Page 17-18
Section III Sub-section 17
AVIONICS
P/N 140-590032-0007
Revision A4: Sep, 2010
Pilot’s Operating Manual
EGPWS Operating Modes
There are 7 modes of operations:
Mode
Operational Envelope
MODE 1
Excessive Descent Rate
Alert/Warning
This mode is active for all phases of flight when the radio altimeter
indicates between 10 and 2450 ft AGL. The mode envelope identifies
the minimum radio altitude permitted based on a given descent rate.
If the airplane flight profile goes into the alert envelope, the EGPWS
PULL UP annunciator illuminates and the "SINKRATE" voice warning is
heard. If the airplane flight profile goes into the warning envelope, the
PULL UP annunciator stays on and the voice warning changes to a
continuous "PULL UP".
Upon going out of the Mode 1 envelope, the voice message stops and
the PULL UP annunciator extinguishes.
MODE 2
Terrain Closure Rate
Warning
This mode is active for all phases of flight and airplane configurations.
The Mode 2 warning envelope changes with airplane speed and
configuration and has two sub-modes:
• Mode 2A is active when the flaps are in any position other than
landing and the airplane is not on the glideslope centerline.
• Mode 2B is active when the flaps are in the landing position or when
ILS is in use and the airplane is on the glideslope with less than 2
dots deviation.
When the airplane flight profile goes into either the Mode 2A or 2B
envelope, the PULL UP annunciator illuminates and the "TERRAIN
TERRAIN" voice warning sounds. After the "TERRAIN TERRAIN"
warning, one of three results will occur:
1. If the airplane flight profile goes out of the warning envelope, no
additional warnings are generated and the PULL UP annunciator
extinguishes.
2. If the flight profile stays in the warning envelope and the flaps or gear
are not in the landing configuration, a continuous "WHOOP
WHOOP" tone and "PULL UP" message is heard until the airplane
goes out of the Mode 2 warning envelope.
3. If the flight profile stays in the warning envelope and the flaps and
gear are in the landing configuration, the "TERRAIN TERRAIN"
message continues until the airplane goes out of the Mode 2
warning envelope.
Upon going out of the Mode 2 warning envelope, the voice messages
stop and the PULL UP annunciator extinguishes.
