UNITED STATES PATENT AND TRADEMARK OFFICE
`
`———————
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`———————
`
`
`
`General Electric Company,
`Petitioner,
`
`v.
`
`United Technologies Corporation,
`Patent Owner
`
`———————
`
`Case No. IPR2016-00952
`
`———————
`
`
`
`PETITIONER’S REPLY BRIEF IN SUPPORT OF ITS PETITION FOR
`INTER PARTES REVIEW OF U.S. 9,121,412
`(Claims 1-2, 4-5, 7-8, and 11)
`
`
`
`
`
`
`
`

`

`
`
`TABLE OF CONTENTS
`
`INTRODUCTION ........................................................................................... 1
`I.
`II. DAVIES DISCLOSES A FAN TIP SOLIDITY OF 0.74 FOR THE
`M45SD-02 ....................................................................................................... 3
`A.
`The Tip Solidity of 0.83 Does Not Correspond to the M45SD-
`02 ........................................................................................................... 4
`B. UTC’s Argument That the Fan Dimensions in Davies Are
`Approximations is Baseless .................................................................. 7
`C. Dr. Mathioudakis’ Arguments Regarding the Fan Dimensions
`are Conclusory and Inconsistent with the Prior Art .............................. 8
`III. CLAIM CONSTRUCTION OF BFPPR ......................................................... 9
`IV. DAVIES ANTICIPATES THE CLAIMED BFPPR RANGE ...................... 11
`A. UTC Overstates the Pressure Losses in the Bypass Flow
`Passage ................................................................................................ 12
`1.
`Dr. Mathioudakis Considered Irrelevant Structures ................. 12
`2. Many Structures in Davies Are Conventional for a Turbofan
`Engine ....................................................................................... 14
`UTC Mischaracterizes the Unconventional Structures in the
`Bypass Flow Passage ................................................................ 15
`The Pressure Losses in the Davies Bypass Flow Passage Would
`Be No Greater than 7% ....................................................................... 17
`V. DAVIES RENDERS THE BFPPR RANGES OF CLAIMS 1, 2, AND
`4 OBVIOUS ................................................................................................... 19
`A. Optimizing to a Low FPR Results in a Low BFPPR .......................... 19
`B. A POSITA Would Have Been Motivated to Optimize FPR and
`BFPPR ................................................................................................. 20
`C. UTC has Not Demonstrated Unexpected Results for the
`Claimed BFPPR Ranges ...................................................................... 22
`D. Optimizing the FPR of a Turbofan Engine is Routine ........................ 24
`VI. THE N/R RATIO IN DEPENDENT CLAIM 11 IS OBVIOUS .................. 24
`
`B.
`
`3.
`
`i
`
`

`

`
`
`A. A POSITA Would Have Been Motivated to Increase Tip Chord
`Dimension ........................................................................................... 25
`B. UTC’s Inoperability Argument is Based on a
`Mischaracterization of Davies ............................................................. 27
`VII. PETITIONER’S OBVIOUSNESS ANALYSIS CONSIDERED THE
`INVENTION AS A WHOLE ........................................................................ 28
`VIII. CONCLUSION .............................................................................................. 29
`
`
`ii
`
`

`

`
`
`TABLE OF EXHIBITS
`
`GE-1006
`
`GE-1001 U.S. Patent No. 9,121,412
`
`GE-1002 Prosecution File History of U.S. Patent No. 9,121,412
`
`GE-1003 Declaration of Reza Abhari Under 37 C.F.R. § 1.68.
`
`GE-1004 Curriculum Vitae of Reza Abhari
`
`GE-1005 D.G.M. Davies, et al., A Variable Pitch Fan for an Ultra Quiet
`Demonstrator Engine (1976)
`
`614: VFW’s Jet Feedliner, Flight International (November 4, 1971)
`
`GE-1007 U.S. Patent No. 7,374,403 to Decker, et al.
`
`GE-1008 NASA SP-7037 (92), A Cumulative Index to the 1977 Issues of
`Aeronautical Engineering: A Special Bibliography (January 1978)
`(excerpt)
`
`John W. Schaefer et al., Dynamics of High-Bypass-Engine Thrust
`Reversal Using A Variable-Pitch Fan (May 1977).
`
`GE-1010 NASA Technical Reports Server Record Details for GE-1016
`
`GE-1011 William S. Willis, Quiet Clean Short-Haul Experimental Engine
`(QCSEE) Final Report (August 1979).
`
`GE-1012 Bill Sweetman et al., Pratt & Whitney’s surprise leap, INTERAVIA
`(June 1998).
`
`GE-1013 Gerald Brines, The Turbofan of Tomorrow, Mechanical Engineering
`(August 1990).
`
`GE-1014 Excerpts from Jack D. Mattingly, Elements of Gas Turbine
`Propulsion (1996).
`
`
`GE-1009
`
`iii
`
`

