What is a primary function of the Flight Management System (FMS) on the Longitude 700?

• A. It displays weather radar imagery to pilots
• B. It computes optimal route, fuel burn, speeds, thrust, and altitude constraints; provides guidance and auto-flight features based on entered data
• C. It performs automatic tax calculations for revenue management
• D. It controls cabin lighting and entertainment systems

Answer: (B)

The main function of the Flight Management System is to optimize the flight plan and drive the aircraft guidance. It takes the route you enter, along with the aircraft’s performance data, weights, and any constraints (like altitude or speed limits), and computes the most efficient combination of route, fuel burn, speeds, thrust settings, and altitude constraints. It then provides guidance and flight automation—managing flight guidance and autothrust in supported modes (like LNAV/VNAV)—based on that data, so the aircraft can fly the chosen plan with minimal manual input. This is the system that reduces workload by planning the flight and translating it into automated guidance.

The other options describe functions that belong to different systems: weather radar imagery is a weather sensing system, tax calculations are unrelated to flight operations, and cabin lighting/entertainment are cabin systems.