Unmanned Systems Technology 005 | Selex ES Falco UAV | Sense and avoid systems | RCV Engines DF70 | DSEI show report | Fuel cells | CUAV Expo, InterDrone and CUAV Show reports | SLAM

26 propeller from the parachute as it opens. This was validated through full-scale parachute deployment tests carried out in a large wind tunnel in Milan. Setting a target endurance of about 14 hours for the Falco – a very long flight time for an aircraft of this size – called for exceptional aerodynamic performance. A major factor in obtaining that was opting for a wing consisting of main element plus slotted flap that provides high lift for a given level of drag. This was a concept presented a few years earlier at the 1996 International Council of Aeronautical Sciences (ICAS) conference held in Sorrento, Italy. The presentation of the concept by senior UAV aerodynamicists demonstrated that a narrow chord makes for a high aspect-ratio wing that has a high lift-to- drag ratio at the low Reynolds numbers associated with a craft of this size and operating speed. The Falco’s wing section was optimised in conjunction with CIRA, the Italian Aerospace Research Centre, based near Naples, using state-of- the-art CFD for aerofoil aerodynamic analysis and optimisation tools based on genetic algorithms. A wind tunnel test programme, using a 22% scale model of the entire craft and running at very low Reynolds numbers in natural transition, validated the Falco’s aerodynamics and confirmed the optimisation carried out specifically for the low-speed regimes typical of this kind of vehicle. A particular challenge at the early design stage was the paucity of options for a suitable engine. A particular Wankel-type rotary was identified as the best available, and this proven 85 bhp unit from UK-based manufacturer UAV Engines continues to power Falco to this day. The Falco’s payload and the main avionics package are located in the belly, and are protected on landing by substantial landing gear. The size and weight of that gear, which includes shock Dec 2015/Jan 2016 | Unmanned Systems Technology The Falco ground control station The payload and main avionics package are located in the belly, and are protected on landing by substantial landing gear