Mini-X Installation, Setup & User Manual GRT Avionics
Revision A9 90
8.5.3 Pitch Limit Indicator
When enabled on the PFD settings page, the pitch limit indicator appears on the PFD screen when the
angle-of-attack is less than 8 degrees from stall, and goes away when the angle of attack more than 9
degrees from stall. The indicator moves downward toward the nose or bars pitch indicator as the angle
of attack increases. Stall will occur approximately when this indicator is on the nose or bar pitch indicator.
This indicator will be limited to 30 degrees pitch to prevent chasing a pitch limit that could temporarily
be at a very high pitch angle due to high airplane speed.
The pitch limit indicator was originally created to give pilots a maximum pitch angle reference when
performing a windshear escape maneuver. While this may be of little use for the typical experimental
aircraft pilot, it provides a visual representation of the proximity to stall. This data also appears on the
wearable HUD smart glasses.
WARNING: The use of this indication is purely at the judgment of the pilot. The accuracy of this
information is affected by EFIS sensor errors and the accuracy of the calibration procedure. The
EFIS calculation of angle-of-attach, and the pitch limit indicator should not be used as the only
stall warning instrument.
8.5.4 Audio Stall Warning
For versions of the GRT EFIS that include an audio output, an audio alert is provided as stall is approached.
This alert begins as a beeping tone that transitions to a solid tone as the AOA approaches the stall AOA
programmed during the AOA calibration procedure.
