Green aspirations are fuelling some new uses of kites and gliders, and corresponding worries from aviation authorities.
In September, Eurocontrol warned operators of a new breed of kite being used by ships for auxiliary propulsion.
Today, a company called Highest Wind is asking the FAA for exemptions from several rules controlling the use of moored balloons in US airspace. Highest Wind is marketing a 300lb, 40ft tri-wing glider that trades lift for electrical power.
The system, which Highest Wind says will be available in 2011, creates power from lift as the tethered glider flies. The system automatically lauches the aircraft when winds allow, and returns the vehicle to its pad when conditions are not favourable. Generally, the glider can rise high as the base of controlled airspace — either 700ft or 1,200ft above the ground, depending on the location, to take advantage of the winds.
Highest Wind says the system can generate about 30kW of power in any weather, day or night, as it cycles the tether up and down, spinning a flywheel in the land-based power trailer.
A fly in the ointment however is the FAA’s moored balloon rules, which limit the devices from flying in visibility of less than 3mi, higher than 500ft below the base of clouds or more than 500ft above the ground, requirements meant to provide visual separation with low-flying aircraft. Highest Wind wants an exemption from all three.
In addition, the company wants relief on rules requiring the device to be lighted for night operations or to have the mooring line carry colored pennants or streamers attached at intervals not more than 50ft apart above 150ft.