minicar: I would like to build an mini UAV which can be fly without using the electrical energy. I wonder which aerofoil profile should i choose? Thank you in advance.Sellecting the suitable aerofoil profile for mini UAV which fly without using electrical power?without electrical power-- do you mean using a diesel engine?The airfoil is critically dependent on a host of factors, such as the total weight, the desired stall speed, the desired takeoff run, the desired cruising altitude, the desired rate of climb, the size of the operating envelope, the desired amount of resistance to wing icing, the placement of the engines, the location of the fuel tanks, whether there will be flaps, the placement of the landing gear, the construction methods, the materials of construction, whether it will be a stressed skin or space frame design, how many hours do you want the wing to last, etc, etc, etc...