Procedure and system for a quiet takeoff

Abstract

The invention relates to a procedure for a quiet takeoff of an aircraft leaving a starting point, the procedure comprising the following steps: - Providing static start parameters to a simulation device, including at least the starting point, a planned arrival point, parameters of the aircraft itself and meteorological information at the time of the planned takeoff of the aircraft from the starting point; - Providing a population distribution at least along the horizontal flight path planned in the simulation device;- Execution, using the simulation device, of a flight noise simulation for different takeoff sequences, each comprising a combination of dynamic start parameters differing from other combinations, while for each takeoff sequence comprising the corresponding combination of dynamic start parameters and static start parameters, an aircraft model is simulated and, based on a sound emission based on the simulated aircraft model, itself simulated on the local population within an analysis area, at least one noise assessment indicator is determined, taking into account the population distribution data for the analysis area;- Display, on a display means of the simulation device, of takeoff sequences with simulated in-flight noise together with the noise assessment indicator which was determined from the simulated sound emission on the local population within the analysis area; - Execution of an aircraft takeoff in a least noise regime with reference to one of the displayed takeoff sequences with simulated in-flight noise, with its own specific dynamic start-up parameters.

Description

Title of the invention: Procedure and system for a low-noise takeoff

[0001] The invention relates to a quiet takeoff procedure for an aircraft departing from a starting point. The invention also relates to a flight assistance system intended to be integrated into the cockpit of such an aircraft.

[0002] Aircraft noise, particularly from airliners, depends primarily on altitude above ground level and engine thrust during takeoff, while airflow noise is negligible. Due to the significant thrust during the startup phase, noise emissions are, for example, caused by high-lift devices.

[0003] Various takeoff procedures are known for airliners. These are generally defined by the operator (e.g., the airline) and are limited at the PANS-OPS (Procedures for Air Navigation Services - Aircraft Operations) level to a normal takeoff procedure and a noise-reduction takeoff procedure, for a given aircraft type and for all airports. The PANS-OPS propose two noise-reduction takeoff procedures, which can then be adjusted by the operators. In addition, there are, on the one hand, NADP-1 (Noise Abatement Departure Procedure) for noise reduction near airports and, on the other hand, NADP-2 for noise reduction away from airports. The two noise-reduction takeoff procedures differ in that the sequence of segments and piloting actions (e.g.,Thrust reduction, acceleration, flap retraction) is adjusted according to the desired noise distribution along the flight path. These procedures are also known by the older names ICAO-A and ICAO-B, but they offer greater flexibility than the older ones.

[0004] For lateral route guidance, there are various standardized takeoff routes (Standard Instrument Departure, SID) which consist of a series of waypoints and can be followed by the pilot, and air traffic control issues requirements. Noise protection requirements for takeoff procedures may also be specified in the aeronautical information manual (AIP).

[0005] A system widely used in air navigation to reduce noise during takeoff is the Quiet Climb System (QCS). The QCS assists pilots in reducing noise during takeoff by automatically controlling both thrust reduction and its recovery. Furthermore, the pilot selects the altitudes for thrust reduction and for its recovery. When the altitude for thrust reduction is Once reached, the thrust is reduced, the optimal angle of ascent and flight speed are maintained, and when the recovery altitude is reached, the system automatically restores full thrust (Climb-Thrust).

[0006] The Noise Impact Reduction and Optimization System (NIROS) of Deutsche Flugsicherung (German Air Traffic Control Service) simulates takeoff on standardized takeoff routes using a flight management system. Based on flight speed during different phases of flight and the corresponding time of day, it is possible to calculate the duration of the noise impact and the noise pollution at specific locations. The noise emissions are then weighted with population density and indicators determined for the surface features overflown. By integrating the indicators for 100 x 100 m cells of a grid, a noise assessment indicator is obtained for the entire area considered, which constitutes a kind of qualitative value.

