Alternate Index
PEGASUS FMC
The alternate page displays a list of alternate airports. An alternate airport can be selected from this page to change the flight plan destination. The page displays a list of up to four alternate airports sorted in order of the ETA to the airport while airborne. The source of alternate airports can be:
Alternate airports automatically selected from the navigation database are displayed in small font. The presently selected alternate airport is shown on the HSI map in normal airport symbology. All four alternate airports are shown on the HSI in the plan mode.
1 Alternate Airports
Displays the identifier of four alternate airports in ETA order when airborne. Displays the identifier of four alternate airports in distance order when on the ground.
Valid manual entry is an airport from the navigation database. A manual entry replaces the alternate where the entry is made and is shown in large font. After entry, the airports are resequenced according to ETA and the FMC selected airport with the last ETA is removed.
Use the DELETE function or overwrite a manually entered alternate to remove it. Manually entered airports will not be removed by the FMC.
2 Selected (<SEL>), Automatically Selected (<A>) <SEL> indicates a manually selected alternate airport.A manual selection of an alternate airport is made by pushing the line select key left of the airport identifier with nothing in the scratchpad.
When there is no manually selected alternate the FMC automatically selects the alternate airport with the earliest ETA. Automatically selected alternates are indicated by <A> next to the airport identifier.
The selected alternate identifier is shown in the line title of the DIVERT NOW prompt.
Entering a new airport into the list deletes the last airport in the list. After entry, the airports are rearranged in ETA sequence. Manually entered airports are shown in large font and can be removed using the DELETE function.
Use the DELETE function to remove the <SEL> from a manually selected alternate. The automatic selection function selects a new alternate.
3 ETA
Displays the alternate airport ETA.ETA is calculated based on the routing, altitude, and speed shown on the XXXX ALTN page. ETA is blank when the airplane is on the ground.
4 FUEL
Displays the alternate airport predicted arrival fuel.Predicted arrival fuel is calculated based on the routing, altitude, and speed shown on the XXXX ALTN page. The message UNABLE FUEL is shown in the FUEL column if the predicted arrival fuel is less than zero.
Fuel values are blank when the airplane is on the ground.
5 Alternate Select
Selects the XXXX ALTN page, which contains more data about the specific airport.6 Alternate Inhibit (ALTN INHIBIT)
An airport will not be one of the four alternate airports if entered into the alternate inhibit line.
One or two airports can be manually entered.
Valid entries are airports from the navigation database.
7 DIVERT NOW
The DIVERT NOW selection modifies the route to go from the present position to the selected alternate using the route shown on the XXXX ALTN page.Push -
- makes an LNAV route modification for a divert to the selected alternate
- automatically displays the MOD XXXX ALTN page for the selected alternate
- displays SELECTED in this position on the CDUs not involved with the modification
- blank on ground
- blank in the air when a diversion is not permitted.
The DIVERT NOW selection changes the display to the XXXX ALTN page for the diversion airport. The details of the route can be confirmed or modified before the diversion is executed.
Execution of the diversion:
- changes the route destination airport
- includes the route modification into the active flight plan
- deletes all parts of the original route that are not part of the diversion
- if a descent path exists, deletes all descent constraints (the scratchpad message DESCENT PATH DELETED is shown when DIVERT NOW is selected).
After a divert is executed the XXXX ALTN page is not updated until all CDUs are selected off of the XXXX ALTN page.
Standard | 11.43.15 | ALTN XXXX>