3D Connexion GNS 530(A) manual Forward Looking Terrain Avoidance, Pop-Up Alert Aural Message

SECTION 13

TAWS

Table 13-3 shows system status annunciations that may also be issued:

Alert Type	TAWS Page	Pop-Up Alert	Aural Message
	Annunciation
TAWS System Test Fail		None	“TAWS System Failure”
TAWS Alerting is disabled		None	None
No GPS position or excessively degraded		None	“TAWS Not Available”
GPS signal			“TAWS Available” is generated when sufficient
			GPS signal is re-established.
System Test in progress		None	None
System Test pass	None	None	“TAWS System Test OK”
	Table 13-3 Additional System Annunciations

Forward Looking Terrain Avoidance

The Forward Looking Terrain Avoidance (FLTA) alert is used by TAWS 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 13-4. When an RTC or ROC alert is issued, a potential impact point is displayed on the TAWS 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 TAWS Page. The alert is annunciated when the projected vertical flight path is calculated to come within minimum clearance altitudes in Table 13-4.

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 13-4 Minimum Terrain and Obstacle Clearance Values for FLTA Alerts

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.

13-6 GNS 530(A) Pilot’s Guide and Reference 190-00181-00 Rev. E