Procedure and system for a noise-optimized departure

Abstract

Method for a noise-optimized departure of an aircraft from a starting point, wherein the method comprises the following steps: - Providing static start parameters (100) of a simulation device (11) which include at least the starting point, a planned endpoint, parameters of the aircraft itself and weather information at the time of the planned departure of the aircraft from the starting point; - Providing a population distribution at least along the planned horizontal flight path of the simulation device (11);- Performing an aircraft noise simulation (22) for different departure sequences with different combinations of dynamic start parameters (110) using the simulation device (11), wherein for each departure sequence with the corresponding combination of dynamic start parameters (110) and the static start parameters (100) an aircraft model (20) is simulated and at least one noise assessment indicator is determined as a function of a simulated noise immission on the local population within an evaluation area based on the simulated aircraft model (20), taking into account a provided population distribution of the evaluation area; - Displaying the aircraft noise-simulated departure sequences together with the determined noise assessment indicator of the simulated noise immission on the local population within the evaluation area on a display device (12) of the simulation device (11);- Performing a noise-optimized aircraft departure based on one of the displayed simulated flight noise sequences with the respective dynamic takeoff parameters (110).;

Description

The invention relates to a method for a noise-optimized takeoff of an aircraft from a starting point. The invention also relates to a pilot assistance system for installation in the cockpit of an aircraft. Noise emissions from aircraft, especially commercial airliners, are primarily dominated by altitude and engine thrust during takeoff, while airflow noise is negligible. Due to the high thrust levels during takeoff, noise emissions from high-lift devices, for example, are less significant than during approach. Several departure procedures for commercial aircraft are known. These are usually determined by the operator (e.g., the airline) and are limited by PANS-OPS (Procedures for Air Navigation Services - Aircraft Operations) to one standard and one noise-reducing departure procedure for each aircraft type and all airports. PANS-OPS proposes two noise-reducing departure procedures, which can then be adapted by the operators. These are NADP-1 (Noise Abatement Departure Procedure) for noise reduction in the immediate vicinity of the airport and NADP-2 for noise reduction further away from the airport. The two noise-reducing departure procedures differ in that the sequence of segments and pilot actions (e.g., thrust reduction, acceleration, flap retraction) is varied to redistribute the noise along the flight path.The procedures are also known by their old names ICAO-A and ICAO-B, but offer more flexibility compared to the old procedures. For lateral routing, there are various standardized departure routes (Standard Instrument Departure, SID), which consist of a sequence of waypoints and can be flown by the pilot. Air traffic control also specifies requirements for these routes. The Aeronautical Information Publication (AIP) may also contain noise abatement guidelines for departure procedures. An active system for noise reduction during takeoff is the Quiet Climb System (QCS). QCS assists pilots in taking off with reduced noise by automatically controlling thrust reduction and restoration. The pilot selects the altitudes for thrust reduction and restoration. Upon reaching the thrust reduction altitude, the system reduces thrust while maintaining the optimal climb angle and airspeed. Upon reaching the restoration altitude, the system automatically restores full thrust (climb thrust). The Noise Impact Reduction and Optimisation System (NIROS) of the German Air Navigation Service Provider (DFS) simulates departures along standard departure routes using a flight management system. From the airspeed in the individual flight phases and the corresponding time, the duration of noise exposure and the noise levels at specific locations can be calculated. The noise levels are then weighted by population density, and key figures for the overflown area elements are determined. By integrating the key figures from the 100 x 100 m grid cells, a noise assessment score is obtained for the entire area under consideration, representing a kind of quality indicator. German Air Traffic Control, for example, uses the FANOMOS tool. This tool can display flight paths, including their altitude profiles, on topographic maps and is used for the statistical analysis of flight paths and profiles. The system uses radar data and is primarily used for planning tasks. German patent DE 20 2012 105 058 U1 discloses a navigation device for aircraft for determining and displaying a vertical target flight plan. Starting from the aircraft's current position and progressing to a predefined target position, a plurality of setpoints are determined along the vertical target flight plan. At these setpoints, the aircraft is assigned a new target speed, deviating from its current actual speed. A processing unit then calculates the speed error between the target speed and a future predicted actual speed and displays this error as an energy-altitude error surface. With increasing population density, particularly in metropolitan areas, noise abatement at airports, especially during takeoff, is becoming an increasingly important issue. The methods known from current technology are static and not designed for the flight planning of an individual flight. They do not take into account individual parameters