Prosecution Insights
Last updated: April 19, 2026
Application No. 18/920,379

IN-FLIGHT MEASURED PROPULSION MASS FLOW AND THRUST ON AIRCRAFT

Non-Final OA §103§112
Filed
Oct 18, 2024
Examiner
WIEHE, NATHANIEL EDWARD
Art Unit
3745
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Rtx Corporation
OA Round
1 (Non-Final)
52%
Grant Probability
Moderate
1-2
OA Rounds
3y 9m
To Grant
86%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
183 granted / 354 resolved
-18.3% vs TC avg
Strong +34% interview lift
Without
With
+34.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
16 currently pending
Career history
370
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
45.5%
+5.5% vs TC avg
§102
30.7%
-9.3% vs TC avg
§112
21.9%
-18.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 354 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 . Election/Restrictions Applicant's election with traverse of Group I (claims 1-7) in the reply filed on 13 November 2025 is acknowledged. The traversal is on the ground(s) that searching the subject matter of Groups I and II, as outlined in the outstanding office action, does not place a serious burden on the Examiner and points to claim 1 requiring “determine the first and second mass flows in response to performing an imaging process on the gas turbine engine” and claim 8 requiring “calculating, via an optically-based measurement system, the first and second mass flows based at least in part of the imaging process”. This is not found persuasive because the MPEP states that to demonstrate a serious search burden, the examiner must show by appropriate explanation one of the following: (A) Separate classification thereof: This shows that each invention has attained recognition in the art as a separate subject for inventive effort, and also a separate field of search. Patents need not be cited to show separate classification. (B) A separate status in the art when they are classifiable together: Even though they are classified together, each invention can be shown to have formed a separate subject for inventive effort when the examiner can show a recognition of separate inventive effort by inventors. Separate status in the art may be shown by citing patents which are evidence of such separate status, and also of a separate field of search. (C) A different field of search: Where it is necessary to search for one of the inventions in a manner that is not likely to result in finding art pertinent to the other invention(s) (e.g., searching different classes/subclasses or electronic resources, or employing different search queries), a different field of search is shown, even though the two are classified together. The indicated different field of search must in fact be pertinent to the type of subject matter covered by the claims. Patents need not be cited to show different fields of search. In the current instance, Groups I and II were shown to have separate classifications in the restriction requirement of 16 September 2025 which satisfies (A) above. Furthermore, the restriction requirement of 16 September 2025 clearly presented how a different field of search is required for each of Groups I and II, satisfying (C) above. For these reasons the arguments are not persuasive. The requirement is still deemed proper and is therefore made FINAL. Claims 1-7 are being examined. Claims 8-13 are withdrawn. Claim Interpretation The following is a quotation of 35 U.S.C. 112(f): (f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph: An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked. As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph: (A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function; (B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and (C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function. Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function. Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function. Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are: “an optically-based measurement system” in claim 1; “a first imaging system” and “a second imaging system” in claim 2; “a first energy source” and “a second energy source” in claim 5. Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof. If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. Claim Rejections - 35 USC § 112 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 3-4 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 3 recites the limitation “the measurement controller” in line 1. There is insufficient antecedent basis for this limitation in the claim. Claim 4 depends from claim 3 and fails to remedy its deficiencies. 