Airplane An engine-driven vehicle that can fly through the air supported by the action of air against its wings. Airplanes are heavier than air, in contrast to vehicles such as balloons and airships, which are lighter than air. Airplanes also differ from other heavier-than-air craft, such as helicopters, because they have rigid wings; control surfaces, movable parts of the wings and tail, which make it possible to guide their flight; and power plants, or special engines that permit level or climbing flight.