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Part Three: Section 3
TAWS Alerts
WARNING— Estimated potential impact in approximately
15 seconds after a FLTA warning pop-up alert. FLTA warning
pop-up alerts are accompanied by the aural message “
Terrain,
Terrain; Pull Up, Pull Up
” or “
Terrain Ahead, Pull Up; Terrain
Ahead, Pull Up
”. Similarly, a “
Obstacle, Obstacle; Pull Up, Pull
Up
” or “
Obstacle Ahead, Pull Up; Obstacle Ahead, Pull Up
”
alert is also provided. The time to an alert can vary with condi-
tions, therefore there is no guarantee of a 15 second warning
alert being issued.
Phase of Flight
Level Flight
Descending
En Route
700 ft.
500 ft.
Terminal
350 ft.
300 ft.
Approach
150 ft.
100 ft.
Departure
100 ft.
100 ft.
Minimum TERRAIN Clearance Values for FLTA Alerts
NOTE
: 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 is below 125 feet AGL while within 1.0 NM of
the runway.
Premature Descent Alerting (PDA)
The TAWS system issues a Premature Descent
Alert (PDA) when the system detects that the aircraft
is significantly below the normal approach path to a
runway. PDA begins when the aircraft is within 15 NM
of the destination airport.
PDA ends when the aircraft is either:
• 0.5 NM from the runway threshold
OR
• is below an altitude of 125 feet AGL while within
1.0 NM of the threshold.
(EIGHT!BOVE4ERRAIN&EET
$ISTANCE&ROM$ESTINATION!IRPORTNM
0$!!LERTING!REA
0$!!LERTING!REA
2UNWAY
4HRESHOLD
CAUTION — The above annunciation and pop-up
terrain alert are displayed during a PDA alert. For
TAWS, the PDA alert is accompanied by the aural
message “
Too Low, Terrain
”.
190-00356-30 Rev H
