060-4241-000 • Rev. D - March 2000
MK V & MK VII EGPWS Pilot Guide
tween 245 feet at 159 knots to 1000 feet at 250 knots.
Below 245 feet AGL and less than 159 knots airspeed, the Mode
4B aural alert is "TOO LOW FLAPS". For turboprop and select
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 MTC,
the EGPWS caution illuminates and the aural message "TOO
LOW TERRAIN" is enunciated.
For either Mode 4B alert, subsequent alert messages occur only
if penetration of the envelope increases by 20%. 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 continuously until the Mode 4B
envelope is exited.
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.