The MMU is designed to reduce which type of coupling in the flight control system?

• A. Electrical interference
• B. Hydrodynamic stability
• C. Inherent Control Coupling
• D. Mechanical advantage

Answer: (C)

The main idea here is reducing cross-axis interaction in the flight control system so each pilot command produces the intended effect with minimal unintended influence on other axes. The MMU achieves this by carefully mixing and calibrating pilot inputs so that movements of the cyclic, collective, or pedals translate to actuator actions that are as independent as possible. This decoupling minimizes inherent control coupling, which is the unwanted coupling between control axes that can occur due to the mechanical linkages, hydraulic/electrical loops, and aero-dynamic forces acting on the helicopter. In practice, this means smoother, more predictable control responses and easier handling, especially during complex maneuvers.

Electrical interference, hydrodynamic stability, and mechanical advantage aren’t the focus here. EMI is about electrical noise affecting signals, hydrodynamic stability isn’t a factor in the helicopter’s airborne control decoupling, and mechanical advantage relates to force amplification rather than reducing cross-axis coupling in the control system.