that would allow the pilot to consider local conditions before takeoff. Generally, a distinction is only made between NADP-1 or ICAO-A for the protection of the immediate vicinity and NADP-2 or ICAO-B for the protection of the far vicinity. Therefore, predicting the actual noise impact of a single flight on the surrounding population is very inadequate, if not impossible. US patent 2021 / 0043092A1 discloses a flight planning system designed to optimize the flight path of unmanned aerial vehicles (UAVs) for noise reduction. Specifically, the system calculates noise reduction for a given trajectory, taking into account a weather model and, where applicable, a temporary population distribution. Noise reduction is calculated for various trajectories, allowing the selection of the optimal trajectory for the UAV based on a noise reduction index derived from these different trajectories. From US 2021 / 0 233 415 A1, a display for pilots is revealed on which trajectories can be selected to avoid collisions during approach. From CH 713 630 A1 a method for calculating the noise level of aircraft along a defined flight path is known. It is therefore an object of the present invention to provide an improved method and an improved pilot assistance system for noise-optimized takeoff. The problem is solved by the method according to claim 1 according to the invention. Advantageous embodiments of the invention are found in the corresponding dependent claims. According to claim 1, a method for a noise-optimized departure of an aircraft from a starting point is proposed, wherein the method comprises the following steps: - providing static start parameters of a simulation device, which include at least the starting point, a planned endpoint, parameters of the aircraft itself, and weather information at the time of the planned departure of the aircraft from the starting point; - providing a population distribution at least along the planned horizontal flight path of the simulation device;- Performing an aircraft noise simulation for various departure sequences, each with different combinations of dynamic takeoff parameters, using the simulation device, wherein for each departure sequence with the corresponding combination of dynamic and static takeoff parameters, an aircraft model is simulated, and at least one noise assessment indicator is determined as a function of a simulated noise immission on the local population within an evaluation area based on the simulated aircraft model, taking into account a provided population distribution of the evaluation area; - Displaying the simulated aircraft noise departure sequences together with the determined noise assessment indicator of the simulated noise immission on the local population within the evaluation area on a display device of the simulation device;- Performing a noise-optimized aircraft departure based on one of the displayed simulated flight noise sequences with the respective dynamic start parameters. Accordingly, static start parameters for a simulation device are initially provided. These static start parameters are generally unchanging and relate at least to the start point and a planned end point, as well as unchanging parameters of the aircraft itself. Such unchanging aircraft parameters could, for example, include the aircraft's mass. In addition, weather information at the time of the aircraft's planned departure from the start point is provided as static start parameters, so that this information is taken into account during the noise-optimized departure. Providing these static start parameters can be done, for example, by the pilot entering them into a pilot assistance system, such as a flight planning system. However, it is also conceivable that these static start parameters are automatically determined by the simulation device, for example, from other aircraft systems with which the simulation device is appropriately connected. The simulation device is further provided with a population distribution, at least within the evaluation area (e.g., along a planned flight path), which can be stored in a database. This population distribution contains information about the number of inhabitants in a specific, defined area, for example, a 100 x 100 m grid. The evaluation area can be determined based on a planned flight path over ground. However, it is also conceivable that the evaluation area is determined dynamically depending on the simulated noise immission, for example, by only considering an area within which the sound level exceeds a certain limit (e.g., > 50 dB). Alternatively, the evaluation area can also be limited to specific localities. A noise simulation is now being conducted to determine the impact of various departure sequences and procedures on the local population. For each departure sequence and procedure, the impact on the local population is calculated, with each sequence and procedure differing from the others through a unique combination of dynamic start parameters. Each departure sequence and procedure is assigned a specific combination of predefined dynamic start parameters, and a corresponding noise simulation is then performed for each of these sequences. This allows the impact on the local population to be determined for each departure sequence.The aircraft noise simulation determines the noise immission on the ground based on the aircraft model with the dynamic and static start parameters for the specifically planned flight within the evaluation area, whereby by coupling this simulated noise immission with the population distribution within the evaluation area a noise assessment indicator (burden indicator) is determined, which describes the effects of the noise immission on the population in this area. The aircraft noise simulation takes into account both the dynamic takeoff parameters and the previously