The residents of big airports are the most curious to see whether the experiment works out: end of September an Airbus will land again at the Frankfurt airport as quietly as possible. 17 pilots are advised to do so by a Land-Navi.
“Conveniently” is not always positive in real estate ads especially the too easy access to an airport can be nerve wracking, when the wind is blowing the aircraft noise directly into the ear. Specifically, the landings provide considerable noise pollution.
Because it makes a significant difference technically noise, when and at what altitude landing and spoilers are out and retracted. Each pilot uses very individually these keys to generate thrust, to brake, to control the airport even steeper, even flatter. Only, when planes reach their stabilization amounting to approximately 1,000 feet or 300 meters, the landings expire after a precise standard.
Land-Navi Standards make unnecessary loud correction maneuver
German to establish these standards that allow optimal and thus quieter landings DLR ( Deutschen Zentrums für Luft ) already before the stabilization level to eliminate unnecessary and thus unnecessarily loud maneuvers. Help this to the pilot assistance system LNAS (low noise augmentation system), on 28 and 29 September at Frankfurt airport tested under real conditions and in the middle of the high season.
The DLR research aircraft is used Airbus A320 ATRA. Of course, the land navigation device in advance has been tested already extensively and successfully in the Simulator Centre of DLR in Braunschweig. 17 pilots of four different airlines took part in the Simulator flights.
Intuitive understanding of the graphic charts
LNAS leads the pilot a display on the intuitive-to-understand graphics, appear step by step through a streamlined and as quiet landing operations. “The pilot sees the ideal vertical approach profile, which is divided into different phases,” explains LNAS project manager Dr eng. Fethi Pete from the Brunswick DLR Institute of Flight Systems and Technology.
Both setting the flaps, reaching the intermediate altitude and extend the landing gear were each marked, so that the pilot can long-term planning and to the stabilization level as evenly as possible on a low thrust level and without unnecessary thrust changes overcome the descent from cruise flight. So the plan leads to less noise and quite incidentally also to lower energy consumption, that.
Approach profile is adjusted in real time
But not every airport is now equal, and weather conditions play an important role as well as the weight of the aircraft or the requirements of the air traffic management not for nothing the landing maneuver is a particularly labor-intensive phase, which requires a high concentration and responsiveness. Schema F would be there more than an obstacle.
That’s why LNAS is programmed, that the ideal target immediately captured and included different actions of the pilots as well as changing environmental conditions: the assistance program calculates directly a customized approach profile. This adherence to the conditions of stability, a low engine speed and the complete avoidance of the use of noisy brakes are top on the priority list.
Local residents support project for noise reduction
The DLR research project is supported by the environmental and neighborhood House (UNH) in Kelsterbach with several hundred thousand euros. The UNH is an institution of Hessen, which occurred against the backdrop of the conflict situation around the Frankfurt airport and according to neutral wants to mediate between the stakeholders.
That noise reduction is a central theme, not surprising: nearly 16,000 inhabitants city Kelsterbach near Frankfurt airport borders on. Which in turn is the most important air traffic node of in Germany, with appropriate frequency.
Further measures in the testing
The LNAS is not the only adjustment screw to reduce aircraft noise is turned on in Germany. Also in Frankfurt, for example, a system called “RNP to xLS” was tested, subject and if possible exactly to settlements around leading the aircraft, as defined in the online portal airliners.de. Another technique called “Point Merge” based on the principle of the zipper will tested also until the end of the year at Leipzig/Halle.
Counter noise reduces the noise of the engines
But there are also different approaches to reduce aircraft noise. Landing noise also can be reduced by the pilots at low speeds on the runway. Also the DLR also experimented with other sound, to reduce the noise of the engines.