Define Vmc and Vmca in a typical light twin, and explain how weight and altitude influence them.

Define Vmc and Vmca in a typical light twin, and explain how weight and altitude influence them.

• A. Vmc is the maximum takeoff speed; Vmca is the stall speed; both decrease with weight.
• B. Vmc is the minimum speed for maintaining directional control with the critical engine failed; Vmca is the minimum control speed with the non-operating engine failed. Both increase with higher weight and higher altitude and are affected by bank angle, power setting, and configuration.
• C. Vmc and Vmca are identical speeds unaffected by weight or altitude.
• D. Vmc is the minimum speed for straight-and-level flight with all engines operating; Vmca is the minimum speed for turning with one engine inoperative.

Answer: (B)