search

FMS Temp Compensation

For VNAV approaches, you have the option of selecting VNAV temperature compensation to assure the FMS meets obstacle clearance standards by the published altitude constraints. The VNAV temp compensation function adjusts all FMS waypoint altitude constraints for the defined approach, approach transitions, andmissed approach segments of the flight plan to compensate for nonstandard day temperatures.

  • OFF (assumes standard day temperature)

  • COLD applies temperature compensation only when approach is flown in COLD conditions (0 to --50 degrees DISA (deviation ISA))

  • HOT/COLD applies temperature compensation when approach is flown in any temperature condition (limited to --50 to 70 degrees DISA). This configuration is an option and must be enabled separately from COLD.

hashtag
Select Temp Config

In the MCDU, COLD is set to default. If you want to change it follow these steps:

  1. Select MAINTENANCE from page 2 of NAV INDEX.

  2. Select SETUP from page 2 of FMS MAINTENANCE.

  3. Select FLT CONFIG on FMS SETUP.

  4. Got o page 2 of FLIGHT CONFIG pages.

  5. At TEMP COMP CONFIG select OFF/COLD/HOT&COLD

hashtag
Add Temp Correction

The FMS determines the compensated altitude constraint values automatically once an outside air temperature value has been entered on the LANDING page and an arrival has been inserted into the active flight plan. However, pilot confirmation by the MOD flight plan is required before the altitude compensation is applied to the active waypoints.

The TEMP COMP page is accessed either through the LANDING INIT page or from the FLIGHT PLAN pages. For the TEMP COMP access prompt to be available on the flight plan pages, the following conditions must be met:

  • The active TEMP COMP CONFIG mode is COLD or HOT and COLD

  • The aircraft is within 30 NM of the destination

  • An approach has been activated

  • Valid OAT (on the Landing page) is entered.

This is an example of the steps necessary for defining and activating the VNAV temperature compensation values in the active flight plan:

  1. Select LANDING INIT page via PERF INDEX.

  2. Enter LDG TEMP of your destination airport.

  3. Select TEMP COMP on RSK5.

  4. Verify the altitude changes and select APPLY on RSK6 to insert the new altitudes into the flightplan.

  5. Select ACTIVATE on RSK6 at MOD FLT PLAN to activate the modified flightplan.

PreviousNavdata UpdaterNextHoldings

Last updated