A SERVICE OF

logo

57
Section 3
TAWS Alerts
Excessive Descent Rate Alert (EDR)
The purpose of the Excessive Descent Rate alert is to provide suitable alerts when the aircraft is deter-
mined to be closing (descending) upon terrain at an excessive speed. Figure 3-4 shows the parameters for
the alert as defined by TSO-C151b.
Excessive Descent Rate Severity Levels
WARNING—The annunciation and pop-up terrain alert
are accompanied by the aural message “Pull Up”.
CAUTION—The annunciation and pop-up terrain alert
are accompanied by the aural message “Sink Rate”.
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
2000 4000 6000 8000 10000 12000
"PULL UP""
P
U
L
L
U
P
"
"
S
I
N
K
R
A
T
E
"
Descent Rate (FPM)
Height Above Terrain (Feet)
Figure 3-4 Excessive Descent Rate Graph