Inside the X-65, DARPA’s Active Flow Control Plane

How Active Flow Control Could Redefine Aircraft Design

Since the dawn of aviation, almost every component of an aircraft has evolved. Rotating blades were replaced by turbines, the sound barrier was broken, and piloting shifted to electronic controls.

Still, one element has not changed for almost a century, which is flight control mechanisms. All planes rely on elements like flaps and rudders to control the aircraft’s direction and angle (pitch, roll, and yaw).

Source: BoffinPanda

The way traditional flight controls work is by changing the aerodynamic profile of the airplane, increasing or reducing resistance in a given part of the aircraft. A radically different way to do it, at least in theory, is Active Flow Control (AFC). This method focuses on actively controlling the air flow using energy, instead of just passively increasing or decreasing air drag. So far, this has been a promising, but mostly theoretical concept, only tested in labs.

This is going to change soon, with the recently announced decision to move forward with the X-65, an airplane prototype with a unique look, conceived as a demonstrator for AFC technology.

Source: Aurora Flight Sciences

Built by Aurora Flight Sciences, a division of Boeing (BA +2.46%), the X-65 airplane might soon be ready and give back to engineers the real-life experience in building an AFC-controlled aircraft.

Active Flow Control Explained

Active Controls

The usual flight control systems use fixed shapes or surfaces to control air flow around an aircraft. In contrast, active flow control directly modifies the behavior of flow fields with tools like sensors, actuators, and control algorithms.

For example, puffs or streams of air are extracted from a jet engine through 1-4mm wide holes in the relevant parts of an aircraft’s skin. In theory, this allows AFC to be a lot more reactive and flexible, reacting in real time to changing conditions like turbulence. The method should also make the aircraft more efficient.

Challenges of Active Flow Control Systems

One issue with AFC is that the system is a lot more complex. In particular, it requires an almost perfect coordination between sensors, actuators, and control algorithms. And any error, lag, or improper reaction can quickly become deadly with a real aircraft.

Another issue is that due to the active nature of the system, any power or mechanical failure can drastically change the behavior of the plane. So redundancy and high levels of reliability are required, even more so than with traditional flight control systems.

Lastly, most AFC designs are more energy-demanding than traditional flight controls, which can be an issue in aircraft constrained by power supply and weight.

X-65 Overview

The X-65 is a joint project between DARPA (Defense Advanced Research Projects Agency) and Aurora Flight Sciences, with an agreement to jointly develop the plane signed in August 2025. The program is part of CRANE (Control of Revolutionary Aircraft with Novel Effectors), a research program to develop “a novel X-plane that incorporates Active Flow Control (AFC) as a primary design consideration.”

“The X-65 platform will be an enduring flight test asset, and we’re confident that future aircraft designs and research missions will be able to leverage the underlying technologies and flight test data.”

Larry Wirsing – VP of aircraft development at Aurora Flight Sciences.

So the X-65 is first and foremost a technology demonstrator, designed with AFC as a focus to learn more about how to deploy this technology in actual commercial aircraft.

The plane will have a 30-ft wingspan (9 meters) and 7000 lb gross weight (3,175 kg). It will be entirely unmanned and is expected to reach Mach 0.7.

AFC Design

The aircraft will initially be equipped with both traditional flaps and rudders, as well as AFC effectors.

This way, the scientists will be able to compare AFC to traditional flight controls as a baseline for performance comparison.

Later tests will progressively rely more on AFC effectors, minimizing the use of moving surfaces.

The plane will contain inner pipes and a power unit to control the air flow in the plane. The 14 different AFC effectors are built to be modular and possible to swap with other designs during the testing phase.

“We’ll have sensors in place to monitor how the AFC effectors’ performance compares with traditional control mechanisms, and these data will help us better understand how AFC could revolutionize both military and commercial craft in the future.”

Richard Wlezien – DARPA’s program manager for CRANE

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X-65 Timeline

Aurora started to work on the CRANE program in 2020, with wind tunnel tests performed in 2022.