`

`
`
`GE-1015 Bill Gunston, Pratt & Whitney PW8000, Jane’s Aero-Engines Issue 7
`(March 2000).
`
`GE-1016 Bruce E. Wendus et al., Follow-On Technology Requirement Study
`for Advanced Subsonic Transport (August 2003).
`
`GE-1017 Richard Whitaker, ALF502: plugging the turbofan gap, Flight
`International (Jan. 30, 1982).
`
`GE-1018 About NASA Technical Reports Server (www.sti.nasa.gov/find-sti).
`
`GE-1019 University of California at Davis MARC record for Davies
`
`GE-1020 NASA Technical Reports Server Record Details for Schaefer
`
`GE-1021 U.S. 5,141,400 to Murphy et al.
`
`GE-1022 S.A. Savelle et al., Application of Transient and Dynamic
`Simulations to the U.S. Army T55-L-712 Helicopter Engine (1996).
`
`GE-1023 A Summary of Commonly Used Marc 21 Authority Fields, Library of
`Congress
`
`GE-1024 U.S. Patent Application No. 2009/0314881 to Sucui et al. (published
`Dec. 24, 2009).
`
`GE-1025 U.S. Patent No. 3,898,799 to Pollert et al. (1975).
`
`GE-1026 W.K. Lord et al., Flow Control Opportunities in Gas Turbine
`Engines (2000).
`
`GE-1027 Dale Rauch, Design Study of an Air Pump and Integral Lift Engine
`ALF-504 Using the Lycoming 502 Core (1972).
`
`GE-1028 U.S. Patent No. 3,820,719 to Clark (1974).
`
`GE-1029 David A. Sagerser et al., Reverse-Thrust Technology for Variable-
`Pitch Fan Propulsion Systems (1978).
`
`GE-1030 R.M. Denning, Variable Pitch Ducted Fans for STOL Transport
`Aircraft (1971).
`
`iv
`
`

`

`
`
`GE-1031 Deposition Transcript of K. Mathioudakis (April 20, 2017).
`
`GE-1032 N.A. Cumptsy, Compressor Aerodynamics (2004).
`
`GE-1033 Gunter Wilfert, Geared Fan, Aero-Engine Design: From State of the
`Art Turbofans Towards Innovative Architectures (March 3-7, 2008).
`
`GE-1034 Declaration of Reza Abhari Under 37 C.F.R. § 1.68.
`
`v
`
`

`

`INTRODUCTION
`
`Petitioner has presented substantial evidence demonstrating that Davies
`
`
`
`I.
`
`
`
`(GE-1005) anticipates and/or renders obvious the challenged claims of the 412
`
`Patent, which cover ranges of fan blade tip solidity and bypass flow passage
`
`pressure ratio (“BFPPR”) for a turbofan engine. In response, UTC
`
`mischaracterizes Davies and the 412 Patent, and ignores clear disclosures in the
`
`prior art. UTC’s arguments should be rejected.
`
`
`
`First, in an attempt to suggest that there is some novelty in the 412 Patent,
`
`UTC and its declarant Dr. Mathioudakis assert that “[t]he ‘412 patent identifies and
`
`claims specific combinations of gas turbofan engine features that lower losses in
`
`the bypass flow passage.” UTC-2015, ¶ 17; see also PO Response at 6-7. This is
`
`simply not true. The specification and claims of the 412 Patent are not limited to
`
`an engine with “lower” pressure losses in the bypass flow passage. The
`
`specification and claims specify a BFPPR range (e.g., 1.1 – 1.35), but no fan
`
`pressure ratio (“FPR”) range, and no range of allowable losses in the bypass flow
`
`passage. Both experts agree that BFPPR is equal to the FPR minus the pressure
`
`losses from the other structures in the bypass flow passage. Thus, the claims cover
`
`an engine having a high FPR with high losses in the bypass flow passage. GE-
`
`1034, ¶ 5 [Abhari Reply Decl.]. Morever, the specification of the 412 Patent does
`
`not describe how to design a bypass flow passage with “lower losses.” GE-1034,
`
`1
`
`

