Final answer:
Vmc, or minimum control speed, is determined by the aircraft manufacturer during design and testing and must meet certification requirements by aviation authorities. Factors such as aircraft weight, center of gravity, and environmental conditions influence Vmc, which is published in the flight manual.
Step-by-step explanation:
Vmc or minimum control speed is a critical performance parameter in aviation, defined as the minimum speed at which an aircraft can maintain controlled flight with one engine inoperative (critical engine in multi-engine aircraft). It is primarily determined by the aircraft manufacturer during the design and testing phases. These tests are accomplished under controlled conditions and are required for certification by aviation authorities, such as the Federal Aviation Administration (FAA) in the United States. Factors that affect Vmc include aircraft weight, center of gravity, altitude, and environmental conditions. Manufacturers publish Vmc in the aircraft's flight manual, which must be adhered to by pilots to ensure safe operation, especially in critical phases of flight like takeoff and landing.