What do Boeing 737 PFD and navigation display symbols mean?
Understand Boeing 737 PFD and navigation display symbols, colours, FMA modes, route cues, ILS guidance, traffic, terrain and common faults.
In real-world aviation and accurate Boeing 737 simulations, the primary flight display (PFD) shows attitude, speed, altitude, vertical speed and flight-guidance modes. The navigation display (ND) shows route, track, waypoints, weather, terrain and traffic. Magenta generally marks commanded guidance; green, white, amber and red indicate other states or alert levels.
The exact presentation differs between the 737 Classic, Next Generation and MAX, as well as between airline options and simulator add-ons. The descriptions below match the modern EFIS layout associated mainly with the 737NG and 737 MAX; the core meanings remain similar across those variants.
What do the display colours mean?
Colour identifies the role or urgency of information, but its meaning depends on where it appears. In particular, magenta guidance is not proof that an autopilot mode is active—the flight mode annunciator determines that.
| Colour | Usual meaning on a 737 display |
|---|---|
| Magenta | Selected targets, flight-director commands, the active FMC route and other commanded guidance. |
| Green | Active flight modes, engaged systems, valid status information and some tuned radio-navigation data. |
| White | Scales, labels, present aircraft information and armed flight modes. Pending route modifications may also be white or dashed on some installations. |
| Cyan | Background map information, selectable navigation symbols or ADF data, depending on the display standard. |
| Amber | A caution, operating limit, degraded condition or information requiring prompt attention. |
| Red | A warning or immediate hazard, including resolution-advisory traffic and certain speed or terrain threats. |
What do the Boeing 737 PFD symbols mean?
The PFD combines the aircraft's immediate flight state with the targets and commands being generated by the mode control panel, flight director and flight management computer.
| PFD area or symbol | Meaning |
|---|---|
| Blue and brown attitude sphere | Blue represents sky and brown represents ground. The horizon line, pitch ladder and bank scale show pitch and roll attitude. |
| Fixed aircraft symbol | Represents the aeroplane against the moving attitude background. It is not the same as the flight-path vector. |
| Magenta command bars | Flight-director steering commands. Pitch or bank to place the aircraft symbol on the bars when manually following the flight director. |
| Flight-path vector | An optional circular symbol showing where the aircraft is actually travelling relative to the horizon. It can differ from the nose attitude during a climb, descent, sideslip or strong crosswind. |
| Airspeed tape | Indicated airspeed appears on the left. It can include a magenta selected-speed bug, acceleration trend, V-speed labels, flap manoeuvre references and coloured low- or high-speed limits. |
| Altitude tape | Pressure altitude appears on the right, with the MCP-selected altitude marked in magenta. The barometric setting, minimums and radio altitude near the ground may appear nearby. |
| Vertical-speed scale | Shows climb or descent rate. A selected vertical speed is displayed when V/S mode is being used. |
| Heading and track scale | Shows the aircraft's heading or track across the bottom of the PFD. Wind makes track differ from heading. |
| Slip/skid indication | The small marker associated with the bank pointer shows lateral balance, broadly serving the role of a conventional slip indicator. |
| Localiser and glideslope pointers | Deviation pointers show the position of the ILS localiser and glideslope relative to the aircraft. A centred pointer means the relevant beam is centred. |
The speed and altitude bugs show selected targets, not necessarily what the aircraft will achieve. For example, a selected altitude above the aircraft does not command a climb unless an appropriate pitch mode is active.
What do the flight mode annunciations mean?
The flight mode annunciator, or FMA, tells you what the autothrottle, roll and pitch systems are actually doing. It occupies the top of the PFD and should be checked after every autopilot, flight-director or MCP mode selection.
| FMA section | Common labels | What it controls |
|---|---|---|
| Autothrottle | N1, MCP SPD, FMC SPD, THR HLD, RETARD, ARM | Thrust or speed control. |
| Roll | HDG SEL, LNAV, VOR/LOC, ROLLOUT | Lateral guidance and bank commands. |
| Pitch | V/S, ALT ACQ, ALT HOLD, VNAV SPD, VNAV PTH, VNAV ALT, G/S, FLARE | Vertical path, speed-through-pitch and altitude control. |
An active mode is normally green; an armed mode waiting to capture is normally white beneath it. A temporary box around a new annunciation draws attention to a mode change. The lower FMA area can show autopilot or flight-director status such as CMD, FD or SINGLE CH, with autoland annunciations varying by installation.
A mistake we see constantly is watching the magenta route or flight-director bars while overlooking the FMA. If LNAV or a VNAV mode is only armed—or absent—the aeroplane is not yet following that mode. Our guide to diagnosing 737 LNAV and VNAV engagement problems explains the usual capture and arming conditions.
What do the Boeing 737 navigation display symbols mean?