provided and defined static takeoff parameters, which together simulate a corresponding aircraft model. The simulation of such an aircraft model is then used in conjunction with a noise simulation to determine the noise immission affecting the local population within the evaluation area. The noise immission can, for example, refer to the locally occurring sound pressure level caused by the aircraft in the simulation. The impact of this noise immission on the population distribution within the evaluation area is then determined for each departure sequence as a noise assessment index. This noise assessment index represents the burden on the local population as a function of the noise immission. Such a noise assessment index can, for example, be determined as a function of the sound pressure level. The various departure sequences considered by the noise simulation can be determined, for example, based on existing statically optimized departure sequences. Therefore, prior to the noise simulation, the simulation device can determine different departure sequences, which are based, for example, on various known static departure sequences. Subsequently, the simulated departure sequences, along with the determined effects of the simulated noise emissions on the local population, are displayed to the pilot on a screen of the simulation device. This allows the pilot to select one of these departure sequences and thus execute a corresponding noise-optimized departure procedure, which was previously simulated with regard to noise emissions using the takeoff parameters for the selected departure procedure. The display should at least include the determined noise assessment score for each departure sequence considered. The planned endpoint can also be an intermediate point on the way to the planned endpoint, serving as a landing point. A flight route can be proposed from the starting point to the planned endpoint, which, for example, defines the evaluation area on the ground for determining the impact of noise pollution on the population. The present invention thus makes it possible to provide the pilot with a recommendation for an individually noise-optimized takeoff for flight planning, thereby reducing the impact of aircraft noise on the local population. Actual takeoff parameters, population data, and weather information are taken into account to simulate noise emissions as accurately as possible. According to one embodiment, the dynamic launch parameters include a vertical takeoff profile from the launch point, at least one thrust reduction altitude, an acceleration altitude, a measure of thrust reduction, a standardized instrument departure route (SID) and / or an aircraft configuration. According to one embodiment, a planned horizontal flight path of the aircraft, starting from the launch point and ending at the planned destination, is provided as a static or dynamic launch parameter. The planned horizontal flight path can be static and unchanging. However, it is also conceivable that the flight path, as part of the dynamic launch parameters, is incorporated into the optimization, so that different flight paths are considered as dynamic launch parameters for different departure procedures or sequences. Based on the flight path – whether as a dynamic or static starting parameter – the evaluation area on the ground for the noise simulation can be determined. This evaluation area can also depend on other external factors, such as wind direction and wind speed. According to one embodiment, the aircraft parameters include the aircraft mass or an aircraft mass profile that decreases over time due to fuel consumption. The aircraft's mass is a fixed parameter at the start of takeoff. However, due to fuel consumption, the aircraft's mass decreases during the takeoff procedure. Because of the short timeframe considered, this decrease in mass due to fuel consumption can be disregarded for the noise simulation, meaning the aircraft has a constant mass during takeoff. Alternatively, a decreasing mass profile over time due to fuel consumption could be taken into account, thus accounting for the aircraft's mass reduction. Either way, the aircraft's mass can be provided as a static takeoff parameter. According to one embodiment, the weather information includes wind direction, wind speed, temperature, and / or air pressure. Knowing the wind direction and speed, the impact of noise pollution in the evaluation area on the ground can be estimated in conjunction with a horizontal flight path, since wind deflects sound from the sound source towards the ground. Wind also has a significant influence on flight performance, which can also be taken into account in the noise pollution simulation. The evaluation area can also be defined considering the weather information, particularly the wind direction and speed. According to one embodiment, the noise assessment index is determined by calculating a number of awakening reactions, depending on the simulated noise immission and the provided population distribution, to represent the effects of the simulated noise immission on the local population. These awakening reactions thus constitute a noise assessment index that can describe the effects of the simulated noise emission. According to one embodiment, for each departure sequence, an estimated fuel consumption and / or flight time is determined and displayed on the display device, depending on the static and dynamic start parameters. This enables pilots to evaluate the various departure sequences not only with regard to their optimal noise reduction, but also with regard to characteristic flight performance parameters, such as estimated fuel consumption and flight time, which represent important information during flight operations. According to one embodiment, some of the dynamic start parameters are