How does the center of gravity (CoG) position affect VMCG/A?

The center of gravity (CoG) position significantly influences the aircraft's performance characteristics, particularly during takeoff, which is relevant when discussing minimum control speeds (VMCG and VMCG/A).

When the CoG is positioned further aft (towards the tail), the aircraft's stability and control can be affected. An aft CoG typically results in a higher VMCG/A because the aircraft is more sensitive to changes in control inputs, making it harder to maintain directional control in the event of an engine failure during takeoff. The nose of the aircraft tends to lift more easily, which can lead to a reduced effective control authority on the aircraft’s vertical stabilizer, requiring a greater airspeed to maintain control.

This is critical because VMCG/A is the minimum speed at which the aircraft can maintain directional control with one engine inoperative. Therefore, with an aft CoG, pilots need to reach a higher speed to safely maintain control, which directly correlates to the higher VMCG/A required. Understanding this relationship helps in safe aircraft operation and performance calculations during takeoff and ensures pilots can react appropriately in the event of an engine failure.