Patent Description:
Various types of aircraft are used to transport passengers and cargo between various locations. Each aircraft typically flies between different locations according to a defined flight plan or path. For example, an aircraft departs from a departure location and flies to an arrival location.

Certain governmental regulations and airport restrictions define a maximum gross weight for a particular aircraft upon landing at an airport. That is, if the gross weight of the aircraft of the aircraft upon landing at the airport exceeds a predefined maximum weight threshold, the operating airline may be assessed a fine, for example.

The gross weight of the aircraft is the total weight of the aircraft including freight, fuel, passengers, and the like. As can be appreciated, the amount of fuel aboard an aircraft prior to take off is substantially more than the amount of fuel aboard the aircraft after the aircraft has landed at an arrival airport. That is, as fuel is burned, there is less fuel onboard the aircraft, and therefore the weight of the aircraft decreases.

However, known methods of estimating gross weight of an aircraft may not be accurate in relation to fuel quantity. Such methods may lead to overweight conditions at an arrival airport. <CIT>, in accordance with its abstract states, a system for validating ground determination of gross weight of aircraft includes sensor(s) that generates information regarding ground determination of gross weight while parked at parking bay; processing device that receives information regarding ground determination of gross weight of the aircraft from sensor(s); and computer memory communicatively coupled to processing device. Processing device determines ground determination based on information regarding ground determination of gross weight generated by sensor. Processing device determines gross weight in air after takeoff based on indicated airspeed, angle of attack, and thrust applied to aircraft. Processing device determines error between ground determination and air determination of gross weight taking into account reduction in gross weight due to fuel consumed since receiving ground determination. Processing device updates information regarding relationship between ground determination and air determination of gross weight. Computer memory stores updated information regarding relationship for use next time aircraft parks at parking bay.

A need exists for a system and method for accurately estimating and determining a gross weight of an aircraft. Further, a need exists for a system and method that allow an aircraft operator to confidently predict a gross weight of an aircraft at an arrival location. Moreover, a need exists for a system and method for accurately determining a gross weight of an aircraft during a flight and predict the gross weight upon landing.

With those needs in mind, certain examples of the present disclosure provide an aircraft landing weight determination system that is configured to determine an accurate gross weight of an aircraft.

The gross weight determination control unit may determine the accurate gross weight of the aircraft at any point during a flight of the aircraft between a departure gate at a departure location and an arrival gate at an arrival location.

In at least one example, the gross weight determination control unit may predict a gross weight of the aircraft at an arrival location before landing based on the accurate gross weight of the aircraft.

The aircraft landing weight determination system may also include a flight computer in communication with the gross weight determination control unit. The flight computer stores flight data for the aircraft.

The aircraft landing weight determination system may also include one or more fuel sensors in communication with the gross weight determination control unit. The fuel sensor(s) are configured to determine an amount of fuel onboard the aircraft.

The aircraft landing weight determination system may also include one or more weight sensors in communication with the gross weight determination control unit. The weight sensor(s) are configured to detect a gross weight of the aircraft.

The aircraft landing weight determination system may also include a weight threshold database in communication with the gross weight determination control unit. The weight threshold database stores a maximum weight threshold for the aircraft at an arrival location. The gross weight determination control unit is configured to compare the accurate gross weight of the aircraft with the maximum weight threshold to determine if the aircraft is in an overweight condition.

In at least one example, the gross weight determination control unit ignores first data gaps in the first source, and ignores second data gaps in the second source. The gross weight determination control unit combines accurate gross weight data from the first source and the second source to determine the accurate gross weight of the aircraft.

Certain examples of the present disclosure provide an aircraft landing weight determination method that is configured to determine an accurate gross weight of an aircraft. The aircraft landing weight determination method includes determining, by a gross weight determination control unit, an accurate gross weight of an aircraft based on a first source of gross weight data of the aircraft and a second source of gross weight data of the aircraft.

In at least one example, the determining includes comparing a gross weight <NUM> to a maximum weight threshold in response to determining that the gross weight <NUM> is not constant during at least a portion of a flight, comparing a gross weight <NUM> to the maximum weight threshold in response to determining that the gross weight <NUM> is constant and the gross weight <NUM> is not constant during at least a portion of a flight, and determining that the aircraft is in an overweight condition when the gross weight <NUM> or the gross weight <NUM> exceeds the maximum weight threshold.

