User Guide

Garmin G1000 Pilot’s Guide for the Columbia 350/400
190-00552-00 Rev. A6-46
HAZARD AVOIDANCE
REQUIRED TERRAIN CLEARANCE (RTC) AND REQUIRED OBSTACLE CLEARANCE (ROC)
Required Terrain Clearance (RTC) and Required Obstacle Clearance (ROC) provide alerts when the
aircraft flight path is above terrain and/or obstacles, yet is projected to come within minimum clearance
values given in Table 6-5. When an RTC or ROC alert is issued, a potential impact point is displayed on
the TAWS Page as a yellow or red ‘X’.
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 6-5 ITI and IOI Minimum Clearance Alert Altitude
IMMINENT TERRAIN IMPACT (ITI) AND IMMINENT OBSTACLE IMPACT (IOI)
Imminent Terrain Impact (ITI) and Imminent Obstacle Impact (IOI) provide 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 Page and Navigation Map Page as a yellow or red ‘X’
(Figure 6-54). The alert is given when the projected vertical flight path is calculated to come within
minimum clearance altitudes given in Table 6-6.
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.