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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Status of Claims
This Office Action is in response to the Applicant’s Response dated 3/30/2026. Applicant has filed a provisional application and thus the domestic benefit of 4/14/2023 is the effective filing date. Claims 1, 4-8, and 11-25 are presently pending and are presented for examination.
Information Disclosure Statement
The information disclosure statement (IDS) was submitted on 3/30/2026. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Response to Amendment
Applicant’s amendments, see page 9 of 12, filed 3/30/2026, with respect to claim objections, specification objections, and some of the 112(b) indefiniteness rejections have been fully considered and are persuasive. The claim objections and specification objections have been withdrawn, whereas only some of the 112(b) indefiniteness rejections have been withdrawn. The 112(b) indefiniteness rejections which have not been corrected and overcome are again presented in detail below.
Response to Arguments
Applicant’s arguments, see pages 9-12 of 12, filed 3/30/2026, with respect to independent claims 1, 8, and 15 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. Claims 1, 8, and 15 are now rejected under 35 U.S.C. 103 as being unpatentable over Mallette et al. (US-2020/0223555; hereinafter Mallette; already of record) in view of Tascillo et al. (US-2018/0347493; hereinafter Tascillo) and DeDe et al. (US-2013/0031911; hereinafter DeDe; already of record).
A detailed rejection follows below.
Claim Objections
Claims 1, 6, 8, 13, 15, 18, and 20-25 are objected to because of the following informalities:
Claim 1 and claim 8 as currently presented state “…an APU cooldown timer interval…the APU cooldown time interval…” which the Examiner recommends updating to instead state “…an APU cooldown time interval…the APU cooldown time interval…” similar to analogous claim 15 so as to avoid potential misinterpretation.
Claim 6, claim 13 and claim 18 as currently presented state “…the APU operating temperature…” which the Examiner recommends updating to instead state “… an APU operating temperature…” so as to avoid potential misinterpretation.
Claims 15 as currently presented state “…automatically initiating an APU cooldown operation of the APU, including start timing an APU cooldown time interval…” which the Examiner recommends updating to instead state “…automatically initiating an APU cooldown operation of the APU, including a start of timing of an APU cooldown time interval…” or the like to correct improper grammar.
Claims 20-25 as currently presented state “…the duration…” which the Examiner recommends updating to instead state “… a duration…” so as to avoid potential misinterpretation.
Appropriate correction is required.
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.
Claims 5, 12, 17, 21, 23, and 25 are rejected under 35 U.S.C. 112(b), as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding claims 5, 12, and 17, the claims state that the at least one processor “conditions” specific tasks, however, as the claims are currently written, these phrases are indefinite. Turning to the specification, paragraphs [0016]-[0043] lead one to believe that "conditions" are certain events which trigger automatic shutdown of the APU, whereas paragraph [0084] leads one to believe that "conditions" are specific criteria in which the at least one processor is trained with. The Examiner recommends updating the claims to elaborate on how the different conditioning occurs.
Regarding claims 21, 23, and 25, the term “quickly” is a relative term which renders the claim(s) indefinite. The term “quickly” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Figure 5 depicts an “immediate shutdown” which is definitive however the Examiner notes the subtle difference between “quick” and “immediate”. Paragraph [0066] of the instant specification also refers to an “immediate shutdown” but then also states “…(or sometimes delayed by a certain amount of time)…” which does not provide a definitive timing for shutdown to occur.
For the sake of compact prosecution, the Examiner will interpret “quickly” as being any amount of time between a shutoff signal/command and the actual termination of control signals to an APU.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 5-8, 12-15, and 17-25 are rejected under 35 U.S.C. 103 as being unpatentable over Mallette et al. (US-2020/0223555; hereinafter Mallette; already of record) in view of Tascillo et al. (US-2018/0347493; hereinafter Tascillo) and DeDe et al. (US-2013/0031911; hereinafter DeDe; already of record).