fixed and not varied during the flight noise simulation. The pilot can, for example, predefine certain dynamic start parameters, such as the flap configuration, by entering them into the assistance system, if required by external conditions. According to one embodiment, each departure sequence for which a noise simulation has been performed is compared with a reference departure sequence for which a noise simulation has also been performed, with the result of the comparison being displayed on the display device for each departure sequence. The comparison with a static reference departure sequence allows the pilot to compare with a nominal value that is useful both with regard to noise emissions and with regard to other information such as fuel consumption and flight time. The problem is also solved according to the invention with the pilot assistance system for installation in an aircraft cockpit according to claim 10, wherein the pilot assistance system has a simulation device and a display device and is configured to carry out the method described above. The display device can be integrated into an existing system in the cockpit. The invention is explained by way of example with reference to the accompanying figures. These show: Fig. 1 a schematic representation of the pilot assistance system according to the invention; Fig. 2 an exemplary representation of a display; Fig. 3 a diagram of wake-up reactions versus acceleration altitude; Fig. 4 various diagrams; Fig. 5 a diagram of sound pressure level versus distance from railway sleeper. Fig. 1 shows a highly simplified schematic representation of the assistance system 10, which has a simulation device 11 and a display device 12. Static start parameters 100 are initially provided to the simulation device 11; these parameters can, for example, originate from pilot input or be automatically determined from other systems. These static start parameters 100 are thus supplied as input to the pilot assistance system 10. The simulation device 11 has an aircraft model 20, which is configured to simulate the aircraft based on the takeoff parameters. In addition to the static takeoff parameters 100, the aircraft model also receives dynamic takeoff parameters 110, which are varied for different departure procedures. This results in different takeoff sequences for the aircraft model 20 in the simulation. Furthermore, the simulation device 11 has a noise simulation 22 which is set up to calculate a noise immission for an evaluation area on the ground based on the aircraft model 20 and the static and dynamic start parameters 100, 110 provided by the aircraft model 20. Furthermore, the simulation device 11 has a database with the population density 21 or population distribution in order to obtain the number of population units per sub-area, at least in the local vicinity of the airport or within the evaluation area. Both the calculated noise immission from the noise simulation 22 and the population density 21 now serve as input to the evaluation 23 in order to calculate the effects of the simulated noise immission on the population and to determine at least one noise assessment indicator for this purpose. This noise simulation is performed for various departure sequences, each differing in its dynamic start parameters, so that at least one corresponding noise rating can be determined for each departure sequence based on the noise simulation. The departure sequences with their dynamic start parameters and their respective assigned noise ratings are then displayed to the pilot on a display device 12, allowing him to select an appropriate procedure and execute a corresponding departure based on the dynamic start parameters of the selected departure sequence. The display on the pilot assistance system, as provided by the display device 12, is shown by way of example in Fig. 2. The table shown displays the various departure sequences in series, with a comparison to a reference in column ΔNoise for each departure sequence. The pilot can thus recognize the noise-related effects of the respective departure sequence. In addition, a corresponding delta in terms of fuel consumption and flight time relative to the reference is displayed. Furthermore, an optimally evaluated departure procedure can also be suggested. This will be illustrated by an example. The following assumes a takeoff mass of 75.5 t, a flap setting of Conf-2, and maximum takeoff thrust for a NADP-2 aircraft departing from runway 7 at Stuttgart Airport. The SID chosen for the lateral flight path is ETASA2H, which initially runs east and then north. This demonstrates the influence of a headwind of 15 knots and a tailwind of 10 knots, in the direction of travel, on the noise distribution and thus on the different optimal acceleration altitudes. For the two scenarios of headwind and tailwind, the following awakening responses can be calculated for a variation in acceleration height between 500 ft and 3000 ft as an example for noise assessment. The awakening responses are calculated using the maximum sound level and population data. The calculations show that the fewest awakening responses are to be expected with headwind at a low acceleration height than with tailwind at a high acceleration height. The scenario shown in Fig. 3 can significantly reduce the number of awakening reactions during acceleration at 3000 ft compared to 500 ft when there is a tailwind. This is due to the altered noise distribution along the flight path and the associated change in its impact on population distribution. Fig. 4 shows, for the tailwind case, the altitude profile above the runway threshold (Above Ground Level, AGL), the airspeed (Calibrated Airspeed, CAS) and the engine speed (N1) over the distance traveled to the runway threshold. The velocity plot (b) additionally includes the selected target