3D Connexion GNS 530(A) Premature Descent Alerting, Is displayed in the Terrain annunciator field

SECTION 12

TERRAIN

Premature Descent Alerting TERRAIN Inhibit

A Premature Descent Alert (PDA) is issued when the system detects that the aircraft is significantly below the normal approach path to a runway (Figure 12-5).

PDA alerting begins when the aircraft is within 15 nm of the destination airport. PDA alerting ends when the aircraft is either:

•0.5 nm from the runway threshold

OR

•at an altitude of 125 feet AGL while within 1.0 nm of the threshold.

TERRAIN also has an inhibit mode that deactivates the FLTA/PDA visual alerts. Pilots should use discretion when inhibiting TERRAIN and always remember to enable the system when appropriate.

Inhibiting TERRAIN:

1)Select the TERRAIN Page and press the MENU Key. ‘Inhibit Terrain?’ is selected by default (Figure 12-6).

Height Above Terrain (Feet)

700
600																		Figure 12-6 TERRAIN Page Menu
500																		2) Press the ENT Key. The ‘TER INHB’ annunciation
400																		is displayed in the TERRAIN annunciator field
300																		when TERRAIN is inhibited (Figure 12-7).
																		Annunciator Field
200								“Too		Low			Terrain”
100
Runway	1	2	3	4	5	6	7	8	9		10	11		12	13	14	15
Threshold				Distance From Destination Airport (nm)														Figure 12-7 Annunciator Field
			Figure 12-5			PDA Alerting Threshold												Enabling TERRAIN:
																		1) Select the TERRAIN Page and press the MENU
																		Key. ‘Enable Terrain?’ is selected by default.

2) Press the ENT Key. The TERRAIN system is functional again.

190-00181-00 Rev. E GNS 530(A) Pilot’s Guide and Reference 12-7