System Inputs - Honeywell MK VI Pilot's Manual

System
Inputs
Air Data
Radio
Altitude
060-4314-000 • Rev. C - May 2004
MK VI & MK VIII EGPWS Pilot Guide
The EGPWS uses various input signals from other on-board
systems. The full complement of these other systems is depen-
dent on the EGPWS configuration and options selected. Systems
providing Altitude, Airspeed, Attitude, Glideslope, and position
are required for basic and enhanced functions. Inputs are also
required for discrete signal and control input.
CONTROL/
DISCRETS
INPUTS
AIRCRAFT
AIRCRAFT
PARAMETERS
SENSORS
AND
SYSTEMS
The EGPWS utilizes signals from the following systems:
Uncorrected and corrected Barometric Altitude, Altitude rate,
Computed Airspeed, and Static Air Temperature are provided by
an Air Data system.
Radio Altitude is provided by a Radio Altimeter system. Decision
Height is provided by a Radio Altimeter system or sub-system.
The EGPWS performs Radio Altitude reasonableness checks based
on the Computed Terrain Clearance (pseudo-radio altitude).
Computed Terrain Clearance is computed by subtracting the ele-
vation of the (database) terrain below the aircraft from Geometric
Altitude (ASL). Radio Altitude is considered unreasonable when
it indicates a terrain clearance that is less than the Computed
Terrain Clearance by more than 2000 feet. For example, if the
Computed Terrain Clearance is 10,000 feet and the Radio Alti-
tude is any value (0-2500) then the Radio Altitude is considered
unreasonable. This is only performed if TAD is enabled, high
integrity terrain and position data is available (based on GPS/Geo-
metric Altitude), and the Computed Terrain Clearance is greater
than 4000 feet (2500 feet with version -022 or later).
This feature reduces the potential for nuisance alerts caused by
false tracking of the Radio Altimeter.
AUDIO ALERT
GPWS MESSAGES
ALGORITHMS
AURAL
O
CALLOUTS
I
U
N
T
P
TERRAIN
P
AWARENESS &
U
U
OBSTACLE
T
VISUAL ALERT
T
ALERTING AND
MESSAGES
DISPLAY
P
ALGORITHMS P
R
R
O
O
C
C
E TERRAIN
E
CLEARANCE
S
S
FLOOR
S
S
ALGORITHMS
I
I
N
N
G
G
TERRAIN DISPLAY
WINDSHEAR
DETECTION
AND ALERTING
ALGORITHMS
EGPWC
FLIGHT DECK
SPEAKERS AND
INTERPHONE
ALERT LAMPS
OR EFIS
DISPLAY
EFIS NAV.
DATA DISPLAY OR Wx
RADAR
INDICATOR
41