Evaluating the influence of continuous flap settings on the take-off performance of an airliner using flight simulation

This paper describes a method to investigate the benefits of a continuously moving high-lift system for departure. During take-off and climb, a typical airliner accelerates. The slat/flap setting is configured stepwise after the acceleration altitude is reached. Thus, most of the time the configuration is not in its aerodynamic optimum. The continuous moving system adapts the slat/flap setting based on the airspeed and aircraft mass and enables the aircraft to fly with the aerodynamic optimal configuration. The performance is analysed using a flight simulation of a typical short-to-mid-range airliner and under variation of a standard take-off procedure. The tool continuous flap assessment (CoFA), developed in the project Con.Move, is capable of analysing performance benefits of continuous slat/flap settings. This paper describes and demonstrates the method by showing the influences of continuously moving high-lift systems on flight path, energy balance, and fuel consumption for different control laws for the retraction of the slats/flaps using a first version of the tool CoFA. It gives an overview of the simulation environment and the developed modules for the tool, describes the comparison take-off procedure, and shows the resulting flight paths for the different control laws.