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 .
Drawings
The drawings were received on 12/31/2025. These drawings are entered.
The drawings [especially Figs. 1-4] of 9/23/2024 are not approved as they do not conform with the requirements of 37 CFR “1.84 Standards for drawings.”
“(l) Character of lines, numbers, and letters. All drawings must be made by a process which will give them satisfactory reproduction characteristics. Every line, number, and letter must be durable, clean, black (except for color drawings), sufficiently dense and dark, and uniformly thick and well-defined. The weight of all lines and letters must be heavy enough to permit adequate reproduction. This requirement applies to all lines however fine, to shading, and to lines representing cut surfaces in sectional views. Lines and strokes of different thicknesses may be used in the same drawing where different thicknesses have a different meaning.”
Specification
The disclosure is objected to because of the following informalities: pressure “in lb inches per second squared per inch squared” on page 105, lines 18-19 of the excerpt does not make sense as a unit of pressure, which is understood to be force per area.
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Appropriate correction is required.
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.
Claims 20, 21 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 20, 21 rely on highly specific and narrow ranges for the ratio. However, applicant has not disclosed the particular SAF fuel in the disclosure that would meet the highly specific ranges and/or the blend ratio and/or other parameters of the fuel that would allow for meeting these highly specific ranges. Furthermore, as SAF fuels do not appear to be standardized, there is no way to determine which fuels would meet the claimed range without undue experimentation. “wherein the fuel-flow nvPM emissions index ratio is in the range of 0.00111 to 0.0109.
“wherein the fuel-flow nvPM emissions index ratio is in the range of 0.00124 to 0.00986.
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.
Claims 1-11, 13-21 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.
Claims 1, 15 “and the sustainable aviation fuel is not from fossil-based hydrocarbons” is unclear because applicant does not make whether this is intended to preclude the use of all fossil- based hydrocarbons from the system. In other words, a fossil fuel blended with SAF can be broadly considered an SAF fuel as it contains SAF. Hence, the sustainable aviation fuel is not from fossil- based hydrocarbons is unclear whether this precludes fossil- based hydrocarbons fuel blends.
Claim 11 “one or more ignitors and the ignitor” is unclear as the usage is not consistent.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 8 recites the broad recitation of a range, and the claim also recites a narrower “preferably …” statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
“the sustainable aviation fuel is not from fossil- based hydrocarbons” limitation has been carefully considered. Note that since applicant’s specification [e.g. ¶ 1009 from the PG-pub] teaches the SAF can be as low as 1% in the fuel blend, even a miniscule portion of the fuel being SAF can read on the claim, e.g. use 1% hydrogen or methane sourced from renewable or other sources. Alternately, replacing 1% of the hydrogen in a fuel with hydrogen from an SAF is well within the ordinary skill in the art and would still read on the claims.
[1009] By “fuel comprising SAF” we may mean that the fuel provided to the combustor 16 (and to the combustion chamber 401), via the fuel spray nozzles 403, 404, comprises a % SAF in the range of 50% to 100%, preferably in the range 70% to 100%, and more preferably in the range 90% to 100%. More generally, by “fuel comprising SAF” we may mean a fuel comprising any blend of SAF and fossil kerosene fuel, including up to 100% SAF and no fossil kerosene fuel. The fuel comprising SAF may be a fuel comprising a percentage SAF of 1%, 2%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 100%, or within any range defined between any two of those values.
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) 1-7, 13-21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Razak (2015/0292402) in view of Swann et al (11,591,973) in view of Anderson et al, "Alternative Aviation Fuel Experiment" (AAFEX), NASA, NASA/TM-2011-217059, (February 2011) in view of Stickles et al “TAPS II Technology Final Report and Aubuchon et al. “CFM56-3 Turbofan Engine Description” and Everllence webpage and optionally in view of Durdina et al “Reduction of Nonvolatile Particulate Matter Emissions of a Commercial Turbofan Engine at the Ground Level from the Use of a Sustainable Aviation Fuel Blend” of the IDS. Razak teaches (1) A gas turbine engine for an aircraft, comprising: a fan 12; a bypass duct 36; a reduction gearbox 42 configured to drive the fan; and an engine core 20 with a rich burn, quick quench, lean burn (RQL) combustor 20 having quench ports 85 and a number of fuel spray nozzles 83; wherein a bypass ratio defined as a ratio of mass flow rate through the bypass duct to mass flow rate through the engine core is from 8 to 20 [¶ 0046]. (15) A method of operating a gas turbine engine, the gas turbine engine comprising: a fan 12; a bypass duct 36; a reduction gearbox 42 configured to drive the fan; and an engine core 20 with a rich burn, quick quench, lean burn (RQL) combustor 20 having quench ports 85 and a number of fuel spray nozzles 83; wherein a bypass ratio defined as a ratio of mass flow rate through the bypass duct to mass flow rate through the engine core is from 8 to 20 [¶ 0046].
