Prosecution Insights
Last updated: April 19, 2026
Application No. 17/864,974

Environmentally Friendly Aircraft

Final Rejection §103§112
Filed
Jul 14, 2022
Examiner
IGUE, ROBERTO TOSHIHARU
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Embraer S A
OA Round
4 (Final)
58%
Grant Probability
Moderate
5-6
OA Rounds
2y 7m
To Grant
75%
With Interview

Examiner Intelligence

Grants 58% of resolved cases
58%
Career Allow Rate
25 granted / 43 resolved
-11.9% vs TC avg
Strong +17% interview lift
Without
With
+17.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
32 currently pending
Career history
75
Total Applications
across all art units

Statute-Specific Performance

§101
2.0%
-38.0% vs TC avg
§103
57.3%
+17.3% vs TC avg
§102
8.0%
-32.0% vs TC avg
§112
29.2%
-10.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 43 resolved cases

Office Action

§103 §112
DETAILED 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 . This is in response to the correspondence filed on 12/29/2025. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 1, 10, 19 and their dependent claims are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Claims 1, 10, 19: the limitation “a typical range mission burning no non-cryogenic fuel” does not appear to be supported by the specification. Figure 2 appears to show a “typical range mission” but the “alternate” portion, which is included in the typical range mission figure and in the timeline of the graph, appears to require JetA; additionally, Figure 7 step 506 also indicates the use of non-cryo fuel in a typical mission. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1, 10, 19 and their dependent claims are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1: in “plural non-cryogenic fuel tanks inside the aerodynamic structure on board the aircraft,” it is unclear if the aerodynamic structure is on board the aircraft of if the non-cryogenic fuel tanks are inside the aircraft. It is also unclear how the aerodynamic structure configured to fly (as recited in lines 3-4 of claim 1) is also on board the aircraft. Claims 1, 10, 19: in claim 1 “a volumetric capacity sized to store sufficient cryogenic fuel to fuel the engines to propel the aircraft for a the typical range mission without reserves”, it is unclear the stored cryogenic fuel is sufficient to fly a typical range mission without the need of reserve fuel, or if the quantity of fuel is sufficient to complete a typical range mission but would not have any reserves, or if a typical range mission does not account for any reserves, or something else. Similar issues are found in claims 10 and 19. Claim 9: it is unclear how the limitation “plural engines” in claim 9 relates to the limitation “engines” in claim 1. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1, 4, 6-7, 9-10, 13-17, 19-21 are rejected under 35 U.S.C. 103 as being unpatentable over Swann 20220316410 in view of Kamath 20150321767, Kawai 20160076461. Regarding claim 1, Swann teaches: 1. (Currently Amended) An aircraft (Title; aircraft (abstract); aircraft propulsion system enters air [0011]) comprising: an aerodynamic structure having an overall geometry and design weights (inter alia, aircraft (Abstract) has fuselage) configured to fly (aircraft propulsion system enters air [0011]) at least a design long range mission (a long range [0003]) burning non-cryogenic fuel (“an engine system capable of producing thrust by: an engine system capable of producing thrust by: [0008] (i) combusting hydrocarbon fuel; (i) combusting hydrocarbon fuel” [0007-0008]) and a typical range mission (flights not requiring a long range [0003]) burning no non-cryogenic fuel (the aircraft propulsion system is capable of burning cryogenic fuel [0004, 0006, 0026, 0091], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]), wherein the typical range mission is shorter in distance than the design long range mission (flights not requiring a long range [0003]) and the distance ratio between the typical range mission and the design long range mission is between 0.2 and 0.5 ( Swann teaches “For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003], “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]; Swann is silent about a ratio of typical range mission to design long range mission is between 0.2 and 0.5. However, “the ratio between the typical range mission and the design long range mission” was recognized as a result-effective variable, i.e., a variable which achieves a recognized result, in the prior art, in this case the ratio of typical range mission to design long range mission is between 0.2 and 0.5 depending on sizing and capacity ratios between the different tanks, such that the determination of the optimum or workable ranges of said variable, in this case the ratio between the quantity of the different types of fuel that would allow flights with ranges between 0.2 to 0.5 of the design long range mission, may have been characterized as routine experimentation. