Therefore, before downloading any materials for use, you need to ask permission. So far, we have discussed only induced drag. There are also skin-friction drag and form drag, which are referred to as parasite drag. All drag other than induced drag is parasite drag. Skin-friction drag is caused by the friction between outer surfaces of the aircraft and the air through which it moves.
Form drag is also a resistance to the smooth flow of air.
Streamlining the aircraft will help eliminate form drag. Parts of an aircraft which do not lend themselves to streamlining are enclosed either partially or wholly in covers called fairings which have a streamlined shape. All rights reserved worldwide.