Energy compensated target speed for aircraft descent

Abstract

Abstract Energy compensation means (64) for an onboard aircraft flight management system (12). The energy compensation means may be used to eliminate unwanted throttle activity during unscheduled level segments (80) in a descent path. The flight management system includes means for enabling selection of various flight modes including a descent mode, means for determining a descent path, including target speed and target altitude (70) profiles as a function of aircraft position, and means for providing information regarding the aircraft current altitude, current position, current calibrated airspeed (CAS) and current true airspeed (TAS). The flight management system also includes means operative in descent mode for providing a target signal (V TGT ) representing the target speed for the descent path for the current aircraft position, and display means (16) responsive to the target signal for displaying the target speed. The energy compensation means operates to adjust the target speed downward when the current altitude of the aircraft exceeds the target altitude for the current aircraft position. The adjustment may be computed such that the total kinetic plus potential energy of the aircraft is equal to the total kinetic plus potential energy that the aircraft would have if it were flying at the target speed and altitude for its current position. An approximate energy compensation technique may be used in which the target speed is adjusted downward by an amount proportional to the difference (Δh) between the current altitude and the target altitude for the current aircraft position.

Inventors

• 👤 Ralph S. Leslie
• 👤 Robert L. Allison

Bibliographic Details