Here's an edited question asked by an AOPA member who contacted our aviation services staff through the AOPA Pilot Information Center. Test your knowledge.
Question: What are three types of parasite drag?
Answer: They are form drag, interference drag, and skin friction drag. Form drag is generated by airflow around the shape of the aircraft. Interference drag occurs when two or more airstreams intersect; eddys are created, which restrict smooth airflow. For an example of interference drag, consider airflow over the wing root meeting airflow over the fuselage. Skin friction drag is caused by moving air coming into contact with the surface of an aircraft. Refer to Chapter 4 of the Pilot's Handbook of Aeronautical Knowledge for more information.