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). Where the general conditions of a claim are disclosed in the prior art, in this case adjusting the fuel capacities on a flight -by-flight or seasonal basis [0092], it has been held that the discovery of optimum or workable ranges, in this case a range ratio between 0.2 and 0.5, by experimentation requiring only routine skill in the art, in this case the ability to adjust capacities, would have been an obvious extension of prior art teachings. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A). engines carried by the aerodynamic structure capable of burning non-cryogenic fuel and cryogenic fuel (“An aircraft propulsion system includes a hydrocarbon fuel store, a hydrogen fuel store, an engine system capable of producing thrust by combusting hydrocarbon fuel and/or combusting or oxidising hydrogen fuel”, abstract) at least one cryogenic fuel tank inside the aerodynamic structure on board the aircraft (“An aircraft propulsion system includes […] a hydrogen fuel store”, abstract; also see 112(b) rejection above), the at least one cryogenic fuel tank having a volumetric capacity sized to store sufficient cryogenic fuel to fuel the engines to propel the aircraft for a-the typical range mission without reserves (““For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003]), the designed volumetric capacity sizing of the at least one cryogenic fuel tank being smaller than a size that would be required for cryogenically fueling the aircraft to propel the aircraft for a mission that includes the typical range mission and an additional portion of the design long range mission to exceed the distance of the typical range mission plus reserves (Dual-fuel aircraft have therefore been proposed which use both hydrogen fuel and hydrocarbon fuel (typically kerosene) in order to allow the range of an aircraft to be extended beyond that achievable using hydrogen fuel alone [0003], and it is noted that [0003] as a whole teaches the relationship between tank size and range, and presents pros and cons to be considered when the different types of fuels are used; and “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]); plural non-cryogenic fuel tanks inside the- aerodynamic structure on board the aircraf, the plural non-cryogenic fuel tanks configured to store a quantity of non-cryogenic fuel as a reserve fuel for the aircraft (“An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]”), a controller on board the aircraft configured to selectively control fuel flow from the at least one cryogenic fuel tank and the plural non-cryogenic fuel tanks to the engines ([0010]), the controller configured to supply the cryogenic fuel is-to the engines as a main fuel that will normally be used by the engines to propel the aircraft during the typical range mission, the controller being further configured to reserve the non-cryogenic fuel as a reserve or range extending fuel, which the controller is configured to provide to the engines to propel the aircraft only on an exception basis such as for missions that exceed the distance of the typical range mission plus reserves (“so that the fraction x may be varied between zero and unity during any part of a flight mission” [0055] shows the controller can be configured to use each type of fuel and any combination at any portion of the flight and “an engine system capable of utilising hydrocarbon fuel, and a combination of hydrocarbon fuel and hydrogen fuel, as well as hydrogen fuel alone” [0055], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]; furthermore classifying fuel as either “main” or “reserve or range extending” amounts to simple nomenclature of renaming the fuels and/or amounts to simply their intended uses, for which MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim)., wherein the at least one cryogenic fuel tank and the plural non-cryogenic fuel tanks are volumetrically configured to together enable the aircraft to be adequately fueled to fly the design long range mission without running out of fuel, while enabling the controller to control the engines to burn only the cryogenic fuel to propel the aircraft in normal flight during the typical range mission (“For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003], “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]; furthermore MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim) Swann is silent about: a venting system configured to monitor temperature and pressure of the cryogenic fuel stored by the at least one cryogenic fuel tank and provide controlled venting of the at least one cryogenic fuel tank to the atmosphere to avoid excessive pressure buildup within the at least one cryogenic fuel tank as the cryogenic fuel contained by the at least one cryogenic fuel tank boils off; However Kamath teaches: a venting system configured to monitor temperature and pressure of the cryogenic fuel stored by the at least one cryogenic