> Air resistance goes up by the square of the velocity This is true of form drag. Airplanes are also subject to a somewhat counterintuitive induced drag that i

> Air resistance goes up by the square of the velocity This is true of form drag. Airplanes are also subject to a somewhat counterintuitive induced drag that is inversely proportional to airspeed. The minimum total drag is therefore somewhere between a slow speed and a fast speed. There are three optimal speeds depending on what you're trying to optimize. Maximum range (distance per unit of fuel) is best glide speed, which would be a painfully slow way to get somewhere. Maximum endurance (time per unit of fuel) is roughly max endurance divided by 1.316—even slower. "Optimum cruise," or Carson's speed (max speed per unit of fuel) is roughly max endurance times 1.316.