HAZARD AVOIDANCE

6.3 TERRAIN PROXIMITY

WARNING: Do not use Terrain Proximity information for primary terrain avoidance. Terrain Proximity is intended only to enhance situational awareness.

NOTE: Terrain data is not displayed when the aircraft latitude is greater than 75° North or 60° South.

NOTE: Terrain Proximity is only available when TAWS is not enabled.

G1000 Terrain Proximity is a non-TSO-C151b-certified terrain awareness system. It increases situational awareness and aids in reducing controlled flight into terrain (CFIT).

Do not confuse Terrain Proximity with Terrain Awareness and Warning System (TAWS). TAWS is more sophisticatedandrobust,anditisTSO-C151bcertified. TerrainProximitydoesnotprovidewarningannunciations or voice alerts. It only provides color indications on map displays when terrain and obstacles are within a certain altitude threshold from the aircraft. Although the terrain and obstacle color map displays are the same, TAWS uses more sophisticated algorithms to assess aircraft distance from terrain and obstacles.

REQUIREMENTS

Terrain Proximity requires the following components to operate properly:

•Valid 3-D GPS position

•Valid terrain/obstacle database

GPS POSITION AND GPS-MSL ALTITUDE

The G1000 GPS receiver provides the horizontal position and altitude. GPS altitude is derived from satellite position. GPS altitude is then converted to a mean sea level (MSL)-based altitude (GPS-MSL altitude) and is used to determine terrain and obstacle proximity. GPS-MSL altitude accuracy is affected by satellite geometry, but is not subject to variations in pressure and temperature that normally affect pressure altitude sensors. GPS-MSL altitude does not require local altimeter settings to determine MSL altitude. It is a widely-used MSL altitude source.

Terrain and obstacle databases are referenced to MSL. Using the GPS position and altitude, the Terrain Proximity feature portrays a 2-D picture of the surrounding terrain and obstacles relative to the position and altitude of the aircraft. GPS position and GPS-MSL altitude are used to calculate and predict the aircraft’s flight path in relation to the surrounding terrain and obstacles. In this way, the pilot can view predicted dangerous terrain and obstacle conditions.

DISPLAYING TERRAIN PROXIMITY DATA

Terrain and obstacle information can be displayed on the following pages:

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• Terrain Proximity Page	• AUX - Trip Planning Page
• Navigation Map	• Flight Plan Pages
• PFD Inset Map

To display terrain and obstacle data on any page other than the Terrain Proximity Page, press the MAP Softkey, then press the TERRAIN Softkey. Obstacles with heights greater than 200 feet above ground level (AGL) are displayed in three color levels (Table 6-6). The G1000 adjusts colors automatically as the aircraft altitude changes.

Terrain Proximity may also be deselected from the Inset Map without affecting the terrain display on the MFD maps.

Obstacles are displayed only at certain map zoom ranges, on certain maps, and will only be displayed if an obstacle database is loaded on the SD card. In addition, all map zoom ranges are dependent on the zoom range setting in the Navigation Map. If the zoom range on the Navigation Map is adjusted to below 20 nm, the highest zoom range on all other maps is also adjusted proportionally.

Table 6-5 shows the map pages and the highest zoom range at which obstacles are displayed.

Map	nm
Navigation Map Page	50
Inset Map	10
Terrain Proximity Page	10
AUX - Trip Planning Page	10
Active Flight Plan Pages	15

Table 6-5 Zoom Ranges for Displaying Obstacle Data

If an obstacle and the projected flight path intersect, the Terrain Proximity Page automatically zooms in to place the potential point of impact on the display.

LIMITATIONS

Terrain Proximity displays altitudes of terrain and obstructions relative to the aircraft position and altitude with reference to a database that may contain inaccuracies. Terrain and obstructions are shown only if they are in the database. Terrain and obstacle information should be used as an aid to situational awareness. They should never be used to navigate or maneuver around terrain.

Note that all obstructions may not be available in the terrain and obstacle database. No terrain and obstacle information is shown without a valid 3-D GPS position.

