Unmanned rotorcraft passes stringent German Navy shipboard tests

#weaving #autoclave #outofautoclave


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Intelligence, Surveillance, Target Acquisition and Reconnaissance (ISTAR) platforms typically take the form of unmanned aerial vehicles (UAVs). To add ISTAR capability to Germany’s Navy fleet, the country’s Ministry of Defense (MoD) selected the CAMCOPTER S-100 UAV, a vertical takeoff and landing (VTOL) system from Schiebel (Vienna, Austria). Measuring 3,110 mm/10.2 ft long by 1,040 mm/41 inches high by 1,240 mm/49 inches wide, with a rotor diameter of 3,400 mm/11.2 ft and a maximum takeoff weight of 200 kg/441 lb, CAMCOPTER can carry a 50 kg/110 lb payload in excess of six flight hours.

CAMCOPTER’s high strength-to-weight ratio is made possible by composite materials. Advanced Composites Group Ltd. (ACG, Heanor, Derbyshire, U.K.), provided trademarked MTM49 prepregs for the UAV’s carbon fiber monocoque design fuselage, as well as LTM212 prepreg for the fuselage tooling. ACG’s MTM49, supplied in uni tape and woven formats, in both carbon and glass, features a toughened epoxy matrix  that has an 80°C to 160°C (176°F to 320°F) cure temperature. Specifically formulated for ambient and hot/wet mechanical performance and impact resistance, it exhibits good tack and drape, long out life and flexible processing via autoclave, vacuum bag or press molding.

To determine the prepreg’s suitability, tests were carried out on ACG-manufactured material specimens in accordance with Schiebel’s exacting specifications at ACG’s fully equipped Technology Centre, built in late 2006 with funding from parent company Umeco plc. Mike Davies, ACG’s test and evaluation manager, oversaw aging and overall mechanical performance tests, as well as fuel-resistance testing a prolonged (30-day) soak in aviation fuel heated to 40°C/104°F, Davies says the testing, performed using standard ASTM test methods, proved that MTM49 was ideally suited for the intended application. The tooling and fuselage components were subsequently hand layed using the test-proven material and then were autoclave cured.

During shipboard maneuvers, the resulting CAMCOPTER S-100 successfully completed more than 130 takeoffs and landings over a 20-hour period, in winds from all possible directions, some as high as 40 knots (46 mph). CAMCOPTER has been in service with several countries since 2006, and has previously been proven at sea with Indian, Pakistani and Spanish forces.