fuel tank and provide controlled venting of the at least one cryogenic fuel tank to the atmosphere to avoid excessive pressure buildup within the at least one cryogenic fuel tank as the cryogenic fuel contained by the at least one cryogenic fuel tank boils off (“The fuel storage system 10 may further comprise a safety release system 45 adapted to vent any high pressure gases that may be formed in the cryogenic fuel tank 22” [0047], and “An LNG tank with one or more vent lines 41 for removal of gaseous natural gas, formed by the absorption of heat from the external environment” [0059]). It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Swann with Kamath's structure discussed above in order to “release any high pressure gases in the event of an over pressure inside the fuel tank” [0047]. Swann in view of Kamath is silent about: and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling without consuming the stored quantity of non-cryogenic fuel However, Kawai teaches a dual fuel gas turbine (title), and : and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling (the fuels may be used for ancillary purposes such as oil cooling or providing hydraulic pressure in the engine. For example, the fuel may pass through an oil cooler and/or through a hydraulic system before going to fuel nozzles in the gas turbine engine [0013]) without consuming the stored quantity of non-cryogenic fuel (the tanks in Kawai do not consume he stored fuel) It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Swann in view of Kamath with Kawai’s structure as discussed above in order to provide “the liquid fuel to satisfy the ancillary systems, such as oil cooling and/or engine hydraulic pressure” (Kawai [0014]) since “[cryogenic] fuels may not be able to provide oil cooling or hydraulic pressure” as taught by Kawai [0013]. Regarding claim 4, Swann in view of Kamath and Kawai teaches the invention as discussed claim 1. Swann further teaches: the controller is configured to control the engines to uses the non- cryogenic fuel and the cryogenic fuel independently or in conjunction to provide energy to propel the aircraft in flight ([0055], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]). Regarding claim 6, Swann in view of Kamath and Kawai teaches the invention as discussed for claim 1. Swann in view of Kamath and Kawai is silent about using the cryogenic fuel as claimed. However, Kamath teaches: the aircraft is further configured to use a cryogenic fuel (Kamath Fig 8 and paragraph [0084] “LNG”) to cool the non-cryogenic fuel to thereby keep non-cryogenic fuel temperatures down in order to reduce non-cryogenic fuel vapor flammability (Fig 8 and paragraph [0084] “Fuel-to-fuel Cooler (FFC) 504 for heat exchange between gasified LNG and the jet fuel”; Fig 8 shows a “return to Aircraft Tank 524” line on the left side of the image; “to transfer heat between the first fuel in the first fuel system and the second fuel in the second fuel system […] and/or from jet fuel to gasified LNG at high LNG % demand” [0087], [0092]). The recitation “in order to reduce non-cryogenic fuel vapor flammability” simply states an intended purpose and amounts to a statement of intended use or desired result, for which MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim. In this case, the prior art teaches all the structural limitations of the claims as mapped and discussed as well as heat being transferred between jet fuel and LNG (Kamath [0084, 0087, 0092]) with the clear purpose of ”controlling fluid temperatures in an aircraft utilizing dual fuels” (Kamath [0092]), the system being capable of achieving the claimed intended uses and desired results; thus teaching all the structural requirements of the claim. Regarding claim 7, Swann in view of Kamath and Kawai teaches the invention ad discussed for claim 1. Swann in view of Kamath and Kawai is silent about: The controller is further configured to use the non-cryogenic fuel to heat the cryogenic fuel before the cryogenic fuel enters the engines However, Kamath teaches: the controller is further configured to use a non-cryogenic fuel to heat a cryogenic fuel before the cryogenic fuel enters the engines (Kamath Claim 1, where ‘first fuel’ is jet fuel [0084] and ‘second fuel’ is LNG [0084]). Regarding claim 9, Swann in view of Kamath and Kawai teaches the invention as discussed for claim 1. Swann further teaches: Wherein the controller is further configured to switch each of plural engines individually (Swann [0025]; and Fig 1 shows an individual engine and a dedicated controller 130; [0087]) between cryogenic fuel and the non-cryogenic fuel during flight ([0010-0025, 0068]). Regarding claim 10, Swann teaches: A method of operating an aircraft designed and configured to fly a design long range mission (Title; aircraft [0073]; aircraft propulsion system enters air [0011]) and a typical range mission, the method comprising: Configuring aircraft aerodynamic structure overall geometry