PFD Explained: The Screen Pilots Actually Fly

Modern flight decks can look overwhelming at first.

There are screens, numbers, tapes, colours, symbols, modes and alerts everywhere. But when it comes to flying the aircraft, one display does most of the heavy lifting: the Primary Flight Display, or PFD.

In this guide, we will break down the Primary Flight Display using an Airbus-style PFD as an example. We will look at the Flight Mode Annunciator, speed, altitude, heading, attitude indication and pressure setting — all neatly packed into one screen.

Instrumentation: Latest ATPL Exam Questions ExplainedPractise how PFD, EFIS, flight instruments and display-system concepts appear in real ATPL-style exam questions.

What is a Primary Flight Display?

A Primary Flight Display, or PFD, is the pilot’s main electronic reference for flying the aircraft. It is part of the Electronic Flight Instrument System, or EFIS, where flight information is shown on electronic displays rather than traditional electromechanical instruments.

Most PFD layouts follow the same basic logic. The attitude indicator sits in the centre, because aircraft attitude is the foundation of instrument flying. The airspeed scale is usually on the left, while altitude and vertical speed are shown on the right. The heading or track is normally displayed along the bottom.

Across the top of the display, pilots can also see automation information, including flight director, autopilot and autothrust modes. This part is especially important in modern aircraft, because the pilot must always know what the aircraft is doing and what the automation is commanding.

The exact layout depends on the aircraft type and manufacturer. Still, the purpose stays the same: to reduce workload, improve situational awareness and help the pilot build a clear picture of the aircraft’s current flight path.

Six-Pack Basics: Your Guide to Primary Flight InstrumentsReview the traditional flight instruments behind the modern PFD, including attitude, airspeed, altitude, heading and vertical speed.

Flight Mode Annunciator

The Flight Mode Annunciator, or FMA, sits at the top of the Primary Flight Display.

This is where the pilot checks what the aircraft automation is doing right now. It shows the active and armed modes for autothrust, vertical guidance, lateral guidance, approach capability and auto flight status.

In the Airbus-style PFD example, the FMA is divided into clear columns.

The first column shows the autothrust mode. This tells the pilot how thrust is being managed. For example, the display may show whether speed, Mach or thrust is being controlled automatically.

The next column shows the vertical mode. This tells the pilot how the aircraft is being guided up or down. It may relate to climb, descent, altitude capture, vertical speed, or glide slope tracking during an approach.

The next column shows the lateral mode. This tells the pilot how the aircraft is being guided sideways. It may show navigation tracking, heading mode, localiser capture or another lateral guidance mode.

The approach capability area shows the aircraft’s current landing capability. In the example, CAT 3 DUAL indicates a high-level automatic approach and landing capability, with the required systems available.

On the right side, the auto flight status shows which autopilots, flight directors and autothrust systems are active. This helps the pilot confirm whether the aircraft is being hand-flown, flight-director guided, or autopilot controlled.

The rows also matter.

Row 1 shows the engaged modes. These are the modes active right now. Row 2 shows armed modes. These are ready to become active when conditions are met. Row 3 may show messages or reminders.

The FMA is a mode awareness tool. It is not enough to select something on the flight control panel. The pilot must confirm it on the FMA.

Pitot Tube 101: How Your Airspeed Indicator WorksGo deeper into the system behind airspeed indication, including pitot pressure, static pressure and common airspeed errors.

Speed, Altitude and Heading

The PFD places the main flight references around the attitude indicator.

On the left side, you normally see the airspeed tape. This shows the aircraft’s current indicated airspeed. Instead of a round dial, the speed is presented as a vertical scale, with the current value marked clearly.

The speed tape also shows important speed references and limits. These may include the maximum airspeed limit, the lowest selectable speed, and protection speeds such as alpha protection. This is important because speed is never just one number. The pilot needs to know whether the aircraft is safely within the operating range, too slow, too fast, or approaching a protection threshold.

On the right side, you normally see the altitude tape. This shows the aircraft’s current altitude. The selected altitude is also displayed, so the pilot can compare where the aircraft is now with where it has been cleared or programmed to go.

Next to the altitude tape, the vertical speed indicator shows whether the aircraft is climbing or descending, and at what rate. This helps the pilot confirm the aircraft’s vertical trend. For example, the altitude may look correct, but the vertical speed may show that the aircraft is still climbing or descending.

At the bottom of the display,you can read heading and track. The heading shows where the aircraft nose is pointing. The track shows the actual path over the ground. These two values are not always the same, especially when there is wind.

In some phases of flight, the PFD also shows radio altitude. This is the aircraft’s height above the terrain directly below, measured by the radio altimeter. It becomes especially important close to the ground, during approach and landing.

The key point is that these references should not be read separately. Speed, altitude, heading, track and vertical speed all work together.

Know Your Airspeed: From Indicated to True A useful next read if you want to understand IAS, TAS, CAS and why the speed shown on the PFD is only one part of the picture.

Attitude Indicator

The attitude indicator sits in the centre of the Primary Flight Display.

This is the main visual reference for the aircraft’s attitude relative to the horizon. It shows whether the aircraft is level, climbing, descending, banking left or banking right.

The blue area represents the sky. The brown area represents the ground. The line between them is the artificial horizon. The aircraft symbol stays fixed in the middle. The horizon moves around it. This helps the pilot see the aircraft’s pitch and bank at a glance.

