Office Action 2: Final Rejection (2025-10-24)
Rejection types: 103 - Obviousness

CLAIMS:
Amendments to the Claims:

The following listing of claims will replace all prior versions, and listings, of claims in the application:

1\. (Currently Amended) A method of determining one or more fuel characteristics of an aviation fuel suitable for powering a gas turbine engine of an aircraft, the method comprising:determining a mass of a fuel being loaded, or which has been loaded, onto the aircraft;
determining a corresponding volume of the fuel; and
determining one or more fuel characteristics of the fuel based on the determined mass and volume, wherein the one or more fuel characteristics are determined by either or both of (i) comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table and (ii) calculating a deviation of a value derived from the determined fuel mass and fuel volume from an expected value.

2\. (Original) The method of claim 1, wherein determining the one or more fuel characteristics comprises calculating a fuel density based on the determined fuel mass and fuel volume.

3\. (Original) The method of claim 1, wherein:a) determining the mass of the fuel comprises measuring a mass flow rate at a point within a fuel supply line used to convey fuel to one or more fuel tanks on board the aircraft; and/or

b) determining the volume of the fuel comprises measuring a volume flow rate at a point within a fuel supply line used to convey fuel to one or more fuel tanks on board the aircraft.
4\. (Currently Amended) The method of claim 1, wherein:
a) determining the mass of the fuel comprises measuring the mass and/or a change in the mass of any one or more of: the aircraft; one or more fuel tanks on board the aircraft; a fuel tanker vehicle from which the fuel is supplied; and a storage vessel from which the fuel is supplied to the aircraft; and/or b) determining the volume of the fuel comprises measuring the volume and/or a change in the volume of fuel stored in one or more fuel tanks on board theaircraft and/or stored in a fuel storage vessel from which the fuel is supplied to the aircraft.

5\. (Currently Amended) The method of claim 1, wherein the one or more fuel characteristics determined include any one or more of:(i) a hydrocarbon distribution of the fuel;
(ii) a percentage of sustainable aviation fuel in the fuel; and (iii) an aromatic hydrocarbon content of the fuel.

6\. (Currently Amended) The method of claim 1, wherein the one or more fuel characteristics include an indication that the fuel is a fossil fuel.
7\. (Original) The method of claim 1, wherein the one or more fuel characteristics are further determined based on a signal indicative of the temperature of the fuel.

8\. (Currently Amended) A fuel characteristic determination system for determining one or more fuel characteristic of an aviation fuel suitable for powering a gas turbine engine of an aircraft, the system comprising:

a fuel characteristic determination module omprising a processor programmed to:receive a fuel mass signal indicative of a mass of the fuel being loaded, or which has been loaded,onto the aircraft;
receive a fuel volume signal indicative of a volume of fuel being loaded, or which has been loaded, onto the aircraft; and determine one or more fuel characteristics of the fuel based on the fuel volume and fuel mass signals, wherein the one or more fuel characteristics are determined by either or both of (i)comparing a value derived from the indicated fuel mass and fuel volume to values in a lookup table and (ii) calculating a deviation of a value derived from the indicated fuel mass and fuel volume from an expected value.
9\. (Currently Amended) The fuel characteristic determination system of The fuel characteristic determination system of
wherein the processor of the fuel characteristic determination module is programmed to calculate a density of the fuel based on the fuel mass signal andthe fuel volume signal.

10\. (Original) The fuel characteristic determination system of claim 8, further comprising:a mass sensor arranged to measure a mass of the fuel, wherein the fuel mass signal is received from the mass sensor; and/ora volume sensor arranged to measure a volume of fuel, wherein the fuel volume signal is received from the volume sensor.

11\. (Original) The fuel characteristic determination system of claim 10, wherein:the mass sensor is a mass flow rate meter; and/or the volume sensor is a volume flow rate meter.

12\. (Currently Amended) The fuel characteristic determination system of claim 11, wherein the mass flow rate meter is arranged to measure mass flow rate at a point within a fuel supply line used to convey fuel to one or more fuel tanks on board the aircraft.
13\. (Original) The fuel characteristic determination system of claim wherein the volume flow rate meter is arranged to measure a volume flow rate at a point within a fuel supply line used to supply fuel to one or more fuel tanks on board the aircraft.SVG {EMBED HERE} 0.130.18
14\. (Currently Amended) The fuel characteristic determination system of claim 8,wherein a) the fuel mass signal is based on a measured mass and/or change in the mass of any one or more of: the aircraft; one or more fuel tankson board the aircraft; a fuel tanker vehicle from which the fuel is supplied; and\_a storage vessel from which the fuel is supplied to the aircraft; and/or b) the fuel volume signal is based on a measured volume and/or change in the volume of fuel stored in one or more fuel tanks on board the aircraft and/or stored in a fuel storage vessel from which the fuel is supplied to the aircraft.
15\. (Currently Amended) The fuel characteristic determination system of claim 8,wherein the one or more fuel characteristics determined include any one or more of:(i) a hydrocarbon distribution of the fuel;SVG {EMBED HERE} 0.1330.383
(ii) a percentage of sustainable aviation fuel in the fuel; (iii) an aromatic hydrocarbon content of the fuel.

16\. (Currently Amended) The fuel characteristic determination system of The fuel characteristic determination system of
wherein the one or more fuel characteristics include an indication that the fuel is a fossil fuel .

17\. (Currently Amended) The fuel characteristic determination system of claim 8,wherein the processor of the fuel characteristic determination module is further programmed to determine the one or more fuel characteristics based on a signal indicative of the temperature of the fuel.

