Proteus

Proteus is designated as a high-altitude, multi-mission aircraft. It is a new, special-purpose aircraft and the latest project from Scaled Composites. Proteus is a twin turbofan high altitude multi mission aircraft powered by Williams International FJ44-2E engines. It is designed to carry payloads in the 2000-pound class to altitudes above 60,000 feet and remain on station up to 14 hours.

The Proteus designed with long wings and a low wing loading needed for efficient high altitude loiter, shows grace, stability, and low noise during demonstrations. The aircraft can undergo dynamic maneuvers showing the aircraft's agility, and can easily operate in adverse conditions. It utilizes a crisp, short takeoff and landing illustrating the unique "three-mains" landing gear design intended to increase crosswind and wet runway capability without the use of spoilers. The Proteus graphite composite cabin is a structure, which incorporates several new design concepts, had recently been tested to 3.5 times the required operating cabin pressure.
In recent testing Proteus has flown as high as 36,000 feet and demonstrated speeds from stall speed, as low as 65 knots (75 mph), to 250 Knots (288 mph). Takeoff weights up to 9000 pounds have been demonstrated, and the maneuvering envelope has been opened to 2.5 g. Cabin pressurization system tests are now in work, which will allow pressurized flights to begin soon. This will allow expansion of the altitude envelope while providing for the crew's safety.

Heavier payloads can be carried for shorter missions. It is intended for piloted as well as for UAV missions. Potential missions for Proteus include telecommunications, reconnaissance, atmospheric research, commercial imaging, and space launch.