R Mod : 4654 or 4885 or 5020
ATR 42 Model 400/500
GNSS
NAVIGATION SYSTEM
GLOBAL NAVIGATION SATELLITE SYSTEM
P 8
NOV 00
090
1.15
.
60
EADI
Alerting messages and displays related to the HT 1000 operation.
(1) RNV MSG is triggered by one of the following messages displayed on the MCDU:
- UNABLE RNP: message annunciated when ANP exceeds RNP or integrity is greater
than twice the selected RNP (Once the value for approach). The conditions for
displaying this message are flight phase dependent as follows:
PHASE OF FLIGHT
DEFAULT RNP (NM)
Unable RNP Time to Alarm (s)
OCEANIC
12
80
EN ROUTE
2
80
TERMINAL
1
60
APPROACH *
0.3
10
* Not applicable
- DEAD RECKONING: message annunciated when NAV source becomes dead reckoning
(GPS and DME modes are lost).
- VERIFY RNP ENTRY: message annunciated when the pilot entered RNP is greater than
default current RNP.
- VERIFY RNP-POS REF: message annunciated when flight phase changes and current
pilot
entered RNP is greater than the default RNP for new flight mode.
- UNABLE APPROACH: message annunciated when within 2 NM from the FAF, and RAIM
prediction at FAF/MAP fails, or navigation source is not GPS.
In addition there are some advisory messages such as:
- RAIM LIMIT EXCEEDS XX NM: message annunciated when the GPS RAIM protection
Limit
exceeds TSO-C129 requirement for current flight phase.
- CHECK DEST RAIM-POS REF: message annunciated within 30 NM of destination airport
if active route contains approach and approach RAIM predicted to be non available for
some period of time within 15 minutes of destination ETA.
RNV MSG will extinguish when the associated MCDU message is cancelled.
AA
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