Technical data

Product Specification
HIF-2121/R5 CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 965-1176-601 REV: D SHEET 88
LOCAL TERRAIN
PROCESSING
SURFACE TERRAIN,
OBSTACLE, AND
AIRPORT DATABASES
TERRAIN THREAT
DETECTION AND
DISPLAY PROCESSING
Altitude (MSL)
Flight Path Angle
Ground Speed
AUDIO OUTPUT
TERRAIN DISPLAY
OUTPUT
PROCESSOR
(DSP)
Range Scales #1,2
Terrain Display
Selects #1,2
DISPLAY CONTROL
LOGIC
Display Override
and Range Control
Display Config.
External Display Switching
Display #1
Display #2
Wx Display Bus #1
Wx Display Bus #2
Local Terrain and
Obstacle Data
(Overlay Format)
EGPWS
Input
Processing
and Signal
Selection
rng scale #1
rng scale #2
Predictive
Windshear Alerts
Aircraft Position
Aircraft Heading
Aircraft-dependent Inputs
Terrain Display Bus #1 Terrain Display Bus #2 Terrain Status (ARINC-429)
Terrain
Display Data
Aircraft Position
Aircraft Position
Nearest Runway
Data
LAMP OUTPUTS
External LRU Interface
(Optional EGPWS Display)
Aircraft Heading
Pop-Up Enable
Wx/TERR Select/Pop-up-Display #1
Wx/TERR Select/Pop-up-Display #2
Ground Track
Altitude Rate
Roll Attitude
FIGURE 6.7-1: TERRAIN AWARENESS FUNCTIONS
6.7.1.2 Aircraft Data Inputs
Aircraft position latitude and longitude are required for Terrain Awareness operation and are preferably received from an
aircraft Global Positioning System (GPS) or an optional internal GPS-PXPRESS card. Refer to section 6.7.10 for more detail
on position source selection.
Additionally, aircraft ground track and ground speed data are also received from the GPS.
Aircraft altitude for the Terrain Awareness functions is computed from pressure altitude and SAT received from the Air Data
Computer (ADC), altitude from the GPS, and height above ground provided by the computed Geometric Altitude (see section
6.7.8.). Other aircraft inputs include aircraft heading, and flight path angle (gamma, derived by the EGPWC).