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Revolutionizing VTOL Warfare: DARPA’s ANCILLARY Program and the Future of Infrastructure-Free UAS
DARPA’s ANCILLARY program is redefining drone warfare with VTOL, hybrid-electric propulsion, and infrastructure-free operations — a game-changer for naval and expeditionary missions.
The U.S. Defense Advanced Research Projects Agency (DARPA) is accelerating its vision for next-generation vertical takeoff and landing (VTOL) unmanned aircraft systems (UAS) through the AdvaNced airCraft Infrastructure-Less Launch And RecoverY (ANCILLARY) program. Building on advancements in commercial eVTOL technology, ANCILLARY aims to eliminate bulky launch/recovery infrastructure while enhancing payload, endurance, and operational flexibility for naval and expeditionary missions. Here’s an update on the latest developments reshaping this ambitious initiative.
ANCILLARY’s Vision for Infrastructure-Less Operations
DARPA’s ANCILLARY program envisions a new class of Group 3 UAS that combines the logistical simplicity of smaller drones with the endurance and payload capacity of larger systems. The goal is to enable launch and recovery from confined spaces, such as ship decks or remote land locations, without specialized equipment, thereby reducing the operational footprint and increasing deployment versatility.
In an animated video released in September 2022, a glistening silver-white drone flies towards a modest warship. The drone turns 90 degrees vertically, its rotors allowing it to descend gradually as its wings pivot at elbow joints to take up only a fraction of the ship’s helipad.
In one scene, the ANCILLARY drone descends onto a marked-out landing zone on a road through a jungle. The landing indicators are a handful of lights, and next to them sit soldiers in dark uniforms that suggest a night mission by special operations forces. While the squad provides armed overwatch (looking out for enemies with weapons drawn), one member unloads a cylinder of supplies, and another prepares to send the drone on a return mission with a quick command on the tablet.
The concept video shows ANCILLARY drones flying in teams, cameras and other sensors pointed below to surveil an archipelago, all while staying in communication with the small ship that launched the scouts. DARPA is service-agnostic, but the scenario described is likely for the US Navy in support of marine advances.
Leveraging Commercial eVTOL Innovations
The program draws inspiration from advancements in the commercial electric VTOL (eVTOL) sector, particularly in urban air mobility (UAM).
Urban Air Mobility or UAM is a new system for air passenger and cargo transportation within a metropolitan area (including operations over densely populated urban areas). DOD is also looking for UAM as their future requirement personal air vehicle (PAV). To remove the need for runways, these cars will rely on vertical take-off and landing technology, known as VTOL. Sometimes long runways aren’t available to use and there is a need for an aircraft to use no runways at all. Vertical take-off and landing VTOL technology means aircraft can theoretically take off and land almost anywhere, making them far more flexible.
By integrating technologies like hybrid-electric propulsion, advanced energy storage, and modular payload systems, ANCILLARY aims to create drones capable of efficient, infrastructure-less operations suitable for various military applications.
Challenges with Current UAS Operations
Traditional ship-launched fixed-wing drones, such as the RQ-7 Shadow and MQ-21 Blackjack, require cumbersome equipment like catapults and nets for launch and recovery. These systems demand significant logistical support and are challenging to deploy in austere or rapidly changing environments, limiting their effectiveness in expeditionary operations.
These older systems require extensive ground infrastructure for launch and recovery, limiting their operational flexibility. Launching the UAV from a catapult is a relatively straightforward mechanical process. Retrieving one is not. Capturing a UAV at the end of a flight requires an operator to use a radio transmitter to send flight control commands to the UAV to fly it into a recovery device, such as a recovery net, or arresting cable device. Even with the aid of guidance methods, such as Global Position System (GPS) or Inertial Measurement Unit (IMU) sensor-based navigation, skilled UAV operators require extensive training and experience to safely recover these expensive drones. Onboard a surface in motion such as a truck or ship, successful recovery is challenging.
ANCILLARY’s new generation of drones can launch and recover from confined environments, including ship decks and unimproved land sites, significantly expanding mission flexibility. Naval applications, in particular, stand to benefit from ANCILLARY’s compact footprint. Ships can potentially host and deploy multiple UAS simultaneously, supporting coordinated ISR, electronic warfare, and strike missions. Additionally, the reduced operator burden—just two to four personnel per drone—offers a sharp contrast to the larger ground teams required by traditional Group 3 systems. This increased efficiency enhances rapid deployment and makes the systems ideal for expeditionary and dispersed operations.