The pitch scale shows the aircraft’s nose-up or nose-down attitude. On the Airbus-style display, pitch values are marked above and below the horizon line.

The bank scale sits above the attitude indicator. It shows the angle of bank during a turn. The bank pointer moves along this scale, helping the pilot monitor roll attitude.

The flight directors are also displayed over the attitude indicator. These guidance bars show the pitch and roll commands needed to follow the selected flight path. If the pilot is hand-flying, the aim is to follow the flight director cues smoothly.

This is an important point. The flight director does not show where the aircraft is going. It shows what the guidance system is asking the pilot or autopilot to do.

The display may also show a sideslip indicator or beta target, depending on the aircraft state and conditions. This helps the pilot monitor lateral balance, especially in abnormal situations such as asymmetric thrust.

During an approach, the PFD can also show vertical guidance, such as the glide slope deviation scale. This helps the pilot see whether the aircraft is above, below or on the required descent path.

For pilots, the attitude indicator remains the heart of the PFD. Before checking anything else, you need to know the aircraft’s basic attitude: pitch, bank and flight path guidance.

Altitude Basics: 5 Types of Altitude ExplainedReview pressure altitude, indicated altitude, true altitude and radio altitude — all essential for understanding what the PFD is really showing.

Pressure Setting

The pressure setting is shown on the PFD near the altitude scale. It tells the pilot which barometric reference the altimeter is using to calculate altitude. This is a small part of the display, but it matters a lot.

At lower levels, pilots usually use QNH. QNH sets the altimeter so it reads altitude above mean sea level. This is the setting used for departure, arrival and approach when operating below the transition altitude or transition level.

In the cruise, pilots usually use STD, or standard pressure. Standard pressure is 1013.25 hPa. It is used when flying at flight levels, so all aircraft in the same airspace use the same reference.

The pressure setting does not change the aircraft’s real height. It changes the reference used by the altimeter. If the setting is wrong, the displayed altitude can be wrong too.

That is why pilots must check the pressure setting carefully. A wrong QNH or a late change from QNH to STD can affect altitude awareness and vertical separation.

On the Airbus-style PFD example, the selected altitude is shown near the altitude tape. The barometric reference is shown lower on the display. Together, they help the pilot confirm two things: the altitude target and the pressure reference being used to read altitude.

How Pilots Scan the PFD

The scan usually starts with attitude. Is the aircraft level, climbing, descending or banking? This is the quickest way to understand what the aircraft is doing.

Then comes airspeed. The pilot checks the current speed, speed trend and limits. Is the aircraft stable, slowing down, speeding up, or approaching a protection speed?

Next, the pilot checks altitude and vertical speed. The altitude tape shows where the aircraft is now. The selected altitude shows where it is expected to go. The vertical speed indicator confirms whether it is climbing, descending or levelling off.

The scan then moves to heading, track and navigation guidance. Heading shows where the nose points. Track shows where the aircraft is actually moving over the ground. Deviation scales show whether it is on the required lateral or vertical path.

The Flight Mode Annunciator is also part of the scan, especially after any autopilot, flight director or autothrust change. The pilot confirms what is engaged, what is armed, and what the aircraft will do next.

During approach, the scan becomes more focused: speed, localiser, glide slope, altitude, radio height, flight directors, landing capability and auto flight status all need to agree.

In simple terms:

Attitude shows what the aircraft is doing. Speed and altitude show whether it is stable. Heading and deviations show where it is going. The FMA shows what automation is commanding.

Common Student Mistakes About the PFD

A common mistake is treating the PFD as just an electronic version of the old “six-pack” instruments. It is more than that. The PFD combines attitude, airspeed, altitude, vertical speed, navigation deviation, radio height, flight director guidance and automation information in one place.

Another common mistake is ignoring the Flight Mode Annunciator. During an auto-coupled approach, the aircraft’s landing capability is checked on the FMA. It is not guessed from the autopilot panel alone.

Students also confuse engaged and armed modes. Engaged modes are active now. Armed modes are ready to become active when the right conditions are met.

The vertical speed indication can also catch students out. On a modern PFD, the VSI is usually shown as a vertical scale next to the altitude tape, not as a separate round instrument.

Navigation indications are another exam trap. Localiser and glide slope deviation pointers may appear on the PFD during an approach. They show whether the aircraft is left or right of the localiser, and above or below the glide slope.

Radio height is easy to miss too. The PFD can show radio altitude close to the ground. This is different from barometric altitude, which depends on the pressure setting.

Students may also misread the flight director. It does not show the aircraft’s actual path. It shows guidance commands for the pilot or autopilot to follow.

Unreliable airspeed questions require careful thinking. The indication may involve flags, warnings, disagreeing speed sources, abnormal aircraft behaviour, or unusual speed trends.

HUD questions are also linked to PFD knowledge. A Head-Up Display can repeat key flight information while allowing the pilot to keep looking outside. It supports the PFD scan, but does not replace understanding the PFD.

The main exam lesson is simple: know what the PFD shows, where it appears, and what each indication means.

Want to practise real ATPL Instrumentation questions? Open the Airhead ATPL Question Bank and test how well you understand PFD indications, EFIS displays and flight deck instruments.