and design weights (aircraft (abstract) has fuselage) as a function of both a design long range mission (a long range [0003]) burning non-cryogenic fuel (“an engine system capable of producing thrust by: an engine system capable of producing thrust by: [0008] (i) combusting hydrocarbon fuel; (i) combusting hydrocarbon fuel” [0007-0008]) and a typical range mission burning no non-cryogenic fuel (the aircraft propulsion system is capable of burning cryogenic fuel [0004, 0006, 0026, 0091], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]), wherein the typical range mission is shorter in distance than the design long range mission (flights not requiring a long range [0003]) and the distance ratio between the typical range mission and the design long range mission is between 0.2 and 0.5 ( Swann teaches “For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003], “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]; Swann is silent about a ratio of typical range mission to design long range mission is between 0.2 and 0.5. However, “the ratio between the typical range mission and the design long range mission” was recognized as a result-effective variable, i.e., a variable which achieves a recognized result, in the prior art, in this case the ratio of typical range mission to design long range mission is between 0.2 and 0.5 depending on sizing and capacity ratios between the different tanks, such that the determination of the optimum or workable ranges of said variable, in this case the ratio between the quantity of the different types of fuel that would allow flights with ranges between 0.2 to 0.5 of the design long range mission, may have been characterized as routine experimentation. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). Where the general conditions of a claim are disclosed in the prior art, in this case adjusting the fuel capacities on a flight -by-flight or seasonal basis [0092], it has been held that the discovery of optimum or workable ranges, in this case a range ratio between 0.2 and 0.5, by experimentation requiring only routine skill in the art, in this case the ability to adjust capacities, would have been an obvious extension of prior art teachings. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A); provisioning at least one cryogenic fuel tank inside the aerodynamic structure on board the aircraft to store cryogenic fuel (“An aircraft propulsion system includes […] a hydrogen fuel store”, abstract; also see 112(b) rejection above), including volumetrically sizing cryogenic fuel storage capacity of the at least one cryogenic fuel tank for a typical range mission without reserves (““For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003]), the volumetrically sizing of the storage amount comprising volumetrically sizing cryogenic fuel storage amount of the at least one cryogenic fuel tank to be smaller than an amount required for cryogenically fueling the aircraft for a mission that includes the typical range mission and an additional portion of the design long range mission to exceed the distance of the typical range mission plus reserves (Dual-fuel aircraft have therefore been proposed which use both hydrogen fuel and hydrocarbon fuel (typically kerosene) in order to allow the range of an aircraft to be extended beyond that achievable using hydrogen fuel alone [0003], and it is noted that [0003] as a whole teaches the relationship between tank size and range, and presents pros and cons to be considered when the different types of fuels are used; and “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]); provisioning plural non-cryogenic fuel tanks inside the aerodynamic structure on board the aircraft to store non-cryogenic fuel as a reserve fuel for the aircraft (“An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]”); the at least one cryogenic fuel tank and the plural non-cryogenic fuel tanks being volumetrically configured to together enable the aircraft to be adequately fueled to fly the design long range mission without running out of fuel, while enabling the engines to burn only the cryogenic fuel to propel the aircraft in normal flight during the typical range mission (“For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003], “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]; furthermore MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim); and configuring the aircraft to selectively route non-cryogenic fuel or cryogenic fuel to engines ([0010]), including routing the cryogenic fuel from the at least one cryogenic fuel tank to the engines as a main fuel to propel the aircraft during the typical range mission, and reserving the non-cryogenic fuel as a reserve or range extending fuel for routing to the engines only on an exception basis such as for missions that exceed the distance of the typical range mission plus reserves (“so that the fraction x may be varied between zero and unity during any part of a flight