Dynetics undertook the first flight of its X-61A Gremlins Air Vehicle (GAV) in November last year, the company revealed on January 17. Gremlins is a Defense Advanced Research Projects Agency (DARPA) program, handled by the agency’s Tactical Technology Office. The aim is to demonstrate the feasibility of the air-launch and mid-air recovery of low-cost unmanned air systems (UASs) that could perform reconnaissance and other missions in “volley" quantities.
The first flight test campaign was conducted at the Dugway Proving Ground in Utah and employed a C-130A Hercules provided by TBM Inc., a flight test company based in Atwater, California. A captive-carry mission was conducted before the X-61A GAV was launched on a 1-hour, 41-minute free flight.
The flight successfully demonstrated launch, during which the GAV’s wings were deployed and its engine started from cold before transitioning to stable flight. The GAV then performed various maneuvers, during which its datalink and control systems were checked. Deployment of its docking arm was verified, although for the initial demonstration the air vehicle was equipped with a parachute recovery system. While the engine was shut down and drogue chute deployed as intended, the main chute failed and the vehicle was destroyed. However, the operationally relevant elements of the mission were all successfully completed.
“This flight marks a historic milestone for Dynetics and the Gremlins program," said Tim Keeter, Dynetics Gremlins program manager. "The GAV flew beautifully and our command and control system kept us in total control of the GAV for the entire flight. The loss of our vehicle validates our decision to build five GAVs for Phase 3; we still have four remaining. Overall, I am proud to see all the hard work pay off and we are excited to continue this momentum towards the first airborne recovery in early 2020.”
The Dynetics Gremlins solution employs a stabilized capture device—known as the “bullet”—that is towed behind the C-130’s ramp. The GAV deploys a docking arm that mates with the bullet in a similar way to that of a refueling probe engaging a towed drogue. Once secure, the GAV is reeled back aboard the aircraft. The system can be adapted for underwing and internal bay use.
The Gremlins program started in 2016 with the award of Phase 1 study contracts to four companies. Two of them—Dynetics and General Atomics—were selected for Phase 2 development in March 2017, and Dynetics was chosen to proceed to the 21-month, $38.6 million Phase 3 demonstration in April 2018. The November 2019 flight test was an important milestone along the path to achieving the main Phase 3 objective of being able to recover four GAVs in under 30 minutes.
In February 2019 the docking system was flight-tested, while the GAV’s avionics system was trialed in March aboard the Variable Stability System (VSS) Learjet operated by Calspan. In August the Gremlins vehicle was officially designated as the X-61A. The five test vehicles were built by Kratos Unmanned Aerial Systems, a key partner in the Dynetics team. Other partners include Williams International (engine), Applied Systems Engineering (flight computer), Kutta Technologies (multi-vehicle control system), Moog (control actuators), Sierra Nevada Corporation (precision navigation for rendezvous/docking), Systima Technologies (C-130 pylon and launch controller), and Airborne Systems (recovery systems).