DARPA’s Naval VTOL X-Plane Drone Program Narrows Down To Two Designs

The Defense Advanced Research Projects Agency (DARPA) has chosen designs for the next phase of its AdvaNced airCraft Infrastructure-Less Launch And RecoverY (ANCILLARY) program, to demonstrate an autonomous vertical takeoff and landing (VTOL) X-plane. The effort aims to develop and flight test a drone that will offer long endurance and the ability to launch and recover from ship flight decks and small austere land locations in adverse weather and without additional infrastructure equipment. It’s part of an increasing focus on platforms to support expeditionary deployments of the kind that will be required in a future conflict in the Pacific.

So far, we know that Northrop Grumman and Sikorsky have been down-selected for Phase 1b of ANCILLARY, with potentially other companies involved as well. In addition to these two firms, Phase 1a of the program also involved AeroVironment, AVX Aircraft, Griffon Aerospace, Karem Aircraft, Leidos, Method Aeronautics, and Piasecki Aircraft.

Concept artwork from Northrop Grumman showing its ANCILLARY drone design on a warship’s flight deck. Northrop Grumman

Phase 1b will include air vehicle design and system technology maturation. Over a period of 10 months, the chosen contractors will “increase modeling fidelity, perform critical subsystems testing, and reduce key technical risks,” according to Northrop Grumman. This will bring the program a step closer to the construction of a flight demonstrator, for which flight tests are planned to begin in early 2026.

Northrop Grumman will head up a collaborative team, also including Leigh Aerosystems and Near Earth Autonomy on its ANCILLARY offering.

The Northrop Grumman ANCILLARY design has a straight wing, with pods at each tip that support a horizontal rotor for VTOL flight. A pusher propeller is fitted at the rear of the fuselage, which also supports an inverted V-tail. This is a fairly common configuration of VTOL drones in use around the globe today.

Northrop Grumman describes its design as “a cost-efficient, multiple-mission capable vehicle built on an agile platform that will not rely on complex launch and recovery infrastructure. It meets DARPA’s challenging performance objectives, weighs no more than 330 pounds, and can be deployed and retrieved anytime or anywhere with no special infrastructure, including ship-based operations.”

A drone from Volansi, which shares a similar configuration as Northrop Grumman’s offering, is seen completing the first-ever autonomous ship-to-ship drone deliveries. The trials, between a U.S. Navy ship and a U.S. Coast Guard vessel off the coast of Key West, Florida, in 2021. Volansi

As well as ship-to-ship and ship-to-shore logistical missions, the Northrop Grumman design will be expected to undertake critical intelligence, surveillance, reconnaissance, and targeting missions, for which it will employ artificial intelligence and machine-learning-enabled automated targeting capability.

Reportedly, Northrop Grumman’s ANCILLARY demonstrator will be capable of carrying a 60-pound sensor payload, offer more than 20 hours’ time on station, and have a mission radius range of 100 nautical miles.

While Northrop Grumman’s ANCILLARY is designed to take off and land much like a familiar quadcopter-type drone, the rival from Sikorsky is a VTOL tail-sitter design. This includes a long straight wing with twin proprotors. The drone sits on its tail, supported by its twin tailfins, taking off and landing like a helicopter before transitioning to horizontal forward flight for long-endurance missions.

Sikorsky announced yesterday that it’s already conducting flight tests “to mature the control laws and aerodynamics of a novel vertical takeoff and landing uncrewed aerial system,” a reference to the ‘rotor blown wing’ configuration.

A sailor prepares a Sikorsky ANCILLARY drone for vertical takeoff in concept artwork from the company. Sikorsky

“Flight tests are underway to verify our tail-sitting rotor blown wing UAS can launch and land vertically with high stability, and cruise efficiently on wing,” said Igor Cherepinsky, director of the rapid prototyping group Sikorsky Innovations. “Key enablers to flight maneuverability, and future vehicle scalability, are our MATRIX autonomy flight control system, and an articulated rotor system similar to those in traditional helicopters.”

The initial Sikorsky flight tests involve a battery-powered proof-of-concept vehicle. The manufacturer plans to follow this with a 300-pound hybrid-electric version that will include a 60-pound intelligence, surveillance, and reconnaissance (ISR) payload.

Both Northrop Grumman and Sikorsky designs ensure that the drones can be deployed and retrieved without the need for cumbersome mechanical launchers and landing/recovery equipment.

Not only are the VTOL drones expected to be able to operate from small landing areas — whether on the deck of a ship, or a small austere location on land — but they also have to do this in adverse weather, without additional infrastructure equipment.

A generic DARPA concept for an ANCILLARY drone. DARPA

The concept of operations is heavily influenced by the kinds of expeditionary operations that the Pentagon expects will define a future large-scale conflict with China in the Pacific theater.

The kinds of missions envisaged will require drones that have notably long endurance, too, which is also a factor stressed in the ANCILLARY program.

The relatively small size of the ANCILLARY drones means that multiple examples can be stored and operated from a single warship, for example. This will not only provide a resilient and long-range logistics connector with other vessels and land bases, but it will also help in fielding a new kind of networked sensor capability.

In this way, multiple ANCILLARY drones fitted with ISR payloads will be used to establish a tactical beyond-line-of-site (BLOS) multi-intelligence sensor network. Multiple nodes in this network spread out over geographical area can then create a mesh data-exchange network over a broad area that can provide some of the capabilities satellite communications can.

Clearly, there is a great demand for a drone in this class, especially to support U.S. Navy and Marine Corps expeditionary operations in the Pacific, but the requirements are also challenging.

After all, ANCILLARY stresses a combination of low weight and large payload, difficult enough to achieve without the additional requirement of VTOL capability.

“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,” explained Steve Komadina, the DARPA program manager for ANCILLARY.

“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,” Komadina added.

The goal of a drone that can take off and land like a helicopter but fly the main part of its mission like an efficient winged aircraft, while carrying an operationally relevant payload is an enduring one, but one that has so far proven generally elusive. The Pentagon hope that DARPA’s ANCILLARY program will successfully reverse that trend.

Contact the author: thomas@thewarzone.com

Thomas Newdick

Staff Writer

Thomas is a defense writer and editor with over 20 years of experience covering military aerospace topics and conflicts. He’s written a number of books, edited many more, and has contributed to many of the world’s leading aviation publications. Before joining The War Zone in 2020, he was the editor of AirForces Monthly.