Available from http://www.cybercom.net/~copters/helo_aero.html. Accessed January, 2010 How Helicopters Work. Available from http://science.howstuffworks.com/helicopter.htm. Accessed January, 2010 Introduction A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine driven rotors . In contrast with fixed-wing aircraft , this allows the helicopter to take off