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 Action is responsive to the Amendment filed 24 November 2025. Claims 1-7 are pending. Claim 1 has been written in independent form.
Specification
The disclosure is objected to because of the following informalities:
Page 13 – In line 3 of the paragraphs beginning with “A key conceptual feature,” the word “decent” should, perhaps, be the word “descent” instead.
The following reference characters throughout the specification are designated with multiple names or the same reference character is used to designate different parts:
reference character 10 has been designated as both “hybrid propulsion system” and “dual fuel propulsion system;”
reference character 20 has been designated as “two-engine regional aircraft” and “airplane” and “conventional shoulder-wing aircraft” and “hydrogen aircraft” and “commuter aircraft” and “aircraft” without any disclosure stating that reference character 20 can alternatively be designated by these six different names;
reference character 23 has been designated as “cockpit” and “forward facing cabin section” and “cabin section;”
reference character 50 has been designated as “transmission unit” and “hydrogen fuel system” and “second fuel system;”
reference character 60 has been designate as both “controller” and “central controller;”
reference character 51 has been designated as “fuel storage tanks” and “the second set of tanks” and “hydrogen tanks” and “spherical or cylindrical tanks” and “the set of hydrogen tanks” and “feeder tank;”
both reference characters “23” and “29” have both been used to designate cockpit;
reference characters “31, 32” and “41, 42” have all been used to designate gas turbines, specifically on page 13 in the initially filed specification.
Appropriate correction is required.
Claim Objections
Claims 1 and 7 are objected to because of the following informalities:
Claim 1 – In line 4, it appears that the word “decent” is a typographical error, and should be the word “descent” instead.
Claim 1 – In line 11, it appears that a strikethrough was inadvertently placed through the letter “s” in the word “tanks” and should be the word “tanks” should have been left intact. By striking through the “s” in tanks, a lack of antecedent basis is created in the claim limitation the second set of fuel storage tanks” in line 15.
Claim 7: The “blank” underline in line 2 in front of the word “defining” should be deleted. Should these claims ever get allowed, that “blank” underline will be printed in the claims in the issued patent.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 USC § 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 USC § 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.
Claim(s) 1 and 3-4 is/are rejected under 35 USC § 103 as being unpatentable over Sankrithi et al., U.S. Patent Application Publication 2014/0339367 A1 (hereinafter called Sankrithi), and further in view of RIBEIRO et al., U.S. Patent Application Publication 2024/0199230 A1 (hereinafter called RIBEIRO).
Regarding claim 1, as best understood, Sankrithi teaches a transport aircraft (See e.g., FIG. 3 element 300; FIG. 15 element 1500; ¶s [0049]-[0050]) comprising a fuselage (See e.g., FIG. 3, the fuselage is not labeled; FIG. 15 element 1512) hosting passengers and/or freight in a cabin (See e.g., FIG. 3, the seats are evidence that passengers can be hosted; FIGS. 15 & 16 elements 1540, 1604, 1618; ¶s [0052]-[0053] & [0066]), wings (See e.g., FIG. 3 element 306; FIG. 15 elements 1508; ¶s [0050], [0069], & [0081]) attached to the fuselage to generate lift (See e.g., FIGS. 16 & 17 elements 1606, 1708; ¶s [0051], [0069], & [0081]) and a dual fuel propulsion system (See e.g., FIG. 15 elements 1530, 1532; ¶s [0051] & [0056]-[0057]), wherein the aircraft is capable of performing a flight mission comprising flight sections of at least take-off, climb, cruise, decent, approach and landing during which a first or a second fuel is selectively useable, the aircraft comprising:
