Learn what flight director commands mean, how to follow pitch and roll cues, verify active modes, and fix misleading or missing command bars.
A flight director calculates the pitch and bank needed for selected guidance modes, then shows the commands as bars or a cue on the attitude indicator or primary flight display. It does not move the controls: in manual flight, you pitch and roll until the aircraft reference symbol is centred on the cue.
In real-world aviation and flight simulation, the principle is the same. The flight director uses targets and navigation data selected by the pilot, but it cannot decide whether those settings are correct, safe or consistent with an ATC clearance.
What the flight director actually controls
Its job is to convert an active lateral mode and vertical mode into immediate attitude commands. The director continually recomputes the required bank and pitch as the aircraft responds.
Those commands may come from a heading bug, altitude selector, navigation radio, GPS/FMS route, ILS or air-data system. Our explanation of how navigation systems generate lateral and vertical guidance covers what feeds the director in more detail.
| Selected mode | What the director commands | Common mistake |
|---|---|---|
HDG | A turn towards the selected heading | Moving the heading bug while another lateral mode remains active |
NAV or LOC | Intercept and tracking of the selected navigation source | Selecting the wrong GPS, FMS, VOR or localiser source |
VS or FLC | Pitch guidance for a selected vertical speed or airspeed | Setting an altitude without selecting a climb or descent mode |
ALT | Pitch changes needed to hold the captured altitude | Assuming an armed altitude mode is already controlling pitch |
APP, LOC or GS | Approach-course and vertical-path guidance where available | Trying to capture with unsuitable geometry or incorrect tuning |
Mode names and behaviour vary between aircraft. Switching on the flight director may engage basic pitch and roll modes automatically, but it does not necessarily activate the heading, navigation or altitude mode you intended.
How do I follow flight director commands?
Set up and verify the guidance modes before trying to centre the command bars.
- Stabilise and trim the aircraft. Establish a sensible attitude, airspeed and power setting first. Starting while badly out of trim encourages large corrections and oscillation.
- Select the navigation source and targets. Set the heading, course, altitude, vertical speed or speed required for the manoeuvre. Confirm the active flight-plan leg if using GPS or FMS guidance.
- Turn on the flight director and select the modes. Choose one lateral mode and one vertical mode appropriate to the task. Setting a target alone usually does not activate guidance towards it.
- Read the flight-mode annunciator. Check which modes are active and which are merely armed. The labels and colours vary, so read the words rather than relying on colour memory; our A320 PFD and flight-mode annunciator walkthrough shows where this information appears in a typical airliner.
- Fly towards the cue. On a conventional cross-pointer display, pitch towards the horizontal bar and bank towards the lateral displacement. If the pitch bar rises above the aircraft symbol, raise the nose; if the roll cue moves right, bank right. With a V-bar or single-cue display, fit the aircraft symbol into the command cue.
- Reduce the input as the cue centres. Do not chase the bars with abrupt control movements. Ease off pitch or roll as the symbols align, then trim away sustained control pressure.
- Cross-check the result. Monitor attitude, airspeed, altitude, vertical speed and track. The flight director normally does not control thrust, so manage power yourself unless a separate autothrottle system is active.
The flight-mode annunciator is the real authority: it explains why the bars are moving. A mistake we see constantly is following a plausible-looking command while the aircraft is still in a basic pitch mode or tracking the wrong navigation source.
What is the difference between a flight director and autopilot?
The flight director displays guidance; the autopilot uses servos to move the controls and follow that guidance automatically.
With the autopilot disconnected, you manually fly the command bars. With it engaged, monitor the modes and flight path rather than trying to move the controls yourself. Depending on the aircraft, overriding the controls may fight or disconnect the autopilot. We explain the relationship in our guide to autopilot servos, selected modes and flight-director guidance.
Some systems can operate the autopilot without visible command bars, while others automatically enable one or both flight directors when the autopilot is engaged. Autothrottle is separate again: an autopilot may control pitch and bank while leaving thrust entirely to the pilot.
Why are the command bars missing or pointing the wrong way?
Missing or misleading flight director bars usually indicate a configuration, mode or input problem rather than a faulty display.
- No command bars: Check that the correct flight director is on, the avionics are powered and a compatible guidance mode is selected. In advanced simulator add-ons, a generic keyboard binding may not operate the aircraft's custom avionics.
- Wrong-direction guidance: Verify the heading bug, selected navigation source, course, active flight-plan leg and any route discontinuity. The director faithfully follows incorrect inputs.
- No localiser or glideslope capture: Confirm that the mode is armed, tuning and course are correct, and the aircraft is within a suitable intercept. Glideslope capture is normally arranged from below.
- Unexpected climb or descent: Recheck the selected altitude, vertical mode, pressure setting and units. Look for an automatic transition from an armed mode to an active capture mode.
- Oscillating around the bars: Use smaller inputs, stabilise and trim. In a simulator, also calibrate the controller and remove duplicate pitch or roll axis assignments.
When should I stop following the flight director?
Stop following it whenever the commands conflict with the clearance, expected route, known aircraft position or a safe attitude and airspeed.
Maintain control, establish a safe basic attitude, manage power and then correct the source, target or selected mode. During visual or raw-data flying, turn the flight director off if its unused cues are becoming a distraction. In a real aircraft, follow the approved procedure and instructor or operator guidance rather than troubleshooting through unsafe flight conditions.