18\. (Currently Amended) A method of operating an aircraft having a gas turbine engine, the method comprising:determining one or more fuel characteristics using the method of claim 1; and
operating the aircraft according to the determined one or more fuel characteristics.
19\. (Currently Amended) The method according to claim 18, wherein operating the aircraft according to the one or more fuel characteristics comprises:a) modifying a control parameter of the aircraft in response to the determined one or more fuel characteristics; and/or b) providing a fuel having different fuel characteristics during refuelling of the aircraft.

20\. (Original) An aircraft comprising the fuel characteristic determination system of claim 8, further comprising a control system arranged to control operation of the aircraft according to the one or more fuel characteristics determined by the fuel characteristic determination system.

OFFICE ACTION:
Notice of Pre-AIA  or AIA  Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA  35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art.  The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph:
(A)	the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B)	the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C)	the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier.  Such claim limitation(s) is/are:
“a fuel characteristic determination module arranged to receive a fuel mass signal … a fuel volume signal … determine one or more fuel characteristics” in claim 8, interpreted to be a generic computer component, a processor, or a controller, or equivalents thereof, as described according to the specification on page 62 lines 29-35: as seen in Figure 16, the determination module 105 in communication with mass and volume sensors 103, 104 to communicate to EEC 42.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph, applicant may:  (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA  35 U.S.C. 112, sixth paragraph.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-2, 7-10, 14, and 17-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Momenthy (US 4809174 A) in view of Galati (US 20220120599 A1) and Drancea (US 20200216188 A1).
Regarding claim 1
Momenthy discloses a method of determining one or more fuel characteristics (energy content of the fuel, Col 3 lines 25-32, interpreted to be one of the fuel characteristics) of an aviation fuel (jet fuel for flight, Col 1 lines 6-7) suitable for powering a gas turbine engine of an aircraft (aircraft and engine, Col 4 lines 32-34), the method comprising:
determining a corresponding volume of the fuel (fuel quantity meter 20 measures the volume of fuel loaded in the aircraft fuel tank, Fig 1, Col 6 lines 6-7); and
determining one or more fuel characteristics of the fuel (fuel density from densitometer 24, Col 3 lines 23-31, where fuel density is interpreted to be a fuel characteristic).
Momenthy is silent on determining a mass of the fuel being loaded onto the aircraft,
determining one or more fuel characteristics of the fuel based on the determined mass and volume, wherein the one or more fuel characteristics are determined by either or both of
(i)	comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table and
(ii)	calculating a deviation of a value derived from the determined fuel mass and fuel volume from an expected value.
However, Galati teaches to determine an amount of fuel in an aircraft fuel system (Abstract) by determining a mass of the fuel being loaded onto the aircraft (the actual fuel volume is multiplied by the measured density to determine the fuel mass, Para 0040 middle),
determining a fuel characteristic of the fuel based on the determined mass and volume (for determining fuel density, a first densitometer located in the center fuel tank and a second densitometer located in one of the wing fuel tanks, Para 0069, where the fuel density is determined by densitometers,
another determining method is that density equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, density can be calculated based on the determined mass and volume).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to use the fuel volume and fuel density in Momenthy to determine a mass of the fuel being loaded onto the aircraft, as suggested and taught by Galati, and
to determine a fuel characteristics being a fuel density based on the determined mass and volume, as known in the art, because mass and density of the fuel are important parameters in an aircraft fuel supply system.
Momenthy in view of Galati is silent on the fuel characteristic being a fuel density is determined by 	(i) comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table.
However, Drancea teaches an aircraft fuel system (Fig 1A) having a fuel characteristic being a fuel density is determined by (i) comparing a value derived from the determined fuel mass and fuel volume (fuel density value equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, taught by Momenthy in view of Galati, density can be calculated based on the determined mass and volume) to values in a lookup table (fuel density can be determined via look-up tables, Para 0069 bottom).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to also determine the fuel characteristic being a fuel density in Momenthy in view of Galati by comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table, as suggested and taught by Drancea, because fuel density is important in determining the fuel distribution of the aircraft which is used to determine an imbalance in the center of gravity of the aircraft (Para 0005, 0009), and
by comparing the value derived from the determined fuel mass and volume to a value in a lookup table, the system can verify if the derived value is close to or completely wrong from the value in the lookup table.
Regarding claim 2
Momenthy in view of Galati and Durance discloses the method of claim 1.
Momenthy in view of Galati and Durance further discloses wherein:
wherein determining the one or more fuel characteristics comprises calculating a fuel density based on the determined fuel mass and fuel volume (determining fuel density equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, density can be calculated based on the determined mass and volume).
Regarding claim 7
Momenthy in view of Galati and Durance discloses the method of claim 1.
Momenthy further discloses wherein the one or more fuel characteristics (one of the fuel characteristics being a fuel density determined by densitometer 24, Fig 1, Col 3 lines 13-15) are further determined based on a signal indicative of the temperature of the fuel (densitometer 24 has temperature compensation, Col 3 lines 59-61, indicates that there is a signal indicative of the temperature of the fuel).
Regarding claim 8
Momenthy discloses a fuel characteristic determination system (Fig 1) for determining one or more fuel characteristics (energy content of the fuel, Col 3 lines 25-32) of an aviation fuel (jet fuel for flight, Col 1 lines 6-7) suitable for powering a gas turbine engine of an aircraft (aircraft and engine, Col 4 lines 32-34), the system comprising:
