Parasite drag is best described as which of the following?

• A. A type of drag caused by lift
• B. Drag caused by interference
• C. Drag due to friction only
• D. A type of drag that acts on an object moving through a fluid

Answer: (D)

Parasite drag is the portion of drag that does not come from generating lift. It arises from the aircraft’s surfaces and shape moving through air, including skin friction (the shear of air rubbing against the surface), form drag (pressure differences around the body), and interference drag where surfaces meet. It increases with speed because it’s tied to how the air flows around and over the surface, not to the energy used to create lift.

This description fits best because it captures that parasite drag is a type of drag experienced by an object moving through a fluid and is not tied to lift production. Drag caused by lift describes induced drag, which is produced by the generation of lift. Interference drag is a component of parasite drag, not the whole concept. Friction alone neglects form and interference effects, so it’s incomplete.