How it works: Meet the primary flight display

In a six-pack the attitude indicator is top row center. It’s prominent in a PFD as well; in fact, the horizon line stretches all the way across the colorful display. In the center, markers show your pitch up and down, and your angle of bank.

The airspeed indicator is just to the left of the attitude indicator in a six-pack, and it’s the same in a PFD. Instead of a needle on a round dial, however, the airspeed is displayed vertically in a tape format. And just like on a round dial, a white arc indicates your flap operating range; the green arc is your normal operating range; yellow indicates your maximum airspeed in rough air; and red is your never-exceed airspeed. As a bonus, many PFDs also calculate and display your true airspeed.

To the top right of a six-pack is the altimeter, and below it is the vertical speed indicator. Their functions are combined in the area of the PFD just to the right of the attitude indicator. Closest to the center, a vertical tape displays your altitude in feet above mean sea level. To the right of that a pointer shows your rate of climb or descent.

Below the round-dial attitude indicator and to the left of the vertical speed indicator is the heading indicator. Yes, you’re picking up on a theme here—on the PFD, the same information is just below the attitude information. The little airplane on this horizontal situation indicator, basically a heading indicator on steroids, is you; your current heading is shown directly above, both numerically and on a compass rose. The HSI also incorporates navigation information; a magenta line indicates a GPS course and blue denotes VHF navigation such as a VOR or ILS. The display shows the active navigation source.

Just below the digital heading readout is the turn rate indicator. As you turn left or right, a turn rate vector will appear. Your slip/skid indicator is found at the top of the attitude indicator display.

The accompanying video shows the building-block nature of the digital PFD.