`

`
`
`¶ 4; GE-1031 at 22:25-23:6 (“The patent does not give details as to how to
`
`minimize pressure losses.”).
`
`
`
`UTC not only fails to properly explain the scope and disclosure of its own
`
`patent, but it also misinterprets the prior art. UTC incorrectly contends that a fan
`
`tip solidity value of 0.83 disclosed in Davies corresponds to the M45SD-02 engine,
`
`which is the subject of Petitioner’s anticipation and obviousness case. The 0.83
`
`solidity value is disclosed in a general design philosophy section for a fan having a
`
`design pressure ratio of 1.27. This solidity value is not correlated with the
`
`M45SD-02 fan. A person of ordinary skill in the art (“POSITA”) reading Davies
`
`in its entirety would understand that the M45SD-02 fan has a design pressure ratio
`
`of less than 1.27 and a tip solidity of 0.74 based on the fan blade dimensions
`
`disclosed in Davies.
`
`
`
`UTC further mischaracterizes Davies in an attempt to argue that the claimed
`
`BFPPR range is not anticipated. The testimony of Dr. Abhari and UTC’s own
`
`cited evidence regarding expected losses in the bypass passage confirm that the
`
`FPR disclosed in Davies corresponds to a BFPPR that falls within the claimed
`
`ranges. UTC and its declarant Dr. Mathioudakis can only conclude otherwise by
`
`(1) misconstruing how the 412 Patent measures BFPPR; (2) including pressure
`
`losses caused by structures not located in the bypass flow passage; (3) categorizing
`
`many conventional components of a bypass flow passage as unconventional; and
`
`2
`
`

`

`
`
`(4) overstating pressure losses associated with two structures located in the Davies
`
`bypass flow passage.
`
`
`
`Finally, UTC misstates Petitioner’s obviousness position regarding the
`
`claimed BFPPR. The obviousness of the claimed BFPPR range does not depend
`
`on FPR and BFPPR being equal. Rather, the obviousness of the claimed BFPPR
`
`range is based on the following undisputed facts: (i) it is routine to optimize the
`
`FPR of a turbofan engine; (ii) high bypass ratio turbofans optimize at a low FPR
`
`overlapping with the claimed range; and (iii) a low FPR correlates with a low
`
`BFPPR because it is well known that pressure losses in the bypass passage should
`
`be minimized.
`
`
`
`For the reasons set forth in the Petition and in this Reply, GE respectfully
`
`requests that the Board cancel the challenged claims of the 412 Patent.
`
`II. DAVIES DISCLOSES A FAN TIP SOLIDITY OF 0.74 FOR THE
`M45SD-02
`
`
`
`Davies discloses that the fan of the M45SD-02 engine has 14 blades having
`
`a tip chord dimension of 10 inches and a diameter of 5 feet. GE-1005.009. Based
`
`on those dimensions, a POSITA would understand that the tip solidity of the
`
`M45SD-02 fan is 0.74. Petition at 29-30; GE-1003, ¶¶ 80-82. In response, UTC
`
`argues that the fan tip solidity of the M45SD-02 is 0.83 (PO Response at 24) and
`
`that a POSITA would not have used the dimensions of the fan disclosed in Davies
`
`3
`
`

`

`
`
`to calculate solidity (PO Response at 26-31). As explained below, neither
`
`argument has any merit.
`
`A. The Tip Solidity of 0.83 Does Not Correspond to the M45SD-02
`
`The text of Davies does not correlate a tip solidity of 0.83 with the M45SD-
`
`
`
`02. The tip solidity of 0.83 is disclosed in a section of Davies describing the
`
`general design philosophy for a variable pitch fan. See e.g., GE-1005.006 (“Fan
`
`Blade Design Philosophy”); GE-1034, ¶ 8. In this section, Davies states that for a
`
`design pressure ratio of “say 1.27,” the corresponding fan tip solidity would be 0.8.
`
`GE-1005.007 (“to achieve a design pressure ratio of say 1.27:1, with a blade mean
`
`solidity less than unity and an area ration near unity, a transonic blade design was
`
`required with a tip solidity of .8….”). On the following page in the same section,
`
`Davies discloses a design pressure ratio of 1.27 with tip and root pressure ratios of
`
`1.36 and 1.18, respectively, and a tip solidity of 0.83. Notably the table is not
`
`labeled as data for the M45SD-02.
`
`4
`
`

