Multi-Engine Airplanes
Minimum Controllable Airspeed (Vmc)
V_mc is the minimum airspeed at which, after the sudden critical loss of thrust, it is possible to maintain control of the airplane. It is marked with a red radial line on the airspeed indicator.
Note that there is no requirement that the airplane be capable of climbing at this airspeed. VMC only addresses directional control such that the aircraft can maintain heading.
Best Rate of Climb Speed (Vyse)
The best rate of climb speed with one engine inoperative (OEI). Marked with a blue radial line on most airspeed indicators. Above the single-engine absolute ceiling, VYSE yields the minimum rate of sink