DARPA has postponed the maiden flight of the X-65, an experimental air jet-controlled aircraft, by more than two years due to major costs and technical challenges.
Summary
The X-65 program, developed by DARPA as part of the CRANE (Control of Revolutionary Aircraft with Novel Effectors) project, aims to demonstrate a technology called active flow control (AFC): the aircraft is controlled without traditional movable control surfaces, but by air jets directed onto the flight surfaces. The demonstrator is being developed by Aurora Flight Sciences (a Boeing subsidiary). It will have a wingspan of 9.1 m (30 ft), a mass of approximately 3,175 kg (7,000 lb), and is expected to reach speeds of up to Mach 0.7 (~857 km/h). The first flight, initially planned for 2025, has been postponed to the end of 2027 due to cost, supply chain, and technical complexity challenges. This technology could open up new options for military and civil aircraft by reducing weight, mechanical complexity, and potentially radar signature.
Background and challenges of the program
DARPA’s CRANE program aims to validate the feasibility of active flow control (AFC) as the primary flight control mechanism. The idea is to replace control surfaces—flaps, ailerons, rudders—with pneumatic effectors that blow jets of air or directly modify the flow over the aircraft’s surfaces. This would reduce the number of moving parts, lighten the structure, improve aerodynamics, and reduce maintenance.
The decision to develop a demonstrator such as the X-65 is part of a technological breakthrough. Current military and civil aircraft have been based on the mechanics of moving surfaces for over a century. The proposed change is therefore radical. The context is one of increased technological competition in the aeronautics industry, but also pressure to reduce costs and complexity while increasing performance. The X-65 must therefore meet several objectives: demonstrate AFC control in flight, provide measurable data, and open up a path for future design.
To illustrate the challenges, consider that on a conventional aircraft, the control surfaces and their mechanisms can weigh several hundred kilograms and require many hours of maintenance each year. Eliminating these can reduce weight and mechanisms—which translates directly into gains in performance, cost, and reliability.
But there are many challenges: how can maneuverability, safety, redundancy, and robustness be ensured in the face of damage or reduced maintenance? These are the questions that the program is addressing, and they also explain the accumulated delays.
Technical characteristics and architecture of the X-65
The X-65 is an unmanned fixed-wing demonstrator aircraft. According to several sources, it will have a wingspan of 9.1 m (~30 ft) and a maximum weight of approximately 3,175 kg (~7,000 lb). Its target speed is approximately Mach 0.7, or nearly 857 km/h.
In terms of architecture, the aircraft has a triangular wing (delta or modified shape) with minimal or no tailplane, as maneuverability will be provided by 14 pneumatic actuators integrated into the lifting surfaces of the fuselage and wings. The AFC system will include conventional flaps during the experimental phase, but the aircraft will gradually be flown without them to test the full capacity of the air effectors.
The principle is as follows: instead of moving a surface, a directed jet of air inflates or locally modifies the flow at the edge of the wing or on a fixed aileron, causing a variation in roll, pitch, or yaw. This mechanism requires a source of compressed air, piping, and distributed effectors, which poses constraints in terms of weight, reliability, redundancy, and integration.
The fact that the aircraft is unmanned reduces survival and oxygen constraints, but this makes the technical challenge of ensuring reliability even greater. The X-65 is therefore a tactical-scale flying laboratory, but one geared towards the future generation of military and civil aircraft.
Delays, costs, and development challenges
The initial schedule called for a first flight in the summer of 2025. However, in November 2025, it was announced that this flight would be postponed until the end of 2027, a delay of more than two years.
There are several reasons for this. First, high production costs: the prototype manufacturing phase proved to be more expensive than expected for DARPA. Supply chain issues slowed down deliveries of critical components. Second, the technical challenges associated with AFC—integration of effectors, redundancy, software control, sensor validation—proved to be more complex than expected. The fact that the device is modular (replaceable wings, exchangeable effectors) also adds mechanical and organizational complexity. Finally, the restructuring of the partnership between DARPA and Aurora introduced a co-investment phase, which changed responsibilities and financing.