The determining may include determining the accurate gross weight of the aircraft at any point during a flight of the aircraft between a departure gate at a departure location and an arrival gate at an arrival location.

The aircraft landing weight determination method may also include predicting, by the gross weight determination control unit, a gross weight of the aircraft at an arrival location before landing based on the accurate gross weight of the aircraft.

In at least one example, the determining includes ignoring first data gaps in the first source, ignoring second data gaps in the second source, combining accurate gross weight data from the first source and the second source, and determining the accurate gross weight of the aircraft based on the combining.

Further, references to "one embodiment" (or "one example") are not intended to be interpreted as excluding the existence of additional examples that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, examples "comprising" or "having" an element or a plurality of elements having a particular condition may include additional elements not having that condition.

Certain examples of the present disclosure provide an aircraft landing weight determination system that is configured to obtain real time aircraft weight inputs including gross weight <NUM> (initially determined or otherwise initially established when the aircraft is on the ground) and gross weight <NUM> (determined when the aircraft is in the air with no weight on wheels). The two aircraft weight inputs, namely gross weight <NUM> and gross weight <NUM>, are combined to derive an accurate estimate of aircraft weight, and/or an accurate fuel quantity measurement. In at least one example, a pilot may take remedial action (such as flying via a different flight path to the arrival location) to ensure that the aircraft complies with governmental and airport regulations and restrictions upon landing.

Certain examples of the present disclosure provide systems and methods for monitoring and evaluating aircraft weight. In at least one example, the systems and methods include receiving two sources of aircraft weight data. A first source is gross weight <NUM>, which includes pre-flight and taxi data. A second source is gross weight <NUM>, which includes in-flight data. The first source and the second source are both analyzed to determine an accurate gross weight of the aircraft, whether in flight or on the ground.

As described herein, certain examples of the present disclosure provide an aircraft landing weight determination system that includes a gross weight determination control unit that is configured to determine an accurate gross weight of an aircraft based on a first source of gross weight data of the aircraft and a second source of gross weight data of the aircraft. The first source of gross weight data may be gross weight <NUM>, and the second source of gross weight data may be gross weight <NUM>. In at least one example, the gross weight determination control unit is configured to analyze the gross weight <NUM> and the gross weight <NUM> for the aircraft, such as at any point during a flight. The gross weight determination control unit is configured to determine an accurate gross weight of the aircraft based on one or both of the gross weight <NUM> and the gross weight <NUM>. In at least one example, the gross weight determination control unit predicts a gross weight of the aircraft at an arrival location before landing based on the accurate gross weight of the aircraft. That is, the gross weight determination control unit may determine the accurate gross weight of the aircraft at any point during a flight before landing at the arrival location, and use the accurate gross weight to predict the gross weight of the aircraft upon landing.

<FIG> illustrates a simplified representation of an aircraft <NUM> traveling from a departure gate <NUM> to an arrival gate <NUM>. The departure gate <NUM> is at a departure location <NUM> (such as a first airport) that includes taxiway(s), runway(s), and the like. The arrival gate <NUM> is at an arrival location <NUM> (such as a second airport) that includes taxiway(s), runway(s), and the like. At the departure gate <NUM>, crew, passengers, cargo, freight, and/or the like are boarded onto the aircraft <NUM>. At a scheduled time, the aircraft <NUM> pushes back from the departure gate <NUM> and taxis on the ground to a runway, at which point the aircraft <NUM> takes off at point <NUM>, at which the wheels of the aircraft are no longer on the ground. The aircraft <NUM> ascends to a cruising altitude <NUM> and descends towards the arrival location <NUM>, at which point the aircraft touches down at point <NUM>, at which the wheels of the aircraft <NUM> are on the ground. The aircraft <NUM> then taxis to the arrival gate <NUM>, where the passengers, and crew may depart the aircraft <NUM>.

