Prosecution Insights
Last updated: April 19, 2026
Application No. 18/389,096

AIRCRAFT ENGINE ENTRAINED PARTICLE SEPARATION SYSTEM AND METHOD

Final Rejection §103
Filed
Nov 13, 2023
Examiner
NGUYEN, ANDREW H
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Rtx Corporation
OA Round
2 (Final)
75%
Grant Probability
Favorable
3-4
OA Rounds
3y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 75% — above average
75%
Career Allow Rate
662 granted / 882 resolved
+5.1% vs TC avg
Strong +43% interview lift
Without
With
+43.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
27 currently pending
Career history
909
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
46.6%
+6.6% vs TC avg
§102
21.9%
-18.1% vs TC avg
§112
28.8%
-11.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 882 resolved cases

Office Action

§103
Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . DETAILED ACTION Claim 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) 1-4, 10-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over EP 0599502 (Rodgers) in view of US 2021/0332764 (Saripella). Regarding claim 1-3, Rodgers teaches a method of removing particles entrained within an air flow that has entered a turbine engine disposed within a nacelle (Fig 1-2; engine with nacelle 20), the turbine engine (col 2 l. 28, Fig 1), the nacelle including a nacelle inlet cavity disposed forward of the fan section (inlet cavity inside leading edge 22), the nacelle inlet cavity defining an air inlet path into the turbine engine (Fig 1), the method comprising: providing a fluid injection system configured to inject a fluid into the air inlet path from a plurality of nozzles in communication with the nacelle inlet cavity (plurality of nozzles/holes 32; col 2 l. 44 – col 3 l. 19), the plurality of nozzles extending within a leading edge panel of the nacelle (col 2 l. 28 – col 3 l. 19; panel 24 is part of the leading edge of the nacelle); and controlling the fluid injection system to inject the fluid into the air inlet path from the plurality of nozzles during at least one predetermined segment of an aircraft flight mission, the aircraft flight mission including an idling segment, a taxiing segment, a take-off segment, an ascent segment, a descent segment, and a landing segment (col 2 l. 44 – col 3 l. 19; in operation “as the aircraft is taking off or landing”); wherein particles wetted by the injected fluid are subject to centrifugal force in and aft of the fan section and are directed radially outward for flow through the bypass duct (liquid is injected through the nozzles 32, and would therefore “wet” particles of air flowing over the surface 27 of the nacelle, and into the bypass duct; the rotation of the fan blades would impart centrifugal force), wherein the step of controlling the fluid injection system includes injecting the fluid into the air inlet path below a predetermined altitude value, and not injecting the fluid into the air inlet path above the predetermined altitude value (fluid is injected from the nozzles during a takeoff or landing segment, which is below a predetermined altitude value; the claim does not define what the altitude is; the takeoff and landing segment is implicitly below some altitude value), wherein a portion of the ascent segment and a portion of the descent segment are below the predetermined altitude value (the aircraft’s takeoff and landing operations are below a predetermined altitude value; the claim does not define what the altitude value is, or how it is calculated; thus, the “altitude value” can be construed as some maximum flight altitude). Rodgers fails to teach a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path. However, Saripella teaches that gas turbine engines may comprise a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path (Fig 1, para 37-39; bypass duct 140; core gas path for flow 148; axial centerline 102). It would have been obvious to one of ordinary skill in the art at the time of the invention to provide a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path in order to generate thrust, as taught by Saripella. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, providing a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path yields predictable results (engine operation). Regarding claim 4, Rodgers in view of Saripella as discussed thus far fails to teach wherein each nozzle has an ejection centerline, and the ejection centerline of each nozzle is oriented to inject the fluid in a forward first direction that is parallel to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a radial second direction that is perpendicular to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction. However, Rodgers teaches each nozzle with an ejection centerline that is perpendicular to the nacelle surface (annotated below). It is unknown how the nacelle surface is angled relative to the axial centerline of the turbine engine. However, Saripella teaches that the leading edge may comprise a nacelle surface that is inclined relative to the axial centerline (annotated below; the ejection centerline for a nacelle surface as presented in Saripella would result in the ejection centerline of each nozzle oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction). It would have been obvious to one of ordinary skill in the art at the time of the invention to make the ejection centerline of each nozzle is oriented to inject the fluid in a forward first direction that is parallel to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a radial second direction that is perpendicular to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction, as taught by Rodgers and Saripella. