Breakthrough: Flapless UAV gets airborne
control the boundary layer across the wing with air jets,…which would also help change lift/drag characteristics for takeoff and landing. “We’ll see if anything comes of this, but it sure does look promising,” an analyst says.
The DEMON UAV is shaped in a blended wing body configuration, which allows it to mimic the aerodynamic forces normally provided by flaps, elevators, and ailerons by blowing jets of air from a nozzle over Coanda surfaces installed across the wing. The flapless system, based on a concept called fluidic flight control, would require less maintenance and would produce less noise, affording the aircraft a more stealthy profile for military missions. It could also allow for planes with significantly reduced wing size.
The unmanned craft uses hundreds of tiny air jets to control its movement in flight rather than using traditional flap mechanisms. This new technology would give military aircraft a more stealthy profile by reducing edges and gaps that can be picked up by radar, said its developers.
Such an approach offers several advantages over moving flap technology, in that it means fewer moving parts and a more stealthy profile for the aircraft. DEMON’s trial flights were the first ‘flapless flights’ ever to be authorized by the U.K. Civil Aviation Authority.
The UAV successfully demonstrated flapless flight when, for a planned portion of a test-flight, the conventional flap control system was turned off and the aircraft flew and maneuvered using the new technology. It promoted the development of the FLAVIIR (Flapless Air Vehicle Integrated Industrial Research) program which led to the DEMON demonstrator after laying down a Grand Challenge to U.K. universities five years ago.
Richard Williams, BAE Systems program director for Future Capability, says, “What the FLAVIIR team have achieved in such a short time is nothing short of remarkable. What makes it even more poignant is that this is the result of British brains collaborating to produce world-leading technology. It, and other initiatives like it, will help ensure we maintain both a level of sovereign capability and a competitive edge.”
While DEMON itself is not expected to become a production aircraft, a number of the technologies it contains have and will continue to filter through to a range of other aviation platforms.
DEMON key facts
- Weight: 200 lbs (90 kg); dimensions: approximately 8-foot (2.5m) wingspan Flight speed 70-150kts.
- It was developed by BAE Systems and Cranfield University in the United Kingdom. It incorporates fluidic flight controls developed at Cranfield and Manchester Universities and flight control algorithms developed at Leicester University and Imperial College
- The DEMON is designed to fly with no conventional elevators or ailerons, getting its pitch and roll control from technologies which rely on blown air and so requires much fewer moving parts, therefore making it a lot easier to maintain and repair.
- DEMON can fly parts of its mission by itself but, as it is currently an experimental vehicle, is not fully autonomous unlike, for example, BAE Systems’ MANTIS.
- The shape of the DEMON aircraft is referred to as a blended wing-body configuration.
