Preflight - Introduction

FMC preflight is required before flight.

Completion of the FMC preflight requires data entry in all minimum required data locations. Additional entry of optional preflight data optimises FMC accuracy.

Preflight Page Sequence

The usual FMC power-up page is the Identification page. Preflight flow continues in this sequence:

• Identification (IDENT) page
• Position Initialisation (POS INIT) page
• ROUTE page
• DEPARTURES page (no automatic prompt)
• Performance Initialisation (PERF INIT) page
• Takeoff Reference (TAKEOFF REF) page

Some of these pages are also used in flight.

Minimum Preflight Sequence

During preflight, a prompt in the lower right directs the flight crew through the minimum requirements for preflight completion. Selecting the prompt key displays the next page in the flow. If a required entry is missing, a prompt on the Takeoff page leads the crew to the preflight page missing data.

When the TAKEOFF REF page is reached it confirms that all required preflight entries have been made by displaying PRE-FLT COMPLETE.

Airplane inertial position is necessary for FMC preflight and flight instrument operation.

A route must be entered and activated. The minimum route data is origin and destination airports, and a route leg. When ACTIVATE is selected on the route page the EXEC key illuminates. The EXEC key should then be pushed to complete the task of making the route active before continuing the sequence.

Performance data requires the airplane weight and cruise altitude.

PEGASUS/SPEED TAPE as installed
Takeoff data requires a flap setting.

Supplementary Pages

Supplementary pages are sometimes required, these pages have no prompts and interrupt the usual sequence. Discussions of each page include methods to display the page.

When the route includes SIDs and STARs, they can be entered using the DEPARTURES or ARRIVALS pages.

Route discontinuities are removed and the route is modified on the ROUTE and RTE LEGS pages. Speed/Altitude restrictions are entered and removed on the RTE LEGS page. The RTE LEGS page is described in the FMC Cruise section.

PEGASUS FMC
With the PEGASUS FMC installed, alternate airports are added on the ALTN page. The ALTN page is described in the FMC Descent and Approach section.

Waypoint, navaid, airport and runway data is referenced on the REF NAV DATA page. The REF NAV DATA page is described in the FMC Cruise section.

VNAV performance is improved if forecast winds and temperatures are entered during the preflight.

PEGASUS FMC
Wind and temperature data for specific waypoints is entered on the WIND page. The WIND page is described in the FMC Cruise section.

NON PEGASUS FMC
Wind and temperature data for the initial portion of the route is entered on the PERF INIT page. Forecast winds for other waypoints may be entered on the RTE DATA page to improve FMC performance predictions.

Preflight Pages - Part 1

The preflight pages are presented in the sequence used during a typical preflight.

Standard | 11.40.1 | INIT/REF INDEX>