Three friends in south-west Germany have built a remarkable aircraft that looks similar to a yoga balance ball surrounded by 16 model helicopters. The 16-rotor E-volo can hover motionless without pilot input, be steered by a simple joystick, and is powered solely by Lithium ion batteries. One of the machine's engineers, Thomas Senkel, took the craft on its first manned flight this week which lasted 1 minute 30 seconds. Check it out at Mail Online.