ABOVE: The X-65 CRANE will manoeuvre by disrupting airflow thanks to a compressed air system, with no moving surfaces
An odd-looking prototype of an aircraft without control surfaces is taking shape in a Boeing facility in Bridgeport, West Virginia. The X-65 Control of Revolutionary Aircraft with Novel Effectors (CRANE) uncrewed demonstrator is being developed by Boeing subsidiary Aurora Flight Sciences.
It will test the use of puffs of air (not quite the same as vectored thrust) to disrupt the flow over the lifting surfaces to effect pitch, roll and yaw instead of changing the shape of the aerofoils themselves with elevators, ailerons, and rudders. The problem with the conventional approach is that even the stealthiest design will light up radar when a control surface moves even slightly. It’s not all just about having a military advantage though, since all those gaps, hinges, and actuators also add weight and drag to the airframe.
The X-65 employs a compressed air system that uses fourteen nozzles to disrupt airflow in order to create the control inputs. The system can also increase lift by altering airflow over the wing’s leading edges. The type of engine, required horsepower, or fuel, isn’t specified, but a small SAF burning turboprop turning a massive generator to drive the electric compressor and nozzles seems likely.
The prototype has movable control surfaces in case the air puffs aren’t effective. The weird shape of the wings and tail helps make the most of the disrupted airflow in controlling the aircraft. The X-65 has been designed as a pure testbed for new technology, and at the moment it is not intended to be the precursor of a production aircraft.
PHOTO: BOEING
