Embraer EMB145, Operation Manual

Page: 541 / 2662

AIRPLANE
OPERATIONS
MANUAL
ABNORMAL
PROCEDURES
REVISION 38
1-03-59
Page
7
Code
03
A
O
M-145/1
114
FMS NAVIGATION PERFORMANCE DEGRADED /
FMS IN DEAD RECKONING MODE
Verify airplane position by using VOR/DME information (enroute and
terminal operations) or other sources as appropriate (oceanic).
If conducting an instrument approach, discontinue use of FMS for
approach guidance and select an alternate source of navigation, if
available.
In case of one FMS (single FMS) or both FMS (dual FMS) entering in
Dead Reckoning Mode and EGPWS is installed:
EGPWS TERRAIN SYS OVRD Button ................... PRESS
The Terrain Awareness Alerting and Display functions on MFD will
be inhibited. This will not affect the basic GPWS functions (modes
1 to 7).
If the FMS is restored after a period of inadequacy:
EGPWS TERRAIN SYS OVRD Button .............. PRESS
The Terrain Awareness will be enabled.
NOTE: - For the FMZ 2000 FMS, the DGRAD annunciator indicates
that the FMS cannot guarantee that the accuracy of the
system meets the requirements for the current phase of
flight.
- Except in the case of conducting an instrument approach
procedure, the FMS may still be accurate and may be used
for navigation, provided the crew can confirm the position
through other means, such as cross checking the VOR/DME
raw data.