Gliders & Sailplanes
Gliders are planes that do not typically have any type of propulsion. Unpowered glider flight must be sustained through exploitation of the natural lift produced from thermals or wind hitting a slope. Dynamic soaring is another popular way of providing energy to gliders that is becoming more and more common. However, even conventional slope soaring gliders are capable of achieving speeds comparable with similar sized powered craft. Gliders are typically partial to slow flying and have high aspect ratio, as well as very low wing loading (weight to wing area ratio). Two and three-channel gliders which use only rudder control for steering and dihedral or polyhedral wing shape to automatically counteract rolling are popular as training craft, due to their ability to fly very slowly and high tolerance to error.