Razak does not teach a number of fuel spray nozzles 83 in the range 14-22 nor a fuel-flow nvPM emissions index ratio is defined as: EIidle×Wf,idle/EImaxTO×Wf,maxTO where: EIidle is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 7% available thrust for given operating conditions; and EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 100% available thrust for the given operating conditions; Wf,idle is the rate of fuel flow to the fuel spray nozzles in kg/s at around 7% available thrust for the given operating conditions; and Wf,maxTO is the rate of fuel flow to the fuel spray nozzles in kg/s at around 100% available thrust for the given operating conditions; and the fuel-flow nvPM emissions index ratio of the gas turbine engine is less than 0.08 when the gas turbine engine provides fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles, and the sustainable aviation fuel is not from fossil- based hydrocarbons and the gas turbine engine is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles, wherein the method comprises providing fuel comprising a sustainable aviation fuel to the fuel spray nozzles at around 7% available thrust and at around 100% available thrust, and the sustainable aviation fuel is not from fossil-based hydrocarbons. Razak additionally do not teach the other claimed ranges of the dependent claims 2-7, 13, 16-21. Using a number of fuel spray nozzles 83 in the range of 14-22 is highly conventional in the art as evidenced by Swann et al [col. 43, lines 30+] as is the use of SAF fuels [col. 38] to promote the use of renewable fuels and/or for lower emissions. It would have been obvious to one of ordinary skill in the art to employ a number of fuel spray nozzles 83 in the range 14-22 and provide SAF fuels to the fuel nozzles, as taught by Swann et al, as the typical number of fuel injectors utilized in the art in order to promote the use of renewable fuels and/or for lower emissions. Anderson et al teach the CFM56-2C1 gas turbine engines were utilized for the data [see page 9]. Stickles et al [the manufacturer] teach that the CFM56 engine uses the single annular combustor design [SAC,] with rich quench lean (RQL) burn combustion [see bottom of page 8 and particularly pages 10-11]. Note Stickles et al teach the double annular combustor [DAC] design did not enter service until the much later generations of CFM56-5B and –7B engines.
“After many years of intermittent development, the DAC entered service in the CFM56-5B and –7B engines in the mid-1990s” [excerpted from page 11].
Hence, all previous generation engines [including the 2C1, 3 versions] utilized the single annular combustor design [SAC] design with the RQL. As for the number of fuel spray nozzles, these are well known for the SAC design to be 20 fuel spray nozzles [20 swirl fuel nozzles, e.g. from specifications cited by Aubuchon et al].
