Region of reverse command
The ‘region of reverse command’, often called the back side of the power curve, is a part of flight where the usual
relationship between power and airspeed reverses. In normal flight, adding power makes the aircraft accelerate
and reducing power slows it down. However, at very low airspeeds and high angles of attack, this relationship
flips: adding power may not increase speed, and reducing power can lead to a sharp loss of performance. This
reversal happens because of how drag changes with airspeed. As an aircraft slows down, it must increase its
angle of attack to maintain lift. A higher angle of attack greatly increases induced drag, which is the drag caused
by producing lift. Induced drag rises rapidly as airspeed decreases, while parasite drag (from the airframe and
fittings) falls with speed. At very low speeds, the rise in induced drag dominates, creating a ‘back side’ of the
drag curve where more power is needed just to maintain level flight.
