Urban Aeronautics, which is developing the X-Hawk vertical take-off and landing (VTOL) vehicle, has added a new model intended for operation by law enforcement agencies.
The X-Hawk LE is a more powerful version of the vehicle designed primarily for operation in urban and other confined environments. Presented at the recent Airborne Law Enforcement Association (ALEA) conference in Charlotte, North Carolina, the vehicle is designed to carry a pilot and three fully equipped police officers and cruise for 3h plus reserves at speeds of up to 140kt (259km/h).
The Israeli company is also developing an emergency medical service (EMS) version for which it is collaborating with design partner The Center for Emergency Medicine/STATMedEvac based in Pittsburgh, Pennsylvania.
In its final US Federal Aviation Administration-certificated version, the X-Hawk is expected to cost some 15% less than a similarly equipped twin-engine helicopter due to the absence of a complex rotar system, says Urban Aeronautics.
The need for articulated rotor heads is eliminated by Urban's patented vane control system. Two internally mounted variable-pitch rotors provide the lift the vehicle needs to support its useful load plus fuel.
The control system relies on two rows of movable vanes, positioned at the entrance and exit of each of the two ducted lift-fans. By rotating the vanes in the same direction, the incoming flow through the ducts creates side forces without rolling. Alternatively, rotating the upper and lower vanes in opposite directions produces rolling moments without side forces.
Combining these two basic modes through a fly-by-wire system and sensor suite should enable the X-Hawk to operate in urban areas even in adverse weather conditions.
Urban Aeronautics has signed an agreement with Israeli engine company Bet Shemesh for the supply of turbine engines for its two planned X-Hawk prototypes.
The company's CityHawk proof-of-concept vehicle recently completed hover testing near Ben Gurion Airport in Israel.
Dr Rafi Yoeli, Urban Aeronautics president, says the tests demonstrated that the vane control system provided "more control than we expected".
ARIE EGOZI / TEL AVIV
Source: Flight International
