The Pentagon’s secretive technology incubator has revealed six competing designs for a new ship-based, vertical take-off and landing (VTOL) aircraft.
Known as the Advanced Aircraft Infrastructure-Less Launch and Recovery – or ANCILLARY – programme, the effort aims to radically improve the range, payload, endurance and weight of VTOL aircraft.
The effort was launched in 2022 by the Defense Advanced Research Projects Agency (DARPA), with the stated goal of building an aircraft able to launch from ship flight decks and small austere land locations in adverse weather, without any launch or recovery equipment.
In 2023, DARPA announced nine competitors for the ANCILLARY project. On 22 May, the agency revealed three of those have been eliminated, leaving a mixed field of defence industry mainstays and relative newcomers in contention.
Sikorsky, Karem Aircraft, Griffon Aerospace, Method Aeronautics, AeroVironment and Northrop Grumman were all advanced to the next stage of the programme – dubbed Phase 1b – according to DARPA.
“The goal of ANCILLARY is to increase small vertical take-off and landing uncrewed aerial system (UAS) capabilities by a factor of three over the current state-of-the-art flying today,” says Steve Komadina, DARPA programme manager for the project.
“Our performers are searching for innovative ways to increase payload weight and range/endurance of small, ship-launched UAS by means of novel configurations, propulsion and controls while also removing the need for special infrastructure,” he adds.
Among the original ANCILLARY participants, AVX Aircraft, Leidos and Piasecki Aircraft were eliminated.
Imagery released by DARPA shows the six prototype designs still under development, with a number of similarities visible. Five of the six aircraft feature a high-wing structure and all are propeller driven.
However, the designers appear to be pursuing a range of propulsion strategies, including both forward- and rear-mounted propellers, as well as pivoting rotor systems.
While few details are available about most of the concepts, rotorcraft heavyweight Sikorsky is touting its proposal – a new configuration the company calls a “rotor blown wing” (RBW).
Sikorsky describes the novel design as a twin proprotor that sits on its tail to take-off and land vertically like a helicopter, with the entire aircraft subsequently rotating for horizontal flight.
Company imagery shows two engines mounted below a high-wing, situated on either side of the central fuselage. The two propellers are oriented forward of the main wing surface.
Speaking the US Army’s annual aviation summit in April, Sikorsky president Paul Lemmo described the RBW as a flying-wing, but rather than jet engines it generates lift and thrust by rotors pushing air over the wing.
“It’s a tail-sitter aircraft that launches vertically, can fly vertically, but then also [can] tip over and fly like a wing,” Lemmo said.
Sikorsky says it is already flight testing the RBW prototype, intending to demonstrate the “efficiency and scalability” of the new rotorcraft configuration.
“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,” says Igor Cherepinsky, director of the company’s rapid prototyping group.
He notes the RBW will incorporate Sikorsky’s MATRIX flight autonomy technology and an articulated rotor system similar to those found on traditional helicopters.
DARPA says Phase 1b of ANCILLARY will last 10 months and focus on design refinement and risk reduction. The process will include component and configuration hover testing.
After that 10-month period, the six teams will submit competitive proposals for Phase II, which includes detailed design, fabrication and flight testing, the agency says.
The project is expected to culminate with X-plane flight tests starting in early 2026.
