AAI is flying testbeds for next-generation developments of its RQ-7 Shadow tactical unmanned aircraft that are now in the final stages of design.

Two Shadow Technology Test Beds (STTB) have been modified with a larger fuselage able to accommodate dual payload bays. In addition to the Shadow’s electo-optic/infrared/laser-designator payload “we are working with SAR [synthetic-aperture radar] and sigint [signals intelligence] packages,” says Steve Reid, AAI senior vice president and general manager for unmanned aircraft.

The testbeds are a “mid step,” he says, toward two advanced Shadows now in development. The M variant adds an unpowered rotor to the “modestly larger” STTB airframe to provide a vertical-takeoff-and-landing (VTOL) capability.

The M2 combines the RQ-7B’s long wing with a larger “blended wing” fuselage able to accommodate a second payload and additional fuel. The M2 will be powered by a new heavy-fuel engine under development by Lycoming, AAI’s sister company within Textron.

The M2 will use the current Shadow launcher and ground equipment and is aimed at enabling the U.S. Army to upgrade its existing RQ-7 fleet at minimum cost and risk. The heavier M variant dispenses with the pneumatic launcher and instead uses slowed-rotor/compound (SR/C) VTOL technology licensed by AAI from Carter Aviation Technologies.

The SR/C is essentially an autogyro in which the rotor is spun up by the engine on the ground to enable a “jump” takeoff, while the high-inertia rotor blades enable the aircraft to autorotate to a “zero-roll” landing.

After completion of dual-payload flights with the STTBs, Reid says AAI will convert the two testbeds to SR/C configuration. First flight of the M variant is planned for the first quarter of 2012.

The M2 is still in design and is planned to be available in 18 months to two years, but Reid says AAI is looking at accelerating development in response to increasing customer interest.

The M2 would have an endurance of up to 15 hr. and a payload of 100-120 lb. depending on fuel load. The payload bays can accommodate fuel cells. The long-wing RQ-7B has an endurance of 6-7 hr.

The 60-hp, heavy-fuel powerplant now on dynamometer testing at Lycoming is a three-cylinder aviation gasoline engine modified to be able to burn multiple fuels, including diesel, JP-5 and JP-8 jet fuel, Reid says.