A prototype rotorless, easy-to -handle helicopter that can dock with skyscrapers is to be built by 2006, following successful tests of the plane’s unique controlsystems.
The X-Hawk, currently under development by Israeli firm Urban Aeronautics, is designed to fly amid skyscrapers and land inside damaged buildings for use by emergency staff such as paramedics and firefighters.
Dr Rafi Yoeli, president of Urban Aeronautics, was previously a senior engineer at Boeing and was also a head of Israel’s aborted Lavi fighter plane project.
Earlier this year a smaller concept demonstrator, the City Hawk, completed 10 piloted hover tests at a height of two to three metres. This incorporated a unique vane control system that eliminates the need to tilt the vehicle during turning.
The results were claimed to be so successful that the firm has announced it should have a working X-Hawk prototype available for flight tests within 18 months, and commercial release is planned for around 2009.
The prototype will also feature a fly-by-wire, multi-channel flight control system and autostabilisation systems allowing the plane to withstand gusts of up to 50 knots.
Unlike a conventional helicopter, the turbine-powered VTOL plane’s propellers are incorporated into the body of the aircraft, consisting of two ducted fans contained inside the fuselage.
The control system comprises four layers of moveable vanes: two layers at exits of the ducts and two separately actuated layers at their entrance. Each layer has around 100 vanes. All four layers can be moved separately to control the vehicle’s direction.
‘Controllability has been a problem for aircraft like this in the past, but our vane control system has solved this,’ said Janina Frankel-Yoeli, vice-president of marketing. ‘You can now fly laterally without having to tilt. it is like driving a car but with a vertical dimension.’
The X-Hawk is expected to have a maximum speed of 80-100 knots and remain airborne for an hour and a half.
The rotorless design means it is able to pull in close to buildings or dock at windows without danger of collision. This will allow it to be used by emergency staff to rescue people from tall buildings, or deliver rescue services and equipment to upper floors.
As far as possible, Urban Aeronautics has built the X-Hawk using available components that have already been passed for use by the FAA. The company hopes this will allow the plane to become certified for general use with relative ease.