An artist’s rendering of Lockheed Martin’s ARES (Lockheed Martin Photo)

The Defense Advanced Research Projects Agency (DARPA) and the Marine Corps have canceled the Aerial Reconfigurable Embedded System (ARES) program because of cost overruns and schedule slips.

Lockheed Martin‘s [LMT] Skunk Works had teamed with Piasecki Aircraft Corp. and Sierra Nevada Corp. on a design that included twin tilting wing-mounted ducted fans providing vertical lift and then transitioning to deliver forward thrust. Last September at the Modern Day Marine Expo, Lockheed Martin had said that it was readying ARES for a flight demonstration by mid-October.

“Following extensive component, integrated system and ground testing of the ARES aircraft, DARPA and the USMC have decided to end further investment in the program due to significant cost growth and delays,” DARPA said on May 8. “The program was a research effort that addressed technical risks for a future vertical takeoff and landing concept that would transition to fixed-wing forward flight. The investment provided risk reduction to potential future DoD programs by developing flight control software to manage complex configurations, and maturing a unique ducted fan approach to propulsion.”

The program cancellation adds a wrinkle in the Marine Corps’ competition for the Marine Air-Ground Task Force Unmanned Aerial System Experimental (MUX) vertical takeoff and landing (VTOL) drone, which the service wants to begin fielding in 2025-26. The Marine Corps wants to create a network of early warning and intelligence, surveillance and reconnaissance MUX drones for the protection of maritime forces, and ARES was expected to compete for MUX.

Lockheed Martin said on May 8 that it was unsure, given the cancellation of the ARES Science and Technology (S&T) demonstration, if the company would bid on MUX.

“As DARPA announced today, they have decided to end investment for the DARPA Aerial Reconfigurable Embedded System (ARES) unmanned air system and work has stopped,” Lockheed Martin said on May 8. “ARES is a high-risk developmental program to develop a modular, multi-mission, vertical takeoff and landing aircraft to address a broad range of emerging needs within DoD. The program successfully completed ground testing and flight test risk reduction to mature a unique ducted fan approach to propulsion. We appreciate the partnership with DARPA, AFRL [Air Force Research Laboratory] and the USMC in advancing the next generation of VTOL systems.”

The field of likely MUX competitors has now narrowed to Bell [TXT], which is offering a V-247 tiltrotor Unmanned Aircraft System; Boeing ]BA], which is developing a tail-sitting unmanned flying wing, the MUX-1; and Northrop Grumman [NOC], which is also developing a tail-sitting flying wing called the tactically exploited reconnaissance node, or Tern.

Last September at the Modern Day Marine Expo, Bob Allison, Lockheed Martin’s director of business development for Advanced Mobility Advanced Development Systems, said that ARES was “going very well in testing with the Marines at Yuma,” and said that the program had benefited from Piasecki’s “years of experience in ducted fans.”

The ARES was to have the ability to carry a 3,000-pound payload and have a landing zone half that of conventional helicopters such as the UH-60 Black Hawk, which is made by Lockheed Martin’s Sikorsky. It was also to feature fly-by-wire controls, and cruise at speeds up to 200 kt.

ARES has been under development at DARPA for a number of years, and Lockheed Martin officials had expected flight testing to ramp up at the end of 2015 and for DARPA’s involvement to end soon thereafter to be replaced by Army and Marine Corps funding.

DARPA said on May 8 that it had invested $89 million in ARES since program kickoff and concept exploration in 2009, and of that total DARPA had spent $74 million in the Phase III aircraft fabrication flight test program since 2013. The Marine Corps has invested more than $6 million to advance ARES flight testing, according to DARPA.

ARES “faced engineering challenges with completing ground testing necessary to progress into a full airborne test program,” DARPA said. “The extended ground test program solved basic engineering challenges, but additional testing was required to complete ground based full-power testing that resulted in cost, schedule and performance issues that made progression into a flight test program infeasible.”

Asked last fall why ARES had experienced development delays, DARPA said that technical complexity was a significant contributing factor.

“The ARES program is advancing the state of the art for a vertical takeoff and landing aircraft that can rapidly transition into horizontal flight,” Andrew Nuss, the DARPA program manager for ARES, said at the time. “The technology development for this complex system has warranted additional ground testing, which the Lockheed Martin/Piasecki team is currently addressing to ensure a successful flight test program. The aircraft is completing those ground tests at Yuma Proving Ground in advance of hover, transition and forward flight testing in the coming months.”

Beyond supporting troops from ship to shore and shore to shore in remote environments, Lockheed Martin also believed ARES would have commercial applications, such as product delivery and disaster relief.