What is Vmc?

Vmc, or Minimum Control Speed with the critical engine inoperative, is an important aerodynamic concept primarily discussed in the context of multi-engine aircraft. It represents the minimum speed at which the airplane can maintain controlled flight with one engine inoperative, meaning that if the aircraft drops below this speed, it may lose control or become difficult to manage.

Understanding Vmc is crucial for pilots because it informs them of the necessary operating speed during critical phases of flight, such as takeoff and climb out, especially if an engine fails. If the aircraft operates below this speed, the asymmetrical thrust from one functioning engine could cause the plane to roll or yaw uncontrollably toward the inoperative engine, which can lead to loss of control.

While other speeds mentioned in the options, such as maximum control speed with one engine inoperative or takeoff decision speed, serve different purposes in flight operations, they do not specifically define the point at which control can be easily maintained with one engine out. Thus, Vmc is fundamentally centered on the ability to maintain control, making the provided answer correct.