a fuel characteristic determination module (energy management computer 22, Fig 1) comprising a processor (Col 3 lines 50-52) programmed to:
receive a fuel volume signal indicative of a volume of the fuel being loaded, or which has been loaded, onto the aircraft (fuel quantity meter 20 measure the volume of fuel loaded in the aircraft fuel tank, Fig 1, Col 6 lines 6-7); and
determine a fuel characteristic of the fuel (fuel density from densitometer 24, Col 3 lines 23-31).
Momenthy is silent on to receive a fuel mass signal indicative of a mass of the fuel,
to determine one or more fuel characteristics of the fuel based on the fuel volume and fuel mass signals, wherein the one or more fuel characteristics are determined by
(i)	comparing a value derived from the indicated fuel mass and fuel volume to values in a lookup table and.
However, Galati teaches to determine an amount of fuel in an aircraft fuel system (Abstract) by determining a mass of the fuel being loaded onto the aircraft (the actual fuel volume is multiplied by the measured density to determine the fuel mass, Para 0040 middle),
determine a fuel characteristic of the fuel based on the determined volume and fuel mass signals (for determining fuel density, a first densitometer located in the center fuel tank and a second densitometer located in one of the wing fuel tanks, Para 0069, where the fuel density is determined by densitometers,
another determining method is that density equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, density can be calculated based on the determined mass and volume).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to use the fuel volume and fuel density in Momenthy to determine and generate a fuel mass signal indicative of a mass of the fuel being loaded onto the aircraft, as suggested and taught by Galati, and
to determine a fuel characteristic being a fuel density based on the fuel volume and fuel signals, as known in the art, because mass and density of the fuel are important parameters in an aircraft fuel supply system.
Momenthy in view of Galati is silent on the fuel characteristic being a fuel density is determined by 	(i) comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table.
However, Drancea teaches an aircraft fuel system (Fig 1A) having a fuel characteristic being a fuel density is determined by (i) comparing a value derived from the determined fuel mass and fuel volume (fuel density value equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, taught by Momenthy in view of Galati, density can be calculated based on the determined mass and volume) to values in a lookup table (fuel density can be determined via look-up tables, Para 0069 bottom).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to also determine the fuel characteristic being a fuel density in Momenthy in view of Galati by comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table, as suggested and taught by Drancea, because fuel density is important in determining the fuel distribution of the aircraft which is used to determine an imbalance in the center of gravity of the aircraft (Para 0005, 0009) , and
by comparing the value derived from the determined fuel mass and volume to a value in a lookup table, the system can verify if the derived value is close to or completely wrong from the value in the lookup table.
Regarding claim 9
Momenthy in view of Galati and Durance discloses the fuel characteristic determination system of claim 8.
Momenthy in view of Galati and Durance further discloses wherein:
wherein the processor of the fuel characteristic determination is programmed to calculate a fuel density based on the fuel mass signal and the fuel volume signal (determining fuel density equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, density can be calculated based on the determined mass and volume).
Regarding claim 10
Momenthy in view of Galati and Durance discloses the fuel characteristic determination system of claim 8.
Momenthy further discloses a volume sensor (means for measuring the quantity of fuel is a fuel quantity meter 20 located on the aircraft to sense the change in volume of fuel in tank 18, Col 3 lines 17-21, Fig 1) arranged to measure a volume of fuel, wherein the fuel volume signal is received from the volume sensor (fuel volume signal is received from the volume sensor 20).
Regarding claim 14
Momenthy in view of Galati and Durance discloses the fuel characteristic determination system of claim 8.
Momenthy further discloses wherein
b) the fuel volume signal is based on a measured volume and/or change in the volume of fuel (means for measuring the quantity of fuel is a fuel quantity meter 20 located on the aircraft to sense the change in volume of fuel in tank 18, Col 3 lines 17-21, Fig 1): stored in a fuel tank on board the aircraft (18).
Regarding claim 17
Momenthy in view of Galati and Durance discloses the fuel characteristic determination system of claim 8.
Momenthy further discloses wherein the processor of the fuel characteristic determination module is further programmed to determine the one or more fuel characteristics (one of the fuel characteristics being a fuel density determined by densitometer 24, Fig 1, Col 3 lines 13-15) based on a signal indicative of the temperature of the fuel (densitometer 24 has temperature compensation, Col 3 lines 59-61, indicates that there is a signal indicative of the temperature of the fuel).
Regarding claim 18
Momenthy in view of Galati and Durance discloses the method of claim 1.
Momenthy in view of Galati and Durance further discloses a method of operating an aircraft (Momenthy discloses a method of refueling an aircraft fuel tank 18, Fig 1) having a gas turbine engine (Durance teaches a gas turbine engine 20, Fig 1A), the method comprising:
determining one or more fuel characteristics (Durance teaches the fuel characteristic being a fuel density, Para 0009) using the method of claim 1; and
operating the aircraft according to the determined one or more fuel characteristics (Durance teaches to determine the fuel distribution based on fuel density to prevent center of gravity imbalance of the aircraft, Para 0005).
Regarding claim 19
Momenthy in view of Galati and Durance discloses the method of claim 18.
Momenthy further discloses wherein operating the aircraft according to the one or more fuel characteristics comprises:
b) providing a fuel having different fuel characteristics during refuelling of the aircraft (Momenthy discloses to refuel the aircraft using a fuel with different fuel characteristics such as a density of the fuel measured by densitometer 24, volume of the fuel by fuel quantity meter 20, and flow meter 31, to determine a total required energy content of the fuel for a selected flight, Col 2, lines 1-10).
Regarding claim 20
Momenthy in view of Galati and Durance discloses an aircraft comprising the fuel characteristic determination system of claim 8 (Momenthy discloses aircraft 26, Fig 1).
