Avidyne IFD540 Pilot's Manual page 100

Each unique FLTA alert will generate a new Master Caution lamp
illumination (flashing yellow or red "AUX" Page Function key), a
new CAS message, a new aural alert, and display the elliptical
solid yellow/red coloration on the maps.
Each unique FLTA alert can be acknowledged by touching the
CAS message or pressing the "CLR" function key on the right
edge of the IFD which turns off the Master Caution lamp flashing,
the CAS message and the aural alert. The FLTA
acknowledgment does not turn off the solid red or yellow
coloration on the maps.
It is possible to have multiple terrain and obstacle FLTA caution
and warning conditions at the same time. However, the CAS
visual alerts and associated aural alerting will only honor the
highest priority alert. The priority order is Terrain Warning,
Obstacle Warning, Terrain Caution, Obstacle Caution.
FLTA aural alerts repeat every 6 seconds for the duration of the
alert condition or until acknowledged/muted by the pilot.
There is a rectangular suppression area for all runways in the
FMS database. Terrain and obstacles inside this suppression
area will not generate any FLTA alerts. Dimensions of the FLTA
runway suppression area are 2.0 nm laterally and 4.0 nm off each
runway end when runway orientations are known or a circle with
a radius of 1 nm centered on the Airfield Reference Point (ARP)
when the on-board databases do not know the runway
orientations. Note that for airfields with multiple runways, this may
have the effect of looking like several irregular shapes around the
airfield. If the aircraft position or the aircraft flight path projected
impact point is anywhere within that runway suppression area, no
FLTA alert will be generated. Obstacle threat bubbles can still
appear inside the suppression area.
FLTA alerts are inhibited if any of the following conditions are
met:
 FLTA is manually turned off via the pilot-accessible "User
Options" LSK on the "SETUP" tab of the AUX page
(generates a "FLTA OFF" top datablock strip message);
 The ownship position is inside the rectangular (or circular,
in the case of no known runway orientation) FLTA Inhibit
3-24 Map Pages