Regarding claim 1, Mallette discloses an auxiliary power unit control system (see Mallette at least Abs) comprising:
a computing arrangement comprising at least one processor that is operatively connected to control an auxiliary power unit (APU) for an aircraft (see Mallette at least [0025] "The APU control unit 104 is in operable communication with the APU 102 and and is configured to control the APU 102. In particular, the APU control unit 104 includes one or more processors 128 that, in response to operator commands and feedback from one or more sensors 130 (e.g., 130-1, 130-2, 130-3 . . . 130-N), are configured to execute start-up, operational, and shutdown control logic."), the at least one processor being configured to perform operations comprising:
automatically initiating an APU cooldown operation (see Mallette at least [0027] "...Regardless of the source of the shutdown signal 132, the shutdown control logic 200 then reduces the rotational speed of the APU 102 to a predetermined cooldown speed magnitude (204)…");
timing an APU cooldown timer interval for the initiated APU cooldown operation (see Mallette at least [0028] "It will additionally be appreciated that the APU control unit 104 may be configured to reduce the rotational speed of the APU 102 to the predetermined cooldown speed using any one of numerous techniques... The APU 102 rotational speed may be reduced at a constant predetermined rate or a variable rate, or it may be reduced at a predetermined rate for a predetermined time period.");
… receiving a manual APU shutdown command (see Mallette at least [0025] "...The shutdown control logic is executed by the APU control unit 104 upon receipt of a shutdown signal 132…");
when the manual APU shutdown command is received before the APU cooldown time interval has expired, waiting until the APU cooldown time interval has expired before shutting down the APU in response to the manual APU shutdown command (see Mallette at least Fig 5 and [0038] "Turning now to the process 500, it too is initiated by the APU control unit 104 upon receiving the shutdown signal 132 (502). Thereafter, the normal shutdown/cooldown cycle is initiated (504) and a determination is made as to whether the shutdown/cooldown cycle can be (or needs to be) adjusted (506). If not, the normal shutdown/cooldown cycle is completed (508)..."); and
…
However, while Mallette describes a cooldown cycle for an APU in response to a shutdown command, Mallette does not explicitly disclose the following:
…following initiating the APU cooldown operation, receiving a manual APU shutdown command…
…when the manual APU shutdown command is received after the APU cooldown time interval has expired, shutting down the APU in response to the manual APU shutdown command only after first confirming the aircraft is not demanding any electrical or pneumatic power from the APU.
Tascillo, in the same field of endeavor, teaches the following:
…following initiating the APU cooldown operation, receiving a manual APU shutdown command (see Tascillo at least [0074]-[0076] "At T4, responsive to engine temperature reaching threshold 425, the cooling fan is turned on to prevent engine overheating. Responsive to cooling fan operation, air flow through thermal encapsulation increases. At T5, cooling fan is turned off. The cooling fan may be turned off responsive to engine temperature lower than a threshold. As another example, the cooling fan may be turned off after operating for a predetermined duration. At T6, engine shutdown command is received...")…
…
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the cooldown cycle as disclosed by Mallette with a shutdown command occurring afterwards such as taught by Tascillo with a reasonable expectation of success so as to allow for full thermal adjustment prior to terminating usage of an APU (see Tascillo at least [0077]).
However, neither Mallette nor Tascillo explicitly disclose or teach the following:
…when the manual APU shutdown command is received after the APU cooldown time interval has expired, shutting down the APU in response to the manual APU shutdown command only after first confirming the aircraft is not demanding any electrical or pneumatic power from the APU.
DeDe, in the same field of endeavor, teaches the following:
…when the manual APU shutdown command is received after the APU cooldown time interval has expired (see DeDe at least [0019] "Instead, as shown in FIG. 2, once a shutdown decision 100 is reached, the temperature challenge is identified. The temperature challenge is compared to the same threshold 102. If the temperature challenge (ambient and/or exhaust gas temperatures or some other variable, for example) is indicative of a potential of heat damage to the tail cone, then the cool down cycle is run 104. If it is not, the APU is simply shut down 106..."), shutting down the APU in response to the manual APU shutdown command only after first confirming the aircraft is not demanding any electrical or pneumatic power from the APU (see DeDe at least [0016] "Both of these steps can be taken, since the time for the APU 22 to be shut down is typically associated with the main gas turbine engines on the aircraft being operational, and thus able to supply electricity and air on their own.").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the cooldown cycle as disclosed by Mallette with a shutdown based upon temperature such as taught by DeDe with a reasonable expectation of success for the sake of cooling an APU prior to shutdown to avoid damaging materials of an aircraft (see DeDe at least [0004]-[0006]).
