System onboard an aircraft connected with a flight plan

Abstract

An evaluation method and an evaluation system onboard an aircraft in communication with a flight management system to access a flight plan stored in memory of the flight management system, where the flight plan defines a cruising level and a minimum fuel reserve to destination objective. The evaluation system comprises circuitry to calculate a fuel consumption deviation between flight at a selected cruising altitude level and flight at an altitude level initially planned by the flight plan, where the selected altitude level is lower than the altitude level initially planned, and to determine a climb limit point from the selected cruising altitude level as a function of the fuel consumption deviation and the minimum fuel reserve objective, where the climb limit point represents the last climb point respecting the minimum fuel reserve to destination objective; and interface circuitry to provide the climb limit point and anticipative information concerning the climb limit point.