Design Objectives and Technical Challenges
The ANCILLARY program is designed to overcome several critical technical challenges that have traditionally limited the operational flexibility of unmanned aerial systems. One of the foremost objectives is to develop reliable vertical takeoff and landing (VTOL) capabilities that enable drones to operate from confined, unprepared, or mobile environments without relying on external launch and recovery infrastructure. This is especially vital for naval and expeditionary operations where space and logistical support are limited.
Another key goal is to significantly enhance the range and endurance of Group 3 UAS platforms. The system is expected to support long-range missions of up to 500 nautical miles and maintain loiter times as long as 24 hours, all while maintaining an optimal payload-to-weight ratio. Achieving this requires innovative solutions in propulsion efficiency, power management, and aerodynamic performance.
Maintaining robust and secure communications links is also a fundamental design consideration. The system must support both line-of-sight (LOS) and beyond-line-of-sight (BLOS) communications to ensure effective command and control over extended distances and in contested environments. Furthermore, airframe designs must be capable of stable, precise control in a range of challenging environmental conditions, including high winds, precipitation, and the dynamic motions of shipboard deployment platforms.
Performance Metrics
The UAS developed under the ANCILLARY programme will feature a small form factor, low weight and high payload capacity. It can take off and land on ship decks and rough land sites in adverse weather conditions without the need for additional equipment, making them suitable for expeditionary missions.
DARPA intends that the ANCILLARY air vehicle should be a Group 3 type of between 250 and 330 lb (113.4–149.7 kg) in weight. As well as the ability for launch and recovery without infrastructure, other primary design objectives include extended endurance and range, a high payload-to-weight ratio at tactical scale, and robust flight controls and relative navigation.
The aim is to allow just two to four personnel to set up, launch, and recover the drone without the need for additional equipment, such as catapults or recovery nets. This requires innovative airframe configurations and autonomous systems that can safely manage VTOL operations under varying conditions.
The compact size of the UAS allows for multiple aircraft to be stored and operated from a single ship, creating a tactical beyond-line-of-sight (BLOS) multi-intelligence sensor network capability. With its low weight and compact form factor, ANCILLARY allows multiple drones to be deployed from a single ship, offering the U.S. military a scalable, shipboard-compatible, beyond-line-of-sight multi-intelligence sensor network—extending surveillance and reconnaissance capabilities into previously inaccessible domains. Additionally, the UAS will support special operations, as well as ship-to-ship and ship-to-shore logistical missions, offering cost-effective advantages for delivering essential parts and supplies.
The ANCILLARY UAS is envisioned to deliver a high-performance platform that balances endurance, payload, and operational versatility. At its core is the ability to perform fully autonomous vertical take-off and landing, allowing the aircraft to launch and recover from a wide array of environments without external support systems.
In terms of range, the aircraft is expected to cover up to 500 nautical miles, making it suitable for extended surveillance, logistics, or strike missions across vast operational theaters. For endurance, the platform aims to sustain 24-hour missions while operating within a 100-nautical-mile radius, providing persistent coverage for intelligence, surveillance, and reconnaissance tasks.
The system is also being designed for agility and speed, with a projected maximum speed of 150 knots. It will operate at altitudes well above 5,000 feet during loiter phases, with a ceiling exceeding 15,000 feet, ensuring operational flexibility across a wide range of mission profiles and terrain.
Achieving long-range and extended endurance without compromising VTOL capability is another major objective. Advanced propulsion technologies and power architectures are being explored to optimize fuel efficiency and energy density, enabling the aircraft to meet ambitious goals—such as a 500 nautical mile maximum range and 24-hour endurance at a 100 nautical mile loiter radius. These performance metrics are particularly demanding given the need to maintain a high payload fraction. The airframe must also sustain aerodynamic efficiency through all flight phases, from hover to high-speed cruise, while operating in harsh environments including high altitudes, extreme temperatures, and turbulent weather.
Payload capacity is another defining characteristic, with a target of up to 60 pounds. This allows for the integration of advanced sensors, communications equipment, or lightweight precision munitions. Additionally, the platform will provide up to 350 watts of electrical power during loiter, supporting onboard systems critical for surveillance, target acquisition, and autonomous operations.
This program is designed to accomplish a small vehicle size that will allow deployment in a variety of settings. ‘The ability for the warfighter to deploy and retrieve such systems in challenging conditions without reliance on infrastructure would minimize personnel, costs, and vulnerability during sensitive operations,’ said Steve Komadina, the DARPA program manager for ANCILLARY.
Breakthrough Technologies Driving ANCILLARY
DARPA, remarks that the recent advancements in small hybrid electric propulsion systems, high capacity, onboard energy storage —through high-density, low-weight batteries, fuel cells, materials and electronics —, advanced structures, and low-cost manufacturing technologies have enabled new designs to be examined in this technological field.
