the JSF program. Supposedly, Lockheed's method of achieving S/VTOL requirements was more appealing than that of the X-32. However, in addition to this, numerous problems in demonstrated flight and design plus the failure to provide a prototype which met all requirements surely had something to do with it. However, the F-35 program has also run into issues post-production.
The probably causes for such issues in the F-35 program seem to be similar to the issues found in the X-32 program's attempt to normalize aircraft platforms into a single design to fit a series of roles. Such an attempt began as early as World War II however, mission requirements have made such a task much more difficult. The F-4 Phantom, was arguably the last aircraft to successfully meet all of the requirements and effectively complete it's mission set. Attempts to reunify aircraft across the three fixed-wing military branches occurred again in 1965, 1974, and 1983. All of these attempts were scrapped before prototypes could be produced for one reason or another. The major concern for all of these was also cost-overrun and the ability to create a design that could effectively deliver on mission requirements across the board.
Whether or not the F-35 has run into massive cost overruns is a matter of natural occurrence from the mission set required from it or not, the X-32 surely would have encountered similar issues. One report cited that the mode of VTOL flight achievement used caused increased temperature for the engine which could result in overheating or explosion.
Ultimately, the X-32 program was effectively terminated as of 2003, and Boeing has made no attempts to revive or cannibalize the program. Instead, Boeing's current endeavors have been to focus on it's new F/A-XX concept, a design that will one day replace the F-22 Raptor.
Still, the X-32 provided us with some great laughter, and seems to be excellent at even laughing at itself - a true champion.