3D Connexion GNS 530(A) Shows system status annunciations that may also be issued, Alert Type

SECTION 12

TERRAIN

Table 12-3 shows system status annunciations that may also be issued:

Alert Type		TERRAIN Page	Pop-Up Alert
		Annunciation
TERRAIN System Test Fail			None
TERRAIN Alerting is disabled			None
No GPS position or excessively degraded			None
GPS signal
System Test in progress			None
System Test pass		None	None
	Table 12-3 Additional System Annunciations

Forward Looking Terrain Avoidance

The Forward Looking Terrain Avoidance (FLTA) alert is used by TERRAIN and is composed of:

•Reduced Required Terrain Clearance (RTC) and Reduced Required Obstacle Clearance (ROC) -These alerts are issued when the aircraft flight path is above terrain, yet is projected to come within the minimum clearance values in Table 12-4. When an RTC or ROC alert is issued, a potential impact point is displayed on the TERRAIN Page.

•Imminent Terrain Impact (ITI) and Imminent Obstacle Impact (IOI) - These alerts are issued when the aircraft is below the elevation of a terrain or obstacle cell in the aircraft’s projected path. ITI and IOI alerts are accompanied by a potential impact point displayed on the TERRAIN Page. The alert is annunciated when the projected vertical flight path is calculated to come within minimum clearance altitudes in Table 12-4.

During the final approach phase of flight, FLTA alerts are automatically inhibited when the aircraft is below 200 feet AGL while within 0.5 nm of the approach runway or below 125 feet AGL while within 1.0 nm of the runway threshold.

	Phase of Flight		Minimum Clearance	Minimum Clearance
			Altitude Level Flight (ft)	Altitude Descending (ft)
	Enroute		700	500
	Terminal		350	300
	Approach		150	100
	Departure		100	100
	Table 12-4 Minimum Terrain and Obstacle Clearance Values for FLTA Alerts
12-6		GNS 530(A) Pilot’s Guide and Reference			190-00181-00 Rev. E