‘ANCILLARY plans to use a multi-disciplinary approach that will bring together developments in advanced control theory, aerodynamic modelling, and advanced propulsion to solve a combination of challenging design objectives,’ said Komadina.
Autonomous Control Systems
A cornerstone of the ANCILLARY initiative is advanced autonomy. Sikorsky’s MATRIX software, already validated in piloted autonomous Black Hawk flights, serves as a foundation for fully autonomous UAS control. MATRIX facilitates obstacle detection, precision landing, and seamless human-machine interaction. These capabilities are essential for reducing the personnel footprint required for UAS operation and for expanding the aircraft’s utility in denied or complex environments.
Hybrid-Electric and Hydrogen Propulsion
To meet range and endurance goals, DARPA’s partners are integrating hybrid-electric propulsion systems. Northrop Grumman and Sikorsky are at the forefront of these efforts, developing concepts that marry the vertical lift capabilities of helicopters with the cruise efficiency of fixed-wing aircraft. Sikorsky’s Phase II design proposes a 300-pound UAS capable of carrying a 60-pound ISR payload while using a hybrid-electric powertrain optimized for long-range and multi-domain missions.
Although not officially part of ANCILLARY, hydrogen-powered UAS are also influencing the broader development landscape. Israeli startup Heven Drones has unveiled the Raider, a hydrogen-powered UAV offering quieter operations and longer endurance. While still in early stages, such technologies may eventually converge with ANCILLARY’s objectives for high-endurance, infrastructure-independent drones.
Advanced Aerodynamics
Innovative airframe configurations are another area of focus. Karem Aircraft is refining a tilt-rotor design that provides optimal performance during both vertical and horizontal flight. Method Aeronautics is also developing unconventional designs aimed at achieving DARPA’s targets of a 150-knot cruise speed, extended endurance, and a meaningful payload, all without the need for conventional launch and recovery aids.
Robust and reliable communications are equally critical. ANCILLARY is expected to maintain command, control, and communication links through both line-of-sight (LOS) and beyond-line-of-sight (BLOS) technologies. This requires the integration of resilient, low-latency communication systems that can function in contested or remote regions. Additionally, aerodynamic controllability is a focal point of innovation, with research into novel control effectors, configurations, and advanced control algorithms that allow the drone to adapt dynamically to wind gusts, shipboard movements, and other unstable operating conditions.
From Concept to Reality: ANCILLARY’s Progress
Launched by DARPA in September 2022, the ANCILLARY programme aims to address complex design goals by integrating advancements in VTOL aircraft configurations, propulsion architectures, and control theory.
Phase Ia of the ANCILLARY programme, which spanned six months, involved the investigation of conceptual designs from nine companies, both traditional and non-traditional, within the military sector. These companies include Northrop Grumman, AeroVironment, AVX Aircraft, Griffon Aerospace, Karem Aircraft, Leidos, Method Aeronautics, Piasecki Aircraft, and Sikorsky.
In May 2024, six companies, namely AeroVironment; Griffon Aerospace; Karem Aircraft; Method Aeronautics; Northrop Grumman; and Sikorsky, moved to Phase Ib to further advance the development of their X-plane designs. DARPA has progressed to Phase 1b of the ANCILLARY program, selecting six out of nine initial contractors to refine their UAS designs. The focus during this phase will be on air vehicle design and system technology maturation over ten months. The objectives include enhancing modelling accuracy, conducting crucial subsystem testing, and addressing significant technical challenges to progress the programme.
Their focus is the development of a Group 3 UAS, weighing between 250 and 330 pounds, capable of operating without traditional launch and recovery systems. These aircraft are expected to take off and land on ship decks or remote locations without requiring catapults, nets, or runways. Furthermore, the designs must demonstrate a 500-nautical-mile range, a 24-hour loiter time, and a 60-pound payload capacity suitable for sensors, supply delivery, or precision-guided munitions. They must also maintain operational effectiveness in adverse weather conditions, including high winds, rain, and temperature extremes.
Northrop Grumman’s ANCILLARY demonstrator represents a significant leap in unmanned aerial system capabilities. Engineered to carry a 60-pound sensor payload, the platform promises exceptional endurance, capable of remaining on station for up to 20 hours with a mission radius of 100 nautical miles. One of its standout features is the ability to operate in challenging maritime environments, including shipboard landings under adverse weather conditions. This capability, combined with a design that minimizes reliance on external support infrastructure, sets it apart from conventional VTOL systems and enhances its operational adaptability.
