The Question at the Heart of American Air Power
The Pentagon's storied X-plane program, which produced legendary aircraft like the X-1 and X-15, now faces a modern existential question: are these expensive experimental demonstrators still necessary when swarms of cheap drones can perform many of the same missions? Defense officials, aerospace engineers, and military strategists are grappling with this issue as the Department of Defense drafts its budget for the next decade. The answer will shape the future of American air superiority.
A Legacy of Breakthroughs, A Future of Uncertainty
Since the 1940s, X-planes have pushed the boundaries of flight, breaking speed and altitude records while testing radical designs like swept wings, vertical takeoff, and stealth. The Bell X-1 broke the sound barrier in 1947, and the North American X-15 reached the edge of space in the 1960s. More recently, the X-35 led to the F-35 Joint Strike Fighter, and the X-47B demonstrated carrier-based unmanned combat. Each program yielded invaluable data, but they also consumed billions in taxpayer dollars.
Today, the Pentagon's latest X-plane initiatives, such as the X-65 for active flow control and the X-67A for collaborative combat aircraft, aim to mature technologies that could define sixth-generation fighters. However, the rise of low-cost drones—some costing as little as $20,000—has prompted a fundamental reassessment. During recent conflicts, relatively inexpensive unmanned systems have destroyed tanks, ships, and even advanced air defenses, raising doubts about the need for multi-million-dollar manned demonstrators.
The Drone Revolution and Cost Pressures
The war in Ukraine has become a live-fire laboratory for drone warfare. Commercially available quadcopters and purpose-built one-way attack drones have proven devastatingly effective against armored columns and static positions. This real-world evidence has accelerated the Pentagon's interest in attritable systems—drones designed to be lost in combat. The Air Force's Collaborative Combat Aircraft (CCA) program, which pairs manned fighters with semi-autonomous drone wingmen, is a direct response to this trend.
Cost analysts note that a single F-35 fighter costs around $80 million, while a CCA drone could cost as little as $10 million. This disparity has led some defense experts to argue that the era of big-ticket X-planes is waning. They point to the Navy's decision to cancel the X-47B's follow-on, the Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) program, in favor of a cheaper refueling drone. The economics are stark: for the price of one advanced fighter, the Pentagon could field a fleet of dozens of networked drones.
Why X-Planes Still Matter for Innovation
Proponents of X-planes argue that they remain essential for testing unproven technologies that drones cannot yet carry. Advanced propulsion systems, directed-energy weapons, and hypersonic flight require dedicated testbeds with flexible instrumentation and human oversight. The X-59 QueSST, for instance, is designed to demonstrate quiet supersonic flight, a capability that could open new commercial and military routes. Without such demonstrators, these breakthroughs might never transition to operational platforms.
Moreover, X-planes serve as incubators for the next generation of aerospace engineers and test pilots, preserving a skill set that cannot be replicated on simulators alone. The Air Force Research Laboratory's X-60A, a low-cost hypersonic test vehicle, exemplifies this role. By flying frequently and cheaply, it generates data that informs both drone and manned programs. In this view, X-planes are not competitors to drones but complementary tools that de-risk future systems, including autonomous ones.
The Pentagon's Balancing Act
The Department of Defense is navigating a delicate balance between tradition and transformation. In its 2025 budget request, the Air Force allocated $2.7 billion for Next Generation Air Dominance (NGAD), which includes a manned sixth-generation fighter and its drone companions. However, the program has faced internal scrutiny, with some officials questioning whether the manned component is worth its price tag. A recent defense briefing indicated that the NGAD platform may be redesigned to lower costs, potentially incorporating more autonomous features.
Meanwhile, the Navy is pursuing a separate NGAD variant, and the Army is exploring drone swarms for ground support. Each service is placing bets on different mixes of manned and unmanned systems. Industry analysts suggest that the Pentagon will continue to fund a small number of X-planes to prove key technologies, but will increasingly rely on digital simulations and rapid prototyping to reduce development timelines. The goal is to field systems faster and at lower cost, without sacrificing technological surprise.
What the Future Holds for X-Planes
Looking ahead, the X-plane program is likely to evolve rather than disappear. The Pentagon's 2024 Strategic Impact Plan emphasizes the need for 'highly autonomous, low-cost, and attritable' systems, but it also calls for 'leap-ahead technologies' that require experimental platforms. The key will be to select X-plane projects that offer the greatest potential payoff for both manned and unmanned fleets. Hypersonics, advanced sensors, and electronic warfare are prime candidates.
Another factor is the global competition. China and Russia are investing heavily in both drones and hypersonic vehicles, and their X-plane equivalents are advancing rapidly. To maintain an edge, the United States must continue to innovate. However, the days of billion-dollar demonstrators may be numbered. Instead, expect modular X-planes that can test multiple technologies in a single campaign, and increased use of commercial off-the-shelf components to cut costs.
A Pragmatic Path Forward
Ultimately, the debate over X-planes versus cheap drones is not a zero-sum game. The future force will likely feature a mix of a few highly capable manned platforms and many expendable unmanned systems. X-planes will serve as the testbeds that refine the technologies for both. The challenge is to ensure that these demonstrators are affordable and relevant. As one defense official noted, 'We need to be smart about what we fly and what we simulate.'
The Pentagon is already taking steps in this direction. The Defense Innovation Unit is funding small, rapid X-plane prototypes, and the Air Force's eXperimental Program (X-planes) is now focused on 'disruptive capabilities' with a budget cap. These shifts suggest that while the era of giant X-plane programs may be fading, the spirit of experimentation will live on. The next breakthrough in aviation may come from a drone—or from an X-plane that looks very different from its predecessors.
