Joint Strike Fighter

The Joint Strike Fighter, JSF, is the program that produced the F-35 Lightning II, an ambitious effort to develop a single stealth fighter design in variants serving multiple US services and allied nations. The idea driving the program was that developing one basic aircraft in a few variants for many users, rather than separate aircraft for each, would save money through commonality and shared development, while producing an advanced stealth fighter that many nations would fly, spreading costs and creating a large, interoperable fleet. The F-35 that resulted became one of the most significant and most controversial military programs in history, the largest defense acquisition program ever undertaken, and its story illustrates both the promise and the perils of the ambitious approach the Joint Strike Fighter program embodied.

The concept and the three variants

The Joint Strike Fighter program's central concept was commonality, developing one basic aircraft in variants tailored to different users' needs so that the shared development and common components would reduce cost compared to developing separate aircraft, while giving multiple services and nations an advanced stealth fighter. The program produced three variants of the F-35, sharing a common basic design but adapted to different requirements: the F-35A, a conventional version for the US Air Force and many allied air forces, taking off and landing from runways; the F-35B, a short-takeoff and vertical-landing version for the US Marine Corps and others, able to operate from short fields and small ships by taking off in a short distance and landing vertically; and the F-35C, a carrier version for the US Navy, strengthened and adapted for catapult launches and arrested landings on aircraft carriers. This one-design-three-variants approach aimed to serve the different needs of the air force, marines, and navy, and of the many allied nations that would buy the aircraft, with a common basic design, achieving the economies of commonality while meeting the diverse requirements, and the program attracted many international partners and buyers, creating a large multinational fleet of a common advanced fighter. The F-35 that resulted is a genuinely advanced aircraft, a stealth fighter with sophisticated sensors, fused into a single picture for the pilot, and advanced capabilities that make it far more than a traditional fighter, more a networked sensor and information platform that happens to be a fighter, and its stealth, sensors, and networking represent a significant advance in capability, so the program delivered a capable aircraft, whatever the controversies about its cost and development.

The Joint Strike Fighter program also became a byword for the difficulties of ambitious defense acquisition, running massively over budget and behind schedule and encountering serious technical problems, so that its story is a cautionary tale about the perils of the ambitious commonality approach. The effort to develop one aircraft serving so many different needs proved far harder and more expensive than anticipated, since the three variants, despite sharing a basic design, diverged more than hoped to meet their different requirements, reducing the commonality savings, and the ambition to pack so much advanced capability, stealth, sensors, networking, into the aircraft created enormous technical challenges and complexity that drove cost and delay. The program's total cost, including development, procurement, and the vast expense of operating and sustaining the fleet over its lifetime, reached the trillions of dollars, making it the most expensive weapons program ever, and it ran years behind schedule with a long list of technical problems that had to be worked through, from software difficulties to issues with the aircraft's complex systems, problems that continued even after the aircraft entered service, as with the delayed Technology Refresh 3 upgrade that paused deliveries. These difficulties made the F-35 a frequent target of criticism, held up as an example of defense acquisition gone wrong, of the way ambitious programs overrun and underdeliver, and of the problems of trying to develop one aircraft for too many purposes, and the criticism has real substance, since the program did overrun enormously and encountered serious problems. Yet the aircraft that resulted is capable and is now fielded in growing numbers by the US services and many allies, so the fuller assessment is that the program delivered a genuinely advanced and capable aircraft, but at enormous cost and after great difficulty, an outcome that vindicates neither the harshest critics who dismiss the aircraft nor the boosters who minimize the problems, but reflects the mixed reality of an ambitious program that achieved its capability goals while badly missing its cost and schedule ones.

The Joint Strike Fighter's lessons and legacy

The Joint Strike Fighter program left important lessons about the ambitious approach it embodied, about the promise and the perils of developing a single common aircraft for many users, lessons that inform how such programs are conceived. The promise, that commonality across variants and users would save money while producing an advanced aircraft for many, proved partly illusory, since the commonality savings were less than hoped as the variants diverged and the ambition drove cost and complexity, so the program did not achieve the economies its concept promised, a lesson about the limits of commonality when the users' needs differ significantly. The perils, that packing so much ambition into one program creates enormous risk of overrun, delay, and technical difficulty, were amply demonstrated, a lesson about the dangers of overly ambitious programs that try to do too much, and the F-35's troubled development has made planners more cautious about such ambition, more attentive to the risks of commonality and complexity. At the same time, the program's eventual delivery of a capable aircraft fielded by many nations shows that the ambitious approach, for all its difficulties, did produce an advanced, interoperable fleet, so the legacy is not simply a cautionary tale but a mixed one, of an ambitious concept that delivered its capability at great cost and difficulty, offering lessons about both what such ambition can achieve and what it risks. The F-35 itself is now a central aircraft of American and allied air power, its capabilities significant and its large multinational fleet providing the interoperability the program envisioned, so whatever the troubles of its development, the aircraft is now a reality and a major capability, and the Joint Strike Fighter program's ultimate significance is as both the source of this important aircraft and a landmark example, studied and debated, of the promise and the perils of ambitious defense acquisition, a program that achieved a great deal while illustrating how such achievement can come at enormous cost and through great difficulty, lessons that continue to inform the perennial challenge of developing advanced military capabilities effectively and affordably.

Why build one aircraft in three variants instead of three separate aircraft?

The idea was to save money and gain other benefits through commonality, developing one basic aircraft adapted into variants for different users rather than developing three entirely separate aircraft, on the theory that shared development and common components would cost less than three independent programs while producing a common, interoperable fleet. Developing a military aircraft is enormously expensive, so the reasoning was that developing one basic design and adapting it into variants for the different services and their needs would spread the development cost across the variants and users and allow common components, achieving economies that three separate aircraft programs, each bearing its own full development cost, could not, while also creating a common fleet whose shared design would ease maintenance, training, and interoperability across the services and nations flying it. This commonality logic is appealing in principle, since it promises to avoid the duplication of developing separate aircraft for similar purposes and to gain the benefits of a common fleet, which is why the Joint Strike Fighter program adopted it, aiming to serve the air force, marines, and navy, and many allies, with variants of one aircraft. In practice, however, the commonality proved less economical than hoped, because the variants, despite sharing a basic design, had to diverge significantly to meet their very different requirements, the conventional, short-takeoff-and-vertical-landing, and carrier versions each needing substantial adaptation, which reduced the common components and the savings, while the ambition of the common program drove cost and complexity, so the expected economies were substantially eroded. This is one of the key lessons of the program, that commonality across variants and users saves less than hoped when the users' needs differ significantly, since the divergence required to meet different needs undercuts the commonality, a lesson that tempers the appeal of the one-aircraft-many-variants approach and that has made planners more cautious about assuming such commonality will deliver the savings it promises, even as the F-35 program did ultimately produce a common, interoperable, capable fleet, achieving that goal of the commonality concept while falling short of the cost savings that were its other main justification.