at least one internal combustion engine (See e.g., FIG. 15 element 1506) capable of generating propulsive thrust (See e.g., ¶s [0056], [0070], & [0080]);
two independent fuel systems (See e.g., FIG. 3 elements 302, 310; FIG. 15 1504; ¶ [0057]), including a first fuel system (See e.g., FIG. 3 element 310; FIG. 15 element 1508) feeding the jet fuel (See e.g., ¶ [0038]; FIG. 15 elements 1528; ¶s [0051]-[0052], [0056], & [0065], all of which teach jet fuel 1528) from a first set of fuel storage tanks (See e.g., FIG. 310; ¶ [0038]; FIG. 15 elements 1510) to the internal combustion engine (See e.g., FIG. 15 element 1506) and a second fuel system (See e.g., FIG. 3 element 302; FIG. 15 element 1512) feeding the hydrogen fuel (See e.g., ¶ [0038]; FIG. 15 element 1520; ¶ [0060]) from a second set of fuel storage tank (See e.g., FIG. 3 element 302; FIG. 15 elements 1514; ¶ [0050], which teaches that FIG. 15 applies to all of the aircrafts in FIGS. 3-14);
at least two separate sets of fuel storage tanks (See e.g., FIG. 3 elements 302, 310; FIG. 15 elements 1510, 1514) with a first set of fuel storage tanks (See e.g., FIG. 3 element 310; FIG. 15 elements 1510) storing a jet fuel (See e.g., ¶ [0038]; FIG. 15 elements 1528) and a second set of fuel storage tank (See e.g., FIG. 3 element 302; FIG. 15 elements 1514) storing a hydrogen fuel (See e.g., ¶ [0038]; FIG. 15 element 1520; ¶ [0060]), wherein both sets of the at least two separate sets of fuel storage tanks host the required fuel for the flight (See e.g., ¶s [0051]-[0052] & [0056]; FIG. 15 elements 1528, 1520), wherein
the wings host an internal first set of fuel storage tanks (See e.g., FIG. 3 elements 306, 310; FIG. 15 elements 1508, 1510) and
the second set of fuel storage tanks is hosted in a fuselage cabin (See e.g., FIG. 15 element 1512; ¶ [0053]) or attached as external fuel storage tanks on the wings or on the fuselage,
where the at least one internal combustion engine is using selectively a first kerosene based jet fuel (See e.g., ¶ [0003]) and a second hydrogen fuel (See e.g., ¶ [0056], which teaches “… the airplane propulsion system 1506 (airplane propulsor 1506) comprises one or more burners 1542 (combustors 1542) configured to burn both the jet fuel 1528 and the cryogenic fuel 1520.” And, given that these two propulsion systems also independently burn its own respective fuel, and can also burn both jet fuel and cryogenic fuel, indicates that the at least one internal combustion engine is designed to burn both types of fuel, therefore the reference in their entirety teach the instant claim limitation);
the second fuel system (See e.g., FIG. 3 element 302; FIG. 15 element 1512) is feeding the hydrogen fuel (See e.g., ¶ [0038]; FIG. 15 element 1520; ¶ [0060]) from the second set of fuel storage tanks (See e.g., FIG. 3 element 302; FIG. 15 elements 1514) to the internal combustion engine (See e.g., FIG. 15 element 1506); and
the first set of fuel storage tanks (See e.g., FIG. 3 element 310; FIG. 15 elements 1510) host at least sufficient fuel for the flight (See e.g., ¶ [0038]; FIG. 15 elements 1528) and the second fuel storage tank (See e.g., FIG. 3 element 302; FIG. 15 elements 1514) host at least sufficient fuel for the flight sections (See e.g., ¶ [0038]; FIG. 15 element 1520; ¶ [0060]).
Although Sankrithi teaches all of the claimed structure in the instant claim as set forth hereinabove, Sankrithi is silent regarding both sets of the at least two separate sets of fuel storage tanks host the required fuel for the flight mission plus reserve fuel and the first set of fuel storage tanks host at least sufficient fuel for the flight mission required reserve.
However, RIBEIRO teaches both sets of the at least two separate sets of fuel storage tanks host the required fuel for the flight mission plus reserve fuel and the first set of fuel storage tanks host at least sufficient fuel for the flight mission required reserve (See e.g., FIGS. 12A-12B; ¶s [0075], [0103], [0114], [0120], & [0125]).