A first source of aircraft weight is gross weight <NUM> (GW1). Gross weight <NUM> for the aircraft is determined from the departure gate <NUM> before the aircraft pushes back from the departure gate <NUM> to the arrival gate <NUM>, and includes the time that the aircraft <NUM> is airborne, that is, in the air (off the ground), between points <NUM> and <NUM>. In at least one example, the pilot inputs the gross weight <NUM> of the aircraft <NUM> before pushing back from the departure gate <NUM>. Gross weight <NUM> is calculated as an initial gross weight at the departure gate <NUM> minus fuel burn during the flight.

As noted, the pilot inputs the gross weight <NUM> at the beginning of the flight (such as at the departure gate <NUM>, before pushback therefrom), and is then assumed constant during the entirety of the flight. For example, based on the flight path and time of flight between points <NUM> and <NUM>, a fuel burn is determined. Based on the determined fuel burn, the fuel weight between the points <NUM> and <NUM> is determined. As such, gross weight <NUM> is based on input from the pilot, and assumes a constant decrease in weight during the in-air phases of the flight.

A second source of aircraft weight is gross weight <NUM> (GW2). Unlike gross weight <NUM>, gross weight <NUM> is not dependent upon pilot input. Gross weight <NUM> is determined from actual flight data between the points <NUM> and <NUM> (when the aircraft <NUM> is off the ground). In at least one example, gross weight <NUM> is determined when there is no weight on wheels of the aircraft <NUM> (that is, when the aircraft <NUM> is off the ground and in the air). Gross weight <NUM> is a complex calculation with different tables. Gross weight <NUM> is an accurate measure of gross weight of the aircraft <NUM> while in the air. In at least one example, gross weight <NUM> is determined from fuel sensors on board the plane, weight sensors, engine operation and output, and/or the like. Unlike gross weight <NUM>, gross weight <NUM> does not assume a constant fuel burn during the flight.

<FIG> illustrates a schematic box diagram of an aircraft landing weight determination system <NUM>, according to an example of the present disclosure. The aircraft <NUM> includes a flight computer <NUM> in communication with an input device <NUM>, such as through one or more wired or wireless connections. The input device <NUM> may be or include a keyboard, mouse, touchscreen interface, and/or the like. The flight computer <NUM> stores flight data between the departure gate <NUM> and the arrival gate <NUM> (shown in <FIG>). The flight data includes the flight path between the points <NUM> and <NUM> (shown in <FIG>), as well as altitudes, airspeeds, and the like for the aircraft <NUM> during the flight.

The aircraft <NUM> also includes one or more fuel sensors <NUM> in communication with one or more fuel tanks <NUM>. The fuel sensor(s) <NUM> may be on or within the fuel tank(s) <NUM> and are configured to determine an amount of fuel within the fuel tank(s) <NUM>.

In at least one example, the aircraft <NUM> also includes one or more weight sensor(s) <NUM>. The weight sensor(s) <NUM> are configured to detect a gross weight of the aircraft <NUM>.

The aircraft landing weight determination system <NUM> may be onboard the aircraft <NUM> or may be remotely located from the aircraft <NUM>. In at least one example, the aircraft landing weight determination system <NUM> is onboard the aircraft <NUM>.

The aircraft landing weight determination system <NUM> includes a gross weight determination control unit <NUM> that is in communication with the flight computer <NUM>, the fuel sensor(s) <NUM>, the weight sensor(s) <NUM>, and a weight threshold database <NUM>, such as through one or more wired or wireless connections. As shown, the gross weight determination control unit <NUM> is onboard the aircraft <NUM>. In at least one example, the gross weight determination control unit <NUM> is separate and distinct from the flight computer <NUM>. In at least one other example, the gross weight determination control unit <NUM> is part of the flight computer <NUM>. For example, the flight computer <NUM> may include the gross weight determination control unit <NUM>.

The weight threshold database <NUM> stores landing weight thresholds (for example, a maximum weight threshold) for the aircraft <NUM> (and optionally for various other aircraft) at the arrival location <NUM> (shown in <FIG>). A landing weight threshold is a gross weight magnitude at or above which the aircraft <NUM> is determined to be in an overweight condition at the arrival location <NUM>.

As shown, the gross weight determination control unit <NUM> and the weight threshold database <NUM> may both be onboard the aircraft <NUM>. In at least one other example, one or both of the gross weight determination control unit <NUM> and the weight threshold database <NUM> may be remotely located from the aircraft <NUM>. For example, the gross weight determination control unit <NUM> and/or the weight threshold database <NUM> may be at a central monitoring location (such as at an airport) and in communication with the aircraft <NUM>.