Anderson et al teach: A gas turbine engine for an aircraft, comprising: a rich burn, quick quench, lean burn (RQL) combustor [inherent, as evidenced by Stickles] having a number of fuel spray nozzles in the range 14-22 [20 as the published number for the SAC combustor of the CFM56 engine, e.g. from Aubuchon et al] or a number of fuel spray nozzles per unit engine core size in the range 2 to 6; and wherein: a fuel-flow nvPM emissions index ratio is defined as: EIidle×Wf,idle/EImaxTO×Wf,maxTO where: EIidle is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 7% available thrust for given operating conditions; and EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 100% available thrust for the given operating conditions [see page 51, Fig. 28, left Fig. which shows the nvPM at idle and at 100% thrust/power – see also page 172, Fig. 5 in Appendix G from which the data was sourced]; Wf,idle is the rate of fuel flow to the fuel spray nozzles in kg/s at around 7% available thrust for the given operating conditions; and Wf,maxTO is the rate of fuel flow to the fuel spray nozzles in kg/s1 at around 100% available thrust for the given operating conditions [see page 194, Fig. 7 which teaches that fuel flow rate is linear based on power at idle to at 100% thrust/power]; the fuel-flow nvPM emissions index ratio of the gas turbine engine is less than 0.08; and the gas turbine engine is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles [page 172, Fig. 5 in Appendix G, shows different SAF fuels, i.e. everything but the JP-8]. Note the ratio of EIidle×Wf,idle/EImaxTO×Wf,maxTO is the same as EIidle /EImaxTO× Wf,idle/ Wf,maxTO and examples of these values on Figs. 5 (pg. 172) and Fig. 7 (pg. 194) include about 2E12 / 2E14 x 1000/8000 = 1/100 x 1/8 = 0.0125. (2) wherein the fuel-flow nvPM emissions index ratio is less than 0.0798. (3) wherein the fuel-flow nvPM emissions index ratio is less than or equal to 0.06. (4) wherein the fuel-flow nvPM emissions index ratio is less than or equal to 0.0119. (5) wherein the fuel-flow nvPM emissions index ratio is greater than or equal to 0.000993. (7) wherein: a) Wf,idle is in the range of 0.0516 to 0.119 kg/s and preferably in the range of 0.0581 to 0.109 kg/s and more preferably in the range of 0.0645 kg/s to 0.0990 kg/s [Fig. 7 (pg. 194): 800 pounds / hour converts to 0.1 kg/s]; and/or b) Wf,maxTO is in the range 0.441 to 1.23 kg/s and preferably in the range of 0.496 to 1.13 kg/s and more preferably in the range of 0.551 kg/s to 1.03 kg/s [Fig. 7 (pg. 194): 8000 pounds/hour is 1kg/s]. (13) wherein the fuel provided to the combustor comprises a %SAF in the range of 50% to 100%, preferably in the range 70% to 100%, and more preferably in the range 90% to 100% [up to 100% SAF tested, see page 10](16) wherein the fuel-flow nvPM emissions index ratio is less 0.0731.
(17) wherein the fuel-flow nvPM emissions index ratio is less than 0.0665.
(18) wherein the fuel-flow nvPM emissions index ratio is greater than or equal to 0.00111.
(19) wherein the fuel-flow nvPM emissions index ratio is greater than or equal to 0.00124.
(14) A method of operating the gas turbine engine of claim 1, the method comprising providing the fuel comprising a sustainable aviation fuel to the fuel spray nozzles [up to 100% SAF tested, see page 10]. (15) A method of operating a gas turbine engine, the gas turbine engine comprising: a rich burn, quick quench, lean burn (RQL) combustor having a number of fuel spray nozzles in the range of 14-22 or a number of fuel spray nozzles per unit engine core size in the range 2 to 6; and wherein: a fuel-flow nvPM emissions index ratio is defined as: EIidle×Wf,idleEImaxTO×Wf,maxTOwhere: EIidle is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 7% available thrust for given operating conditions; and EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 100% available thrust for the given operating conditions; Wf,idle is the rate of fuel flow to the fuel spray nozzles in kg/s at around 7% available thrust for the given operating conditions; and Wf,maxTO is the rate of fuel flow to the fuel spray nozzles in kg/s at around 100% available thrust for the given operating conditions; the fuel-flow nvPM emissions index ratio of the gas turbine engine is less than 0.08; and the gas turbine engine is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles, wherein the method comprises providing fuel comprising a sustainable aviation fuel to the fuel spray nozzles. The method of claim 15 is treated analogously to claim 1. Anderson teaches the fuel FT-1 may be Fischer Tropsch products made from natural gas [page 1, bottom paragraph]. Note that Everllence webpage teaches that synthetic natural gas is sourced from waste biomass and its composition is as close as possible to natural gas. Accordingly, using synthetic natural gas from waste biomass as the source for the Fischer-Tropsch fuel 1, FT-1, is well within the ordinary skill in the art. As the compositions of the two are the same, the composition of the FT-1 fuel should be analogous in FT-1 made from Fischer Tropsch products made from synthetic natural gas. It would have been obvious to one of ordinary skill in the art to utilize FT-1 made from SAF sources, e.g. synthetic natural gas is sourced from waste biomass, in order to utilize a renewable resource and lessen reliance on fossil-fuels. It would have been obvious to one of ordinary skill in the art that the ranges selected by