The US Defense Advanced Research Projects Agency (DARPA) is planning to apply innovation and technology from the commercial electric vertical take-off and landing (eVTOL) sector to a next-generation VTOL unmanned aircraft system (UAS).
Many ship-launched fixed-wing drones, which boast useful range for sea scouting, launch from rails, and land by crashing into nets or catching skyhooks on approach. RQ-7 Shadow is an American unmanned aerial vehicle (UAV) used by the United States Army, Australian Army and Swedish Army for reconnaissance, surveillance, target acquisition and battle damage assessment. Launched from a trailer-mounted pneumatic catapult, it is recovered with the aid of arresting gear similar to jets on an aircraft carrier.
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.
Other Current Group 3 military UAS (e.g., MQ-21 Blackjack, RQ-7B Shadow, and others) also require an extensive and burdensome launch and recovery infrastructure. These costly systems require a large logistics tail including large launchers/catapults and retrieval systems or runways, which significantly hinders expeditionary operations and limits operating in austere environments.
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.
DARPA seeks to revolutionize the design of the next generation UAS and dramatically improve performance through the development and maturation of aircraft configurations and propulsion that allow for “infrastructureless” launch and recovery without compromise to long endurance flight and payload fraction.
Industry have been developing vast landscape of vertical takeoff and landing (VTOL) configurations research investments, and advanced controls for UAM. DARPA believes industry maturation across a broad set of UAS technologies will allow for novel designs that can be both efficient and meet the needs of the expeditionary warfighter.
The US Defence Advanced Research Projects Agency (DARPA) is seeking innovative launch and recovery concepts for small tactical unmanned aircraft systems (UASs) under the banner of AdvaNced airCraft Infrastructure-Less Launch And RecoverY (ANCILLARY).
DARPA’s AdvaNced airCraft Infrastructure-Less Launch And RecoverY (ANCILLARY) X-Plane programme intends to develop and flight-demonstrate critical technologies required for a ‘leap ahead’ in low-weight, high-payload, long-endurance VTOL capabilities. The eventual objective is to build a tactical UAS that can operate from ship flight decks and small austere land locations in adverse weather without launch-and-recovery equipment.
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.
In a Request for Information (RFI) released in February 2020, DARPA’s Tactical Technology Office said it was seeking to “revolutionize the design of the next generation UAS and dramatically improve performance through the development and maturation of aircraft configurations and propulsion that allow for ‘infrastructureless’ launch and recovery without compromise to long endurance flight and payload fraction”
‘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.
This program is designed to accomplish a small vehicle size that will allow deployment in a variety of settings.
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.
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.
DARPA is brainstorming ideas to help frame future UAS program investments. The ultimate goal is to design, build and demonstrate a Group 3 UAS capability with an equivalent Group 1 logistics footprint (i.e., entire system can be launched/recovered by two people) while also increasing range/endurance/payload and reducing unit cost over existing systems. The UAS will be able to launch from any location (approximately 8-ft. x 8-ft. area) without launch equipment infrastructure and precisely recover in an equivalent area.
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.
Specific technical challenges include:
Launch and Recovery: What innovation and novel configurations will allow for VTOL launch and recovery of a Group 3 UAS (gross launch weight 150 – 250 lbs.) with only 2-4 people (set up, launch, and recover) and no infrastructure (i.e., no additional launch or recovery equipment)?
Range and Endurance: What advanced power and propulsion technologies, and architectures will allow for VTOL capability without compromise to long range/endurance and high payload fraction capability?
Communications: What technologies will allow for extended range line-of-sight (LOS) and beyond-line-of-sight (BLOS) command, control and communications of a small Group 3 UAS?
Aerodynamic Controllability: What new configurations, control effectors, advanced control theory, and aerodynamic modelling will solve a triad of competing objectives while operating in challenging wind or moving landing area conditions?
System design will enable launch, cruise, loiter, and recovery in challenging conditions (e.g., winds, rain, day/night, extreme temperatures, high altitude austere locations, etc.).
Initial concepts and performance predictions of a tactical UAS that meets the following metrics (standard day conditions, no inflight refueling or power transfer):
- Precision autonomous VTOL (hover capability at landing)
- Maximum range = 500 NM (beyond line-of-sight communications)
- Goal endurance at 100 NM range = 24 hours
- Goal maximum speed = 150 knots
- Loiter speed = speed for longest endurance
- Loiter altitude = best altitude for longest endurance (> 5,000 ft.)
- Maximum altitude > 15,000 ft.
- Multi-mission modular payload, Maximum = 60 lbs.
- Power for payload during loiter > 350 W
The low weight/small form factor of ANCILLARY is intended to enable multiple aircraft to be stored and operated from a single ship, enabling the creation of a tactical beyond-line-of-sight multi-intelligence sensor network capability.
DARPA has selected nine companies to produce initial operational system and demonstration system conceptual designs for a vertical takeoff and landing (VTOL) uncrewed aerial system (UAS) that can be deployed and retrieved without the large mechanical launchers and landing/recovery equipment used today. The AdvaNced airCraft Infrastructure-Less Launch And RecoverY program, nicknamed ANCILLARY, ultimately plans to flight demonstrate innovative aircraft configurations and critical technologies needed for a low-weight, large-payload, long-endurance VTOL uncrewed X-plane.
AeroVironment, AVX Aircraft, Griffon Aerospace, Karem Aircraft, Leidos, Method Aeronautics, Northrop Grumman, Piasecki Aircraft, and Sikorsky will develop VTOL UAS designs, with Navy and Marine missions in mind, during the six-month Phase Ia. Teams then will submit competitive proposals for more detailed X-plane design work.
“The objectives of the program are to develop a small UAS that takes off and lands vertically, like a helicopter, and flies its mission like very efficient winged aircraft, while carrying a significant amount of payload for a variety of missions,” said Steve Komadina, the DARPA program manager for ANCILLARY. “We are looking for a VTOL UAS that can operate from ship flight decks and small out-of-the-way land locations in most weather conditions without using typical launch and recovery equipment that is needed for current long endurance, high payload weight aircraft.”
Northrop Grumman was awarded the contract to develop the ANCILLARY prototype on February 16, 2023. The contract is worth $100 million and is expected to be completed in 2026. The prototype will be developed in two phases. The first phase, which is scheduled to be completed in 2024, will focus on the design and development of the aircraft’s airframe, propulsion system, and avionics. The second phase, which is scheduled to be completed in 2026, will focus on the integration of the aircraft’s sensors and payloads. The project is expected to culminate with X-plane flight tests in early 2026.
ANCILLARY aims to solve a combination of challenging design objectives by bringing together technology developments in advanced VTOL aircraft configurations, advanced propulsion architectures, and advanced control effectors/theory from traditional and non-traditional industry companies.
“The major challenge is developing an integrated flight vehicle that meets the hard objective of combining VTOL, long endurance, and large payload while also meeting requirements for shipboard storage and operations,” said Komadina. “A key element is the propulsion system, which needs to have enough power to lift the X-plane vertically while also being extremely efficient in forward flight when power needs are lower.”
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