Referring to <FIG>, in operation, a pilot of the aircraft <NUM> inputs an initial gross weight of the aircraft <NUM> into the flight computer <NUM> via the input device <NUM>. The initial gross weight is determined through the weight sensor(s) <NUM>, the fuel sensor(s) <NUM>, and/or the like. For example, the initial gross weight is the gross weight of the aircraft <NUM> at the departure gate <NUM> including the weight of the aircraft <NUM> itself, plus the weight of the fuel within the fuel tanks(s) <NUM>, passengers, freight, and the like. In at least one example, the initial gross weight is automatically determined and input into the flight computer <NUM> via the weight sensor(s) <NUM> and the fuel sensor(s) <NUM> without manual input.

The gross weight determination control unit <NUM> receives gross weight <NUM> data to determine the gross weight <NUM> of the aircraft <NUM>, such as at any point during the flight of the aircraft <NUM>. For example, the gross weight determination control unit <NUM> receives the initial gross weight of the aircraft <NUM> (whether input by a pilot or automatically determined via the weight sensor(s) <NUM> and the fuel sensor(s) <NUM>) and analyzes the flight plan for the aircraft <NUM> between the departure gate <NUM> and the arrival gate <NUM>. The gross weight determination control unit <NUM> determines the fuel burn of the aircraft <NUM> based on the flight plan. The gross weight determination control unit <NUM> then determines gross weight <NUM> based on the initial gross weight of the aircraft <NUM> and the fuel burn. The gross weight determination control unit <NUM> is configured to determine the gross weight <NUM> of the aircraft <NUM> at any point between the departure gate <NUM> and the arrival gate <NUM> based on subtracting the fuel burn from the initial gross weight.

The gross weight determination control unit <NUM> also receives gross weight <NUM> data to determine the gross weight <NUM> of the aircraft <NUM>, such as at any point during the flight of the aircraft <NUM>. For example, the gross weight determination control unit <NUM> receives weight data from the weight sensor(s) <NUM>, fuel data from the fuel sensor(s) <NUM>, and/or the like during the in-air phases of the flight of the aircraft <NUM> between points <NUM> and <NUM>. As such, the gross weight determination control unit <NUM> determines actual fuel burn and weight of the aircraft <NUM>, instead of assuming a constant fuel burn based on the flight data stored in the flight computer <NUM>. In this manner, the gross weight determination control unit <NUM> also determines gross weight <NUM>.

The gross weight determination control unit <NUM> analyzes both gross weight <NUM> and gross weight <NUM> at any point during the flight between the departure gate <NUM> and the arrival gate <NUM> to determine an accurate gross weight of the aircraft <NUM> at such point in the flight, as well as make an accurate prediction of the gross weight of the aircraft <NUM> when the aircraft <NUM> lands at point <NUM> at the arrival location <NUM>. In this manner, the gross weight determination control unit <NUM> does not rely solely on gross weight <NUM> or gross weight <NUM> to determine the gross weight of the aircraft <NUM> at the arrival location <NUM>. Instead, the gross weight determination control unit <NUM> generates an accurate gross weight determination and prediction based on both gross weight <NUM> and gross weight <NUM> of the aircraft <NUM>.

<FIG> illustrates graphs of altitude <NUM>, phase <NUM>, gross weight <NUM> (GW1), and gross weight <NUM> (GW2) of the aircraft <NUM> (shown in <FIG>) over time t. As shown, the altitude <NUM> of the aircraft <NUM> differs at different phases. For example, the altitude <NUM> at a taxi and takeoff phase <NUM> is at ground level, while the altitude <NUM> may be relatively constant during a cruising phase <NUM>.

As shown, gross weight <NUM> may assume a constant fuel burn from departure until landing. Conversely, gross weight <NUM> provides varying fuel burn determinations between departure and landing, due to actual detection of weight parameters (such as fuel burn) during in-air phases of a flight.