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TERRAIN PROXIMITY SYMBOLS

The symbols and colors in Figure 6-43 and Table 6-6 are used to represent obstacles and aircraft altitude on the Terrain Proximity Page. Terrain Proximity uses black, yellow, and red to represent terrain information relative to aircraft altitude.

Terrain Above Aircraft Altitude

Aircraft Altitude

100 ft Threshold

1000 ft

Figure 6-43 Terrain Altitude/Color Correlation for Terrain Proximity

The color of each obstacle is associated with the altitude of the aircraft. The color of the terrain also uses these color assignments.

Obstacle Symbol

	Unlighted Obstacle		Lighted Obstacle		Color	Terrain/Obstacle Location
	< 1000’ AGL	> 1000’ AGL	< 1000’ AGL	> 1000’ AGL
						Terrain/Obstacle above or
					Red	within 100’ below the aircraft
						altitude
						Terrain/Obstacle between
					Yellow	100’ and 1000’ below the
						aircraft altitude
						Terrain/Obstacle more than
					Black	1000’ below the aircraft
						altitude

Table 6-6 Terrain Proximity Terrain/Obstacle Colors and Symbology

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TERRAIN PROXIMITY PAGE

The Terrain Proximity Page is in the MAP group of pages and displays the following:

•Current aircraft location

•GPS-derived MSL altitude in increments of 20 feet or 10 meters, depending on unit configuration.

•Range marking rings (360ºView: 1 nm, 1 and 2 nm, 2.5 and 5 nm, 5 and 10 nm, 12.5 and 25 nm, 25 and 50 nm, 50 and 100 nm, 100 and 200 nm) (Arc View: 1 nm, 2 nm, 5 nm, 10 nm, 25 nm, 25 and 50 nm, 25 and 100 nm, 25 and 200 nm)

•Heading Box (North Up, Track Up, DTK Up, HDG Up) - Heading on the Terrain Proximity Page displays ‘HDG Up’ map data unless there is no valid heading

•Terrain

•Terrain Range - Indicates the terrain elevation in colors relative to the aircraft altitude (Table 6-6)

Displaying terrain and obstacles on the Terrain Proximity Page:

1)Turn the large FMS Knob to select the Map Page Group.

2)Turn the small FMS Knob to select the last rectangular page icon.

3)Turn the Joystick clockwise to display a larger area or counter-clockwise to display a smaller area.

There are two terrain/obstacle viewing options available (relative to the position of the aircraft), the 360° default display and the radar-like ARC (120°) display.

Black Terrain (Terrain
More than 1000’
Below the Aircraft
Altitude)		Map Range
Yellow Terrain (Terrain
Between 100’ and
1000’ Below the
Aircraft Altitude)
Red Terrain (Terrain
Above or Within 100’
Below the Aircraft
Altitude)
		Terrain Legend

Figure 6-44 Terrain Proximity Page

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Changing the viewing mode between 360° and ARC:

1)Select the Terrain Proximity Page.

2)Press the VIEW Softkey.

3)Press the 360 or ARC Softkey to select the desired view.

OR:

1)Press the MENU Key. The page menu is displayed with either ‘View Arc’ or ‘View 360º’. Press the ENT Key to change the view.

2)Turn the Joystick clockwise to display a larger area or counter-clockwise to display a smaller area. \

Red Terrain (Terrain

Above or Within 100’ Map Range Below the Aircraft

Altitude)

Yellow Terrain

(Terrain Between

100’ and 1000’

Below the Aircraft

Altitude)

Black Terrain (Terrain

More than 1000’

Below the Aircraft Terrain Legend

Altitude)

Figure 6-45 Terrain Proximity Page (ARC View)

Other aviation information such as airports, VORs, and other NAVAIDS can be displayed on the Terrain Proximity Page.

Showing or hiding aviation information:

1)Press the MENU Key.

2)Select ‘Show (or Hide) Aviation Data’.

3)Press the ENT Key.

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