[0007] Deutsche Flugversicherung, for example, uses the FANOMOS tool. This tool is capable of displaying flight tracks, including their altitude profiles, on topographic maps and allows for the statistical analysis of tracks and flight profiles. The system, which uses radar data, is used in particular for planning tasks.

[0008] A flight navigation device for determining and representing an ideal vertical flight path is known from DE 20 2012 105 058 U1. From the aircraft's current position to a predefined target position, a plurality of defined positions are determined along the ideal vertical flight path. If a deviation from the current actual speed is found at each of these positions, a new ideal speed is prescribed for the aircraft. A computing unit then calculates a speed error between the ideal speed and a predicted future actual speed, and represents this error as an error surface based on energy levels.

[0009] With increasing population density, particularly in urban areas, the issue of noise protection near airports, and specifically during takeoff, is becoming increasingly important. The procedures considered in this case are static and do not apply to the flight plan of a given aircraft. In particular, they do not include any individual parameters allowing the pilot to take local conditions into account before takeoff. A distinction is generally made only between NADP-1 or ICAO-A for the protection of areas in the vicinity and NADP-2 or ICAO-B for the protection of areas further away. Any prediction of the actual noise pollution from a given aircraft on the surrounding population is therefore very imperfect, if not virtually impossible.

[0010] The present invention therefore aims to provide an improved procedure and an improved pilot assistance system for takeoff in a low-noise mode.

[0011] This task is solved according to the invention by the procedure for a quiet takeoff of an aircraft departing from a starting point, as well as by a flight assistance system intended to be integrated into the cockpit of an aircraft equipped with a simulation device and a display means for executing the procedure. Advantageous embodiments of the invention are also presented.

[0012] In accordance with the invention, a procedure is proposed for a quiet takeoff of an aircraft leaving a starting point, the procedure comprising the following steps: - Provision of static start parameters to a simulation device, including at least the starting point, a planned arrival point, parameters of the aircraft itself and meteorological information at the time of the aircraft's planned takeoff from the starting point; - Provision of a population distribution at least along the horizontal flight route planned in the simulation device; - Execution, using the simulation device, of a flight noise simulation for different takeoff sequences, each comprising a combination of dynamic start parameters differing from other combinations, while for each takeoff sequence comprising the corresponding combination of dynamic start parameters and static start parameters, an aircraft model is simulated and, based on a sound emission based on the simulated aircraft model, itself simulated on the local population within an analysis area, at least one noise assessment indicator is determined, taking into account the population distribution data for the analysis area; - Display, on a display means of the simulation device, of takeoff sequences with simulation of in-flight noise together with the noise assessment indicator which was determined from the simulated sound emission on the local population inside the analysis area; - Execution of an aircraft takeoff in a low-noise regime with reference to one of the displayed takeoff sequences with flight noise simulation, with its own specific dynamic start-up parameters.

[0013] Static start parameters are first provided to a simulation device. These parameters are, in principle, invariable and concern at least the departure point and a planned arrival point, as well as invariable parameters of the aircraft itself. Such invariable aircraft parameters may include, for example, the aircraft's mass. In addition, meteorological information at the time of the aircraft's planned takeoff from the departure point is provided as part of the static start parameters, so that it can be taken into account during takeoff. noise-free mode

[0014] The provision of these static startup parameters can, in this case, be carried out, for example, by the pilot input into a flight assistance system, such as a flight planning assistance system. However, it is also conceivable that these static startup parameters could be determined automatically by the simulation device, for example, from other aircraft systems with which the simulation device is connected to communicate appropriately.

[0015] The simulation device is further provided with a population distribution at least within the analysis area (e.g., along a planned flight path), with storage, for example, in a database. The population distribution includes, in this case, information on the number of inhabitants in a specific delimited area, for example, a 100 x 100 m cell. The analysis area can, in this case, be determined using a programmed flight path over the ground. However, it is also possible to determine the analysis area dynamically, based on the simulated sound emission, such that, for example, a single area within which the sound level exceeds a certain threshold value (e.g., > 50 dB) is considered the analysis area. Alternatively, the analysis area can also be limited to certain localities.