speed, the minimum flap retraction speed, and the minimum slat retraction speed, which are relevant for retracting the high-lift devices during the acceleration phase. The altitude profile shows that the aircraft initially climbs to 500 ft or 3000 ft, then accelerates to 220 kts at a shallower approach angle, continues to climb to 3000 ft, then accelerates to 250 kts, and subsequently climbs to 10,000 ft (MSL) before settling into level flight. With later acceleration, the result is a continuous acceleration directly to 250 kts. Later acceleration results in a steeper climb angle at the beginning, and thus a higher altitude, a later reduction in thrust, and a lower airspeed up to approximately 9 NM. In the range between 5.5 and 8 NM, a densely populated area is overflown. In this range, with the late acceleration (3000 ft), and a comparable thrust level, the overflight altitude is higher and the airspeed lower. Figure 5 shows the interpolated profile of the maximum sound level below the flight path for both cases. It can be seen that up to approximately 7.5 NM, the sound level is significantly lower for the case of late acceleration (3000 ft). This falls within the section with high population density. Subsequently, the sound level is higher, but the aircraft is then in a sparsely populated area. The noise emissions were redistributed such that the flight phase with a high expected noise level was shifted towards a sparsely populated area. Each variation of parameters results in different flight performance and a different noise redistribution, thus clearly demonstrating the potential for individual optimization by an assistance system. Reference symbol list 10 Pilot assistance system 11 Simulation device 12 Display device 20 Aircraft model 21 Population distribution 22 Noise simulation 23 Evaluation 100 Static start parameters 110 Dynamic start parameters

Claims

Method for a noise-optimized departure of an aircraft from a starting point, wherein the method comprises the following steps: - Providing static start parameters (100) of a simulation device (11) which include at least the starting point, a planned endpoint, parameters of the aircraft itself and weather information at the time of the planned departure of the aircraft from the starting point; - Providing a population distribution at least along the planned horizontal flight path of the simulation device (11);- Performing an aircraft noise simulation (22) for different departure sequences with different combinations of dynamic start parameters (110) using the simulation device (11), wherein for each departure sequence with the corresponding combination of dynamic start parameters (110) and the static start parameters (100) an aircraft model (20) is simulated and at least one noise assessment indicator is determined as a function of a simulated noise immission on the local population within an evaluation area based on the simulated aircraft model (20), taking into account a provided population distribution of the evaluation area; - Displaying the aircraft noise-simulated departure sequences together with the determined noise assessment indicator of the simulated noise immission on the local population within the evaluation area on a display device (12) of the simulation device (11);- Performing a noise-optimized aircraft departure based on one of the displayed simulated flight noise sequences with the respective dynamic takeoff parameters (110).; Method according to claim 1, characterized in that the dynamic launch parameters (110) include a vertical takeoff profile starting from the launch point, at least one thrust reduction altitude, an acceleration altitude, a measure of thrust reduction, a standardized departure route for instrument flights (SID) and / or an aircraft configuration. Method according to claim 1 or 2, characterized in that a planned horizontal flight route of the aircraft from the starting point to the planned endpoint is provided as a static or dynamic starting parameter. Method according to one of the preceding claims, characterized in that the parameters of the aircraft include the aircraft mass or an aircraft mass profile decreasing over time due to fuel consumption. Method according to one of the preceding claims, characterized in that the weather information includes a wind direction, a wind speed, a temperature and / or an air pressure. Method according to one of the preceding claims, characterized in that, in order to determine the noise assessment indicator of the simulated noise immission on the local population, a number of awakening reactions are determined depending on the simulated noise immission and the provided population distribution. Method according to one of the preceding claims, characterized in that for each departure sequence an estimated fuel consumption and / or an estimated flight time is determined as a function of the static and dynamic start parameters (110) and is displayed for each departure sequence on the display device (12). Method according to one of the preceding claims, characterized in that part of the dynamic start parameters (110) are fixed and are not varied during the flight noise simulation (22). Method according to one of the preceding claims, characterized in that each departure sequence for which a noise simulation (22) has been performed is compared with a reference departure sequence for which a noise simulation (22) has also been performed, wherein the result of the comparison for each departure sequence is displayed on the display device (12). Pilot assistance system (10) for installation in an aircraft cockpit comprising a simulation device (11) and a display device (12), wherein the pilot assistance system (10) is configured to perform the method according to one of the preceding claims.

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