Momenthy in view of Galati and Durance further discloses a control system (Momenthy discloses the energy management computer 22, Fig 1; and Durance teaches a control system or aircraft computer, Para 0071) arranged to control operation of the aircraft according to the one or more fuel characteristics determined by the fuel characteristic determination system (Momenthy discloses the computer 22 to determine the fuel characteristics while Selstad teaches controller 130 being a FADEC to control the flow of fuel,
thus, the combination of Momenthy in view of Galati and Durance teaches a control system that control operation of the aircraft according to the fuel characteristics determined by the fuel characteristic determination system).
Claim(s) 3-4, 11-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Momenthy in view of Galati and Durance, as applied to claim 1 above, and further in view of Selstad (US 20170292457 A1).
Regarding claim 3
Momenthy in view of Galati and Durance discloses the method of claim 1.
Momenthy in view of Galati and Durance is silent on wherein:
a) determining the mass of the fuel comprises measuring a mass flow rate at a point within a fuel supply line used to convey fuel to one or more fuel tanks on board the aircraft.
However, Selstad teaches an aircraft fuel system (100 Fig 2) for a gas turbine engine (Fig 1) having a mass flow meter (152, Para 0040) for:
a) determining the mass of the fuel comprises measuring a mass flow rate (a mass flow meter 152, Fig 2, Para 0040) at a point within a fuel supply line used to convey fuel to a fuel tank (fuel line from fuel tank 102 to combustor 56) on board the aircraft (Para 0029).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to add to the fuel system in Momenthy in view of Galati and Durance, a mass flow meter for determining the mass of the fuel comprises measuring a mass flow rate at a point within a fuel supply line used to convey fuel to one or more fuel tanks on board the aircraft, as suggested and taught by Selstad, in order to provide a mass flow meter signal to the controller to measure the exact rate of fuel flowing to the combustor (Para 0041 middle).
Regarding claim 4
Momenthy in view of Galati and Durance discloses the method of claim 1.
Momenthy in view of Galati and Durance is silent on wherein:
b) determining the volume of the fuel comprises measuring the volume and/or a change in the volume of fuel stored in one or more fuel tanks on board the aircraft.
However, Selstad teaches an aircraft fuel system (100 Fig 2) for a gas turbine engine (Fig 1) including a step of:
b) determining the volume of the fuel comprises measuring the volume and/or a change in the volume of fuel (means for measuring the quantity of fuel is a fuel quantity meter 20 located on the aircraft to sense the change in volume of fuel in tank 18, Col 3 lines 17-21, Fig 1): stored in a fuel tank on board the aircraft (18).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to add to the fuel system in Momenthy in view of Galati and Durance, a step of measuring the volume and/or a change in the volume of fuel stored in one or more fuel tanks on board the aircraft, as suggested and taught by Selstad, in order to have an accurate reading of the remaining fuel volume.
Regarding claim 11
Momenthy in view of Galati and Durance discloses the fuel characteristic determination system of claim 10.
Momenthy in view of Galati and Durance is silent on wherein:
the mass sensor is a mass flow rate meter; and/or
the volume sensor is a volume flow rate meter.
However, Selstad teaches an aircraft fuel system (100 Fig 2) wherein:
the mass sensor is a mass flow rate meter (Selstad teaches the mass flow rate meter 152, Para 0040); and/or
the volume sensor is a volume flow rate meter (Momenthy discloses the fuel quantity meter 20 to sense the change in volume of fuel in tank 18, Col 3 lines 17-21, interpreted to be a volume flow rate meter).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to add to the fuel system in Momenthy in view of Galati and Durance, the mass sensor is a mass flow rate meter; and the volume sensor is a volume flow rate meter, as suggested and taught by Selstad, in order to have an accurate reading of the fuel mass flow and volume.
Regarding claim 12
Momenthy in view of Galati, Durance and Selstad discloses the fuel characteristic determination system of claim 11.
Momenthy in view of Galati, Durance and Selstad further discloses wherein the mass flow rate meter (Selstad teaches a mass flow meter 152, Fig 2, Para 0040) is arranged to measure mass flow rate at a point within a fuel supply line (fuel line from fuel tank 102 to combustor 56) on board the aircraft (Para 0029).
Regarding claim 13
Momenthy in view of Galati, Durance and Selstad discloses the fuel characteristic determination system of claim 11.
Momenthy further discloses wherein the volume flow rate meter (fuel quantity meter 20, Fig 1) is arranged to measure a volume flow rate at a point within a fuel supply line (a refueling line 16, Fig 1, Col 2 lines 63) used to supply fuel to a fuel tank (18) on board the aircraft (26).
Claim(s) 5-6 and 15-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Momenthy in view of Galati and Durance, as applied to claims 1 and 8 above, and further in view of Dubois (US 20150191667 A1).
Regarding claims 5 and 15
Momenthy in view of Galati and Durance discloses the method of claim 1 and the fuel characteristic determination system of claim 8.
Momenthy in view of Galati and Durance further discloses the one or more fuel characteristics determined include (iii) an aromatic content of the fuel (energy management computer 22 determines an energy content of the jet fuel, Fig 1, Col 2 lines 25-31, the energy content of the jet fuel is interpreted to be the aromatic content of the fuel).
Momenthy in view of Galati and Durance is silent on the jet fuel being a hydrocarbon fuel.
However, Dubois teaches that jet fuel is a mixture of large number of different hydrocarbon compounds (Para 0031).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to determine the aromatic content of the jet fuel in Momenthy in view of Galati and Durance, to be the aromatic hydrocarbon content of the jet fuel, as suggested and taught by Dubois, because a jet fuel is a type of hydrocarbon fuel that is commonly used as aviation fuel.
Regarding claims 6 and 16
Momenthy in view of Galati and Durance discloses the method of claim 1 and the fuel characteristic determination system of claim 8.
Momenthy in view of Galati and Durance further discloses the one or more fuel characteristics determined is that the fuel is a jet fuel (aircraft fuel tank with jet fuel for flight, Col 1 lines 5-10).
Momenthy in view of Galati and Durance is silent on the jet fuel is a fossil fuel.
However, Dubois teaches that fossil fuels being kerosene-type jet fuels are currently preferred because they offer the best combination in terms of energy content, performance, availability, ease of handling and price (Para 0003 middle).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to use fossil fuel being kerosene-type jet fuels, as suggested and taught by Dubois, in the aircraft fuel tank in Momenthy in view of Galati and Durance, because of kerosene’s advantage in energy content, performance, availability, ease of handling and price (Para 0003 middle).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.