[0016] A simulation of in-flight noise is then performed to determine the effects on the local population for different takeoff sequences or procedures. Specifically, a specific effect on the local population is determined for each takeoff sequence or procedure, with the different sequences or procedures distinguished from one another by a unique combination of dynamic start-up parameters. Each takeoff sequence or procedure is assigned a particular combination of predefined dynamic start-up parameters, allowing for a specific in-flight noise simulation for each of these takeoff sequences. Thus, the effect on the local population can be determined for each takeoff sequence.The simulation of noise in flight makes it possible to determine, by reference to the aircraft model associated with the dynamic and static start-up parameters for the specific flight programmed within the analysis area, the noise emission on the ground, while the cross-referencing of this simulated noise emission with the distribution of the population within the analysis area makes it possible to determine the noise assessment indicator (nuisance indicator), which describes the effects of the noise emission on the population in this area.

[0017] The flight noise simulation takes into account, in this respect, both the dynamic start-up parameters and the static start-up parameters already available and stops, which together allow us to 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 emission on the local population within the analysis area. More specifically, the noise emission could, for example, refer to the locally generated sound pressure level produced by the aircraft in the simulation. The impact of this noise emission on the population distribution within the analysis area is then determined, for each takeoff sequence, as a noise assessment indicator. This noise assessment indicator provides a representation of the nuisance affecting the local population as a function of the noise emission. Such a noise assessment indicator could, in this case, be determined, for example, based on the sound pressure level.

[0018] More specifically, the different takeoff sequences considered by the noise simulation can be determined, for example, using pre-existing, statically optimized takeoff sequences. Before the noise simulation, different takeoff sequences can therefore be determined by the simulation device, by reference to different known static takeoff sequences.

[0019] Next, the takeoff sequences with simulated in-flight noise are presented to the pilot on a display means of the simulation device, together with the established effects of the simulated noise emission on the local population, so that the pilot can select one of these takeoff sequences and thus execute a corresponding low-noise takeoff procedure, this having previously been simulated with respect to noise emission using the startup parameters used for the selected takeoff procedure. In this regard, the display must include at least the noise evaluation indicator determined for each takeoff sequence considered.

[0020] The intended arrival point may, in this case, also represent an intermediate point on the route leading to the intended arrival point as a landing point. From the departure point to the intended arrival point, a flight path may be proposed to define, for example, the ground analysis area for which the effects of the noise emission on the population will be determined.

[0021] With the present invention, it is thus possible to provide the pilot, for flight planning purposes, with a personalized recommendation for a quieter takeoff, thereby reducing the impact of flight noise on the local population. In this regard, actual start-up parameters, as well as population data and meteorological information, are taken into account in order to simulate noise emission as accurately as possible.

[0022] According to a particular embodiment, the dynamic startup parameters are provided to include a vertical takeoff profile from the point of departure, at least one thrust reduction altitude, one acceleration altitude, one measure for thrust reduction, one standard instrument takeoff (SID) route and / or one aircraft configuration.

[0023] According to a particular embodiment, a planned horizontal flight path for the aircraft from a starting point to the intended destination is provided as part of the static or dynamic start-up parameters. The planned horizontal flight path may, in this case, be static and unchanging. However, it is also possible for the flight path to participate in the optimization as a component of the dynamic start-up parameters, so that for different take-off procedures or take-off sequences, different flight paths are also considered as part of the dynamic start-up parameters.

[0024] From the flight path – whether it is based on dynamic or static start-up parameters – it is then possible to determine the ground analysis area for noise simulation. The analysis area may, in this case, also depend on other external factors such as, for example, wind direction and speed.

[0025] According to a particular embodiment, the aircraft parameters are provided to include the mass of the aircraft or a curve of the mass of the aircraft decreasing over time due to fuel consumption.