Regarding claim 5, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 1 wherein the at least one processor conditions shutting down the APU on operation of plural main engines of the aircraft (see DeDe at least [0016] "Both of these steps can be taken, since the time for the APU 22 to be shut down is typically associated with the main gas turbine engines on the aircraft being operational, and thus able to supply electricity and air on their own.").
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Mallette in view of DeDe with APU shutdown based on engine status such as further taught by DeDe with a reasonable expectation of success since a main engine is capable of producing electricity on its own, thus rendering the APU unnecessary (see DeDe at least [0016]).
Regarding claim 6, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 1 wherein the APU cooldown time interval comprises a time period during which the APU operating temperature is stabilized after loading on the APU is removed (see Mallette at least Fig 3, [0029] "...In the post-shutdown stage 302, the rotational speed of the APU 102 is reduced from its operational speed (N.sub.OP) to a predetermined post-shutdown speed value 306 at a first speed reduction rate. Thereafter, in the cooldown stage 304, the rotational speed of the APU 102 is reduced to the predetermined cooldown speed value 308 at a second speed reduction rate..." and [0031] "...For example, the predetermined cooldown speed magnitude 308 may be increased by reducing the second speed reduction rate or, as depicted in FIG. 3, by reducing the time of the cooldown stage 304 by a predetermined amount of time (Δt) (e.g., from t.sub.2 to t.sub.2-Δ), while keeping the second speed reduction rate the same.").
Regarding claim 7, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 1 wherein the at least one processor is further configured to remove loading on the APU upon initiating the APU cooldown operation to allow the APU to cool down (see Mallette at least Fig 3 and [0029] "...In the post-shutdown stage 302, the rotational speed of the APU 102 is reduced from its operational speed (N.sub.OP) to a predetermined post-shutdown speed value 306 at a first speed reduction rate. Thereafter, in the cooldown stage 304, the rotational speed of the APU 102 is reduced to the predetermined cooldown speed value 308 at a second speed reduction rate...").
Regarding claim 8, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 1 as recited in the instant claim and is rejected for similar reasons. Additionally, DeDe teaches the following:
…automatically initiate an APU cooldown operation of an APU on determining that an aircraft is not demanding electrical and/or pneumatic power from the APU (see DeDe at least [0016] "Both of these steps can be taken, since the time for the APU 22 to be shut down is typically associated with the main gas turbine engines on the aircraft being operational, and thus able to supply electricity and air on their own." and [0019] "Instead, as shown in FIG. 2, once a shutdown decision 100 is reached, the temperature challenge is identified. The temperature challenge is compared to the same threshold 102. If the temperature challenge (ambient and/or exhaust gas temperatures or some other variable, for example) is indicative of a potential of heat damage to the tail cone, then the cool down cycle is run 104...")…
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the system as taught by Mallette in view of Tascillo and DeDe with a cooldown operation indicative of engine status such as further taught by DeDe with a reasonable expectation of success for reasons similar to those provided above in claim 5.