APPLICANT REBUTTAL: REMARKS
Claims 1-4, 6-14, and 16-21 are pending in this application. By this Amendment, claims
1 and 8 are amended, claims 5 and 15 are canceled, and claim 21 is added. Support for the amendments may be found in the original claims, so no new matter is added.
Entry of the amendments is proper under 37 CFR §1.116 because the amendments: (a) place the application in condition for allowance for the reasons discussed herein; (b) do not raise any new issue requiring further search and/or consideration; (c) do not present any additional claims without canceling a corresponding number of finally rejected claims; and (d) place the application in better form for appeal, should an appeal be necessary. The amendments are necessary and were not earlier presented because they are made in response to arguments raised in the final rejection. Entry of the amendments is thus respectfully requested. I.    Claim Rejections under 35 U.S.C. §103
The Office:
" rejects claims 1-2, 7-10, 14, and 17-20 under 35 U.S.C. §103 as allegedly being
obvious over U.S. Patent No. 4,809,174 to Momenthy ("Momenthy") in view of
U.S. Pub. No. 2022/0120599 to Galati et al. ("Galati") and further in view of U.S.
Pub. No. 2020/0216188 to Drancea et al. ("Drancea");
" rejects claims 3-4 and 11-13 under 35 U.S.C. §103 as allegedly being obvious
over Momenthy in view of Galati and Drancea and further in view of U.S. Pub.
No. 2017/0292457 to Selstad ("Selstad"); and
" rejects claims 5-6 and 15-16 under 35 U.S.C. §103 as allegedly being obvious over
Momenthy in view of Galati and Drancea and further in view of U.S. Pub. No.
2015/0191667 to Dubois et al. ("Dubois").
Applicant respectfully traverses these rejections.
The Office compares fuel density to the recited "one or more fuel characteristics." Office Action, P5. Claims 1 and 8 each require the "one or more fuel characteristics" to be derived from other values, particularly "fuel mass" and "fuel volume." On the other hand, the Momenthy reference (and Galati for that matter) determines fuel density
directly
by way of a densitometer. Momenthy, C3:L13-15; Galati, 1[0050]. And while the Office contends on page
6 of the Office Action that "another determining method is that density equals to mass divided by volume, https://www.britannica.com/science/density, thus once mass and volume of the fuel are known, density can be calculated based on the determined mass and volume," the Office provides no rationale about why the person of ordinary skill in the art would have modified Momenthy (and Galati) to depart from their direct measurements of density. A simple statement that "mass and density of the fuel are important parameters in an aircraft fuel supply system," as made by the Office on page 6 of the Office Action, is insufficient, especially since Momenthy and Galati already disclose obtaining fuel density.
Applicant accordingly submits that the Office's §103 rejections are in error. But in the interest of expediting prosecution, claims 1 and 8 are amended to recite, respectively, the features of claims 5 and 15. The Office alleges in connection with claim 5 only that the cited references disclose the third alternative for the "one or more fuel characteristics," i.e., "(iii) an aromatic hydrocarbon content of the fuel." The Office particularly contends that "the energy content of the jet fuel is interpreted to be aromatic content of the fuel." Office Action, P17. But even if this were correct, which Applicant does not concede, Momenthy discloses that its energy content per unit quantity E is determined by way of the following linear function: E = xD + y. Momenthy, C3:L30-38. This energy content is therefore not disclosed as being "determined by either or both of (i) comparing a value derived from the determined fuel mass and fuel volume to values in a lookup table and (ii) calculating a deviation of a value derived from the determined
fuel mass and fuel volume from an expected value," as required by claims 1 and 8, nor has the Office set forth any reason why it would have been obvious to the person skilled in the art to have calculated Momenthy's energy content differently.
Amended claims 1 and 8 are therefore allowable over Momenthy, Galati, and Drancea. Selstad and Dubois provide no additional teachings of relevance. And because the remaining rejected claims are likewise allowable at least for their dependence from claim 1 or claim 8, withdrawal of the §103 rejections is respectfully requested. II.   New Claims
Claim 21 is similar to prior claim 8, but it is modified from that claim 8 to recite that "the one or more fuel characteristics are determined by
either or both of (i) comparing a value derived from the determined fuel ma
ss
and fuel volume to values in a lookup table and (ii)
calculating a deviation of a value derived from the determined fuel mass and fuel volume from an expected value." After having acknowledged the failings of Momenthy and Galati here, the Office turns to Drancea, which discloses that "[o]ther manners for determining fuel density in the tanks are contemplated,
including via one or more look-up table(s) or schedule(s),
among other possibilities." Drancea,  1[0069] (emphasis added). The cited references are thus only alleged to disclose alternative (i) in prior claim 8, so Applicant submits that claim 21 overcomes at least the current rejections by deleting that alternative and thereby requiring that the "one or more fuel characteristics" be determined by calculating the recited "deviation." Consideration and allowance of claim 21 are thus respectfully requested. III.  Conclusion