Accordingly, because Sankrithi and RIBEIRO teach fuel systems in environmentally friendly aircraft (See e.g., Sankrithi ¶ [0082] and RIBEIRO title), it would have been obvious to the skilled artisan in the art, having the prior art of Sankrithi and RIBEIRO before him, before the effective filing date of the claimed invention, to modify the transport aircraft of Sankrithi to incorporate both sets of the at least two separate sets of fuel storage tanks host the required fuel for the flight mission plus reserve fuel and the first set of fuel storage tanks host at least sufficient fuel for the flight mission required reserve, as taught in the analogous art of RIBEIRO. The skilled artisan in the art would have been motivated to make such a combination to achieve the predictable result of providing mission fuel reserves, which are important to provide contingency plans for pilots, if the destination airport is not able to authorize the landing of the aircraft and an alternate must be sought, and to provide supplementary fuel in critical flight cases, in order to increase safety during special environmental conditions (e.g. rain and hail), emergency flight conditions and/or to minimize the effects of hidden failures, as suggested by RIBEIRO (See e.g., ¶s [0005] and [0043]).
Regarding claim 3, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches where the second set of fuel storage tanks are comprising tanks with spherical or cylindrical shape (Sankrithi See e.g., FIG. 13 elements 1302, 1304; RIBEIRO See e.g., FIGS. 12A & 12B; ¶ [0125]).
Regarding claim 4, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches where the fuselage (Sankrithi See e.g., FIG. 3, the fuselage is not labeled; FIG. 13 element 1310; FIG. 15 element 1512; RIBEIRO See e.g., FIGS. 12A & 12B; ¶ [0075]) comprises a forward cabin section to host passengers (Sankrithi See e.g., FIG. 3, the seats are evidence that passenger can be hosted; FIG. 13 the foremost section of element 1310; RIBEIRO See e.g., FIGS. 12A & 12B Pax cabin; ¶ [0125]) and / or freight and a cabin section in the tail section of the fuselage (Sankrithi See e.g., FIG. 3, the fuselage is not labeled; FIG. 13 element 1310; FIG. 15 element 1512) hosting the second set of fuel storage tanks (Sankrithi See e.g., FIG. 13 elements 1308, 1312).
Regarding claim 5, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches where the aircraft comprises at least one controller (RIBEIRO See e.g., FIGS. 2 element 2; FIG. 7; Abstract; ¶s [0021], [0075], & [0079]) connected with the two independent sets of fuel systems (Sankrithi See e.g., FIG. 3 elements 302, 310; FIG. 15 1504; ¶ [0057]; RIBEIRO See e.g., FIG. 1A) to selectively feed the jet fuel and the hydrogen fuel (Sankrithi See e.g., FIG. 17 box 1702; ¶s [0005]-[0006]; RIBEIRO See e.g., ¶ [0075]) to the at least one internal combustion engine (Sankrithi See e.g., FIG. 15 element 1506) during individual sections of the flight mission (RIBEIRO See e.g., FIGS. 2-3, 5-7, 9-11; ¶ [0075]).
Regarding claim 7, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches a process to operate an aircraft (Sankrithi See e.g., FIG. 17; RIBEIRO See e.g., FIG. 7) comprising:
defining the aircraft to be the transport aircraft of claim 1 (Sankrithi see the entire rejection of claim 1 hereinabove; RIBEIRO See e.g., FIGS. 12A-12B; ¶ [0125]); and
choosing (RIBEIRO See e.g., FIG. 7) the first fuel system (Sankrithi See e.g., FIG. 3 element 310; FIG. 15 element 1508; RIBEIRO See e.g., FIGS. 1-1A Non-Cryo Fuel Tank) or the second fuel system (Sankrithi See e.g., FIG. 3 element 302; FIG. 15 element 1512; RIBEIRO See e.g., FIGS. 1-1A Cryogenic Fuel Tank) according to a lowest emission impact of the aircraft (Sankrithi See e.g., ¶s [0006], [0032], & [0082]; RIBEIRO See e.g., ¶s [0060], [0076], [0094], & [0104]) depending on route and flight level (RIBEIRO See e.g., ¶s [0060], [0076], [0094], & [0104]).
