The Boeing Phantom Ray is an American demonstration stealth unmanned combat air vehicle (UCAV) being developed by Boeing using company funds. The autonomous Phantom Ray is a flying wing around the size of a conventional fighter jet, and first flew in April 2011. It will conduct a program of test flights involving surveillance, ground attack and autonomous aerial refueling missions.[2][3] The developers say it can carry 4,500 pounds (2,040 kg) of payload.[4]