Pilot's Operating Handbook
Section 7
Description
Edition 1 - January 15, 2018
Rev. 3
Page 7.14.12
When using barometric altitude for vertical guidance along the final approach
segment, temperature compensation is applied whether the temperature is above or
below standard temperature. The actual compensated altitude is not displayed to the
pilot during an approach.
Compensating Waypoint Altitudes
Depending on the terrain, temperature compensation may be required for waypoints
in the approach prior to the final approach segment due to terrain and/or obstacle
clearance requirements.
Temperature Compensation of Approach Minimums
To enable temperature compensation of the minimum altitude, select the TEMP
COMP, option for the minimum altitude reference type (in addition to OFF, BARO, and
RAD ALT). The temperature at the destination airport is used for this purpose.
The temperature at the destination airport is invalidated when a different approach is
loaded into the active flight plan or when the system powers up.
This disables temperature compensation of both the published approach waypoint
altitudes on the active flight plan page and the minimum altitude.
The minimum altitude selection type changes to BARO if it was previously set to
TEMP COMP.
Temperature compensation of the minimum altitude is not dependent on use of
barometric altitude for vertical guidance on the FAS, and is therefore available for any
type of approach; in fact, only the destination airport and temperature are required.
Compensating the approach minimums bug simply determines where the minimums
reference is displayed on the altimeter.
No adjustment to the barometric altitude is made as a result of temperature
compensating the minimums reference.
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
and a change in the annunciated service level in the HSI.
As the
APR DWNGRADE
may not be triggered under certain circumstances, the
HSI annunciation shall be considered as the primary mean to annunciate any
approach downgrade.
PIM - DO NOT USE FOR FLIGHT OPERATIONS
