Electronic Attitude Director Indicator (EADI)

The Electronic Attitude Director Indicator lies at the very heart of the T-6/A Texan II's EFIS system and is the primary navigation aid used by T-6 pilots when flying. The EHSI and EADI make up the core of the EFIS system.

EADI Composite Mode

In composite mode, the EADI is displayed with an Compass Rose and CDI needle overlayed on top to aid in primary navigation should either the EADI or EHSI display screen fail.

The images below show the EADI in VOR and GPS controlled composite mode. This is one of the more common modes used for primary navigation and displays a great deal of information at a glance for the pilot.

EFIS Composite Mode can be toggled on or off using the 'CMP' button on the bottom left of either display.

The top left shows the following information;

• Distance in nautical miles from the aircraft to the navigation source (NAV1).
• Current indicated airspeed of the aircraft.
• Estimated time of arrival at the current navigation source.

The top right shows the following information;

• Current navigation course heading set by the pilot in the EFIS system.
• Current heading set by the pilot in the EFIS system.

EADI in VOR composite mode

The images below show the EADI in GPS mode. This is one of the more common modes used for primary navigation and displays a great deal of information at a glance for the pilot.

The top left shows the following information;

• Distance in nautical miles from the aircraft to the next GPS waypoint (GPS).
• Current indicated airspeed of the aircraft.
• Estimated time of arrival at the current GPS waypoint.

The top right shows the following information;

• Current Direct To (DTK) heading set by the GPS system.
• Current heading set by the pilot in the EFIS system.

EADI in GPS composite mode

EADI Enroute Mode

The image below shows the EADI in the standard mode often seen during flying and is similar in design to most attitude indicators. The bottom of the display shows the rate of turn gauge.

EADI during standard flight

If however, you enter an unusual attitude such as +/- 65° degrees bank or +30° / -20° pitch, the display will alter to show the unusual attitude display as indicated in the image below;

EADI during 'unusual attitude' mode

As you can see, the attitude ladder has changed format and the EADI now has a bank pipper displayed for orientation.

When the aircraft returns to a pitch orientation of less than 25° up or 15° down and the bank angle is less than 60°, the normal EADI presentation will reappear.

During very high pitch angles, the display will alter once more to show a number of red recovery chevrons. The red chevrons are used to indicate the nearest direction for a level attitude recovery and are displayed between 40° and 85º nose low and between 50° and 85º nose high

EADI during 'unusual attitude' mode with recovery chevrons

EADI Localiser Mode

When in Localiser Approach mode, the EADI changes to display the following items (as shown in the images below);

• Lateral deviation scale
• Selected course (CRS)
• Selected heading (HDG)
• Selected NAV sensor
• TO/FROM information
• Distance Information

For ILS glidepath, a stationary vertical scale is displayed on the right side of the display and marker beacon information is displayed on the EADI (if
being received).

• Outer marker in blue
• Middle marker in amber
• Inner Marker in white

EADI in localiser mode with EHSI localiser mode underneath

Please see the EHSI page for more information on EHSI approach modes.

Failure Annunciations

If the Attitude Indicator fails, the display will show ATTITUDE FAILURE as shown below.