Yates Electrospace Corporation said earlier this week that it has landed a Small Business Innovation Research contract with the Air Force Research Laboratory to develop a smaller version of its coffin-sized autonomous glider called “Silent Arrow” for Air Force Special Operations Command. AFSOC wants it use it for unspecified operations. Like what?
The Silent Arrow GD-2000 is essentially a two-foot by two-foot by eight-foot rectangular box with an aluminum frame and birch plywood panels. Before flight, a nose cone with an autopilot is attached at the front while a twin-tail is attached at the rear. As the UAS is pushed tail-first out of the back of an airplane, four wings stacked in-line atop the box spring out switchblade-style.
Two wings, front and rear, on each side are staggered in a semi-biplane fashion, allowing Silent Arrow to glide up to 40 miles with a 1,600 pound payload. The UAS autonomously follows a pre-programmed flight plan to a desired landing zone. It glides there silently with almost no radar signature and no datalinks to intercept or interrupt. Once on the ground, its cargo can be easily accessed and the box can be abandoned or re-purposed.
These qualities drew attention from the Marine Corps, Army and AFSOC in 2017 as they looked for stealthy, non-parachute means to deliver supplies and critical tactical gear. The Air Force provided C-130 aircraft and crews to test the glider in restricted airspace. Pushing the Silent Arrow out the back cargo door of the Hercules at 25,000 feet, watching its wings spring out in less than a second, and then tracking the payload-laden UAS to its glide aim-point allowed the services to evaluate its potential.
The Marine Corps Warfighting Laboratory funded construction of six GD-2000s for testing but orders from the military have yet to come. The new SBIR contract indicates that demand from AFSOC may change that. The contract title – “Feasibility of Downsizing and Adapting Commercial Silent Arrow Cargo Delivery UAS to Meet Specific AFSOC Operational Requirements” – hints at some of what Air Force special operators are after.
“What AFSOC seems to be leaning towards is reducing the overall length [of Silent Arrow] so that it can be deployed from [the rear] of a CV-22 or out of a [aircraft] side door,” Yates Electrospace CEO Chip Yates says.
The V-22 Osprey, he adds has a particular set of size requirements for bundles that can be air dropped from its aft cargo ramp. These likely require a Silent Arrow that is six feet rather than eight feet long with a subsequent reduction in cargo capacity. (Affixing nose and tail cones adds an additional five feet.) AFSOC’s interest in side-door deployment suggests it would like to use a smaller Silent Arrow with helicopter platforms like the HH-60G/W Pave Hawk or the Army’s MH-47G Chinook.
“We’ve got three or four stakeholders involved in this SBIR,” Yates explains. “We’re going to try to take everyone’s input and merge it into a single solution.”
Such input would include the kind of things an AFSOC-spec Silent Arrow would carry.
“We’ve heard about all kinds of [potential] cargo,” Yates acknowledges. “The original idea was to supply one squad of special operators with one day’s worth of equipment.”
That would conceivably encompass the typical load/items a special operator would carry in a backpack, from weapons to communications gear, apparel, food and even money. A Silent Arrow might also bring fuel, special sensors, ammunition, weapons systems or equipment to deployed teams. Those teams may not even be on terra firma.
Chip Yates says YEC has looked into fiberglass construction for a buoyant Silent Arrow at the behest of elements of the Navy within U.S. Indo-Pacific Command (PACOM).
“There’s an idea to be able to land these on the water and have them float for a little bit. It’s a possibility if PACOM jumps into this SBIR as a sponsor and provides a concept of operations.”
Given the downsizing needed to go from a C-130 to a CV-22 and HH-60 (and the significantly different aerodynamic qualities of these different aircraft), a redesign of the GD-2000 likely won’t be straightforward. Yates says the seven-foot span of each of the four wings on the UAS may need to be clipped and the airfoils otherwise altered.
Timing the spring-out of the wings will likely need attention given the aero wash from the big proprotors of the CV-22 or main rotor of a helicopter. Yates praises the self-righting software that his company tested on the Silent Arrow which could allow it to recover from a roll or tumble associated with launching from an AFSOC aircraft.
The software pairs with an off-the-shelf Pixhawk Cube autopilot system in a nod to low cost and the disposable concept of the autonomous glider. The commercially available autopilot also steers clear of International Traffic in Arms Regulations, avoiding legal complications in spots where it may need to land and for potential customers to whom it may be exported.
Yates says that YEC has sold 20 of its of GD-2000 Silent Arrows to an unnamed “government owned” entity in Europe. The company has also licensed production and sales of the Silent Arrow to a UK company which is building another 40 GD-2000s for unspecified customers.
YEC hopes to license two production lines in North Carolina and Mississippi in the near future as well. The core company will stick to development, leveraging its intellectual property for this and forthcoming projects including widebody and powered-electric versions of Silent Arrow.
Technically, the current phase-one of the SBIR which runs to May 7, 2021, will generate the downsized design. Phase two, though not formally approved yet, will see design work and prototype production for AFSOC. What the command chooses to do with smaller Silent Arrow prototypes is for the Air Force to know and YEC to find out, Yates says.
“I’m not sure what [AFSOC] is targeting. I asked that question and they said, ‘None of your business.’ ”