The program got its official designation in May 2023, after which further testing started.

Construction is now ongoing, with completion of the fuselage expected in January 2026, at Aurora’s Bridgeport, West Virginia, manufacturing facility. The propulsion and AFC system components are also already built and waiting to be integrated into the plane.

Source: Aurora Flight Sciences

What the X-65 Program Aims to Prove

Besides experimenting with AFC, the clear goal is to create a platform on which to build later designs of military and then civilian aircraft.

One key advantage of AFC is that it can handle turbulence a lot better and might ultimately allow for simpler designs, removing the need for large, complex mechanical control surfaces.

It should also reduce drag and increase lift, leading to fuel savings and increased flight range.

From a military perspective, by controlling wakes and aerodynamic signatures, AFC can help to improve stealth characteristics, an important factor as advanced semiconductors like GaN (Gallium Nitride) are used to create ever more efficient radars.

Lastly, AFC can help stabilize and boost the takeoff of a plane, which is very useful for fighter jets or drones taking off from an aircraft carrier.

What the X-65 Means for Future Aircraft

The X-65 and its active flow control systems will not directly be a usable fighter jet or drone, but a technology platform from which future functional aircraft will be built.

It is yet to be seen how efficient and practical these systems will be, which is what the X-65 tests will clarify.

Most likely, the very first application will be for advanced military aircraft, as the requirements of a drone or manned aircraft taking off from an aircraft carrier or requiring stealth are a lot more demanding, and would benefit from AFC.

Later on, once the technology is proven and well established, it is likely that it can be deployed to civilian aircraft. At first, this might come as a complement to traditional flight control, and progressively replace them with newer airliner designs.

Investing In Active Flow Control

Aurora Flight Sciences / Boeing

Aurora Flight Sciences is not just developing the X-65, but also many other aircraft:

• Small flying drones (Unmanned Aircraft Systems – UAS) like the Skyron-X reconnaissance drone.
• The Centaur Optionally Piloted Aircraft is a flown-from-a-ground-station small airplane with an on-board safety pilot, enabling cost-effective flight testing in the National Airspace System (NAS).
• Many experimental aircraft, be it manned or unmanned, electric or traditional, thanks to rapid prototyping and advanced manufacturing methods, including 3D printing, CNC 5-axis machining, automated in-situ metrology, and automated fiber placement.
  • For example, the “Liberty Lifter” seaplane, the SPRINT, a vertical lift X-plane using fan-in-wing technology, NASA’s Electrified Powertrain Flight Demonstration (EPFD), or NASA’s X-66 Sustainable Flight Demonstrator (SFD)

This overall makes Aurora the experimental / R&D branch of Boeing.

Boeing, the larger group, has experienced a rough period lately, notably with a series of crashes of its aircraft and the highly-publicized failure of its Starliner space capsule.

It is still, nevertheless, a giant in aircraft manufacturing, with the delivery volume of the 777X program ramping up, leading to revenues up to $23.5B in Q3 2025 compared to Q3 2024 ($17.8B) and a return to positive free cash flow.

The especially powerful engines of the 777X have notably impressed both experts and the public at the Dubai 2025 Air Show for the plane’s very quick take-off and strong maneuverability.

While the commercial airplane is the most visible part of the company ($11.1B of revenues in Q3 2025), the defense, space, and security segment was also a major contributor ($6.9B of revenues in Q3 2025), with services, mostly parts and maintenance of existing aircraft, bringing $5.4B.

So the company is likely still not fully out of the woods from its past troubles, having to reform some more of its manufacturing process and overhaul its supply chain. It notably re-acquired Spirit Aerospace for $4.7B in 2024.

But the company is getting back on track, and the solid line-up of military orders, for example, a steady stream of orders for air tankers and Apache helicopters by the Pentagon and Israel for $7B, should keep the company going while its civilian aircraft department’s reputation is repaired.

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