Mini-X Installation, Setup & User Manual GRT Avionics
Revision A9 37
4.11 Angle of Attack (AOA) Installation and Calibration
Sensed AOA Installation
The sensed version of the angle of attack option uses a two-port pitot tube, such as the Garmin
GAP-26 heated pitot probe. If a heated probe is not required, a dual port pitot probe may be
fabricated by mounting a second pitot tube, bent downward at approximately a 60 degree angle,
as shown here.
When using a dual-port pitot tube, a pressure connection (typically using the same tubing and
hardware used for the pitot connection) is made from the AOA port on the pitot tube, to the AOA
port (center port on the pitot/static block on the rear of the instrument.
Calculated AOA Installation
No installation is required, as the angle of attack is computed from the AHRS pitch attitude, true
airspeed, and vertical speed. Note that this method, although not requiring any sensors or
additional pressure connections, degrades in accuracy while in rising or falling air.
Calibration of the AOA (Calculated and Sensed)
When in flight, in smooth air and at a sufficient altitude to safely stall the airplane, select the Set
Menu, Primary Flight Display. Near the end of this menu, set “Angle of Attack (AOA)” to “ON”. New
settings will appear below this setting when set to ON. We recommend setting “Pitch Limit Indicator”
to “ON”, following this setting is “AOA Pitch Offset”. Change this setting to activate the calibration
process, and follow the on-screen prompts. The prompts will include a step where you fly the
