Cockpit Reference Guide

Garmin G1000 Cockpit Reference Guide for the Cessna Nav III
190-00384-12 Rev. A
10-36
SECTION 10 – HAZARD
AVOIDANCE
The system test may also be initiated manually,
but only when the aircraft is on the ground. To
manually verify proper operation of the aural and visual
annunciations of the system, perform the following steps.
1) While the TAWS-B Page is displayed, press the
MENU Key.
2) Turn the small FMS Knob to select ‘Test TAWS’.
3) Press the ENT Key. During the test ‘TAWS TEST’ is
displayed in the center of the TAWS-B Page.
When all is in working order, “TAWS System Test,
OK” is heard.
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. When an RTC or ROC alert is issued, a
potential impact point is displayed on the TAWS-B 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 TAWS-B 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.
Table 10-12
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.
Premature Descent Alert (PDA)
A Premature Descent Alert is issued when the system
detects that the aircraft is significantly below the normal
approach path to a runway. The PDA alert mode functions
only during descent to land.
PDA alerting begins when the aircraft is within 15 nm
of the destination airport and ends when the aircraft is
either 0.5 nm from the runway threshold OR is at an alti-
tude of 125 feet AGL while within 1 nm of the threshold.
During the final descent, algorithms set a threshold for
alerting based on speed, distance, and other parameters.
Excessive Descent Rate Alert (EDR)
The purpose of the Excessive Descent Rate alert is to
provide suitable alerts when the aircraft is determined
to be closing (descending) upon terrain at an excessive
speed. EDR alerts have two levels of severity, caution
(sink rate) and warning (pull-up).
Negative Climb Rate After Takeoff Alert (NCR)
The purpose of the Negative Climb Rate After Takeoff
alert is to provide suitable alerts to the pilot when the
system determines that the aircraft is losing altitude
(closing upon terrain) after takeoff. The aural message
“Don’t Sink” is given for NCR alerts, accompanied by an
annunciation and a pop-up terrain alert on the display.