•Parasite drag is due to air coming in contact with non lifting components of the helicopter. Examples: cabin, rotor mast, tail, and landing gear, openings for engine cooling

 

•This drag is present any time the helicopter is moving

 

•It increases with airspeed. (Whenever the airspeed doubles parasite drag increases approximately 400%....its exponential)

 

•Fairings (Body coverings) reduce parasite drag by turning a surface into a more aerodynamic shape

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•Parasite Drag has 2 sub categories form drag and skin friction

 

      –Form drag results from the wake caused by the separation of airflow from the              surface of a structure

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      –The amount of drag is related to the size and shape of the structure that                      protrudes into the relative wind

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     –Skin friction is caused by surface roughness. Even though the surface appears             smooth, it may be rough when viewed under a microscope. A thin layer of air clings       to the rough surface, creates small eddies