What are the main sources of parasitic drag in an aircraft?

The main sources of parasitic drag in an aircraft are form drag, skin friction, and interference drag.

Form drag arises from the shape of the aircraft and the way air flows around it. When an aircraft moves through the air, it displaces air, creating a difference in pressure between the front and rear surfaces, which contributes to the overall drag experienced.

Skin friction is related to the surface texture of the aircraft; as air flows over the surface, it encounters friction. This type of drag increases with altitude and speed and is influenced by the smoothness or roughness of the aircraft's skin.

Interference drag occurs when different airstreams meet, particularly at the junctions of various parts of the aircraft, such as where the wings connect to the fuselage. This can disrupt the smooth flow of air and add to the overall drag.

Understanding these sources is crucial for aircraft design and performance optimization, as reducing parasitic drag can lead to increased efficiency and better fuel economy.