Section 2 System Overview
2-34
IDU-450 EFIS Software Version 8.0H (Rotorcraft)
1
st
Ed Nov 2018
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
TAWS autorotation mode activated
through use of discrete input. **
Alert Tone
TAS indicates lack of
communications with system or
failure indication from system. **
Alert
Tone
Compares the volume of sensed fuel
to the fuel totalizer calculation.
Issued if the difference exceeds the
totalizer mismatch caution threshold.
Only performed if:
1) Totalizer
mismatch
caution
threshold is non-zero;
2) Fuel totalizer is enabled;
3) Unmonitored fuel flag is false;
4) Fuel totalizer has a valid value;
and
5) Fuel levels are valid.
1-minute time delay.
Alert Tone
Indicates lack of inter-system
communications.
32-second delay.
[2] [3]
Alert Tone
Indicates no valid message received
from numbered GPS/SBAS for more
than 5 seconds. ** Inhibited during
and for 10 seconds after unusual
attitude mode.
[1]
“Check Gear,
Check Gear”
Activates if aircraft is below 150’
AGL, is descending, and any landing
gear is not down. (Used on CPU #0
only.) 2-second time delay.
“Caution
Terrain,
Caution
Terrain”
Terrain cell within TAWS FLTA
caution envelope. (Used on CPU #0
only.) Half-second time delay.