What is cdu?
A CDU, or Control Display Unit, is a small computer screen with a keypad that pilots use in the cockpit to talk to the aircraft’s Flight Management System (FMS). It lets them enter flight plans, check navigation data, and see important information like speed, altitude, and route details.
Let's break it down
- Display screen - shows text‑based menus, maps, and data.
- Keypad/buttons - numbered keys, alphanumeric keys, and function keys for entering data.
- Software interface - the menu system that organizes the FMS functions (flight plan entry, performance calculations, etc.).
- Connection - wired to the aircraft’s central avionics computers, sending and receiving data in real time.
Why does it matter?
The CDU makes it possible for pilots to program the aircraft’s navigation and performance settings quickly and accurately, which reduces manual calculations, cuts down workload, and helps keep flights on the correct route and schedule. It also improves safety by providing clear, up‑to‑date information.
Where is it used?
CDUs are found in most modern commercial airliners (Boeing 737, 777, Airbus A320, A350, etc.), many business jets, and some advanced military aircraft. Any plane that has a sophisticated Flight Management System will typically include a CDU.
Good things about it
- User‑friendly: menu‑driven interface is easy to learn for pilots.
- Efficiency: speeds up flight‑plan entry and updates.
- Accuracy: reduces human error in calculations.
- Integration: works seamlessly with other avionics (autopilot, navigation radios).
- Flexibility: can be reprogrammed for different routes, performance data, and airline procedures.
Not-so-good things
- Complexity: the menu system can be overwhelming for new pilots.
- Reliance on electronics: a CDU failure can limit FMS functionality, requiring manual backup procedures.
- Cost: high‑tech hardware and software add to aircraft purchase and maintenance expenses.
- Training required: pilots need specific training to use all features correctly.