Regarding claim 12, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 5 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 13, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 6 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 14, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 7 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 15, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 1 and claim 8 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 17, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 5 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 18, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 6 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 19, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 7 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 20, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 15 wherein the operations further include operating the APU in a low temperature cooldown mode for the duration of the APU cooldown time interval (see DeDe at least [0019] "...If the temperature challenge (ambient and/or exhaust gas temperatures or some other variable, for example) is indicative of a potential of heat damage to the tail cone, then the cool down cycle is run 104... The cool down cycle can operate for a number of minutes, for example less than ten minutes and on the order of about five minutes..."), and upon receiving the manual APU shutdown command, turning off the APU only after the APU has been operating in the low temperature cooldown mode for the duration of the APU cooldown time interval (see Mallette at least [0027] "Turning now to FIG. 2, the shutdown control logic 200 is initiated upon receipt, by the APU control unit 104, of the APU shutdown signal 132 (202)... Regardless of the source of the shutdown signal 132, the shutdown control logic 200 then reduces the rotational speed of the APU 102 to a predetermined cooldown speed magnitude (204)... In all cases, however, the predetermined cooldown speed magnitude is preferably selected to be a speed that ensures at least that the inlet temperature of the combustor 108 has reached a predetermined temperature value to prevent coking." and [0032] "As FIG. 2 further depicts, when a determination is made that a lean blowout has not occurred, the shutdown control logic 200 continues with the remainder of the normal shutdown process. Although this may vary, in the depicted embodiment this results in the APU control unit 104 testing appropriate circuitry and its functionality (210), and thereafter causing the APU 102 to be fully shutdown (212)."; the low temperature cooldown mode taught by DeDe).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the cooldown interval as disclosed by Mallette with a low temperature cooldown mode as further taught by DeDe with a reasonable expectation of success for reasons similar to those provided above in claim 1.
Regarding claim 21, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 15 wherein the operations further include quickly turning off the APU in response to the received manual APU shutdown command after operating the APU in a low temperature cooldown mode for the duration of the APU cooldown time interval (see at least [0029] "...After the cooldown stage 304, fuel flow to the APU 102 is ceased and the APU 102 fully shuts down…"; the low temperature cooldown mode taught by DeDe [0019]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the cooldown interval as disclosed by Mallette with a low temperature cooldown mode as further taught by DeDe with a reasonable expectation of success for reasons similar to those provided above in claim 1.
Regarding claim 22, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 20 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 23, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 21 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 24, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 20 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 25, Mallette in view of Tascillo and DeDe teach the analogous material of that in claim 21 as recited in the instant claim and is rejected for similar reasons.
Claims 4, 11, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Mallette in view of Tascillo and DeDe, and further in view of Romero et al. (US-11,649,763; hereinafter Romero; already of record).
Regarding claim 4, Mallette in view of Tascillo and DeDe teach the auxiliary power unit control system of claim 1. However, neither Mallette nor Tascillo nor DeDe explicitly disclose or teach the following:
…the at least one processor resets the APU cooldown time interval upon detecting a demand of the aircraft for electrical and/or pneumatic power.
Romero, in the same field of endeavor, teaches the following:
…the at least one processor resets the APU cooldown time interval upon detecting a demand of the aircraft for electrical and/or pneumatic power (see Romero at least col 9 lines 13-18 “In some operations, it may be beneficial to have a hybrid electric configuration in which an APU (secondary engine 314) is available on an as-needed basis throughout an entire flight. As such, it may be desired to run APU 314 at idle during the entire flight or keep APU 314 spooled up, but off, to ensure APU 314 is ready when needed.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system as taught by Mallette in view of Tascillo and DeDe with a cooldown time reset such as taught by Romero with a reasonable expectation of success so as to remain at the ready when not in an idle state. Upon return to the idle state, the APU temperature will drop from an operating temperature (see Romero at least col 9 lines 13-18).
Regarding claim 11, Mallette in view of Tascillo and DeDe and Romero teach the analogous material of that in claim 4 as recited in the instant claim and is rejected for similar reasons.
Regarding claim 16, Mallette in view of Tascillo and DeDe and Romero teach the analogous material of that in claim 4 as recited in the instant claim and is rejected for similar reasons.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Devendorf (US-2022/0289398) teaches a method of aircraft engine cooldown period prior to an engine shutdown.
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 extension fee 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 date of this final action.
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/S.P.R./Examiner, Art Unit 3663
/ABBY J FLYNN/Supervisory Patent Examiner, Art Unit 3663
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