In terms of budget, US Department of Defense documents show that the CRANE program spent $38.3 million in 2024 and $23.9 million in 2025, with a planned budget of $4 million for 2026. Aurora’s decision to become a co-investor aims to “bring costs down to a level affordable to the government.”
These delays and costs show that even a demonstrator project can encounter significant “industrial realities”: industrial limitations, supplier dependence, repetitive testing, and logistical adjustments. This serves as a reminder of how slow and costly the technological transition in aeronautics can be, even for a moderately sized aircraft.
The potential impact on military and civil aviation
The AFC technology tested by the X-65 could have significant consequences for the future design of aircraft. First, reducing or eliminating movable control surfaces lightens the structure, reduces the number of moving parts, and decreases maintenance requirements. This can lead to a weight reduction of tens to hundreds of kilograms, which translates into increased range, payload, or fuel savings. Second, the removal of large moving surfaces can improve radar and infrared signatures, which is of interest for military stealth applications. Third, aerodynamic efficiency could be improved through flow optimization, which would reduce induced drag or maintain lift for longer at high frequencies.
For the civil sector, applications could include lighter regional or business aircraft, tactical drones, or long-endurance UAS requiring little maintenance. The fact that the aircraft is unmanned makes it easier to transfer the technology to demonstration applications.
However, there are limitations: the reliability of these effectors, failure management, redundancy, and interoperability with existing systems remain to be demonstrated. The X-65 is a demonstrator and not a production aircraft. Even if the demonstration is successful, it will take several more years to integrate the technology into an operational aircraft.
Finally, the global aerospace industry is subject to fierce competition and budgetary constraints. The delays with the X-65 show that a radical change in concept takes time to mature. Other players (Europe, China) could seize the opportunity if the technology stagnates further.
Strategic and industrial challenges related to aerospace innovation
The case of the X-65 also illustrates a high-risk aeronautical research and development “model.” The CRANE program adopts a “technology push” approach: demonstrating a new concept to open up future architectures. But this approach brings challenges: budgetary trade-offs, project prioritization, time management, and risk control. Some candid thoughts:
- A revolutionary technology may remain on paper if the cost of transitioning to production is too high.
- The fact that the demonstrator is experiencing delays does not mean failure, but serves as a reminder that aeronautical innovation does not tolerate shortcuts.
- Industrial costs (supply chain, qualification, testing, certification) remain the main obstacle, more so than the concept itself.
- For the armed forces or civil industry, waiting for a “revolutionary” technology can delay the implementation of more pragmatic solutions. Sometimes a choice must be made between radical optimization and incremental improvement.
In a context of intensifying international competition for aeronautical technologies, a successful demonstration such as that of the X-65 could offer a strategic advantage. But the risk is that other countries are already advancing on comparable applications or adopting different trajectories. Aeronautical innovation is a balancing act between boldness, time, and resources.
The X-65 is neither an operational aircraft nor an immediate promise: it is a flying laboratory that could redefine the way an aircraft moves through the air. If the test flight takes place at the end of 2027, as planned, it will be an important milestone. But it is only a milestone: the industrialization and widespread adoption of AFC will probably take another decade. It remains to be seen whether the concept will succeed in a sector where technological caution remains the rule.
Sources
– DARPA, “CRANE: Control of Revolutionary Aircraft with Novel Effectors”
– Aurora Flight Sciences, “Aurora Begins Building Full-Scale Active Flow Control X-Plane”
– FlightGlobal, “Aurora progressing on assembly of X-65 active flow control demonstrator”
– Aero-Magazine, “Aurora X-65 to demonstrate active flow control in 2026 flights”
– Defense News, “Two-year flight delay for DARPA X-plane that steers with air bursts”
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