Technical data

Product Specification
HIF-2121/R5 CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 965-1176-601 REV: D SHEET 22
1.3.2 Terrain and Obstacle Awareness
A major feature of the EGPWS is the Terrain and Obstacle Awareness alerting and display functions. These functions use
aircraft geographic position, aircraft altitude and a terrain and obstacle database to predict potential conflicts between the
aircraft flight path and the terrain, and to provide graphic displays of the conflicting terrain or obstacle, as illustrated by the
block diagram, Figure 1.3.2-1.
TERRAIN
CLEARANCE
FLOOR
ALGORITHM
AIRPORT
POSITION
DATABASE
TERRAIN/OBSTACLE
ELEVATION
DATABASE
TERRAIN/OBSTACLE
AWARENESS
ALERTING
ALGORITHMS
DISPLAY
ALGORITHMS
AIRCRAFT
POSITION DATA
(LAT/LNG)
GROUND TRACK
BAROMETRIC
ALTITUDE
GROUND SPEED
VERTICAL SPEED
TERRAIN/OBSTACLE
CAUTION ALERT
TERRAIN/OBSTACLE
WARNING ALERT
DISPLAY DATA
ROLL ATTITUDE
FIGURE 1.3.2-1: TERRAIN & OBSTACLE AWARENESS FUNCTIONS
The MKVIII EGPWS includes a Global Terrain Database, which provides the ability to fly between regions without loss of
Terrain Awareness coverage. The MKVI EGPWS includes a Regional Terrain Database, which is one of three regions (see
Figure 1.3.2-2,3,4). Use of a MKVI EGPWS outside of the loaded Regional Terrain Database will result in the Terrain
Awareness function being unavailable.
The MKVIII EGPWS allows selection between runways greater than 3,500 feet and greater than 2,000 feet. Certain business
jet aircraft require longer runways for operation.