Plain English Meaning

VMC is the slowest speed at which a pilot can still keep a twin-engine airplane flying straight after one engine quits. The 'derivation' is simply the list of conditions and design factors used to figure out that speed, so the same number is determined the same way for every airplane.

Full Definition

The set of aerodynamic and design factors that determine the published minimum control airspeed (VMC) for a multi-engine airplane with one engine inoperative. VMC is established under specific certification conditions: the critical engine failed and windmilling, the operating engine at takeoff power, flaps in the takeoff position, retracted, the airplane for , at the most unfavorable (rearward) , and the airplane with . Under these conditions, VMC is the lowest at which can using and no more than 5 toward the operating engine, while within 20 degrees of the original.