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, the ejection centerline of each nozzle oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction yields predictable results (cleaning the desired surface of the leading edge). PNG media_image1.png 360 595 media_image1.png Greyscale PNG media_image2.png 502 752 media_image2.png Greyscale Regarding claim 10-12, Rodgers teaches an aircraft (Fig 1-2), comprising: a turbine engine (Fig 7 col 6 l. 61-col 7 l. 8; fan 48); a nacelle configured to house the turbine engine (engine with nacelle 20), the nacelle including a nacelle inlet cavity disposed forward of the fan section (inlet cavity inside leading edge 22), the nacelle inlet cavity defining an air inlet path for air drawn into the turbine engine during operation of the turbine engine (Fig 1); a fluid injection system including a plurality of nozzles in fluid communication with a fluid source, the nozzles in communication with the nacelle inlet cavity, the nozzles configured to inject a fluid into the air inlet path (plurality of nozzles/holes 32; col 2 l. 44 – col 3 l. 19), the plurality of nozzles extending within a leading edge panel of the nacelle (col 2 l. 28 – col 3 l. 19; panel 24 is part of the leading edge of the nacelle); and controlling the fluid source to provide the fluid to the nozzles for injection into the air inlet path during at least one predetermined segment of an aircraft flight mission, the aircraft flight mission including an idling segment, a taxiing segment, a take-off segment, an ascent segment, a descent segment, and a landing segment (col 2 l. 44 – col 3 l. 19; in operation “as the aircraft is taking off or landing”); wherein the turbine engine is configured such that particles entrained within the inlet air that are wetted by the injected fluid are directed to flow through the bypass duct (liquid is injected through the nozzles 32, and would therefore “wet” particles of air flowing over the surface 27 of the nacelle, and into the bypass duct; the rotation of the fan blades would impart centrifugal force), wherein the instructions when executed cause the controller to control the fluid source to provide the fluid to the nozzles below a predetermined altitude value, and not provide fluid to the nozzles above the predetermined altitude value, wherein a portion of the ascent segment and a portion of the descent segment are below the predetermined altitude value (fluid is injected from the nozzles during a takeoff or landing segment, which is below a predetermined altitude value; the claim does not define what the altitude is; the takeoff and landing segment is implicitly below some altitude value). Rodgers fails to teach a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path. However, Saripella teaches that gas turbine engines may comprise a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path (Fig 1, para 37-39; bypass duct 140; core gas path for flow 148; axial centerline 102). It would have been obvious to one of ordinary skill in the art at the time of the invention to provide a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path in order to generate thrust, as taught by Saripella. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, providing a fan section, a compressor section, a turbine section, and a bypass duct arranged along an axial centerline, wherein the compressor section and the turbine section are in communication with a core gas path, and the bypass duct is disposed radially outside of the core gas path yields predictable results (engine operation). Rodgers fails to teach a controller in communication with the fluid injection system and a non-transitory memory storing instructions, which instructions when executed cause the controller to control the fluid source. However, Saripella teaches that a fluid injection system may be controlled by a controller in communication with the fluid injection system and a non-transitory memory storing instructions, which instructions when executed cause the controller to control the fluid source (Fig 4A, para 110-114; actuators 402, 404 of a fluid injection system may be controlled by controller 302 which may include a computer readable storage device executing instructions). It would have been obvious to one of ordinary skill in the art at the time of the invention to provide a controller in communication with the fluid injection system and a non-transitory memory storing instructions, which instructions when executed cause the controller to control the fluid source in order to control the system, as taught by Saripella. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, providing a controller in communication with the fluid injection system and a non-transitory memory storing instructions, which instructions when executed cause the controller to control the fluid source yields predictable results (control of the fluid injection system). Regarding claim 13, Rodgers in view of Saripella as discussed thus far fails to teach wherein each nozzle has an ejection centerline, and the ejection centerline of each nozzle is oriented to inject the fluid in a forward first direction that is parallel to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a radial second direction that is perpendicular to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction. However, Rodgers teaches each nozzle with an ejection centerline that is perpendicular to the nacelle surface (annotated below). It is unknown how the nacelle surface is angled relative to the axial centerline of the turbine engine. However, Saripella teaches that the leading edge may comprise a nacelle surface that is inclined relative to the axial centerline (annotated below; the ejection centerline for a nacelle surface as presented in Saripella would result in the ejection centerline of each nozzle oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction). It would have been obvious to one of ordinary skill in the art at the time of the invention to make the ejection centerline of each nozzle is oriented to inject the fluid in a forward first direction that is parallel to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a radial second direction that is perpendicular to the axial centerline of the turbine engine, or the ejection centerline of each nozzle is oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction, as taught by Rodgers and Saripella. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, the ejection centerline of each nozzle oriented to inject the fluid in a direction that is between the forward first direction and the radial second direction yields predictable results (cleaning the desired surface of the leading edge). PNG media_image1.png 360 595 media_image1.png Greyscale PNG media_image2.png 502 752 media_image2.png Greyscale Claim(s) 5-6, 14-15, 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over EP 0599502 (Rodgers) in view of US 2021/0332764 (Saripella), and further in view of US 2020/0157969 (Park). Regarding claim 5-6, 14-15, 19-20, Rodgers in view of Saripella fails to teach the plurality of nozzles includes at least one aft oriented nozzle that has an ejection centerline, and the ejection centerline of the aft oriented nozzle is oriented to inject the fluid in an aft direction at an acute angle relative to a radial line extending perpendicular to the axial centerline, wherein the acute angle is no greater than seventy degrees, the plurality of nozzles are pivotally mounted, wherein the pivotally mounted nozzles are controllable to pivot between a first positional orientation and a second positional orientation. However, Park teaches