Pilot's Operating Handbook
Section 7
Description
Edition 0 - October 31, 2013
Rev. 6
Page 7.14.6
During execution of a GPS approach with LNAV/VNAV service levels, while the
aircraft is between the FAF and MAP, excessive deviation indicators appear as white
vertical lines to indicate an area where the vertical deviation exceeds ±75 feet.
If the glide-path indicator is within an area of excessive deviation, the glide-path
indicator becomes yellow and the vertical lines also become yellow.
RNAV (GPS) or RNAV (GNSS) –
LPV
LPV approaches provide both localizer precision lateral guidance and a vertical path
definition.
SBAS integrity is required to execute the approach.
Approach level downgrade
Some automatic approach service downgrade may be performed automatically upon
loss of SBAS or GPS approach alarm limits being exceeded, depending on the
approach service level that has been loaded in the flight plan and activated.
This automatic downgrade is annunciated to the pilot through an APR DWNGRADE
advisory message and a change in the annunciated service level in the HSI.
As the APR DWNGRADE advisory message may not be triggered under certain
circumstances, the HSI annunciation shall be considered as the primary mean to
annunciate any approach downgrade.
Under certain circumstances, when the GNSS integrity requirement are not met nor
approach level is available the approach may be aborted.
This is annunciated through an ABORT APR advisory message and the service level
annunciation being removed from the HSI.
If SBAS becomes unavailable on an RNAV LNAV/VNAV approach,
L/VNAV
is
shown in yellow, the system will downgrade to LNAV service level (
LNAV
shown in
magenta) and the APR DWNGRADE advisory message will be generated. The VDI
will be flagged NO GP.
If SBAS becomes unavailable on an RNAV LPV approach,
LPV
will be shown in
yellow, but the CDI and VDI will continue to be shown. At one minute to the FAF, an
APR DWNGRADE advisory message will be generated.
The VDI will be flagged NO GP. Depending on the available lines of minima for the
approach, the system will switch to either LNAV/VNAV or LNAV service level.
PIM - DO NOT USE FOR FLIGHT OPERATIONS
