aircraft climbs above a predetermined altitude (defined for the
aircraft type). Because of the nature of this type of G/S
Cancel, a cockpit indication of its activation is required.
Some aircraft may be configured with a G/S inhibit switch.
This switch is separate from the one discussed above but also
results in inhibiting Mode 5 alerting. This switch is intended
for selection during back course approaches to eliminate
unwanted alerts that may result. If a discrete back course
signal is available from another system, this input to the
EGPWC may be connected to that system for automatic Mode
Note: Implementation of the Glideslope Cancel and/or
Inhibit inputs to the EGPWS varies. Verify a particular
application to determine the implementation used.
Pressing the Terrain Inhibit switch inhibits TAD and TCF
alerting and display, including Obstacles and Peaks when
enabled. This is used when position accuracy is inadequate or
when operating at airports or runways not in the terrain
database. Selection of Terrain Inhibit does not cause the
Terrain Inoperative annunciation unless the aircraft is wired
for this to occur. Terrain Inhibit requires manual deactivation.
The EGPWS Flap or Gear Over-ride, TAD/TCF Inhibit, or
other switches (as installed) may be used as required for an
emergency situation (e.g., landing gear up).
For additional information refer to an applicable AFM or
EGPWS AFMS or contact Honeywell.
Mark V and Mark VII EGPWS Pilot's Guide
Rev H, August 2011