Optimized approach procedures with less environmental impact
Aircraft also make noise on approach. A research project with Empa participation has shown that it is possible to reduce the noise of the approach, avoid particularly noisy approaches and at the same time reduce fuel consumption.
Drivers are taught "anticipatory driving" during driving lessons to avoid unnecessary acceleration and braking maneuvers as much as possible. Anticipatory driving helps save fuel, avoids unnecessary noise and also prevents some dangerous situations. Not only on the road, but also in the air, a lot can be gained by "flying with foresight". On the one hand, this saves kerosene and reduces CO2 emissions, while on the other hand it also reduces noise. Current technical approach aids and air traffic control instructions give the pilot direction, altitude and speed. However, it is up to the pilots themselves on approach to reduce thrust at the ideal time and to extend the landing flaps and, if necessary, the airbrakes. Wind strength and direction are only known for the runway itself, but not for the entire approach corridor. This means that the pilots lack important data for making the smoothest possible landing approach. Sometimes the speed must be reduced, for example with airbrakes, then again a little more thrust must be given. On the one hand, this leads to more noise, but also to additional fuel consumption and higher CO2 emissions.
Quieter landing approach thanks to pilot assistance system
The German Aerospace Center (DLR) has therefore developed a new assistance system in recent years. (DLR) has therefore developed a new assistance system in recent years that shows the pilot via a display in the cockpit when exactly which action is to be performed for a low-noise approach. The new system, called LNAS ("Low Noise Augmentation System"), was tested in September 2019 by DLR in a joint research project with the "Swiss SkyLab Foundation" and Empa on board the DLR research aircraft "Atra" (Advanced Technology Research Aircraft) of type A320 during 90 approaches to Zurich Airport. The results of the evaluated flight tests in Zurich were positive: particularly noisy approaches could be avoided, the average noise level was reduced, and annual savings of 3000 tons of kerosene or 9000 tons of CO2 were calculated extrapolated to the Swiss A320 fleet (2017). LNAS is to be implemented in the medium term as an industrialized solution in the flight management system of regular airliners.
Subsequent EU research project
Since July 2020, DLR has been coordinating the continuing research project Dyncat ("Dynamic Configuration Adjustment in the Terminal Manoeuvring Area."), in which Swiss International Air Lines and the Thales Group are also involved in addition to the existing research partners. The aim of the research, which is funded under the European Horizon 2020 and Sesar ("Single European Sky ATM Research Programme") programs, is to enable more environmentally friendly and more predictable flight profiles, particularly on approach. The focus is on assisting pilots with configuration management and analyzing the influence of controller input.
Over the next two years, Dyncat will therefore analyze the impact of current regulations on pilot workload and safety, as well as on the environment (fuel consumption, CO2, noise). Proposals for changes in on-board and ground procedures will be developed and the necessary technical and regulatory requirements identified. In addition, the environmental and economic potential of the proposed improvements will be demonstrated by simulating and testing the new tool as a prototype in a real flight management system at an early stage. The tests will be conducted and evaluated by external pilots using the Thales test platform. In addition, testing in the simulator will already generate realistic flight trajectories, which will be fed directly into the "sonAIR" aircraft noise simulation program to assess the noise impact.
Access to records of actual flight operations data, associated issued air traffic control instructions, weather data and noise measurements for a variety of operations in Swiss airspace on the one hand, and the implementation of the improved functionalities on an industrial test platform on the other hand, enable a high validity and relevance of the results.
Source: Empa
