Which of the following is NOT one of the four mechanical mixes provided by the MMU?

• A. Collective to Pitch
• B. Collective to Roll
• C. Pitch to Roll
• D. Yaw to Pitch

Answer: (C)

The MMU mixes are set up to couple pilot inputs to rotor control along four specific paths: collective to pitch, collective to roll, yaw to pitch, and yaw to roll. These mixes let a pilot influence the helicopter’s attitude and heading without introducing unwanted cross-coupling beyond what's designed. A cross-coupling from pitch to roll would mean pitch input directly drives roll, which isn’t one of the MMU’s configured mixes. So pitch to roll isn’t provided, making it the correct choice as the option that’s NOT part of the four mechanical mixes.