The ND places the aircraft within its horizontal navigation picture and combines FMC routing with heading, radio-navigation, traffic and hazard information.
| ND symbol or feature | Meaning |
|---|---|
| White aircraft symbol | Present aircraft position. In MAP mode the display is normally track-up, while PLAN mode presents the route north-up. |
| Compass scale and magenta heading bug | The compass shows heading around the display; the bug marks the heading selected on the MCP. |
| Track line and trend vector | The track line shows movement over the ground. A segmented trend vector predicts the developing turn using the present bank and groundspeed. |
| Solid magenta route | The active FMC route and active leg. It is a planned path, not confirmation that LNAV is engaged. |
| White or dashed route | Usually an unexecuted route modification or inactive routing, although the exact style varies between avionics versions and simulator aircraft. |
| Waypoint symbols and labels | FMC fixes and selectable map waypoints. The active waypoint's identifier, distance and estimated arrival information normally appear near the top of the ND. |
T/C, T/D and path markers | FMC predictions such as top of climb and top of descent. They move when winds, route, speed, altitude or performance data change. |
| VOR and ADF bearing pointers | Point towards the tuned station when selected and received. A common convention uses green for VOR and cyan for ADF, with source identifiers near the lower corners. |
| Range rings | Provide distance references based on the selected ND range. A symbol can disappear simply because it is outside the displayed range. |
| Wind, GS and TAS readouts | Show wind direction and speed, groundspeed and true airspeed. These are different from the indicated airspeed on the PFD. |
The route comes from the FMC, including every leg, waypoint and discontinuity. If the line is broken or takes an unexpected detour, use the 737 FMC route-building and discontinuity workflow rather than trying to correct it with the heading selector alone.
What do the ND modes change?
The mode changes the presentation, not the aircraft's actual navigation source or autopilot mode.
- MAP: The normal forward-looking route view, usually track-up, with FMC and selectable overlay information.
- PLAN: A north-up overview used to inspect the route, commonly centred on a waypoint selected through the FMC LEGS pages.
- VOR: A compass-rose presentation focused on VOR bearing and course-deviation information.
- APP: A compass-rose presentation intended for approach guidance, especially localiser deviation.
- CTR: Where fitted or available, centres the aircraft in a full compass presentation instead of placing it near the lower edge.
How are ILS symbols shown on the 737 PFD?
The localiser pointer moves across a horizontal deviation scale, while the glideslope pointer moves on a vertical scale beside the attitude display. A pointer to the right means the localiser course lies to the right; a glideslope pointer above centre means the glidepath is above the aircraft.
Before capture, VOR/LOC and G/S normally appear armed in white. They turn green when captured. The rising-runway symbol may appear close to the ground on a valid ILS, but it is supplementary guidance rather than a substitute for the main localiser and attitude indications.
The complete sequence—from tuning and identifying the ILS to reading the capture annunciations—is covered in our practical 737 ILS intercept and capture procedure.
What do weather, terrain and traffic symbols mean?
These overlays use colour for separate purposes, so a red weather return does not mean the same thing as a red TCAS or terrain symbol.
| Overlay | Typical interpretation |
|---|---|
| Weather radar | Green, yellow and red generally represent increasing precipitation reflectivity. Some radar installations use magenta for detected turbulence. Tilt set too low can paint the ground; tilt set too high can miss precipitation. |
| Terrain | Green, yellow and red depict terrain relative to the aircraft and its threat level, not ordinary chart elevation colours. The thresholds change with the terrain-warning system's operating phase. |
| Other traffic | Usually a hollow white or cyan diamond. A filled diamond commonly indicates proximate traffic. |
| Traffic advisory | An amber circle identifies traffic requiring immediate attention. |
| Resolution advisory | A red square identifies an RA threat. Vertical guidance or avoid zones also appear on the PFD vertical-speed indication where supported. |
Traffic labels give relative altitude in hundreds of feet, with a plus or minus sign showing whether the target is above or below. An adjacent arrow indicates that the target is climbing or descending beyond the system's threshold.
Why are PFD or ND symbols missing?
A missing symbol usually means its source, display layer or operating condition is unavailable—not that the display has necessarily failed.
- No magenta route: Select MAP or PLAN, adjust the range, activate and execute the FMC route, resolve route discontinuities and confirm that the inertial system has aligned.
- Route visible but LNAV not steering: Check the FMA for green
LNAV. The aircraft may be outside a sensible intercept, the route may be discontinuous, or LNAV may only be armed. - No ILS pointers: Verify the correct ILS frequency and front course, signal reception, navigation source and approach type. RNAV approaches do not produce an ILS signal. Our explanation of where to verify ILS frequency and course data helps separate bad setup from a display fault.
- No VOR or ADF pointer: Check the EFIS bearing selector, tuned frequency, station reception and source identification.
- No weather returns: Confirm that weather radar is selected and adjust range, tilt and gain. Cloud without enough precipitation may produce little or no return.
- No traffic symbols: Check the transponder and TCAS mode, traffic filter and ND range. Some simulators do not feed all multiplayer or generated traffic into TCAS.
- Blank heading or map: The IRS may still be aligning, its position may not have been initialised, or the display source may be invalid.
Flags such as attitude, heading, airspeed, altitude, localiser or glideslope warnings mean that the associated data is invalid or disagrees between sources. Do not interpret a blank indication as zero. In a simulator, confirm the aircraft's power, IRS alignment and source selectors before assuming the add-on is broken; in an actual aircraft, the operator's approved procedures and manuals take precedence.
What should you scan first?
A disciplined scan separates actual aircraft state from selected targets and planned guidance.
- Read the FMA: Confirm which autothrottle, roll and pitch modes are active and which are merely armed.
- Check attitude, speed and altitude: These show what the aircraft is doing now.
- Compare the selected bugs: Verify MCP speed, heading and altitude against the intended clearance or procedure.
- Cross-check raw guidance: Use localiser, glideslope or radio-navigation deviation rather than relying only on flight-director bars.
- Inspect the ND: Confirm the correct route leg, track, range, waypoint and relevant weather, terrain or traffic overlays.