The stalling speed or the minimum steady flight speed at which the aeroplane is controllable in landing configuration is abbreviated as:

The term for the stalling speed or the minimum steady flight speed at which the aeroplane is controllable in the landing configuration is indeed abbreviated as VS0. This speed is critical because it defines the lowest speed at which the aircraft can maintain controlled flight while in the landing configuration, which typically includes flaps extended and landing gear down.

Understanding VS0 is essential for pilots as it ensures that during landing approaches and final approaches, they do not inadvertently decrease speed to a point where the aircraft may stall. This measurement in a specific configuration helps pilots manage airspeed effectively during crucial phases of flight such as landing and short approaches.

Other options refer to different concepts: VS1 is the stalling speed in a specified configuration, usually at a specified weight, which is greater than VS0. VS is the general term for stalling speed but does not specify the configuration. VMC refers to the minimum control speed with an inoperative engine, which is a different aspect of flight characteristics. Each of these speeds serves a different purpose and understanding their distinctions is vital for safe and effective flying.