Active Noise Abatement Using the Newly Developed Pilot Assistance System LNAS

Abstract

Reducing aircraft noise becomes more and more important due to an increased number of flights and population in the vicinity of airports. An important opportunity to reduce noise during the approach phase is to increase the chronological precision of each task conducted by the pilots. In order to improve the situation the pilot assistance system LNAS is developed. It provides a vertical approach profile with optimal points in time to set flaps, gear and speed. A correction algorithm continuously compensates the actual wind situation and possible deviations from the optimal points as well as speed restrictions which are given by air traffic control. If the pilots follow the LNAS suggestions, the approach can be executed with minimum thrust from cruise altitude to stabilization height. For demonstration and evaluation of the developed system under operational conditions, seventy-four approaches were performed with the DLR research aircraft A320 ATRA during three days in September 2016. The flight trials had been conducted by seventeen type-rated airline pilots in order to assess the benefits of LNAS during approaches at Frankfurt Airport. The evaluation of the measurement data from ten ground-based noise monitoring stations shows that there is a need for flight procedure optimization and a potential for aircraft noise reduction.