Vmca criteria specify that rudder forces must not exceed what value?

• A. 50 kg
• B. 75 kg
• C. 100 kg
• D. 125 kg

Answer: (B)

Vmca is the speed at which the airplane must remain controllable with one engine inoperative, and part of that control requirement is how much rudder input the pilot has to apply to maintain straight flight. The design sets a practical ceiling on the rudder load so a pilot can realistically hold the aircraft on a coordinated path without excessive effort. The specified limit is 75 kg of rudder force, which corresponds to about 165 pounds of push/pull on the rudder pedals. This ensures there’s enough rudder authority to counteract asymmetric thrust, while keeping pilot workload within reasonable bounds. Values lower than this would be unnecessarily restrictive, and higher values would risk loss of controllability if the rudder input needed exceeds what a pilot can apply.