A Multifunction Control and Display Unit (MCDU), also known as a Multipurpose Control and Display Unit, is a vital component of an aircraft’s Flight Management System (FMS). This device features a keypad and a liquid-crystal display, enabling pilots to input and adjust flight plans easily. Additionally, the MCDU acts as the control head for radios, showcasing important flight data such as fuel consumption, elapsed time, and time remaining. It also allows pilots to enter engine thrust ratings and other critical information. Another key function of the MCDU is facilitating communication via the Aircraft Communications, Addressing, and Reporting System (ACARS).
Typically, an aircraft is equipped with two MCDUs: one for the captain and one for the first officer. These units are usually located in the center console, allowing each pilot to enter data independently. This design enhances safety through redundancy; if one MCDU fails, the other can still operate effectively. The MCDU keypads feature function keys that enable pilots to select different pages for radios, flight plans, aircraft performance, fuel planning, and more. Line select keys on either side of the display allow for specific choices within certain functions, while alphanumeric keys permit data entry.
Although the system architecture may differ by aircraft model, MCDUs typically connect through modular avionics units or similar electronic systems. Communication buses link the MCDUs with air data computers, flight control systems, the FMS, and other aircraft systems, ensuring seamless operation.
