Section 2 System Overview
1
st
Ed Nov 2018
IDU-450 EFIS Software Version 8.0H (Rotorcraft)
2-33
Table 2-8: Caution Alerts
Visual Alert
Voice Alert/
Alert Tone
Condition
** No time delay
[1]
Only active in dual-sensor installation with neither sensor in failure condition
[2]
Only active in dual-system (pilot and co-pilot)
[3]
Only active when single-pilot mode discrete not asserted
Alert Tone
Indicates that radar altitude
difference between radar altimeters
is beyond limits. 10 second time
delay. Limits are as follows:
>= 500’AGL
∆
14%
100 – 500’AGL
∆
10%
< 100’AGL
∆
10’
[1]
Alert Tone
OAT FAIL applicable to single ADC
installation. OAT# FAIL applicable
indicates OAT indication is invalid but
other air data parameters are normal
(i.e., air data not red-X’d)
[1]
.
Half-second time delay.
Alert Tone
RALT FAIL applicable to single radar
altimeter installation. RALT# FAIL
applicable to dual radar altimeter
installation. For analog radar
altimeter, indicates the aircraft is
below 2000’ AGL in air mode without
a valid radar altimeter reading. For
ARINC 429 radar altimeter, indicates
an SSM of failure warning is
transmitting. 2-second time delay.
Alert Tone
Indicates both sides are operating
from same ADC source. **
[1]
Alert Tone
Indicates both sides are operating
from same AHRS source. **
[1]
Alert Tone
Indicates both sides are operating
from same DME Source **
[1] [3]
Alert Tone
Indicates both sides are operating
from same GPS/SBAS source.**
[1][2][3]
Alert Tone
Indicates both sides are operating
from same navigation source. **
[2]
Alert Tone
Indicates both sides are operating
from same radar altimeter source. **
[1] [2] [3]