For human beings, true flight is possible only with the aid of mechanical devices. These include balloons, airships, airplanes and helicopters. Human-powered flying machines are possible but difficult to make practical because of the high power-to-weight ratio required to make powered flight possible.
Human beings have developed many means of gliding, from hang gliders to wingsuits. However, true human-powered flight requires a human to be able to generate enough forward-thrust to maintain flight. Most human-powered flying machines have been built in attempts to win engineering prizes. They are not practical for recreational or commercial use. A 2012 video, purporting to show a man taking off unassisted with a homemade flapping wing device, turned out to be a hoax.