What is VMC in Aviation? (Minimum Control Speed With Critical Engine Out)

Aviation is a complex field that requires detailed knowledge of various terminologies and procedures. One such important term is the Minimum Control Speed with Critical Engine Out, commonly known as VMC. VMC is a crucial value for pilots to know and understand, as it directly impacts the safe operation of an aircraft in the event of an engine failure. In this article, we will delve deeper into what VMC is, how it is calculated, and its significance in aviation.

Understanding Minimum Control Speed with Critical Engine Out (VMC)

The Minimum Control Speed with Critical Engine Out (VMC) is defined as the minimum speed at which an aircraft can maintain controlled flight, with the critical engine inoperative, and the aircraft’s remaining engines operating at their maximum available thrust. It represents the boundary between controllability and loss of control.

VMC depends on various factors, including aircraft weight, configuration, atmospheric conditions, and altitude. It is typically lower at lower altitudes due to the denser air, allowing for better control, while higher altitudes may require higher VMC values.

Pilots must be aware of VMC to ensure the safe operation of an aircraft in case of an engine failure during takeoff or low altitude flight. Crossing below VMC in such scenarios can lead to uncontrollable yaw and roll, potentially resulting in a loss of control. Therefore, it is essential for pilots to have a thorough understanding of VMC and its implications on aircraft performance and safety.

Calculating VMC

The calculation of VMC involves several factors. One primary factor is the Center of Gravity (CG) position of the aircraft. VMC is typically higher when the CG is closer to the rear limit, as this configuration causes more adverse yaw.

Other factors influencing VMC include the selected configuration of the aircraft (gear and flaps), power settings, and prevailing environmental conditions such as temperature and pressure altitude.

Several aircraft manufacturers provide VMC charts specific to their aircraft models, which pilots can reference for accurate calculations. These charts consider the aforementioned factors and provide the corresponding VMC values for different weights and configurations.

It is important to note that VMC is specific to each aircraft type and should be recalculated for any changes in weight, configuration, or prevailing conditions. Pilots must consult their aircraft’s operating manual or refer to the manufacturer’s documentation for precise VMC values relevant to their particular aircraft.

The Significance of Minimum Control Speed with Critical Engine Out

VMC plays a critical role in determining the aircraft’s performance and safety in the event of an engine failure. It is a key parameter that directly affects the aircraft’s controllability and the pilot’s ability to maintain control during critical phases of flight.

Knowing the VMC for a specific aircraft allows pilots to make informed decisions during takeoff, approach, and landing, considering the risks associated with an engine failure. It helps them maintain control of the aircraft at or above VMC, reducing the likelihood of entering an uncontrollable situation.

Furthermore, VMC also influences the selection of the appropriate bank angle during an engine failure. Pilots must ensure they maintain a bank angle within the manufacturer’s guidelines to prevent rolling due to asymmetrical thrust.

By understanding VMC and its significance, pilots can better prepare themselves for potential engine failure situations and take the necessary actions to maintain control, enhancing overall flight safety.


The Minimum Control Speed with Critical Engine Out (VMC) is a crucial value in aviation that determines the aircraft’s ability to maintain control in the event of an engine failure. Pilots should always be aware of the VMC specific to their aircraft to ensure the safe operation of the aircraft, especially during takeoff, approach, and landing.

By calculating VMC accurately and considering the factors that influence it, pilots can make informed decisions and take the necessary actions to minimize the risks associated with engine failures. VMC serves as a vital reference point for maintaining control and preventing the onset of uncontrollable yaw and roll.

It is crucial for pilots to stay up-to-date with their aircraft’s operating manual and the manufacturer’s documentation to obtain the precise VMC values relevant to their specific aircraft. By doing so, pilots contribute to the overall safety and efficiency of aviation operations.

For More: What is IFE in Aviation? (In-Flight Entertainment)