A 4-metre-wingspan unmanned aircraft guns its twin engines and takes to the skies. So began the first flight of an uncrewed aircraft early last month that could soon be monitoring two seas – the English Channel and the North Sea – for risks to shipping, illegal fishing operations and even drug-running boats.
Called 2Seas, the UAS is designed to fly lengthy surveillance missions for coastguards in the UK, the Netherlands, Belgium and France. It is a direct descendant of the catapult-launched, 1.5-metre-wingspan, electric-powered SULSA (Southampton University Laser Sintered Aircraft) built at the University of Southampton, UK.
After that success, the European Union commissioned aeronautical engineers led by Southampton’s Jim Scanlan and Andy Keane to develop 2Seas. It’s built on similar design principles to SULSA but thanks to its petrol-driven engines it can fly autonomous surveillance missions for 5 hours at 100 kilometres per hour, sipping just 7 litres of fuel in doing so.
However, where SULSA’s fuselage, wings and tail were entirely 3D-printed in strong ABS plastic, the much bigger 2Seas needs higher-lift wings that were too long for today’s 3D printers to make. So although the heart of 2Seas – the central wing box, fuel tank and engine mountings – was 3D-printed, the wings and tail are made from carbon fibre.
One design feature carried over from SULSA is a criss-cross pattern printed onto the inside of the drone to strengthen it. First used on the British Vickers Wellington bomber in the second world war – at great expense – such geodesics can be built in via 3D printing for virtually no extra cost.
The aircraft has already passed many tests, even coping with strong crosswinds and appalling weather, but faces many more, focusing on its vibration and flight characteristics when carrying surveillance equipment. “If those trials go well this UAScould go into initial service in 2015 or even earlier,” says Scanlan.
Source: New Scientist