<FIG> illustrates graphs of gross weight <NUM> and gross weight <NUM> of the aircraft <NUM> (shown in <FIG>) over time. As shown, both gross weight <NUM> and gross weight <NUM> may include data gaps <NUM> during a flight of the aircraft <NUM>. For example, during a flight, the fuel burn may not be constant (that is, a constant slope indicating a constant and steady fuel burn). Further, during a flight, sensor data may not accurately output fuel burn. For example, during particular maneuvers (such as ascents, descents, banks, and the like) the fuel sensor(s) <NUM> may not accurately detect the fuel within the fuel tank(s) <NUM> (shown in <FIG>), such as when fuel is shifted to a side of a fuel tank during a bank.

Referring to <FIG>, and <FIG>, in at least one example, the gross weight determination control unit <NUM> determines the total gross weight of the aircraft <NUM> at a current time and a future time (such as when the aircraft lands at the arrival location <NUM>) based on accurate data from gross weight <NUM> and gross weight <NUM>. For example, the gross weight determination control unit <NUM> detects accurate gross weight data <NUM>, <NUM>, <NUM>, and <NUM> from gross weight <NUM> during various phases of the flight. The gross weight determination control unit <NUM> ignores the data gaps <NUM> within the gross weight <NUM>. Similarly, the gross weight determination control unit <NUM> detects accurate gross weight data <NUM>-<NUM> from gross weight <NUM> during various phases of the flight. The gross weight determination control unit <NUM> ignores the data gaps <NUM> within the gross weight <NUM>. The gross weight determination control unit <NUM> combines the accurate data <NUM>, <NUM>, <NUM>, and <NUM> from gross weight <NUM> and the accurate data <NUM>-<NUM> from gross weight <NUM> to determine an accurate gross weight of the aircraft <NUM> at any point during the flight.

The gross weight determination control unit <NUM> may also use the accurate gross weight of the aircraft <NUM> to predict a landing weight of the aircraft <NUM> (such as at point <NUM> at the arrival location). For example, the gross weight determination control unit <NUM> may determine the accurate gross weight of the aircraft <NUM>, based on accurate data from gross weight <NUM> and accurate data from gross weight <NUM>, determine a remaining length of the flight on the flight plan stored in the flight computer <NUM>, and subtract a predicted weight of fuel that is to be burned (that is, a predicted fuel burn) for the remaining duration of the flight to predict the landing weight of the aircraft <NUM>.

<FIG> illustrates a flow chart of an aircraft landing weight determination method, according to an example of the present disclosure. Referring to <FIG>, the gross weight determination control unit <NUM> determines gross weight <NUM> and gross weight <NUM> at <NUM> at any point during a flight from the departure gate <NUM> to the arrival gate <NUM>. As described above, the gross weight <NUM> is determined based on aircraft weight data input from the pilot and/or automatically through one or more sensors of the aircraft. The gross weight determination control unit <NUM> then determines gross weight <NUM> for the aircraft <NUM> by subtracting a lost fuel weight as determined from a predicted fuel burn for the flight, as determined from the flight plan stored in the flight computer <NUM>, from the aircraft weight data as determined at the departure gate <NUM>.

The gross weight <NUM> is determined from actual data output by various sensors of the aircraft <NUM> during an in-air portion of the flight of the aircraft, such as between points <NUM> and <NUM>. The gross weight determination control unit <NUM> may determine the gross weight <NUM> and gross weight <NUM> at any point during the flight, and analyze a remaining flight time and flight path of the aircraft to the arrival location <NUM> to predict a the gross weight <NUM> and gross weight <NUM> at the arrival location <NUM>.

At <NUM>, the gross weight determination control unit <NUM> determines if the gross weight <NUM> is constant up until the particular point in the flight (such as at a particular time of a phase of the flight). In at least one example, the gross weight determination control unit <NUM> determines that the gross weight <NUM> is constant if there are no data gaps in the gross weight <NUM> and/or the slope of the gross weight <NUM> (that is, the decreasing slope, as the weight of the aircraft necessarily decreases as fuel is burn) is constant. If the gross weight <NUM> is not constant at <NUM>, the gross weight determination control unit <NUM> determines if the gross weight <NUM> of the aircraft <NUM> (whether at the current point in the flight, or at the arrival location <NUM>) is less than a maximum weight threshold for the aircraft <NUM> as stored in the weight threshold database <NUM>. If the gross weight <NUM> is less than the maximum weight threshold, the gross weight determination control unit <NUM> determines that no overweight condition is present at <NUM>. If, however, the gross weight <NUM> is equal to or greater than the maximum weight threshold, the gross weight determination control unit <NUM> determines an overweight condition at <NUM>, and may output an overweight condition alert to the pilot of the aircraft <NUM>, such as through one or more graphical, video, and/or audio messages.

