Why Is Flying a Drag?

Drag is the force of resistance an aircraft "feels" as it moves through the air. There are several kinds of drag: friction, pressure, and vortex drag, and, in supersonic flight, shock wave drag. But all are caused by friction and air pressure differences.

Why Is Pressure a Drag?
Why Is Friction a Drag?
Why Are Whirls off the Wing Tips Also a Drag?


(Rev. 09/26/96)