Claim(s) 2 is/are rejected under 35 USC § 103 as being unpatentable over Sankrithi, and further in view of Бычков Андрей Иванович, RU 120945 U1 (hereinafter called ‘0945).
Regarding claim 2, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches where the fuselage has pressurised cabin sections (Sankrithi See e.g., FIG. 15; ¶s [0054] & [0059]).
But neither Sankrithi nor RIBEIRO teaches swap cabin seats in return for fuel storage tanks or fuel storage tanks for cabin seats.
However, ‘0945 teaches swap cabin seats (See e.g., FIG. 1 elements 10, 11, 12) in return for fuel storage tanks (See e.g., FIG. 1 elements 8) or fuel storage tanks for cabin seats (See e.g., page 2, 7th paragraph, and page 2 last paragraph continuing to page 3 lines 1-4; page 3, 2nd and 3rd paragraphs after the list of Figures).
Accordingly, because Sankrithi, RIBEIRO, and ‘0945 teach optimizing a passenger cabin for passenger accommodation (Sankrithi See e.g., ¶ [0053]; claim 3 on page 6; RIBEIRO See e.g., ¶ [0125]; ‘0945 see recitations in the rejection hereinabove), and having seats and tanks in the fuselage (Sankrithi See e.g., FIG 13; RIBEIRO See e.g., FIGS. 12A-12B; ‘0945 FIG. 1), it would have been obvious to the skilled artisan in the art, having the prior art of Sankrithi, RIBEIRO, and ‘0945 before him, before the effective filing date of the claimed invention, to modify the combined transport aircraft of Sankrithi and RIBEIRO to incorporate swap cabin seats in return for fuel storage tanks or fuel storage tanks for cabin seats, as taught in the analogous art of ‘0945. The skilled artisan in the art would have been motivated to make such a combination to achieve the predictable result of reducing the volume of fuel tanks inside the fuselage and the placement of passenger seats between them, making the layout of the passenger compartment have a wide passage in the central part, between separately installed seats, and with the same wide passage in front of two seats at the front of the cargo and passenger cabin, which provides the maximum possible volume of a helicopter cabin of this class per passenger and its comfortable landing and disembarkation from the helicopter, as suggested by ‘0945 (See e.g., page 3, 3rd paragraph after the list of Figures).
Claim(s) 6 is/are rejected under 35 USC § 103 as being unpatentable over Sankrithi, and further in view of RIBEIRO, and further in view of Schwarze et al., U.S. Patent Application Publication 2011/0101166 A1 (hereinafter called Schwarze).
Regarding claim 6, Sankrithi, as modified by RIBEIRO in the rejection of claim 1 hereinabove, further teaches a software supported system (Sankrithi See e.g., FIGS. 16 & 17; ¶s [0029], [0066], & [0077]; RIBEIRO See e.g., FIG. 1 elements 7, 8) to choose the type of fuel (RIBEIRO See e.g., FIG. 7) according to a lowest emission impact of the aircraft (Sankrithi See e.g., ¶s [0006], [0032], & [0082]; RIBEIRO See e.g., ¶s [0060], [0076], [0094], & [0104]) depending on route and flight level (RIBEIRO See e.g., ¶s [0060], [0076], [0094], & [0104]).
But neither Sankrithi nor RIBEIRO teaches the aircraft cockpit comprises a software supported system to choose the type of fuel according to the lowest emission impact of the aircraft depending on route and flight level.
However, Schwarze teaches the aircraft cockpit (See e.g., ¶s [0054]-[0056]) comprises a software supported system (See e.g., FIG. 1 elements 6, 8) to choose the type of fuel according to the lowest emission impact of the aircraft depending on route and flight level (See e.g., ¶s [0012], [0020], [0077]-[0080]).