applicant for the EIidle /EImaxTO× Wf,idle/ Wf,maxTO and examples of these values on Figs. 5 (pg. 172) and Fig. 7 (pg. 194) include about 2E12 / 2E14 x 1000/8000 = 1/100 x 1/8 = 0.0125, are typical ranges utilized in the art for an analogous rich-quench lean combustor and would have been obvious to achieve in the Razak combustor based on using the workable ranges in the art, depending on the exact fuel composition. Alternately, Durdina et al teach [see Fig. 1] a fuel-flow nvPM emissions index ratio is defined as: EIidle×Wf,idle/EImaxTO×Wf,maxTO where: EIidle is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 7% available thrust for given operating conditions; and EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine if operating at around 100% available thrust for the given operating conditions; Wf,idle is the rate of fuel flow to the fuel spray nozzles in kg/s at around 7% available thrust for the given operating conditions; and Wf,maxTO is the rate of fuel flow to the fuel spray nozzles in kg/s at around 100% available thrust for the given operating conditions; and the fuel-flow nvPM emissions index ratio of the gas turbine engine is less than 0.08 [see Fig. 1] when the gas turbine engine provides fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles, and the sustainable aviation fuel is not from fossil- based hydrocarbons. Note the ratio of EIidle×Wf,idle/EImaxTO×Wf,maxTO is the same as EIidle /EImaxTO× Wf,idle/ Wf,maxTO and examples of these values on Fig. 2 include about 1 / 175 [from Fig. 2 of Durdina] x 1000/8000 [from Fig. 7 of Anderson (pg. 194), note the ratio of the fuel flows at idle to full thrust should be comparable as fuel flow and thrust are linearly related], resulting in the above ratio being = 1/175 x 1/8 = 0.000714, which covers the independent claims and claims 2-4, 16-17. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges as the typical ranges utilized in the art for an analogous rich-quench lean combustor and would have been obvious to achieve in the Razak combustor based on using the workable ranges in the art, depending on the exact fuel composition. Note for ranges such (6) wherein the fuel-flow nvPM emissions index ratio is in the range of 0.000993 to 0.0119; (20) wherein the fuel-flow nvPM emissions index ratio is in the range of 0.00111 to 0.0109 and (21) wherein the fuel-flow nvPM emissions index ratio is in the range of 0.00124 to 0.00986, the ranges of Anderson and Durdina et al are already below and above these ranges, and thus and using those specific values are regarded as varying the fuel composition or air dilution in the combustor or in the turbine, such that these ranges may be achieved by dilution of the exhaust gas. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges as the typical ranges utilized in the art for claims 6, 20, 21, as an obvious matter of using the workable ranges in the art, depending on the exact fuel composition variations or by air dilution in the combustor or in the turbine, such that these ranges may be achieved by dilution of the exhaust gas. Furthermore since Durdina teaches that lower than each of these above ranges can be achieved for claims 5, 18-19, then raising the emission level to a less stringent level should be achievable by use of lower ratios of SAF fuel in the fuel blend or other changes in fuel composition. It would have been obvious to one of ordinary skill in the art to employ the claimed ranges as the typical ranges utilized in the art for claims 5, 18-19, as an obvious matter of using the workable ranges in the art, then raising the emission level to a less stringent level should be achievable by use of lower ratios of SAF fuel in the fuel blend or other changes in fuel composition.
Claim(s) 8-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Razak (2015/0292402) in view of Swann et al (11,591,973) in view of Anderson et al, "Alternative Aviation Fuel Experiment" (AAFEX), NASA, NASA/TM-2011-217059, (February 2011) in view of Stickles et al “TAPS II Technology Final Report and Aubuchon et al. “CFM56-3 Turbofan Engine Description” and Everllence webpage and optionally in view of Durdina et al “Reduction of Nonvolatile Particulate Matter Emissions of a Commercial Turbofan Engine at the Ground Level from the Use of a Sustainable Aviation Fuel Blend” of the IDS, as applied above, and further in view of Hoke et al (2013/0125556). Razan et al do not teach (8) wherein the fuel spray nozzles comprises one or more duplex fuel spray nozzles and one or more single flow nozzles; (9) wherein the duplex fuel spray nozzles are arranged in groups about the circumference of the combustor; (10) wherein each group of duplex fuel spray nozzles comprises 2-8 nozzles; (11) wherein the combustor comprises one or more ignitors and the ignitor is arranged adjacent to one or more of the duplex fuel spray nozzles. Hoke et al teach a single annular combustor 66 which employs (8) wherein the fuel spray nozzles 86 comprises one or more duplex fuel spray nozzles 86D [Fig. 4] and one or more single flow nozzles 86S. (9) wherein the duplex fuel spray nozzles 86D are arranged in groups about the circumference of the combustor [Fig. 3, ¶ 0028]. (10) wherein each group of duplex fuel spray nozzles 86D comprises 2-8 nozzles [Fig. 3, ¶ 0028]. (11) wherein the combustor comprises one or more ignitors 124 and the ignitor 124 is arranged adjacent to one or more of the duplex fuel spray nozzles 86D.
