Terrain Inhibit

Flying VFR into an area where unique terrain exists could cause the system to annunciate a nuisance alert.

Inhibit TERRAIN-SVS:

While the TERRAIN-SVS Page is displayed, press the INHIBIT Softkey. ‘TER INHB’ is annunciated in the lower right of portion of the screen.

Enable TERRAIN-SVS:

If TERRAIN-SVS has been inhibited, from the TERRAIN-SVS Page press the INHIBIT Softkey. The ‘TER INHB” annunciation is removed.

NOTE: If TERRAIN-SVS alerts are inhibited when the Final Approach Fix is the active waypoint in a GPS WAAS approach, a LOW ALT annunciation may appear on the PFD next to the altimeter if the current aircraft altitude is at least 164 feet below the prescribed altitude at the Final Approach Fix.

Forward Looking Terrain Avoidance (FLTA)

The Forward Looking Terrain Avoidance alert is composed of two sub-functions:

Reduced Required Terrain Clearance (RTC) and Reduced Required Obstacle Clearance (ROC)

This provides alerts when the aircraft flight path is above terrain and/or obstacles, yet is projected to come within minimum clearance values outlined in the following table.

SECTION 10 – HAZARD

AVOIDANCE

When an RTC or ROC alert is issued, a potential impact point is displayed on the TERRAIN-SVS Page as a yellow or red ‘X’.

Imminent Terrain Impact (ITI) and Imminent Obstacle Impact (IOI)

This provides alerts when the aircraft is below the elevation of terrain in the aircraft’s projected path. ITI and IOI alerts are accompanied by a potential impact point displayed on the TERRAIN-SVS Page as a yellow or red ‘X’. The alert is given when the projected vertical flight path is calculated to come within minimum clearance altitudes in the following table.

Phase of Flight	Level Flight	Descending
Enroute	700 ft.	500 ft.
Terminal	350 ft.	300 ft.
Approach	150 ft.	100 ft.
Departure	100 ft.	100 ft.

During the final approach phase of flight, RTC/ROC/ ITI/IOI alerts are automatically inhibited when the aircraft is below 200 feet AGL while within 0.5 nm of the approach runway or is below 125 feet AGL while within 1 nm of the runway.

Unlighted Obstacle	Lighted Obstacle	Unlighted Obstacle	Lighted Obstacle	Potential Impact Points
(Height is less than	(Height is less than	(Height is greater than	(Height is greater than
1000’ AGL)	1000’ AGL)	1000’ AGL)	1000’ AGL)

Figure 10-23 Terrain-SVS Symbols

190-00384-09 Rev. A

Garmin G1000 Cockpit Reference Guide for the Cessna Nav III

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