[0026] The aircraft mass is a fixed parameter at the start of the takeoff procedure. However, due to fuel consumption, the aircraft mass decreases during the takeoff procedure. Because of the short time period considered, the decrease in mass due to fuel consumption can be considered negligible for noise simulation, such that the aircraft has a constant mass during the takeoff procedure. Alternatively, one could consider a curve for the aircraft mass decreasing over time due to fuel consumption, this curve taking into account the decrease in the aircraft mass due to fuel consumption. In any case, the aircraft mass can thus be made available as a static start parameter.

[0027] According to a particular embodiment, the meteorological information is provided to include wind direction, wind speed, temperature, and / or atmospheric pressure. Knowing the wind direction and speed, it is possible to estimate, in relation to a horizontal flight path, the effects of the sound emission in the ground analysis area, since the sound emitted from its source towards the ground is deflected by the winds. Furthermore, the wind exerts a strong influence on flight performance, which can also be taken into account when simulating the sound emission. The analysis area can, in this case, also be defined taking into account the meteorological information, in particular the wind direction and speed.

[0028] According to a particular embodiment, it is provided that, in order to determine the noise assessment indicator as it defines the impact of the simulated noise emission on the local population, a number of awakening reactions are determined as a function of the simulated noise emission and data on the population distribution. With regard to the awakening reactions, this constitutes a noise assessment indicator that makes it possible to describe the effects of the simulated noise emission.

[0029] According to a particular embodiment, an estimated fuel consumption and / or an estimated flight time are determined for each takeoff sequence based on static and dynamic start-up parameters and displayed on the display. This allows pilots to evaluate the different takeoff sequences not only with regard to their optimal noise reduction but also with regard to flight performance characteristics such as, for example, estimated fuel consumption and estimated flight time, which are important information in air navigation.

[0030] According to a particular embodiment, some of the dynamic startup parameters are predefined and do not vary during the flight noise simulation. In this case, the pilot can, for example by entering a specific value into the assistance system, predefine certain dynamic startup parameters, such as the flap configuration, if required, for example, by external circumstances.

[0031] According to a particular embodiment, each takeoff sequence for which a noise simulation has been performed is compared to a reference takeoff sequence for which a noise simulation has also been performed, the result of the comparison being displayed on the display means for each takeoff sequence. The comparison with a static reference takeoff sequence allows the pilot, in this case, to compare it to a nominal value, which is useful both with regard to noise emission and with regard to other information such as fuel consumption and flight time.

[0032] According to the invention, the task is further solved using a flight assistance system intended to be integrated into an aircraft cockpit, the flight assistance system comprising a simulation device and a display means, and being designed to perform the procedure described above. The display means can, in this case, be integrated into an existing system in the cockpit.

[0033] The invention will be described further with the aid of the accompanying figures, given by way of examples.

[0034] They show:

[0035] [Fig.1] Schematic representation of the piloting assistance system according to the invention;

[0036] [Fig.2] representation as an example of a display;

[0037] [Fig.3] diagram of awakening reactions as a function of acceleration altitude;

[0038] [Fig.4] various diagrams;

[0039] [Fig.5] diagram of the sound pressure level as a function of the distance from the runway threshold.

[0040] Figure 1 is a highly simplified representation of the assistance system 10, which includes a simulation device 11 and a display means 12. Static startup parameters 100 are first provided to the simulation device 11. These parameters may, for example, be input from the pilot or automatically determined from other systems. These static startup parameters 100 are then entered into the flight assistance system 10.

[0041] The simulation device 11 includes an aircraft model 20 designed to simulate the aircraft using the startup parameters. In addition to the static startup parameters 100, the aircraft model also receives dynamic startup parameters 110 that vary according to the different takeoff procedures. This results, for the simulation aircraft model 20, in entirely different takeoff sequences.

[0042] The simulation device 11 further has a noise simulation 22, designed, with reference to the aircraft model 20 and the static and dynamic start-up parameters 100, 110 made available to the aircraft model 20, to calculate a sound emission for a ground analysis area.