mission” [0055] shows the controller can be configured to use each type of fuel and any combination at any portion of the flight and “an engine system capable of utilising hydrocarbon fuel, and a combination of hydrocarbon fuel and hydrogen fuel, as well as hydrogen fuel alone” [0055], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]; furthermore classifying fuel as either “main” or “reserve or range extending” amounts to simple nomenclature of renaming the fuels and/or amounts to simply their intended uses, for which MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim). Swann is silent about: monitoring temperature and pressure of the cryogenic fuel stored by the at least one cryogenic fuel tank and providing controlled venting of the at least one cryogenic fuel tank to the atmosphere to avoid excessive pressure buildup within the at least one cryogenic fuel tank as the cryogenic fuel contained by the at least one cryogenic fuel tank boils off However Kamath teaches: monitoring temperature and pressure of the cryogenic fuel stored by the at least one cryogenic fuel tank and providing controlled venting of the at least one cryogenic fuel tank to the atmosphere to avoid excessive pressure buildup within the at least one cryogenic fuel tank as the cryogenic fuel contained by the at least one cryogenic fuel tank boils off (“The fuel storage system 10 may further comprise a safety release system 45 adapted to vent any high pressure gases that may be formed in the cryogenic fuel tank 22” [0047], and “An LNG tank with one or more vent lines 41 for removal of gaseous natural gas, formed by the absorption of heat from the external environment” [0059]). It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Swann with Kamath's structure discussed above in order to “release any high pressure gases in the event of an over pressure inside the fuel tank” [0047]. Swann in view of Kamath is silent about: and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling without consuming the stored quantity of non-cryogenic fuel However, Kawai teaches a dual fuel gas turbine (title), and : and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling (the fuels may be used for ancillary purposes such as oil cooling or providing hydraulic pressure in the engine. For example, the fuel may pass through an oil cooler and/or through a hydraulic system before going to fuel nozzles in the gas turbine engine [0013]) without consuming the stored quantity of non-cryogenic fuel (the tanks in Kawai do not consume he stored fuel) It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Swann in view of Kamath with Kawai’s structure as discussed above in order to provide “the liquid fuel to satisfy the ancillary systems, such as oil cooling and/or engine hydraulic pressure” (Kawai [0014]) since “[cryogenic] fuels may not be able to provide oil cooling or hydraulic pressure” as taught by Kawai [0013]. Regarding claim 13, Swann in view of Kawai teaches the invention as discussed for claim 10. Swann further teaches: using the non-cryogenic fuel and the cryogenic fuel independently or in conjunction to provide energy for the engine to propel the aircraft in flight ([0055]). Regarding claim 14, Swann in view of Kawai teaches the invention as discussed for claim 10. Swann in view of Kawai, as discussed so far, is silent about using the non-cryogenic fuel as a motive or cooling fluid at all flight phases, when the cryogenic fuel is the only fuel the engines are consuming However, Kawai teaches: using the non-cryogenic fuel (“liquid fuel”) as a motive or cooling fluid at all flight phases, when the cryogenic fuel (“gaseous fuel”) is the only fuel the engines are consuming (Kawai [0013-0014]). It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Swann in view of Kawai with Kawai’s structure discussed above in order to allow “the liquid fuel to satisfy the ancillary systems, such as oil cooling and/or engine hydraulic pressure” (Kawai [0014]) since “[cryogenic] fuels may not be able to provide oil cooling or hydraulic pressure” as taught by Kawai, [0013]. Regarding claim 15, Swann in view of Kamath and Kawai teaches the invention as discussed for claim 10. Swann in view of Kamath and Kawai is silent about using the cryogenic fuel as claimed. using cryogenic fuel to cool or keep non-cryogenic fuel temperatures down in the plural non-cryogenic fuel temperatures down in order to reduce non-cryogenic fuel vapor flammability However, Kamath teaches: using cryogenic fuel (Kamath Fig 8 and paragraph [0084] “LNG”) to cool or keep non-cryogenic fuel temperatures down in the plural non-cryogenic fuel temperatures down in order to reduce non-cryogenic fuel vapor flammability (Fig 8 and paragraph [0084] “Fuel-to-fuel Cooler (FFC) 504 for heat exchange between gasified LNG and the jet fuel”; Fig 8 shows a “return to Aircraft Tank 524” line on the left side of the image; “to transfer heat between the first fuel in the first fuel system and the