Embraer 175 - Degraded Navigation

AIRPLANE
FLIGHT
MANUAL
SUPPLEMENT 4
PRIMUS EPIC - FLIGHT
MANAGEMENT SYSTEM
ANAC APPROVED S4-10
REVISION 15 code 01 Page 9
Copyright © by Embraer. Refer to cover page for details.
AFM
-
1385
EMERGENCY AND ABNORMAL PROCEDURES
(LOAD PRIOR TO 27.1)
NOTE: All pages from code 01 of this supplement are applicable to
airplanes equipped with Load prior to 27.1.
All FMS Action/Malfunction Messages are described in the Honeywell
Flight Management System Pilot's Operating Manual.
The airplane abnormal operating procedures are the same as those in
the basic AFM except as follows:
DEGRADED NAVIGATION
The DGRAD annunciator is displayed on the PFD when the accuracy
a
nd integrity of the system does not meet the requirements for the
current RNP or Approach type. The UNABLE RNP or GPS APPR
RAIM UNAVAIL scratchpad message will also be displayed.
If a DGRAD annunciation is displayed, the pilot should select the
offside FMS, if available. If the off-side FMS is not available,
procedures should be followed as described in the following table, and
detailed in the paragraphs below:
DGRAD Procedures (Off-side FMS not Available)
Operation Required Action
Non-RNP Terminal or En-route
(including B-RNAV)
Crosscheck FMS data with raw data
from VOR, DME, and NDB. De-
select error causing sensor, if
detectable.
P-RNAV Contact ATC, advise inability to
continue P-RNAV.
RNP Terminal, En-route,
Remote
Contact ATC and advise inability to
continue RNP operations.
Non-RNP (excluding GPS
required) Approach
Use alternate source (VOR, NDB) if
available. If not, declare Missed
Approach.
RNP 0.3 and GPS required
Approach
Declare Missed Approach.
Non-RNP Remote Crosscheck FMS data with raw data
from GPS, IRS. De-select error
causing sensor, if detectable.