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 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tanriverdi (US 20140268158 A1; also US 9,030,667 B2) in view of deGaribody (US 20150330310 A1; also US 9,334,807 B2). Regarding claim 1, Tanriverdi teaches a system comprising: a gas turbine engine (Fig.1; ¶2, note “”gas turbine engines”) configured to ingest a first mass flow (20) and to exhaust a second mass flow (28); and an optically-based measurement system (this element is interpreted under 35 U.S.C. 112(f) as first and second imaging systems which include a first and second energy sources and first and second sensors, respectively, said first and second energy sources including lasers to accomplish the claimed function, and equivalents thereof. Tanriverdi teaches a display/controller/lasers/detectors configuration, Fig.1, 45/44/32/34) configured to determine the second mass flow in response to performing an imaging process on the gas turbine engine (Fig.2; ¶34, note “an image generated of either the first or second data sets 50 and 52 may have x and y axes, and third axis representing flow mass”). Tanriverdi does not explicitly teach the system being an aircraft and determination of the first mass flow in response to performing an imaging process on the gas turbine engine. However, Tanriverdi teaches that the disclosed “invention relates to three dimensional (3D) directional velocity measurements of gases flowing through a passage of a system such as at an inlet or exhaust of a gas turbine” (¶1; emphasis added) and that the information obtained from the gas flow could be used to adjust fuel flow to the combustor and monitor or adjust other engine operating parameters (¶35). deGaribody teaches an aircraft (Fig.1/2) including a gas turbine engine (Fig.3/4) and fuel monitoring systems and methods and apparatus to determine airflow conditions at an inlet of an engine (¶1). deGaribody further teaches an optically-based measurement system (this element is interpreted under 35 U.S.C. 112(f) as first and second imaging systems which include a first and second energy sources and first and second sensors, respectively, said first and second energy sources including lasers to accomplish the claimed function, and equivalents thereof. deGaribody teaches a laser sensor system, Fig.3/4, 302) configured to determine a first mass flow (¶33, note “the example laser sensor system 302 calculates or measures a mass of air that passes through a cross-sectional area of the inlet 312 over a period of time”) in response to performing an imaging process on the gas turbine engine (¶41, note “the airflow characteristic(s) provided by each of the sensors 340 can be used to map or graph overall airflow characteristics across substantially the entire cross-sectional area of the inlet”). This configuration allows increasing engine efficiency (e.g., increase a commercial aircraft engine efficiency by approximately between 2 percent and 10 percent), reducing fuel consumption, and increasing a travel range (¶24). It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to modify the system of Tanriverdi by having the system being an aircraft and determination of the first mass flow in response to performing an imaging process on the gas turbine engine, in addition to the already determined second mass flow, based on the teachings of deGaribody because this configuration allows increasing engine efficiency (e.g., increase a commercial aircraft engine efficiency by approximately between 2 percent and 10 percent), reducing fuel consumption, and increasing a travel range of the aircraft. The proposed combination could result in a system with both upstream and downstream optically-based measurement systems, where, the systems could be arranged remotely from the gas turbine engine (Tanriverdi’s configuration) or within the gas turbine engine (deGaribody’s configuration). Regarding claim 2, Tanriverdi and deGaribody further teach the optically-based measurement system comprises: a first imaging system (this element is interpreted under 35 U.S.C. 112(f) as a first energy source and first sensor, said first energy source including lasers to accomplish the claimed function, and equivalents thereof. Tanriverdi teaches a display/controller/lasers/detectors configuration, Fig.1, 45/44/32/34; deGaribody teaches a laser sensor system, Fig.3/4, 302) configured to perform a first imaging of a first target area of the gas turbine engine (Tanriverdi Fig.1; engine downstream area); and a second imaging system (this element is interpreted under 35 U.S.C. 112(f) as a second energy source and second sensor, said second energy source including lasers to accomplish the claimed function, and equivalents thereof. Tanriverdi teaches a display/controller/lasers/detectors configuration, Fig.1, 45/44/32/34; deGaribody teaches a laser sensor system, Fig.3/4, 302) configured to perform a second imaging of a second target area of the gas turbine engine (deGaribody Fig.3/4; engine upstream area). Regarding claim 3, Tanriverdi and deGaribody further teach the measurement controller calculates the first mass flow and the second mass flow based at least in part on the first imaging and the second imaging, respectively (Tanriverdi Fig.1, 44; ¶25, note “Information, e.g., data, from the lasers and detectors are sent to a controller 44”; ¶34, note “an image generated of either the first or second data sets 50 and 52 may have x and y axes, and third axis representing flow mass”; deGaribody Fig.5, 508; ¶44). Regarding claim 4, Tanriverdi and deGaribody further teach the measurement controller calculates a thrust force of the gas turbine engine while the aircraft is in flight (deGaribody Fig.8; ¶63-64, note “controller 508 of the illustrated example includes a throttle position detector 802 … the thrust lever position detector 802 communicates the thrust lever position to