Accordingly, because Sankrithi, RIBEIRO, and Schwarze teach the use of software to perform specified functions in and on the aircraft, it would have been obvious to the skilled artisan in the art, having the prior art of Sankrithi, RIBEIRO, and Schwarze before him, before the effective filing date of the claimed invention, to modify the combined transport aircraft of Sankrithi and RIBEIRO to incorporate the aircraft cockpit comprises a software supported system to choose the type of fuel according to the lowest emission impact of the aircraft depending on route and flight level, as taught in the analogous art of Schwarze. The skilled artisan in the art would have been motivated to make such a combination to achieve the predictable result of optimizing the supply of a vehicle with multiple fuel types, so that depending on operating conditions and optimization parameters, optimum performance of the vehicle may always be provided and specified mission parameters may be fulfilled, such as to achieve the least possible climate-relevant emission effects over the entire mission, as suggested by Schwarze (See e.g., ¶s [0007] & [0020]).
Response to Arguments
Some of Applicant’s arguments with respect to claim(s) 1 and 2-7 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Specifically, the arguments on page 7 regarding the fuel for the flight mission required reserve. And, as a result of the new ground of rejection, dependent claims 2-7 are now rejected under the new ground of rejection.
However, Applicant's remaining arguments filed 11/24/2025 have been fully considered but they are not persuasive. On page 6 of the REMARKS, Applicant argues, in part, “Sankrithi does not disclose an internal combustion engine selectively using kerosene and liquid hydrogen. … Sankrithi does not disclose or suggest an internal combustion engine that can selectively use both kerosene-based jet fuel and liquid hydrogen as required by claim 1. Applicant's claimed dual-fuel capability is therefore neither taught nor rendered obvious by Sankrithi.” Examiner respectfully disagrees.
Applicant recites from paragraph [0056] of Sankrithi that two separate propulsor subsystems are distinguished and that two independent engines are each operating exclusively on its respective fuel. However, in that same paragraph [0056] of Sankrithi, Sankrithi also discloses that the airplane propulsion system 1506 (airplane propulsor 1506) comprises one or more burners 1542 (combustors 1542) configured to burn both the jet fuel 1528 and the cryogenic fuel 1520. Consequently, Sankrithi does disclose and suggest an internal combustion engine that can selectively use both kerosene-based jet fuel and liquid hydrogen as required by claim 1; therefore, Applicant's claimed dual-fuel capability is taught and rendered obvious by Sankrithi.
On page 7 of the REMARKS, Applicant argues, in part, “Sankrithi does not disclose allocating fuel capacity … This feature establishes a mission-based functional allocation between jet fuel and hydrogen. … The claimed mission-specific fuel partitioning is therefore absent from-and not suggested by-Sankrithi” Examiner respectfully disagrees.
In response to Applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., allocating fuel capacity and mission-based functional allocation between jet fuel and hydrogen and mission-specific fuel partitioning) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). The claim does not require any fuel allocating nor functional allocation between the fuels as Applicant argues. The claim merely requires sufficient fuel, which is not allocating nor allocation of fuel.
Consequently, the claim 1 limitations as rebutted hereinabove in the Response to Arguments section remain rejected as set forth hereinabove in the instant Office Action, and in the Office Action filed 07/23/2025.
Conclusion
It is noted that any citation to specific pages, columns, lines, or figures in the prior art references and any interpretation of the references should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. In re Heck, 699 F.2d 1331, 1332-33, 216 U.S.P.Q. 1038, 1039 (Fed. Cir. 1983) (quoting In re Lemelson, 397 F.2d 1006, 1009, 158 U.S.P.Q. 275, 277 (C.C.P.A. 1968)).
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TERRI L FILOSI whose telephone number is (571)270-1988. The Examiner can normally be reached Monday-Friday 7:00 AM -3:30 PM EST.
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If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Timothy D Collins can be reached at 571-272-6886. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TERRI L FILOSI/
Examiner
Art Unit 3644
12 December 2025
/TIMOTHY D COLLINS/Supervisory Patent Examiner, Art Unit 3644