At the AVUSI 2010 unmanned vehicle show in Denver, Colo., (Aug. 24-27) a key buzzword was autonomous — referring to the ability of pilotless craft (air, sea or land) to operate not only without a pilot in the cockpit, but without one remotely stationed on the ground as well. Few exhibitors of unmanned systems neglected to mention their autonomous options, and sprinkled among the splashier vehicle exhibits were dozens of booths manned by marketers of the software and control hardware and sensing technologies designed to make unmanned operations free of the need for human intervention.
A big question CompositesWorld (CW) had for show exhibitors was what effect will ongoing and potential military drawdowns in Iraq and then Afghanistan likely to do to the unmanned aerial vehicle (UAV) market? Without exception, those experienced in the market during the large military buildups that powered much UAV development in the past eight years told CW that many governments in the Middle East are writing orders for UAVs as they prepare to shoulder security chores that the presence of large U.S. forces will no longer mitigate. Orders from friendly foreign military forces and at least a short-term need to replenish the Pentagon’s spent equipment, and a vastly expanding civilian and law-enforcement market, are expected to push continued growth in the unmanned market for the foreseeable future.
In the air
Composites continue as the material of choice for UAV airframes as well. Cornerstone Research Group Inc. (GRG, Dayton, Ohio, USA) was one of several purveyors of ducted-fan-powered micro-aerial vehicles. CRG’s aptly named HALO, a vertical take-off and landing (VTOL) airborne sensing system, was on display in two sizes. A robust all-carbon composite round structure almost 2 ft/0.6m in diameter with a centrally mounted, rechargable-battery-powered co-axial, counter-rotating ducted fan, was paired with its similar but smaller predecessor. Targeted to law-enforcement and fire/rescue first responders, the remotely piloted surveillance craft are designed to negotiate labyrinthine urban environments under circumstances dangerous to human agents.
Exemplifying the decidedly entrepreneurial bent to the UAV market, former U.S. Air Force munitions expert Chris Miser (CLMax Engineering, Ft. Walton, Fla., USA) showcased his inexpensive UAV option, the Ox. Miser helped test a series of expensive weaponized UAVs while in uniform, but thought, “I can do this better.” Now out of uniform and in business for himself, he claims he can make a practical airframe for $20,00 to $30,000 — about half the going rate for “low-end” UAVs of the same size and capabilities. Easily assembled/disassembled by one person without tools in less than 15 minutes, the Ox can be transported in two cases and a wing/boom tube container and, in this form, could be checked as luggage on a commercial carrier. With a 15-ft/4.5m wingspan and empty weight of only 70 lb/32 kg, it reportedly can carry a useful load (payload plus fuel) of up 40lb/18.1 kg in payload bays with a useful internal volume of more than 50 liters (1.7 ft²), as well as two underwing “hard points,” each capable of supporting 15 lb/6.8 kg. Depending on the payload-to-fuel ratio, Miser’s aircraft can stay aloft for 1 to 12 hours in autonomous or radio-controlled flight. CLMA has placed six UAVs with Miser’s former employer and expects that low-priced, workhorse UAVs will bring unmanned technology to a much wider range of potential clients.
Several exhibitors showcased target drones, one of the earliest commercial uses of UAVs. Prominent among them was Composite Engineering Inc. (CEI, Sacramento, Calif.) with a display of three miniatures of its full-size (10 ft long, 6.5 ft wingspan) trailer-catapult-launched, jet-powered drones. Lightweight yet tough, CEI’s “top end” composite-airframed drones fly at up to 400 nautical mph during gunnery/anti-aircraft missile tests yet, surprisingly, can be shot down, repaired and then reused, surviving to fly an average of eight missions.
The unmanned vehicle market has been a huge boon to composite propeller manufacturers, who otherwise might have been devastated during the general aviation downturn prompted by the recent recession. Propeller manufacturers on the show floor offered a variety of methods and materials for manufacturing lightweight composite props. Wichita, Kan.-based McCauley Propeller Systems mounted a massive exhibit, offering composite props for systems ranging from full-size pilotless aircraft to ducted-fan craft and micro-drones. Sensenich Propeller Co. (Plant City, Fla., USA), a competitor in the U.S. Federal Aviation Agency’s (FAA) manned experimental aircraft category, was on hand, searching for UAV applications for its light composite produced via a combination of resin transfer molding (RTM) and inflatable mandrels. Long-time marine-prop specialist Piranha Propellers (San Luis Obispo, Calif., USA) promoted its range of propellers for small airborne and underwater unmanned vehicles (UUVs), powered by engines of 100-hp or less. Most unusual was the company’s line of small injection molded, glass-reinforced props, including a proprietary 50 percent glass/nylon 6.6 blade that incorporates a glass-fiber perform.
Under the sea
Hydroid Inc. (Pocasset) displayed its Remus line of of small autonomous deepwater craft and a family of larger HUGIN deepwater AUVs built by parent firm Kongsberg Gruppen (Kongsberg, Norway). A member of the latter, 3m/10 ft long, was used to scout the ocean floor in preparation for offshore oil giant BP’s drilling of the relief well in the Gulf of Mexico that enabled it to plug the well that recently resulted in the world’s largest oil spill.
Meanwhile, Harbor Wing Technologies (Seattle, Wash., Pearl Harbor, Hawaii) explained the technology behind its unique autonomous unmanned surface vessel (AUSV). Designed for surveillance, reconnaissance or environmental monitoring, the wind-powered, tri-hull design eschews a conventional sail in favor of what the company calls a “hard wing” airfoil, or WingSail. The HWRT X-1 subscale prototype, funded in part by the U.S. Navy, performed well in recent tests near Hawaii. Production of the first full-size tri-hull and hard-wing sail is under way.