Mark V and Mark VII EGPWS Pilot's Guide
If overboost is required, adjust throttles back to maximum
rated thrust as soon as safety has been assured.
Overboosting engines while at high angle of attack near
airplane stall may cause engine stall, surge, or flameout.
Maintain escape attitude and thrust and delay retracting flaps
or landing gear until safe climb-out is assured.
Partial system deactivation or compensation can be
accomplished for abnormal procedures as follows:
If steep approaches are to be performed (4º or greater)
EGPWS STEEP APPROACH should be enabled and selected
for these operations. This may be accomplished automatically
by on-board systems or manually selected by a cockpit switch.
When active, Mode 1 alerts are desensitized to compensate for
normally higher descent rates for these types of operation,
eliminating related unwanted alerts. If implemented with a
cockpit switch, this requires manual deactivation.
When required to operate in close proximity to terrain (less
than 2500' above), Mode 2 alerts can be desensitize or
overridden by activating the FLAP OVER-RIDE switch to
eliminate related unwanted alerts. This requires manual
Mode 4 alerts can be reduced by activation of the FLAP
OVER-RIDE switch, or GEAR OVER-RIDE. This is
generally recommended when performing approaches with
less than normal landing flaps selected, or landing gear not
down. This requires manual deactivation.
Mode 5 Glideslope alerts can be manually canceled when
below 2000 feet Radio Altitude (or 1000 feet dependant on
aircraft type) by pressing the G/S Cancel switch (commonly
part of the amber caution annunciators "BELOW G/S" or
"GPWS"). This is typically selected when an unreliable
Glideslope is expected or when maneuvering is required
during ILS final approach. The G/S Cancel is automatically
reset following landing or if the aircraft climbs above the
2000 or 1000 feet dependant on aircraft type.
In some cases, an Alternate G/S Cancel is available. This
allows the Mode 5 alerting to be canceled at any time and any
altitude. In this configuration, which is defined only for
certain aircraft types or by program pin, pressing the G/S
Cancel switch in the cockpit has the effect of inhibiting Mode
5 alerting. It can be manually reset by again pressing the G/S
Cancel switch, or it is automatically reset following landing, if
flap or gear state changes (i.e., down to up), or when the
Rev H, August 2011