Assessment of Energy-Efficient Approaches with Increased Glideslope Angles

Abstract

In order to tackle aviation’s future challenges, aircraft need to fly as energy-efficient as possible. This does not only comprise technical development but also operational means, by which the energy efficiency of the aircraft can be increased through avoiding unnecessary waste of energy. Such operational means can be applied already with today’s aircraft and can thus immediately increase the energy efficiency of today’s aircraft without extensive technical changes. On the other hand, the further reduction of noise immissions of aircraft in the vicinity of airports is another important factor for future aviation. Increased glideslope angles during final approach are one operational means to reduce the noise immissions from aircraft. However, the increase of the glideslope angle must not negatively affect the aircraft’s ability to fly energy-efficiently. In order to investigate the ability of modern transport aircraft to fly steeper approaches energy-efficiently, so-called energy envelopes have been evaluated. For this, a method of backwards simulations of energy-efficient approaches was used. The evaluation was performed for the A320 as representative aircraft type. The variation of fuel consumption and noise within the energy envelope are outlined and discussed. Furthermore, parameters, which influence the shape of the energy envelope, hence the ability of the aircraft to fly energy-efficiently with steeper approaches, are presented as well.