[0043] The simulation device 11 further includes a database with the population density 21 or the population distribution, enabling it to obtain, at least in the immediate environment of the airport or within the analysis area, the number of population units for a cell.

[0044] Both the sound emission calculated from the noise simulation 22 and the population density 21 then constitute inputs in the analysis 23 in order to calculate the impact of the simulated sound emission on the population and to determine at least one indicator for evaluating the correlative noise.

[0045] This noise simulation occurs, in this case, for different takeoff sequences, each distinguished by its own dynamic start parameters, so that for each takeoff sequence, at least one corresponding noise evaluation indicator can be determined from the noise simulation. The takeoff sequences, each with its own dynamic start parameters and noise evaluation indicator, are then displayed to the pilot on the display device 12, enabling the pilot to select an appropriate procedure and execute a corresponding takeoff, based on the dynamic start parameters of the selected takeoff sequence.

[0046] The representation on the pilot assistance system as it may appear The display on the 12-inch screen is illustrated, as an example, in [Fig. 2]. In the table shown, the different takeoff sequences are represented line by line, while a comparison with a reference appears in the ANoise column for each takeoff sequence. The pilot can thus see the noise impact of the different takeoff sequences. In addition, a corresponding delta, relating to fuel consumption and flight time compared to the reference, is displayed. Furthermore, a takeoff procedure considered optimal can also be suggested.

[0047] This deserves to be illustrated with an example. Let us now consider, for a NADP-2 takeoff from runway 7 at Stuttgart Airport, a starting mass of 75.5 t as well as a Conf-2 flap position at startup and a maximum startup thrust.

[0048] With regard to SID, ETASA2H is chosen for the lateral flight path which is initially oriented towards the east, then towards the north. In this context, the influence of a headwind of 15 kts and a tailwind of 10 kts, in the direction of the trajectory, on the noise distribution and consequently on the different optimal altitudes for acceleration, is demonstrated.

[0049] In both cases, with a headwind and a tailwind, for an acceleration altitude variation between 500 ft and 3,000 ft as an example for a noise assessment, the following arousal reactions can be calculated. The arousal reactions are calculated using the maximum noise level and population data. The calculations show that with a headwind and a low acceleration altitude, fewer arousal reactions are expected than with a tailwind and a high acceleration altitude.

[0050] The case shown in [Fig. 3] can, with a tailwind, significantly reduce the number of wake-up reactions for an acceleration at 3,000 ft compared to 500 ft. The reason for this is the change in the noise distribution along the flight path and the corresponding change in the impact on the population distribution.

[0051] Fig. 4 shows, for the case of a tailwind, the altitude curve as a function of the runway threshold (Above Ground Level, AGL), the flight speed (Calibrated Airspeed, CAS) and the engine speed (NI) as a function of the distance traveled from the runway threshold.

[0052] The speed plot (b) further includes the chosen target speed, the Minimum Flap Retraction Speed, and the Minimum Slat Retraction Speed, which are determining factors for the retraction of the high-lift flaps during the acceleration phase. In the altitude curve, it can be seen that the aircraft first climbs to 500 ft or 3,000 ft, then, describing a flatter trajectory angle, accelerates first to 220 kts, continues its climb to 3,000 ft, then accelerates to 250 kts and subsequently climbs to 10,000 ft. (MSL) before transitioning to level flight. In the case of later acceleration, the acceleration is continuous, reaching 250 kts directly. Later acceleration initially results in a steeper climb angle and consequently a higher overflight altitude, a later thrust reduction, and, in the zone extending to approximately 9 NM, a lower flight speed.

[0053] In the zone between 5.5 and 8 NM, the overflight area is very densely populated. In this zone, in the case of late acceleration (3,000 ft), for a comparable thrust level, the overflight altitude is higher and the flight speed lower.

