The Aerial Reconfigurable Embedded System (ARES), an unmanned, vertical-takeoff-and-landing (VTOL) prototype touted for its compact design and interchangeable payload, is on track to begin flight testing in the fourth quarter of this year, according to an industry official.

ARES, which is under development for the Defense Advanced Research Projects Agency (DARPA), is being built and undergoing ground tests, including drivetrain tests, at Piasecki Aircraft in Essington, Pa., near Philadelphia, said Doug Welch, an ARES official for Lockheed Martin [LMT], the program’s prime contractor. The demonstrator vehicle will move to the Army’s Yuma Proving Ground in Arizona for the flight tests.

“We’re just very excited that the ground test program is progressing as we expected, and [we] are really looking forward to first flight later this year,” Welch told sister publication Defense Daily April 30.

With two tilting, 8.5-foot-diameter ducted fans instead of conventional rotors, the aircraft has a compact shape that will allow it to use landing zones half the size of a comparable helicopter, according to Lockheed Martin and DARPA.

The remotely piloted prototype is scheduled to fly 18 times over two to three months at Yuma. For half of those flights, ARES will carry a Joint Modular Intermodal Container (JMIC), a box-like cargo container weighing more than 2,000 pounds.

ARES will transport a payload using a MAU-12 bomb-ejector rack, which is typically mounted underneath an F-16 fighter jet. Although the DARPA-sponsored demonstration will involve only the JMIC payload due to funding constraints, the rack could allow the payload to be swapped out easily, which means the aircraft could perform a wide range of missions, such as cargo and troop transport, reconnaissance and casualty evacuation, according to Lockheed Martin.

“We don’t know what the threats and the needs are going to be in the future, but by simply designing a modular payload to go with the ARES, we can adapt to that and employ it in the field,” Welch said.

Lockheed Martin expects DARPA’s role in ARES to end with the Yuma flight tests. But Welch said the Army and Marine Corps have both expressed interest in the technology, which he believes could feed into other programs, such as potential Marine cargo unmanned aircraft.

“We’re exploring ways that we can further demonstrate the flexible and adaptive nature of the platform by doing additional modules for it [and] additional testing,” Welch said. “We definitely think that this could be a fielded configuration.”