If, at <NUM>, the gross weight <NUM> is constant, the method proceeds to <NUM>, at which the gross weight <NUM> is assessed. At <NUM>, the gross weight determination control unit <NUM> determines if the gross weight <NUM> is constant. If the gross weight <NUM> is constant (as well as the gross weight <NUM> being constant), then at <NUM> the gross weight determination control unit <NUM> determines that both gross weight <NUM> and gross weight <NUM> are both accurate. As such, either the gross weight <NUM> or the gross weight <NUM> may be used to provide an accurate determination and/or prediction of gross weight of the aircraft <NUM>.

If, however, the gross weight <NUM> is not constant at <NUM>, the method proceeds to <NUM>, at which the gross weight determination control unit <NUM> determines whether the gross weight <NUM> is less than the maximum weight threshold, as stored in the weight threshold database <NUM>. If the gross weight <NUM> is less than the maximum weight threshold, the method proceeds to <NUM>, at which the gross weight determination control unit <NUM> determines that no overweight condition is present. If, however, the gross weight <NUM> is equal to or greater than the maximum weight threshold at <NUM>, the gross weight determination control unit <NUM> determines an overweight condition at <NUM>, and may then output an overweight condition alert to the pilot of the aircraft <NUM>.

In response to receiving an overweight condition alert from the gross weight determination control unit <NUM>, a pilot may take remedial action(s) to ensure that the aircraft is under the maximum weight threshold at the arrival location <NUM>. For example, the pilot may request from air traffic control to be placed in a holding pattern to burn additional fuel before landing so that the aircraft <NUM> is under the maximum weight threshold upon landing. As another example, the pilot may request from air traffic control an alternate (for example, longer) route to the arrival location so that additional fuel is burned before landing.

In at least one example, an aircraft landing weight determination method is configured to determine an accurate gross weight of an aircraft. The aircraft landing weight determination method includes determining, by the gross weight determination control unit <NUM> an accurate gross weight of an aircraft based on a first source of gross weight data of the aircraft and a second source of gross weight data of the aircraft. In at least one example, the first source of gross weight data is gross weight <NUM>, and the second source of gross weight data is gross weight <NUM>.

In at least one example, the determining includes comparing the gross weight <NUM> to a maximum weight threshold in response to determining that the gross weight <NUM> is not constant during at least a portion of a flight, comparing the gross weight <NUM> to the maximum weight threshold in response to determining that the gross weight <NUM> is constant and the gross weight <NUM> is not constant during at least a portion of a flight, and determining that the aircraft is in an overweight condition when the gross weight <NUM> or the gross weight <NUM> exceeds the maximum weight threshold. The determining may include determining the accurate gross weight of the aircraft at any point during a flight of the aircraft between a departure gate at a departure location and an arrival gate at an arrival location. In at least one example, the aircraft landing weight determination method also includes predicting, by the gross weight determination control unit <NUM>, a gross weight of the aircraft at an arrival location before landing based on the accurate gross weight of the aircraft.

As used herein, the term "control unit," "central processing unit," "unit," "CPU," "computer," or the like may include any processor-based or microprocessor-based system including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASICs), logic circuits, and any other circuit or processor including hardware, software, or a combination thereof capable of executing the functions described herein. Such are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of such terms. For example, the gross weight determination control unit <NUM> may be or include one or more processors that are configured to control operation thereof, as described herein.

The gross weight determination control unit <NUM> is configured to execute a set of instructions that are stored in one or more data storage units or elements (such as one or more memories), in order to process data. For example, the gross weight determination control unit <NUM> may include or be coupled to one or more memories. The data storage units may also store data or other information as desired or needed. The data storage units may be in the form of an information source or a physical memory element within a processing machine.