second fuel in the second fuel system […] and/or from jet fuel to gasified LNG at high LNG % demand” [0087], [0092]). The recitation “in order to reduce non-cryogenic fuel vapor flammability” simply states an intended purpose and amounts to a statement of intended use or desired result, for which MPEP2114(II) provides that the intended use does not differentiate the claimed apparatus from a prior art apparatus if the prior art apparatus teaches all the structural limitations of the claim. In this case, the prior art teaches all the structural limitations of the claims as mapped and discussed as well as heat being transferred between jet fuel and LNG (Kamath [0084, 0087, 0092]) with the clear purpose of ”controlling fluid temperatures in an aircraft utilizing dual fuels” (Kamath [0092]), the system being capable of achieving the claimed intended uses and desired results; thus teaching all the structural requirements of the claim. Regarding claim 16, Swann in view of Kawai teaches the invention as discussed for claim 10. Swann in view of Kawai is silent about: using the non-cryogenic fuel to heat the cryogenic fuel before the cryogenic fuel enters the engines However, Kamath teaches: using the non-cryogenic fuel to heat the cryogenic fuel before the cryogenic fuel enters the engines (Kamath Claim 1, where ‘first fuel’ is jet fuel [0084] and ‘second fuel’ is LNG [0084]). Regarding claim 17, Swann in view of Kawai teaches the invention as discussed for claim 10. Swann further teaches: Switching between the cryogenic fuel and the non-cryogenic fuel to supply to each of the engines individually (Swann [0025]; and Fig 1 shows an individual engine and dedicated controller 130; see Swann [0087]). Regarding claim 19, Swann teaches: An aircraft configured to fly a design long range mission (Title; aircraft (abstract); aircraft propulsion system enters air [0011]), the aircraft including an engine (abstract), theaircraft comprising: aerodynamic structure overall geometry and design weights (inter alia, aircraft (Abstract) has fuselage) configured as a function of both the design long range mission (a long range [0003]) burning non-cryogenic fuel (“an engine system capable of producing thrust by: an engine system capable of producing thrust by: [0008] (i) combusting hydrocarbon fuel; (i) combusting hydrocarbon fuel” [0007-0008]) and a typical range mission (flights not requiring a long range [0003]) burning no non-cryogenic fuel (the aircraft propulsion system is capable of burning cryogenic fuel [0004, 0006, 0026, 0091], “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058]), wherein the typical range mission is shorter in distance than a design long range mission (flights not requiring a long range [0003]) and the distance ratio between the typical range mission and the design long range mission is between 0.2 and 0.5 (Swann teaches “For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003], “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]; Swann is silent about a ratio of typical range mission to design long range mission is between 0.2 and 0.5. However, “the ratio between the typical range mission and the design long range mission” was recognized as a result-effective variable, i.e., a variable which achieves a recognized result, in the prior art, in this case the ratio of typical range mission to design long range mission is between 0.2 and 0.5 depending on sizing and capacity ratios between the different tanks, such that the determination of the optimum or workable ranges of said variable, in this case the ratio between the quantity of the different types of fuel that would allow flights with ranges between 0.2 to 0.5 of the design long range mission, may have been characterized as routine experimentation. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). Where the general conditions of a claim are disclosed in the prior art, in this case adjusting the fuel capacities on a flight -by-flight or seasonal basis [0092], it has been held that the discovery of optimum or workable ranges, in this case a range ratio between 0.2 and 0.5, by experimentation requiring only routine skill in the art, in this case the ability to adjust capacities, would have been an obvious extension of prior art teachings. