Section 2 System Overview
1
st
Ed Nov 2018
IDU-450 EFIS Software Version 8.0H (Rotorcraft)
2-41
Table 2-13: Audio-Only Caution and Advisory Alerts
Caution or
Advisory Alert
Voice Alert/
Alert Tone
Condition
** No time delay
Loss of Vertical
Navigation
Caution Alert
Alert Tone
Loss of vertical navigation
caution. Inhibited during and
for 10 seconds after unusual
attitude mode. VLON
indication is integrated with
vertical deviation indicator. **
Countdown Timer
Chime
Chime
Sounds when countdown timer
reaches 00:00:00. **
Level-off
Advisory Alert
Altitude Alert
Tone
Within the greater of 1000’ or 50% of
VSI from uncaptured selected or
VNAV waypoint altitude. Inhibited in
approach procedures. **
2.5.8 Voice Alerts and Muting
Only the highest priority (in criticality and recency), unacknowledged voice
alert is played at any given time. Any playing audio message is immediately
muted by activating the warning/caution acknowledge switch.
2.5.9 Visual Alert Prioritization and Declutter
Visual alerts are visually prioritized, so warnings are displayed above
cautions, which are displayed above advisories. Within categories, visual
alerts are stacked in chronological order, so the most recent alert appears
on top.
The maximum number of visual alerts that can be simultaneously displayed
in the standard location is 11. In the event there are more than 11 visual
alerts,
appears for guidance in accessing the EXPAND
CAS menu.
Only the highest priority (in criticality and recency), unacknowledged
audible annunciation is played at a time. In addition, to further minimize
cockpit confusion, annunciations are grouped and prioritized so only one
annunciation is active. Annunciations prioritized in this manner are as
follows (higher in list = higher priority).
In addition, flags are decluttered from all IDUs, which are not “transmit
enabled.” Flags only appear on these IDUs if they are IDU-specific (i.e.,
CHECK IDU #).