NEXT OFFICE ACTION: Notice of Pre-AIA  or AIA  Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Allowable Subject Matter
Claims 1-4, 6-14, and 16-21 are allowed.
The following is an examiner’s statement of reasons for allowance:
i.	In claims 1 and 8, the cited prior art of record fails to anticipate and/or render obvious, either solely or in combination, a fuel characteristic determination system for determining one or more fuel characteristic of an aviation fuel suitable for powering a gas turbine engine of an aircraft comprising, among other features,
a fuel characteristic determination module comprising a processor programmed to:
determine one or more fuel characteristics of the fuel based on the fuel volume and fuel mass signals, by either or both of (i) comparing a value derived from the indicated fuel mass and fuel volume to values in a lookup table and (ii) calculating a deviation of a value derived from the indicated fuel mass and fuel volume from an expected value, and
the one or more fuel characteristics determined include any one or more of:
(i) a hydrocarbon distribution of the fuel;
(ii) a percentage of sustainable aviation fuel in the fuel; and
(iii) an aromatic hydrocarbon content of the fuel.
In claim 21, the cited prior art of record fails to anticipate and/or render obvious, either solely or in combination, a fuel characteristic determination system for determining one or more fuel characteristic of an aviation fuel suitable for powering a gas turbine engine of an aircraft comprising, among other features,
a fuel characteristic determination module comprising a processor programmed to:
determine one or more fuel characteristics of the fuel based on the fuel volume and fuel mass signals, wherein
the one or more fuel characteristics are determined by calculating a deviation of a value derived from the indicated fuel mass and fuel volume from an expected value.
ii.	Claims 2-4, 6-7, 9-14, and 16-20 are allowed at least by virtue of their respective dependency upon an allowable base claim.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion

CITED REFERENCE SUMMARIES: Ref US20220120599A1: Claims:
A fuel gaging system comprising: a capacitance probe; a capacitance measurement circuit component comprising a first excitation generator, an excitation wire connected between the first excitation generator and the capacitance probe, and a signal wire connected to the capacitance probe with the capacitance probe being connected between the excitation wire and the signal wire, wherein the first excitation generator generates an input signal applied to the excitation wire and an output signal is read from the signal wire to determine a capacitance at the capacitance probe; a wire resistance measurement circuit component configured to isolate a contamination resistance to account for variations in wire resistance of the wires in determining the capacitance at the capacitance probe; and a contamination compensation circuit component configured to compensate for fuel contamination in determining the capacitance at the capacitance probe.
a capacitance probe;
a capacitance measurement circuit component comprising a first excitation generator, an excitation wire connected between the first excitation generator and the capacitance probe, and a signal wire connected to the capacitance probe with the capacitance probe being connected between the excitation wire and the signal wire, wherein the first excitation generator generates an input signal applied to the excitation wire and an output signal is read from the signal wire to determine a capacitance at the capacitance probe;
a wire resistance measurement circuit component configured to isolate a contamination resistance to account for variations in wire resistance of the wires in determining the capacitance at the capacitance probe; and
a contamination compensation circuit component configured to compensate for fuel contamination in determining the capacitance at the capacitance probe.
The fuel gaging system of claim 1 , further comprising a switching system that selectively engages the wire resistance measurement circuit component during a wire measurement mode, and selectively engages the contamination compensation circuit component during a fuel gaging mode.
The fuel gaging system of claim 2 , wherein the wire resistance measurement circuit component includes a direct current (DC) voltage source and a sensing wire connected between the DC voltage source and the capacitance probe.
The fuel gaging system of claim 3 , wherein the wire resistance measurement circuit component further includes a first switch connected between the DC voltage source and the sensing wire, and the first switch is in a closed state during a wire measurement mode for isolating contamination resistance from resistance of the wires.
The fuel gaging system of claim 3 , wherein the wire resistance measurement circuit component further includes a measuring device connected to the excitation wire oppositely from the capacitance probe, wherein when the DC voltage source supplies a DC voltage to the sensing wire, the measuring device reads an output from the excitation wire.
The fuel gaging system of claim 6 , wherein the wire resistance measurement circuit component further includes a second switch connected between the excitation wire and the measuring device, and the second switch is in a closed state during a wire measurement mode for isolating contamination resistance from resistance of the wires.
The fuel gaging system of claim 2 , wherein the wire resistance measurement circuit component includes a direct current (DC) voltage source that is switchable between a positive polarity and a negative polarity, and a probe diode connected across the capacitance probe.
The fuel gaging system of claim 8 , wherein the wire resistance measurement circuit component further includes a first switch that is switchable between a first position to connect the excitation wire to the DC voltage source in the wire measurement mode, and a second position to connect the excitation wire to the first excitation generator in the fuel gaging mode.
The fuel gaging system of claim 10 , wherein the wire resistance measurement circuit component further includes a second switch that switches the DC voltage source between the positive polarity and the negative polarity.
The fuel gaging system of claim 1 , wherein the excitation wire and the signal wire are standard wires combined with safety resistors.
The fuel gaging system of claim 1 , wherein the excitation wire and the signal wire are high resistance wires having up to 2 MÎ© resistance.
The fuel gaging system of claim 1 , wherein the contamination compensation circuit component includes a slope sampler that samples an output signal from the signal wire, an inverter that inverts an output of the slope sampler, and a second excitation generator that generates a compensation excitation that compensates for a slope error in the output signal of the signal wire.
The fuel gaging system of claim 1 , further comprising an I-V converter connected to an output of the signal wire and an amplitude sampler connected to an output of the I-V converter for determining the capacitance at the capacitance probe.
- 22 . (canceled)
A method of gaging fuel in a capacitance fuel gaging system including a capacitance probe and high resistance elements through which an input signal is applied and from which an output signal is read, the method comprising the steps of: operating in a fuel gaging mode comprising measuring a capacitance at the capacitance probe based on the output signal and calculating an amount of fuel based on the capacitance measurement; operating in a wire measurement mode to isolate contamination resistance from resistance of the high resistance elements to account for resistance variations in determining the capacitance at the capacitance probe; and wherein the fuel gaging mode further comprises compensating for fuel contamination by compensating an error in the output signal due to fuel contamination in determining the capacitance at the capacitance probe.
operating in a fuel gaging mode comprising measuring a capacitance at the capacitance probe based on the output signal and calculating an amount of fuel based on the capacitance measurement;
operating in a wire measurement mode to isolate contamination resistance from resistance of the high resistance elements to account for resistance variations in determining the capacitance at the capacitance probe; and
wherein the fuel gaging mode further comprises compensating for fuel contamination by compensating an error in the output signal due to fuel contamination in determining the capacitance at the capacitance probe.
The method of gaging fuel of claim 23 , wherein the high resistance elements include an excitation wire and a signal wire, and operating in the fuel gaging mode comprises: applying a first excitation signal through the excitation wire to the capacitance probe, wherein an output of the capacitance probe flows through the signal wire;
applying a first excitation signal through the excitation wire to the capacitance probe, wherein an output of the capacitance probe flows through the signal wire;
measuring the output signal from the signal wire; determining the capacitance measurement at the capacitance probe based on the output signal from the signal wire; and calculating the fuel amount based on the capacitance measurement at the capacitance probe.
determining the capacitance measurement at the capacitance probe based on the output signal from the signal wire; and
calculating the fuel amount based on the capacitance measurement at the capacitance probe.
The method of gaging fuel of claim 23 , wherein operating in the wire measurement mode comprises: applying a DC voltage source through a sensing wire to the capacitance probe; measuring an output from the signal wire in response to the DC voltage source and determining a wire resistance; measuring an output from the excitation wire in response to the DC voltage source and determining a combined wire resistance and contamination resistance of contamination in the fuel; and performing a differential calculation between the combined wire resistance and contamination resistance measurement and the wire resistance measurement to isolate the contamination resistance to account for variations in wire resistance in determining the capacitance measurement at the capacitance probe; and wherein compensating for fuel contamination comprises: sampling the output signal from the signal wire and integrating the sampled output signal to generate a compensation output; transmitting the compensation output through an inverter to generate a contamination current; and applying a second excitation signal to the contamination current to compensate for the error in the output signal from the signal wire.
applying a DC voltage source through a sensing wire to the capacitance probe;
measuring an output from the signal wire in response to the DC voltage source and determining a wire resistance;
measuring an output from the excitation wire in response to the DC voltage source and determining a combined wire resistance and contamination resistance of contamination in the fuel; and
performing a differential calculation between the combined wire resistance and contamination resistance measurement and the wire resistance measurement to isolate the contamination resistance to account for variations in wire resistance in determining the capacitance measurement at the capacitance probe; and
wherein compensating for fuel contamination comprises:
sampling the output signal from the signal wire and integrating the sampled output signal to generate a compensation output;
transmitting the compensation output through an inverter to generate a contamination current; and
applying a second excitation signal to the contamination current to compensate for the error in the output signal from the signal wire.
