Honeywell MK VI Pilot's Manual page 20

M 4C
ODE
Continued
20
Mode 4C is based on an EGPWS computed MTC floor, that in-
creases with Radio Altitude. It is active after takeoff when the
gear or flaps are not in the landing configuration. It is also active
during a low altitude go-around if the aircraft has descended be-
low 245* feet AGL.
*245 feet if bizjet
170 feet if 170' Mode 4B
is selected
150 feet if 150' Mode 4B
is selected
At takeoff, the MTC is zero feet. As the aircraft ascends, the MTC
is increased to 75% of the aircraft's Radio Altitude (averaged over
the previous 15 seconds). This value is not allowed to decrease
and is limited to the same values as the Mode 4A curve. If the
aircraft radio altitude decreases to the value of the MTC, the EG-
PWS caution light illuminates and the aural message "TOO LOW
TERRAIN" is enunciated. The EGPWS caution lights extinguish
and aural messages cease when the Mode 4C alert envelope is
exited.
Unsafe terrain clearance takeoff turboprop
Unsafe terrain clearance takeoff turbofan (Jet)
060-4314-000 • Rev. C - May 2004
MK VI & MK VIII EGPWS Pilot Guide