Definition
The processing unit of a flight director system that receives inputs from the air data computer, attitude and heading sources, navigation receivers, and the mode controller, then calculates the pitch and bank steering commands needed to fly a selected flight path. Its output drives the command bars (or cue) on the attitude indicator and, when coupled, supplies the same steering signals to the autopilot.
Plain English
The 'brain' behind the flight director. It takes information about the aircraft's position, attitude, and the route or approach you've selected, then works out how the airplane should be pitched and banked to follow it. It sends those instructions to the steering bars on your attitude indicator and, if the autopilot is engaged, to the autopilot too.
Context Anchor
Seen in instrument flying when learning how flight director guidance symbols are produced and shown on the cockpit instruments.
Derivation
Flight director' captures the function — directing the pilot or autopilot how to fly — and 'computer' identifies it as the processing box that does the calculating. The name describes the role: it is the component that decides what the steering commands should be.
Why Pilots Care
It reduces pilot workload during instrument procedures by providing immediate visual steering guidance instead of requiring constant manual calculations of course and path deviations.
Intuition Check
Do not picture the flight director computer as something that flies the airplane by itself. It calculates and displays guidance; the pilot or autopilot still follows, monitors, or rejects that guidance.
Example Sentence 1
When the pilot selected the approach mode, the flight director computer began generating pitch and bank commands to capture and track the localizer.
Example Sentence 2
During the missed approach the pilot followed the cues generated by the flight director computer to track the published climb heading.