Hoke et al teach using the duplex and single flow fuel nozzles allows for
“selectively forming a plurality of local circumferential zones with different fuel-air ratios within the combustor [¶ 0005]”
in a manner which controls combustor noise.
It would have been obvious to one of ordinary skill in the art to employ (8) wherein the fuel spray nozzles comprises one or more duplex fuel spray nozzles and one or more single flow nozzles; (9) wherein the duplex fuel spray nozzles are arranged in groups about the circumference of the combustor; (10) wherein each group of duplex fuel spray nozzles comprises 2-8 nozzles; (11) wherein the combustor comprises one or more ignitors and the ignitor is arranged adjacent to one or more of the duplex fuel spray nozzles, as part of a single annular combustor design, as taught by Hoke et al, in order to “selectively form a plurality of local circumferential zones with different fuel-air ratios within the combustor” in a manner which controls combustor noise.
Response to Arguments
Applicant's arguments filed 12/31/2025 have been fully considered but they are not persuasive. Applicant’s alleges Stickles does not teach an RQL combustor but rather [only] a rich combustor. This is incorrect. Stickles teaches that particular engine / combustor type is a lower emissions rich burn combustor (LEC) on page 9, which is then further defined on page 10 and Fig. 4 [see excerpts below].
“Figure 3 shows the evolution of low emissions combustors at GE. Most current fielded products use the GE rich-burn LEC concept. This is an adaption of the RQL (rich quench lean) concept where there is a rich combustor primary zone to provide low CO and HC emissions and good ignition capability. NOx formation rates are low in the primary zone because the flame temperature of the rich primary mixture is relatively low, and there is little free oxygen available to form NOx. Flow exiting the primary zone is rapidly diluted, or “quenched”, to a uniform lean mixture. With this concept, fast and uniform mixing during the quenching process is critical in order to minimize the time available for NOx formation as the mixture goes through stoichiometric fuel air ratio, where maximum flame temperatures lead to maximum NOx formation rates. Over the past 35 years, the LEC combustor has been developed to reduce NOx by 25-50% relative to first generation combustors. The rich burn combustion process is shown in Figure 4.”
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Fig. 4 clearly shows each of the Rich Quench Lean (RQL) regions. Accordingly, applicant’s argument is completely misdirected.
Applicant’s argument about the sustainable aviation fuel is not from fossil- based hydrocarbons is not persuasive for multiple reasons. First, applicant does not make clear whether fossil- based hydrocarbon fuel blends are encompassed or excluded from this and is thus problematic under 35 USC 112. One interpretation of “sustainable aviation fuel is not from fossil- based hydrocarbons” is to exclude any fossil-based hydrocarbon from the fuel sent to the fuel injectors. Even if that were the case, since the FT-1 fuel of Anderson is made by Fischer Tropsch process of natural gas, using synthetic natural gas sourced from waste fuel as the source for the Fischer Tropsch process to make the FT-1 fuel would still encompass a sustainable aviation fuel.
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday.
The fax number for the organization where this application is assigned is 571-273-8300.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118 Alternate inquiries to Technology Center 3700 can be made via 571-272-3700.
Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent
/Ted Kim/
Telephone
571-272-4829
Primary Examiner
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571-273-8300
January 29, 2026
1 Note that while the unit is kg/s, since the ratio divides fuel flows at idle by fuel flow at 100% thrust, the units do not matter since the units cancel. In other words using the conversion factor to convert fuel flows from e.g. lbs/hour to kg/s affects both the numerator and denominator equally and the conversion factor cancels from both the numerator and denominator. Accordingly, since only the ratio of these quantities is being used, it is irrelevant what units are used as long as they are the same since any conversion factors cancel.