The set of instructions may include various commands that instruct the gross weight determination control unit <NUM> as a processing machine to perform specific operations such as the methods and processes of the various examples of the subject matter described herein. The set of instructions may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs, a program subset within a larger program or a portion of a program. The software may also include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine.

The diagrams of examples herein may illustrate one or more control or processing units, such as the gross weight determination control unit <NUM>. It is to be understood that the processing or control units may represent circuits, circuitry, or portions thereof that may be implemented as hardware with associated instructions (e.g., software stored on a tangible and non-transitory computer readable storage medium, such as a computer hard drive, ROM, RAM, or the like) that perform the operations described herein. The hardware may include state machine circuitry hardwired to perform the functions described herein. Optionally, the hardware may include electronic circuits that include and/or are connected to one or more logic-based devices, such as microprocessors, processors, controllers, or the like. Optionally, the gross weight determination control unit <NUM> may represent processing circuitry such as one or more of a field programmable gate array (FPGA), application specific integrated circuit (ASIC), microprocessor(s), and/or the like. The circuits in various examples may be configured to execute one or more algorithms to perform functions described herein. The one or more algorithms may include aspects of examples disclosed herein, whether or not expressly identified in a flowchart or a method.

<FIG> is a diagrammatic representation of a front perspective view of the aircraft <NUM>, according to an exemplary example of the present disclosure. The aircraft <NUM> includes a propulsion system <NUM> that may include two turbofan engines <NUM>, for example. Optionally, the propulsion system <NUM> may include more engines <NUM> than shown. The engines <NUM> are carried by wings <NUM> of the aircraft <NUM>. In other examples, the engines <NUM> may be carried by a fuselage <NUM> and/or an empennage <NUM>. The empennage <NUM> may also support horizontal stabilizers <NUM> and a vertical stabilizer <NUM>. The fuselage <NUM> of the aircraft <NUM> defines an internal cabin, which may include a cockpit <NUM>.

The aircraft <NUM> may be sized, shaped, and configured other than shown in <FIG>. For example, the aircraft <NUM> may be a non-fixed wing aircraft, such as a helicopter. As another example, the aircraft <NUM> may be an unmanned aerial vehicle (UAV).

As described herein, examples of the present disclosure provide systems and methods for accurately estimating and determining a gross weight of an aircraft. Further, examples of the present disclosure provide systems and methods that allow an aircraft operator to confidently predict a gross weight of an aircraft at an arrival location. Moreover, examples of the present disclosure provide systems and methods for accurately determining a gross weight of an aircraft during a flight and predict the gross weight upon landing.

While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front and the like may be used to describe examples of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like.

Claim 1:
An aircraft (<NUM>) landing weight determination system that is configured to determine an accurate gross weight of an aircraft (<NUM>), the aircraft (<NUM>) landing weight determination system comprising:
a gross weight determination control unit that is configured to determine an accurate gross weight of an aircraft (<NUM>) at a point (<NUM>, <NUM>) during a flight between a departure gate (<NUM>) at a departure location (<NUM>) and an arrival gate (<NUM>) at the arrival location (<NUM>) based on a first source of gross weight data (GW1) of the aircraft (<NUM>), and a second source of gross weight data (GW2) of the aircraft (<NUM>) determined from measurements in the flight, including measurement from one or more onboard fuel sensors;
characterized in that
the first source of gross weight data is a first gross weight based on pilot input of the departure gate gross weight when the aircraft (<NUM>) is at the departure gate (<NUM>) minus fuel weight determined based on a calculated fuel burn between the departure gate (<NUM>) and the point assuming a constant decrease in weight during flight,
wherein the gross weight determination control unit is configured to:
compare the first gross weight to a maximum weight threshold in response to determining that the first gross weight is not constant during at least a portion of the flight to determine if the aircraft (<NUM>) is in an overweight condition; wherein determining that the first gross weight is not constant comprises determining a decreasing slope of the first gross weight as fuel is burned is not constant; and
compare the second gross weight to the maximum weight threshold in response to determining that the first gross weight is constant and the second gross weight is not constant during at least a portion of the flight to determine if the aircraft (<NUM>) is in an overweight condition; and
determine that the aircraft (<NUM>) is in an overweight condition when the first gross weight or the second gross weight exceed the maximum weight threshold.