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Section 8 Terrain Awareness Warning System
8-4
IDU-450 EFIS Software Version 8.0H (Rotorcraft)
1
st
Ed Nov 2018
Figure 8-3: Default FLTA INHBT
2)
Other Modes
: For other default FLTA modes, reference point for
automatic FLTA inhibiting and mode envelope is the nearest runway
threshold or the nearest user waypoint with a defined approach
bearing. TAWS continuously searches all runway thresholds at the
nearest three airports to determine the nearest runway threshold.
TAWS performs a search for the nearest three airports and nearest
user waypoints with a defined approach bearing every 3NM of distance
traveled. Modes are as follows:
a)
Approach Mode
: When within 1900 feet and 5NM of the reference
point.
b)
Terminal Mode
: From 5NM to 15NM from the reference point
when below an altitude varying from 1900 feet (at 5NM) to 3500
feet (at 15NM) above the reference point.
c)
Enroute Mode
: When not in any other mode.
Figure 8-4: FLTA INHBT Mode Areas
8.3.4. FLTA Search Envelope
The FLTA search envelope is an area in front of and below the aircraft. If
terrain or obstructions are found within the FLTA search envelope, a
caution or warning is given. Dimensions of the search envelope depend
FLTA
Inhibit
Departure
Mode
Departure
Mode
6NM
6NM
1500’
2NM
2NM
Reference Point
Enroute
Mode
Enroute
Mode
Terminal
Mode
Terminal
Mode
15NM
15NM
3500’
3500’
FLTA
Inhibit
Approach
Mode
Approach
Mode
5NM
5NM
1900’
2NM
2NM
Enroute
Mode
Reference Point