cleaning nozzles including at least one aft oriented nozzle that has an ejection centerline, and the ejection centerline of the aft oriented nozzle is oriented to inject the fluid in an aft direction at an acute angle relative to a radial line extending perpendicular to the axial centerline (annotated below, para 61; nozzles inject flow in the downstream direction/aft direction), wherein the acute angle is no greater than seventy degrees (annotated below), the plurality of nozzles are pivotally mounted, wherein the pivotally mounted nozzles are controllable to pivot between a first positional orientation and a second positional orientation (Fig 3C; nozzles 120 pivot by rotation motor 142; para 74-77; first positional orientation is one angular position and second positional orientation is a second, different angular position). It would have been obvious to one of ordinary skill in the art at the time of the invention to make the plurality of nozzles include at least one aft oriented nozzle that has an ejection centerline, and the ejection centerline of the aft oriented nozzle is oriented to inject the fluid in an aft direction at an acute angle relative to a radial line extending perpendicular to the axial centerline, wherein the acute angle is no greater than seventy degrees, the plurality of nozzles are pivotally mounted, wherein the pivotally mounted nozzles are controllable to pivot between a first positional orientation and a second positional orientation in order to control the cleaning fluid, improve cleaning efficiency, and clean the desired surfaces, as taught by Park. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, the plurality of nozzles including at least one aft oriented nozzle that has an ejection centerline, and the ejection centerline of the aft oriented nozzle is oriented to inject the fluid in an aft direction at an acute angle relative to a radial line extending perpendicular to the axial centerline, wherein the acute angle is no greater than seventy degrees, the plurality of nozzles are pivotally mounted, wherein the pivotally mounted nozzles are controllable to pivot between a first positional orientation and a second positional orientation yields predictable results (cleaning the desired surfaces). PNG media_image3.png 422 559 media_image3.png Greyscale Claim(s) 7-9, 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over EP 0599502 (Rodgers) in view of US 2021/0332764 (Saripella), and further in view of US 2023/0166869 (Albet). Regarding claim 7-8, 16-17, Rodgers in view of Saripella fails to teach the plurality of nozzles are spaced apart from one another around a circumference of the nacelle inlet cavity and are disposed in a lower circumferential half of the nacelle inlet cavity or the plurality of nozzles are circumferentially spaced apart from one another and are disposed in a lower circumferential half of the nacelle inlet cavity and in an upper circumferential half of the nacelle inlet cavity. However, Albet teaches cleaning nozzles that are spaced apart from one another around a circumference of the nacelle inlet cavity and are disposed in a lower circumferential half of the nacelle inlet cavity and in an upper circumferential half of the nacelle inlet cavity (para 44-45; cleaning spray nozzles circumferentially distributed around the entire circumference). Furthermore, Albet teaches that insect residue may be present around a lower circumferential half of the nacelle inlet cavity and in an upper circumferential half of the nacelle inlet cavity (Fig 2, para 7). It would have been obvious to one of ordinary skill in the art at the time of the invention to make the plurality of nozzles spaced apart from one another around a circumference of the nacelle inlet cavity and are disposed in a lower circumferential half of the nacelle inlet cavity or the plurality of nozzles are circumferentially spaced apart from one another and are disposed in a lower circumferential half of the nacelle inlet cavity and in an upper circumferential half of the nacelle inlet cavity in order to clean the nacelle inlet around the entire circumference or at the necessary/desired portions, as taught by Albet. It has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, the plurality of nozzles spaced apart from one another around a circumference of the nacelle inlet cavity and are disposed in a lower circumferential half of the nacelle inlet cavity or the plurality of nozzles are circumferentially spaced apart from one another and are disposed in a lower circumferential half of the nacelle inlet cavity and in an upper circumferential half of the nacelle inlet cavity yields predictable results (cleaning the desired portions of the leading edge). Regarding claim 9, 18, Rodgers in view of Saripella and Albet further teaches the plurality of nozzles includes a first subgroup of nozzles configured to inject the fluid into the air inlet path a first distance and a second subgroup of nozzles configured to inject the fluid into the air inlet path a second distance, wherein the first distance is greater than the second distance (in Rodgers, annotated below; in Albet, para 44-45; cleaning spray nozzles circumferentially distributed around the entire circumference). It would have been obvious to one of ordinary skill in the art at the time of the invention to provide a first subgroup of nozzles configured to inject the fluid into the air inlet path a first distance and a second subgroup of nozzles configured to inject the fluid into the air inlet path a second distance in order to clean the nacelle inlet at the necessary/desired portions, as taught by Albet. PNG media_image4.png 361 586 media_image4.png Greyscale Response to Arguments Applicant’s arguments with respect to the claim(s) 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. 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW NGUYEN whose telephone number is (571)270-5063. The examiner can normally be reached 8 am - 4 pm, Monday-Friday. 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 (Pat) Wongwian can be reached at 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. /ANDREW H NGUYEN/Primary Examiner, Art Unit 3741
Read full office action

Prosecution Timeline

Nov 13, 2023
Application Filed
Nov 05, 2025
Non-Final Rejection — §103
Feb 17, 2026
Response Filed
Mar 04, 2026
Final Rejection — §103 (current)

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3-4
Expected OA Rounds
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Grant Probability
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3y 4m
Median Time to Grant
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