Introduction to Glider Flying > Aerodynamics of Flight > Forces of Flight > Parasite Drag > Interference drag

Interference drag occurs when varied currents of air over a glider meet and interact. Placing two objects adjacent to one another may produce turbulence 50 per-cent to 200 percent greater than the parts tested sepa-rately. An example of interference drag is the mixing of air over structures, such as the wing, tail surfaces, and wing struts.