An unmanned helicopter designed to lift supplies and equipment to troops in Afghanistan is being developed for the US military. The Kaman K-MAX helicopter has been adapted by defence company Lockheed Martin to fly without a pilot and can carry up to 6,000lbs of cargo - more than the aircraft's empty weight. Transporting equipment to troops at Forward Operating Bases on the frontline would be the K-MAX's primary use. It would help reduce the need for large vehicle convoys lowering the risk of soldiers being ambushed or injured by IEDs (improvised explosive devices).