Unmanned System Primes, Suppliers Field New Tech
By Bill Sweetman Washington
Source: Aviation Week & Space Technology
Different ways to achieve vertical takeoff and landing—almost essential for shipboard UAS and valuable for tactical systems—were also in evidence. Latitude Engineering of Tucson showed a prototype of a hybrid quadrotor: A piston engine drives a generator, turning four electrically powered rotors (on the prototype) mounted in front of and behind the wing on booms that carry the tail. The 60-lb. next-generation vehicle will have eight lift rotors installed in pairs, above and below the booms. Latitude says three of the latter vehicles have been ordered by Naval Air Systems Command for a test program.
Tail-sitters are vertical-takeoff-and-landing (VTOL) aircraft that are mechanically simple, but difficult for a pilot, so the layout is not a problem for a UAS. Swift Engineering, the California-based composite company that produced the KillerBee UAS some years back, showed a tail-sitter prototype that comprised a high-aspect-ratio wing with three lifting propellers and a cruise propeller.
Another VTOL concept came from Swiss/Swedish newcomer Unmanned Systems Group in the form of the ATRO-X helicopter UAS, shown in the form of a one-third-scale model. Slightly bigger than rivals such as the Schiebel Camcopter and Saab Skeldar, the ATRO-X revives the hot-cycle tip-jet concept last flown almost 40 years ago: A simple gas-turbine engine is mounted on the rotorhead and exhaust is ducted along the blades to nozzles in the tips. ATRO-X designers point out that the helicopter needs no transmission or tail rotor. The jet engine is simple, inexpensive and easy to remove for maintenance, and burns JP-5 or diesel fuel.
There is a counter for every weapon system, and UAS are no exception. The U.K.'s Plextek Consulting has been testing its Blighter series of active, electronically scanned array radars—including vehicle-mounted and man-portable systems for ground surveillance—in the ground-to-air role and is rolling out a software and human-machine-interface package that can detect small UAS. One application is for airport or facility security, where the same radar can detect ground-moving or airborne intruders. Another is to clear airspace for friendly UAS operations and to reduce the risk of collision.