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A). disposed within the aerodynamic structure, a first fuel tank means for storing a quantity of cryogenic fuel on board the aircraft (“An aircraft propulsion system includes […] a hydrogen fuel store”, abstract; also see 112(b) rejection above), the first fuel tank means having a volumetric capacity sized to store sufficient cryogenic fuel to provide thrust to fly the aircraft for a typical range mission without reserves (““For flights not requiring a long range, an aircraft may run entirely or mostly on hydrogen” [0003]), first fuel tank means being volumetrically sized to be smaller than a size that would be required to store sufficient cryogenic fuel for cryogenically fueling the aircraft to provide thrust to fly the aircraft for a mission that includes the distance of the typical range mission and an additional portion of the design long range mission to exceed the distance of the typical range mission plus reserves (Dual-fuel aircraft have therefore been proposed which use both hydrogen fuel and hydrocarbon fuel (typically kerosene) in order to allow the range of an aircraft to be extended beyond that achievable using hydrogen fuel alone [0003], and it is noted that [0003] as a whole teaches the relationship between tank size and range, and presents pros and cons to be considered when the different types of fuels are used; and “An aircraft propulsion system of the invention preferably allows the capacity for stored hydrogen to be adjusted according to the ranges of flight missions which an aircraft comprising the system is required to carry out. For example, the hydrogen storage capacity of a system of the invention may be provided by a plurality of similar or identical removable tanks, allowing the number, and hence total capacity, of the tanks to be adjusted, for example on a flight-by-flight or seasonal basis” [0092]); disposed within the aerodynamic structure, a second fuel tank means for storing non-cryogenic fuel on board the aircraft (“An aircraft propulsion system includes […] a hydrocarbon fuel store”, abstract; also see 112(b) rejection above), the second fuel tank means for storing a quantity of non-cryogenic fuel as a reserve fuel for the aircraft (“an engine system capable of producing thrust by: an engine system capable of producing thrust by: [0008] (i) combusting hydrocarbon fuel; (i) combusting hydrocarbon fuel” [0007-0008] “the system 100 may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058], “a portion of the initial mass of hydrocarbon fuel in a dual-fuel aircraft is held in reserve” [0055]) a controller on board the aircraft for supplying the engine with the cryogenic fuel from the first fuel tank means to consume and burn to propel the aircraft for the typical range mission without supplying the engine with the non-cryogenic fuel from the second fuel tank means to consume and burn to propel the aircraft for the typical range mission but instead supplying the non-cryogenic fuel from the second fuel tank means to cool components of the Swann is silent about: a venting system configured to monitor temperature and pressure of the cryogenic fuel stored by the first fuel tank means and provide controlled venting of the first fuel tank means to the atmosphere to avoid excessive pressure buildup within the first fuel tank means as the cryogenic fuel contained by the first fuel tank means boils off; However, Kawai teaches a dual fuel gas turbine (title), and : a venting system configured to monitor temperature and pressure of the cryogenic fuel stored by the first fuel tank means and provide controlled venting of the first fuel tank means to the atmosphere to avoid excessive pressure buildup within the first fuel tank means as the cryogenic fuel contained by the first fuel tank means boils off (“The fuel storage system 10 may further comprise a safety release system 45 adapted to vent any high pressure gases that may be formed in the cryogenic fuel tank 22” [0047], and “An LNG tank with one or more vent lines 41 for removal of gaseous natural gas, formed by the absorption of heat from the external environment” [0059]). It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Swann with Kamath's structure discussed above in order to “release any high pressure gases in the event of an over pressure inside the fuel tank” [0047]. Swann in view of Kamath is silent about: and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling without consuming the stored quantity of non-cryogenic fuel; and and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling without consuming the stored quantity of non-cryogenic fuel However, Kawai teaches a dual fuel gas turbine (title), and : and to provide motive flow for engine variable inlet guide vanes actuation and/or engine oil cooling (the fuels may be used for ancillary purposes such as oil cooling or providing hydraulic pressure in the engine. For example, the fuel may pass through an oil cooler and/or through a hydraulic system before going to fuel nozzles in the gas turbine engine [0013]) without consuming the stored quantity of non-cryogenic fuel (the tanks in Kawai do not consume he stored fuel) It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Swann in view of Kamath with Kawai’s structure as discussed above in order to provide “the liquid fuel to satisfy the ancillary systems, such as oil cooling and/or engine hydraulic pressure” (Kawai [0014]) since “[cryogenic] fuels may not be able to provide oil cooling or hydraulic pressure” as taught by Kawai [0013]. Regarding claim 20, Swann in view of Kamath and Kawai teaches the invention as discussed for