The method of gaging fuel of claim 23 , wherein operating in the wire measurement mode comprises: connecting a probe diode across the capacitance probe; applying a DC voltage source to the capacitance probe with the probe diode reverse biased; measuring an output from the signal wire in response to the DC voltage source with the probe diode reverse biased and determining a combined wire resistance and contamination resistance of contamination in the fuel; applying the DC voltage source to the capacitance probe with the probe diode forward biased; measuring an output from the signal wire in response to the DC voltage source with the probe diode forward biased and determining a wire resistance; and performing a differential calculation between the combined wire resistance and contamination resistance measurement and the wire resistance measurement to isolate the contamination resistance to account for variations in wire resistance in determining the capacitance measurement at the capacitance probe; and wherein compensating for fuel contamination comprises: sampling the output signal from the signal wire and integrating the sampled output signal to generate a compensation output; transmitting the compensation output through an inverter to generate a contamination current; and applying a second excitation signal to the contamination current to compensate for the error in the output signal from the signal wire.
connecting a probe diode across the capacitance probe;
applying a DC voltage source to the capacitance probe with the probe diode reverse biased;
measuring an output from the signal wire in response to the DC voltage source with the probe diode reverse biased and determining a combined wire resistance and contamination resistance of contamination in the fuel;
applying the DC voltage source to the capacitance probe with the probe diode forward biased;
measuring an output from the signal wire in response to the DC voltage source with the probe diode forward biased and determining a wire resistance; and
The method of gaging fuel of claim 25 , wherein: the first excitation signal is a triangle waveform and the capacitance probe operates to differentiate the first excitation signal to output a square waveform output signal through the signal wire having a slope error indicative of fuel contamination; integrating the sampled output signal of the signal wire to generate a continuously rising DC voltage; and the second excitation signal is a triangle waveform 180Â° out of phase with the first excitation waveform and whose amplitude is based on a voltage associated with the contamination current to de-slope the slope error in the output signal of the signal wire.
the first excitation signal is a triangle waveform and the capacitance probe operates to differentiate the first excitation signal to output a square waveform output signal through the signal wire having a slope error indicative of fuel contamination;
integrating the sampled output signal of the signal wire to generate a continuously rising DC voltage; and
the second excitation signal is a triangle waveform 180Â° out of phase with the first excitation waveform and whose amplitude is based on a voltage associated with the contamination current to de-slope the slope error in the output signal of the signal wire.
- 29 . (canceled)
The method of gaging fuel of claim 23 , wherein measuring the capacitance at the capacitance probe further comprises, based on the contamination resistance measurement from the wire measurement mode and the compensated output signal of the signal wire, applying a multiplier factor to the capacitance measurement at the capacitance probe to calculate a final capacitance value for calculating the fuel amount.
- 32 . (canceled)
The method of gaging fuel of claim 23 , wherein calculating the fuel amount comprises: determining an immersed length of the capacitance probe within the fuel based on the capacitance measurement at the capacitance probe; obtaining a fuel surface attitude based on the immersed length and probe coordinates of the capacitance probe; and determining a nominal volume of fuel.
determining an immersed length of the capacitance probe within the fuel based on the capacitance measurement at the capacitance probe;
obtaining a fuel surface attitude based on the immersed length and probe coordinates of the capacitance probe; and
determining a nominal volume of fuel.
Ref US20200216188A1: Claims:
A method for providing a lateral center of gravity of an aircraft on an aircraft display, the method comprising: determining a fuel distribution in fuel tanks of a first wing and a second wing of the aircraft; determining a lateral center of gravity of the aircraft based at least in part on the fuel distribution; and sending a signal indicative of the lateral center of gravity to the aircraft display.
determining a fuel distribution in fuel tanks of a first wing and a second wing of the aircraft;
determining a lateral center of gravity of the aircraft based at least in part on the fuel distribution; and
sending a signal indicative of the lateral center of gravity to the aircraft display.
The method of claim 1 , wherein the first wing comprises a first tank that is an inboard tank and a second tank that is an outboard tank, and the second wing comprises a third tank that is an inboard tank and a fourth tank that is an outboard tank.
The method of claim 2 , wherein determining the fuel distribution comprises: determining a first mass of fuel in the first tank from fuel density and fuel volume measurements in the first tank; determining a second mass of fuel in the second tank from fuel density and fuel volume measurements in the second tank; determining a third mass of fuel in the third tank from fuel density and fuel volume measurements in the third tank; determining a fourth mass of fuel in the fourth tank from fuel density and fuel volume measurements in the fourth tank; and determining the fuel distribution based on the first mass of fuel, the second mass of fuel, the third mass of fuel, the fourth mass of fuel and a configuration of the first tank, the second tank, the third tank and the fourth tank.
determining a first mass of fuel in the first tank from fuel density and fuel volume measurements in the first tank;
determining a second mass of fuel in the second tank from fuel density and fuel volume measurements in the second tank;
determining a third mass of fuel in the third tank from fuel density and fuel volume measurements in the third tank;
determining a fourth mass of fuel in the fourth tank from fuel density and fuel volume measurements in the fourth tank; and
determining the fuel distribution based on the first mass of fuel, the second mass of fuel, the third mass of fuel, the fourth mass of fuel and a configuration of the first tank, the second tank, the third tank and the fourth tank.
The method of claim 3 , wherein determining the lateral center of gravity of the aircraft comprises: determining a first moment arm based on the first mass of fuel and a first distance between a first tank center of mass and a substantially centered longitudinal axis of the aircraft; determining a second moment arm based on the second mass of fuel and a second distance between a second tank center of mass and the substantially centered longitudinal axis of the aircraft; determining a third moment arm based on the third mass of fuel and a third distance between a third tank center of mass and the substantially centered longitudinal axis of the aircraft; determining a fourth moment arm based on the fourth mass of fuel and a fourth distance between a fourth tank center of mass and the substantially centered longitudinal axis of the aircraft; and determining the lateral center of gravity using the first moment arm, the second moment arm, the third moment arm and the fourth moment arm.
determining a first moment arm based on the first mass of fuel and a first distance between a first tank center of mass and a substantially centered longitudinal axis of the aircraft;
determining a second moment arm based on the second mass of fuel and a second distance between a second tank center of mass and the substantially centered longitudinal axis of the aircraft;
determining a third moment arm based on the third mass of fuel and a third distance between a third tank center of mass and the substantially centered longitudinal axis of the aircraft;
determining a fourth moment arm based on the fourth mass of fuel and a fourth distance between a fourth tank center of mass and the substantially centered longitudinal axis of the aircraft; and
determining the lateral center of gravity using the first moment arm, the second moment arm, the third moment arm and the fourth moment arm.
The method of claim 1 , further comprising displaying the lateral center of gravity on the display with respect to at least one threshold.
The method of claim 5 , further comprising displacing a pointer indicative of the lateral center of gravity on the display with respect to the at least one threshold when the lateral center of gravity of the aircraft changes.
The method of claim 5 , wherein the at least one threshold comprises at least one on ground threshold for use when the aircraft is on ground and at least one inflight threshold for use when the aircraft is in flight.
The method of claim 5 , further comprising determining the at least one threshold as a function of a total fuel mass.
The method of claim 5 , further comprising triggering a rebalancing of fuel between at least some of the first tank, the second tank, the third tank, and the fourth tank when the lateral center of gravity exceeds a first one of the at least one threshold.
The method of claim 9 , further comprising triggering an alert when the lateral center of gravity exceeds a second one of the at least one threshold.
A system for providing a lateral center of gravity of an aircraft on an aircraft display, the system comprising: a processing unit; and a non-transitory computer-readable mem
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