[0054] Figure 5 shows, for both cases, the interpolated curve of the maximum noise level below the flight path. It can be seen that up to approximately 7.5 NM, the noise level for the late acceleration case (3,000 ft) is significantly lower. This corresponds to the densely populated section. Beyond this point, the noise level is higher, but the aircraft is then in a sparsely populated area. The noise emissions have been distributed so that the flight phase associated with a high expected noise level is shifted towards a sparsely populated region. Each variation of the parameters results in different flight performance and a different noise distribution, which clearly demonstrates the potential for personalized optimization using an assistance system.

[0055] List of references 10 Pilot assistance system 11 Simulation Device 12. Display Method 20 Model airplane 21 Population distribution 22 Noise Simulation 23 Analysis 100 Static startup parameters 110 Dynamic startup parameters

Claims

Claims

1. A procedure for a low-noise takeoff of an aircraft leaving a departure point, the procedure comprising the following steps: - Providing static departure parameters (100) to a simulation device (11), comprising at least the departure point, an expected arrival point, parameters of the aircraft itself and weather information at the time of the expected takeoff of the aircraft from the departure point; - Provision of a population distribution at least along the horizontal flight path provided in the simulation device (11); - Carrying out, by means of the simulation device (11), a flight noise simulation (22) for different take-off sequences each comprising a combination of dynamic start-up parameters (110) differing from the other combinations, while for each take-off sequence comprising the corresponding combination of dynamic start-up parameters (110) and the static start-up parameters (100), an aircraft model (20) is simulated and, depending on a noise emission based on the simulated aircraft model (20), itself simulated on the local population within an analysis area, at least one noise evaluation indicator is determined taking into account the population distribution data for the analysis area; - Display, on a display means (12) of the simulation device (11), of the take-off sequences with simulation of the in-flight noise together with the noise evaluation indicator which was determined from the simulated sound emission on the local population within the analysis zone; - Execution of an aircraft takeoff in a lower noise regime with reference to one of the displayed takeoff sequences with flight noise simulation, with its own dynamic start-up parameters (110).

2. Procedure according to claim 1, characterized in that the dynamic start parameters (110) comprise a vertical takeoff profile from the starting point, at least one thrust reduction altitude, an acceleration altitude, a measure for thrust reduction, a standardized takeoff route for flights at the ins- instruments (SID) and / or an aircraft configuration.

3. Procedure according to one of claims 1 or 2, characterized in that as static or dynamic start parameters, a planned horizontal flight route for the aircraft from a starting point to the planned arrival point is provided.

4. Procedure according to one of the preceding claims, characterized in that the parameters of the aircraft include the mass of the aircraft or a curve decreasing over time of the mass of the aircraft due to the fuel consumption.

5. Procedure according to one of the preceding claims, characterized in that the meteorological information comprises a wind direction, a wind speed, a temperature and / or an atmospheric pressure.

6. Procedure according to one of the preceding claims, characterized in that in order to determine the noise assessment indicator as it defines the impact of the simulated sound emission on the local population, a certain number of awakening reactions are determined as a function of the simulated sound emission and the data on the distribution of the population.

7. Procedure according to one of the preceding claims, characterized in that an estimated fuel consumption and / or an estimated flight time are determined for each take-off sequence as a function of the static and dynamic start parameters (110) and displayed on the display means (12) for each take-off sequence.

8. Procedure according to one of the preceding claims, characterized in that a part of the dynamic start parameters (110) is predefined in a fixed manner and does not vary during the simulation of the in-flight noise (22).

9. Procedure according to one of the preceding claims, characterized in that each take-off sequence for which a noise simulation (22) has been executed is compared with a reference take-off sequence for which a noise simulation (22) has also been executed, the result of the comparison being displayed on the display means (12) for each take-off sequence.

10. A pilot assistance system (10) intended to be integrated into a cockpit of an aircraft equipped with a simulation device (11) and a display means (12), the pilot assistance system (10) being designed to carry out the procedure according to one of the preceding claims.

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