claim 19. Swann further teaches: the cryogenic fuel comprises hydrogen ([0003]) and the noncryogenic fuel comprises fossil fuel (Kerosene, [0003]). Regarding claim 21, Swann in view of Kamath and Kawai teaches the invention as discussed for claim 20. Swann further teaches: the aircraft further comprises a further engine ([0087, 0088] Figs. 2, 3), configured to consume the same one of the cryogenic fuel or the non cryogenic fuel as the first mentioned engine (two separate turboprop engines 222A, 222B, each including a respective propeller, and each of which may combust hydrocarbon only, hydrogen only or a combination of both hydrocarbon or hydrogen within a combustion arrangement described above in relation to the turbofan engine 122 of the system 100.0087]). Claims 2 is rejected under 35 U.S.C. 103 as being unpatentable over Swann 20220316410 in view of Kamath 20150321767, Kawai 20160076461 and Schwarze 20110101166. Regarding claim 2, Swann in view of Kamath and Kawai teaches the invention of claim 1. Swann further teaches: the controller ([0010]) is configured to control provisioning of the non-cryogenic fuel to the engines ([0010]) as: an amount of reserve or range extending fuel (“a portion of the initial mass of hydrocarbon fuel in a dual-fuel aircraft is held in reserve,” Swann [0055], and “a dual-fuel propulsion system for providing an aircraft comprising the system 100 with a range which is extended beyond that achievable using hydrogen fuel only stored in tank 112” [0058] and “may operate throughout a flight mission fueled by hydrocarbon fuel only or hydrogen fuel only or a combination of both hydrocarbon fuel and hydrogen fuel” [0058] and “the hydrocarbon fuel thus serves an additional purpose, beyond enabling range-extension” [0064]; the use of cryogenic fuel or a combination of fuels is also taught on [0003]), Swann in view of Kamath and Kawai does not teach the reserve or range extending fuel being specifically defined based on regulatory requirements as claimed. However, Schwarze teaches: an amount of which complies with regulatory requirements to allow the aircraft to change destination airport from an initially scheduled destination airport and another destination airport different from the initially scheduled destination airport (Schwarze teaches a control unit that controls multiple types of fuel according to different requirements and parameters [0024] and different factors as optimization parameters, including: art of regulatory requirements to allow the aircraft to change destination from a first airport and another airport different from the first airport (Schwarze “fuel is not yet permitted for specific flight phases in specific countries” Schwarze [0017]; examiner’s note: Schwarze use of the allowed type of fuel, enables to aircraft to proceed to another airport/location where other types of fuel are allowed); It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Swann in view of Kamath and Kawai with the teachings of Schwarze in order to take “several different optimization parameters […] into consideration, according to which the supply with multiple fuels may be optimized” as taught by Schwarze [0012]. Furthermore, this portion of the claim describes intended use, and a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. Response to Arguments/Remarks Applicant’s arguments have been considered, but they are not persuasive because they do not apply to the new combination of references, i.e., adding a new reference to the old combination of references, that was necessitated by applicant’s amendment. However, to the extent possible, applicant’s arguments have been addressed in the body of the rejections above, at the appropriate location. 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. Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to Roberto T. Igue whose telephone number is (303)297-4389. The examiner can normally be reached Monday-Friday 7:30-4:30 PT. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Phutthiwat Wongwian can be reached on (571) 270-5426. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ROBERTO TOSHIHARU IGUE/Examiner, Art Unit 3741 /PHUTTHIWAT WONGWIAN/Supervisory Patent Examiner, Art Unit 3741
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Prosecution Timeline

Jul 14, 2022
Application Filed
Oct 05, 2023
Non-Final Rejection — §103, §112
Jan 31, 2024
Examiner Interview Summary
Apr 19, 2024
Response Filed
Aug 01, 2024
Final Rejection — §103, §112
Feb 07, 2025
Request for Continued Examination
Feb 11, 2025
Response after Non-Final Action
Apr 03, 2025
Non-Final Rejection — §103, §112
May 13, 2025
Examiner Interview Summary
Aug 08, 2025
Response after Non-Final Action
Aug 08, 2025
Response Filed
Dec 29, 2025
Response Filed
Feb 06, 2026
Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
58%
Grant Probability
75%
With Interview (+17.1%)
2y 7m
Median Time to Grant
High
PTA Risk
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