Which unit connects the Auto Flight system with navigation and performance data?

The Multifunction Control Display Unit (MCDU) is integral to the A320's Auto Flight system because it is the primary interface for pilots to access and input various navigation and performance data. It allows for the input of flight plans, performance calculations, and activates different phases of flight management, making it essential for coordinating the Auto Flight system with operational data.

The MCDU acts as the communication bridge between the flight crew and the aircraft's systems, ensuring that the Auto Flight system utilizes the correct navigation data for flight management. This interaction is crucial for the aircraft's automation capabilities, enabling precise guidance and control during different stages of flight.

Other units, such as the Primary Flight Display, serve primarily to present flight information to the pilots, and the Navigation Display Unit focuses on visualizing navigational data rather than managing it. Similarly, the Flight Control Unit plays a role in managing the flight control surfaces but does not directly interface for navigation data. Thus, the MCDU stands out as the key unit that connects the Auto Flight system with necessary navigation and performance data.