Navigation & FMS
NOTE
This is a stub page. Full system description pending ingest of FCOM Chapter 15.
Overview
The B777 Flight Management System (FMS) integrates navigation, performance, and guidance functions through two Flight Management Computers (FMC L/R). Navigation sources include GPS, IRS, VOR/DME, and LOC/GS.
Key Components
| Component | Description |
|---|---|
| FMC L/R | Flight Management Computers (dual redundant) |
| CDU L/R/C | Control Display Units for FMC interface |
| IRS (3) | Inertial Reference Systems (L/C/R) |
| GPS (2) | Multi-mode receivers for position updating |
| VOR/DME, ADF | Conventional radio navigation aids |
FMS Functions
- LNAV: Lateral navigation — route following, holds, procedures
- VNAV: Vertical navigation — climb/cruise/descent profiles, speed targets
- Performance: Fuel predictions, optimum altitude, cost index
- Navigation Database: Updated every 28 days (AIRAC cycle)