Scaled Composites' Proteus proof of concept, high-altitude, long operation (HALO) aircraft made a successful first flight from the company's Mojave base in California on 26 July.
The all-composite, canard configured aircraft is one of the most bizarre to emerge from the Burt Rutan stable. Piloted by Mike Melvill, the Proteus was flown for 1h 40min, achieving an altitude of 12,000ft (3,600m) and a speed of 100kt (185km/h).
The Proteus is powered by two Williams-Rolls FJ44-2 turbofans and is designed to be flown at altitudes of between 51,000ft and 60,000ft. Although aimed initially at a communications relay role, the aircraft is also being considered for possible evaluation as an unmanned high-altitude reconnaissance platform, says the manufacturer. In its role as a relay aircraft, the Proteus would orbit at high altitudes over a city for between 12h and 18h.
The aircraft has a maximum take-off weight of 5,700kg (12,500lb), of which 910kg is the payload. This consists of a 6.1m-diameter pod, suspended beneath the tube-like fuselage, which houses a communications antenna. To maintain accurate pointing, the antenna will be mechanically stabilised in pitch and roll.
The anhedral wingtips are also dielectric, rendering them transparent to electromagnetic signals and therefore preventing them from interfering with the antenna when the Proteus is turning, or flying wing down to maintain station in a cross wind.
Although funded by Scaled Composite parent company Wyman-Gordon, the Proteus is aimed at companies such as St Louis, Missouri-based Angel Technologies, which would use the aircraft to provide cellular telephone and broadband data services.
At least three aircraft would be required to maintain a 24h service, two for sequential flights and a third as a "hot spare". Each aircraft would carry two crew, with one crew at a time resting.
Source: Flight International