the thrust manager 804. The thrust manager 804 of the illustrated example determines or receives information from the operating parameter/air data monitor 506 to adjust or schedule a corrected thrust based on measured air parameters or characteristics”), however, do not explicitly teach the thrust force calculation is based at least in part on the calculated first mass flow and the calculated second mass flow. deGaribody further teaches “the thrust manager 804 computes a fan speed to achieve the thrust corresponding to the thrust lever position detected by the thrust lever position detector 802. The fan speed information is communicated to the fuel-to-air ratio determiner 806” (¶64), “fuel-to-air ratio determiner 806 of the illustrated example determines a fuel-to-air ratio, which varies continually during a flight and/or for any given operating condition of the engine 502. For example, the fuel-to-air ratio determiner 806 may determine a fuel-to-air ratio based on an operating condition of the engine … the fuel-to-air ratio is determined based on a calculated thrust … When the fuel-to-air ratio determiner 806 determines the fuel-to-air ratio for a given flight condition and/or operating condition, the fuel-to-air ratio determiner 806 communicates the fuel-to-air ratio to the fuel mass flow rate determiner 808” (¶65), and “fuel mass flow rate determiner 808 of the illustrated example receives the air mass flow rate 522 from the air mass flow rate detector 718 and the fuel-to-air ratio from the fuel-to-air ratio determiner 806. The fuel mass flow rate determiner 808 of the illustrated example calculates or determines the amount of fuel mass flow rate 524 to provide to the combustion chamber 526 based on the fuel-to-air ratio determined by the fuel-to-air ratio determiner 806 and the air mass flow rate 522 determined by the air mass flow rate calculator 512” (¶66). As deGaribody describes, calculated mass flow is used when determining a fuel-to-air ratio and said fuel-to-air ratio is determined based on a calculated thrust, therefore, the thrust force calculation is inherently based at least in part on the calculated mass flow. It would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to further modify the system of Tanriverdi and deGaribody by having the thrust force calculation is based at least in part on the calculated first mass flow and the calculated second mass flow based on the further teachings of deGaribody for the purpose of increasing engine efficiency (e.g., increase a commercial aircraft engine efficiency by approximately between 2 percent and 10 percent), reducing fuel consumption, and increasing a travel range (deGaribody ¶24). Regarding claim 5, Tanriverdi and deGaribody further teach the first imaging system comprises: a first energy source (Tanriverdi Fig.1, 32; or when using deGaribody’s configuration Fig.3/4, 352 located downstream of gas turbine engine) configured to direct first energy at the first target area (Tanriverdi Fig.1, 30/36; deGaribody Fig.3/4, where 404/406 are transmitted/reflected); and a first sensor (Tanriverdi Fig.1, 34; or when using deGaribody’s configuration Fig.3/4, 354 located downstream of gas turbine engine) configured to detect a first energy spectrum at the first target area resulting from the first energy (Tanriverdi ¶23; deGaribody ¶37), and wherein the second imaging system comprises: a second energy source (deGaribody Fig.3/4, 352; or when using Tanriverdi’s configuration Fig.1, 32 located upstream of gas turbine engine) configured to direct second energy at the second target area (deGaribody Fig.3/4, where 404/406 are transmitted/reflected; Tanriverdi Fig.1, 30/36); and a second sensor (deGaribody Fig.3/4, 354; or when using Tanriverdi’s configuration Tanriverdi Fig.1, 34 located upstream of gas turbine engine) configured to detect a second energy spectrum at the second target area resulting from the second energy (deGaribody ¶37; Tanriverdi ¶23). Regarding claim 6, Tanriverdi and deGaribody further teach the first energy source is coupled to a body of the aircraft and is remotely located from the gas turbine engine (Tanriverdi Fig.1; ¶18, note “characteristics of working fluid may be measured by arrays of lasers 32 and detectors 34 positioned in planes along the gas passage”). Regarding claim 7, Tanriverdi and deGaribody further teach the first energy source is disposed within an inlet of the gas turbine engine (deGaribody Fig.3/4). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to NATHANIEL EDWARD WIEHE whose telephone number is (571)272-8648. The examiner can normally be reached M-F approx. 7-4:30 EST. 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, Alford Kindred can be reached at (571) 272-4037. 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. /NATHANIEL E WIEHE/Supervisory Patent Examiner, Art Unit 3745
Read full office action

Prosecution Timeline

Oct 18, 2024
Application Filed
Mar 03, 2026
Non-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

1-2
Expected OA Rounds
52%
Grant Probability
86%
With Interview (+34.1%)
3y 9m
Median Time to Grant
Low
PTA Risk
Based on 354 resolved cases by this examiner. Grant probability derived from career allow rate.

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