Among the most promising prototypes is Sikorsky’s Rotor Blown Wing UAS, which has successfully demonstrated more than 40 transitions between vertical and horizontal flight. Its unique configuration, in which the entire airframe tilts for vertical lift and then transitions to forward flight, enables it to operate on dynamic and unstable ship platforms.
Challenges and Risks
Despite strong progress, ANCILLARY faces notable technical and programmatic risks. One major challenge is balancing the high energy requirements of VTOL operations with the need for long-range cruise endurance. Hybrid systems must manage power output, battery weight, and thermal loads effectively to meet mission demands. Additionally, any increase in aircraft weight resulting from more powerful propulsion systems or additional sensors could limit payload capacity and endurance.
There are also concerns around program execution. The Government Accountability Office (GAO) has historically cited issues such as delayed milestones, cost overruns, and insufficient oversight in U.S. defense innovation programs. These systemic risks could impact ANCILLARY’s ability to deliver prototypes on schedule and meet DARPA’s 2026 test flight deadline.
Future Outlook: 2026 and Beyond
Looking ahead, the ANCILLARY program is on track to deliver full-scale flight demonstrations of an X-plane by 2026. These demonstrations aim to validate the integration of vertical takeoff and landing capabilities with long-endurance performance and substantial payload capacity—all within a compact and logistically efficient airframe. This milestone will mark a pivotal step toward fielding a new generation of autonomous aerial systems tailored for contested and infrastructure-limited environments.
Looking ahead, DARPA’s roadmap for ANCILLARY includes a series of technical milestones culminating in full-scale flight demonstrations by 2026. The transition to Phase II will include finalizing system designs, fabricating prototypes, and conducting rigorous flight testing to validate vertical lift, cruise endurance, and autonomous operation under realistic conditions.
One major milestone will be the X-plane test flights, slated for early 2026. These flights aim to validate the aircraft’s ability to meet DARPA’s range, endurance, and payload specifications. The Navy is expected to integrate ANCILLARY drones into maritime domain awareness and distributed ISR missions, while other services such as the Army, Air Force, and Coast Guard are exploring complementary roles. Potential applications range from Agile Combat Employment and aerial logistics to coastal patrol and interdiction missions.
Another key focus will be the integration of AI-driven technologies for threat detection, mission planning, and autonomous decision-making. These capabilities will further reduce operator workload and improve real-time responsiveness during missions.
Strategic Implications
The deployment of ANCILLARY drones has the potential to redefine the strategic landscape for U.S. military operations. By eliminating the need for conventional launch and recovery infrastructure, these systems will dramatically increase operational flexibility in austere or denied environments. This capability is particularly valuable for missions that demand rapid response, stealth, or extended presence in areas with minimal logistical support.
Beyond flexibility, ANCILLARY platforms are poised to reduce the logistical footprint of unmanned aerial operations, allowing forces to be more agile and less dependent on large, vulnerable bases. Their ability to conduct a wide range of missions—from intelligence, surveillance, and reconnaissance to logistics and tactical support—makes them force multipliers across multiple domains. As the program matures, ANCILLARY drones are expected to become vital assets in both strategic deterrence and dynamic combat operations, reinforcing the U.S. military’s technological and operational edge.
Global Context and Competing Programs
Globally, other nations are developing similar shipboard and infrastructure-less VTOL UAS capabilities. In Japan, for example, ship-launched VTOL drones are being pursued as part of national defense modernization efforts, with Shield AI’s V-BAT among the prime candidates. Europe, through Airbus, is fielding the Aliaca VTOL UAV, currently deployed by the French Navy. This system offers modular capabilities and hybrid propulsion while being designed for integration aboard compact naval platforms. Meanwhile, China continues to invest in drone technologies like the GJ-11 Sharp Sword, though their systems lack the autonomy and VTOL sophistication featured in the ANCILLARY program.
Conclusion
DARPA’s ANCILLARY program is redefining the possibilities for VTOL UAS in expeditionary warfare. By blending advanced autonomy, hybrid-electric propulsion, and infrastructure-less launch and recovery, the program is poised to deliver a transformative capability for the U.S. military. The ability to conduct long-range, persistent missions from ship decks or unprepared land sites with minimal operator support could become a defining feature of next-generation air operations.
As X-plane test flights draw near, the world will be watching to see if ANCILLARY can deliver on its promise. If successful, the program could serve as a blueprint for global adoption of agile, infrastructure-free drone technologies in both military and civilian contexts.
References and Resources also include:
https://www.popsci.com/technology/darpa-ancillary-drone-project-goals/
