Mode 4C - Honeywell EGPWS MK V Pilot's Manual

MODE 4B Below 245 feet AGL and less than 159 knots (185 knots for
Boeing 747-8) airspeed, the Mode 4B aural alert is "TOO
Continued
LOW FLAPS". For turboprop and selected turbofan aircraft,
the "TOO LOW FLAPS" warning curve is lowered to 150
feet AGL and less than 148 knots.
If desired, the pilot may disable the "TOO LOW FLAPS"
alert by engaging the Flap Override switch (if installed). This
precludes or silences the Mode 4B flap alert until reset by the
pilot.
If the aircraft's Radio Altitude decreases to the value of the
Minimum Terrain Clearance (MTC), the EGPWS caution
illuminates and the aural message "TOO LOW TERRAIN"
is enunciated.
For either Mode 4B alert, subsequent alert messages occur for
each 20% degradation in altitude. EGPWS caution lights
extinguish and aural messages cease when the Mode 4B alert
envelope is exited.
If the Aural Declutter
feature is disabled, mode
4B alert messages are
repeated
until
envelope is exited.

MODE 4C

The Mode 4C alert is intended to prevent inadvertent
controlled flight into the ground during takeoff climb into
terrain that produces insufficient closure rate for a Mode 2
alert. After takeoff, Mode 4A and 4B provide this protection.
System Description
16
Mark V and Mark VII EGPWS Pilot's Guide
continuously
the Mode 4B
060-4241-000
Rev H, August 2011