`

`
`
`
`
`GE-1005.008 (annotations in yellow)
`
`
`
`Further confirming that the above solidity value is not for the M45SD-02 is
`
`the fact that Davies discloses that the M45SD-02 did not have a design pressure
`
`ratio of 1.27. As shown below, another table in Davies, which is specifically
`
`labeled for the M45SD-02, discloses a fan outer pressure ratio of 1.27 (i.e., tip) and
`
`fan inner pressure ratio of 1.18 (i.e., hub). GE-1034, ¶ 8. Thus, the design pressure
`
`ratio of the M45SD-02 is between 1.18 and 1.27—approximately 1.21-1.24. Id.
`
`5
`
`

`

`
`
`GE-1005.005 (annotations in yellow)
`
`
`
`
`
`As explained by Dr. Abhari, a POSITA would understand that pressure ratio
`
`and solidity are interrelated, and increasing solidity increases pressure ratio, while
`
`decreasing solidity decreases pressure ratio. GE-1034, ¶ 9; GE-1032.018 (“The
`
`rise in solidity and fall in aspect ratio can both be attributed in the main to a rise in
`
`chord length. With these trends…there is the striking rise in pressure rise….”);1
`
`GE-1030.003 (“low solidity of the fan…limits the design pressure ratio”). The tip
`
`solidity of 0.83 is correlated with a design pressure ratio of 1.27. The M45SD-02
`
`has a lower design pressure ratio, which means a POSITA would expect a lower tip
`
`solidity. GE-1034, ¶ 10. The actual dimensions of the M45SD-02 disclose a 0.74
`
`tip solidity consistent with the lower design pressure ratio. Id. Accordingly,
`
`
`1 Emphasis added, unless otherwise noted.
`
`6
`
`

`

`
`
`based on the complete disclosure in Davies, it is clear that the tip solidity of the
`
`M45SD-02 is not 0.83.
`
`B. UTC’s Argument That the Fan Dimensions in Davies Are
`Approximations is Baseless
`
`UTC argues that the fan dimensions disclosed in Davies are approximations
`
`
`
`that are unsuitable for calculating solidity. PO Response at 29 (“[T]he Fan Blade
`
`Retention section contains approximations unsuitable for accurately calculating
`
`solidity.”). This argument is unsupported by the text of Davies. Davies clearly
`
`indicated when certain parameters disclosed in the “FAN BLADE RETENTION”
`
`section were approximations, for example, describing that the blade weight
`
`“approaches 3.3 lb,” while the total restraint is “about 40 tons.” GE-1005.009-
`
`.010. In contrast, Davies provides no such qualification regarding the blade chord
`
`and fan diameter. GE-1005.009 (“fan diameter is 5 ft”; “blade chord…10 in. (25
`
`cm) at the tip”). There is no reasonable basis to conclude that the dimensions of
`
`the M45SD-02 are other than what the text discloses—5 foot diameter and 10 inch
`
`tip chord.2
`
`
`2 The metric units in parenthesis are consistent with the dimensions disclosed in
`
`British units. 5 feet equals 1.524 meters, which rounds to 1.5 meters. Similarly,
`
`10 inches equals 25.4 cm, which rounds to 25 cm.
`
`7
`
`

`

`C. Dr. Mathioudakis’ Arguments Regarding the Fan
`Dimensions are Conclusory and Inconsistent with the Prior
`Art
`
`Dr. Mathioudakis makes three arguments regarding why the fan blade
`
`
`
`
`
`dimensions disclosed in Davies cannot be used to calculate solidity, each of which
`
`is conclusory and inconsistent with the prior art.
`
`
`
`First, Dr. Mathioudakis contends that companies avoid publishing details
`
`about the exact shapes and sizes of fan blades. UTC-2015, ¶ 57. This bald
`
`assertion is contradicted by evidence of actual industry practice, as both GE and
`
`Lycoming have publicly disclosed the geometry of fan blades designed for low
`
`FPR demonstrator engines. See e.g., GE-1011.061; GE-1027.029. Thus, engine
`
`makers do in fact disclose fan blade dimensions for demonstrator engines, just as
`
`Rolls Royce did for the M45SD-02.
`
`
`
`Second, Dr. Mathioudakis contends that the blade dimensions in Davies
`
`correspond to a hub solidity of 0.91, which is allegedly inconsistent with a reported
`
`hub solidity of 0.98 and a statement in Davies that hub solidity is near 1.3 UTC-
`
`2015, ¶ 60. Neither of these rationales has any merit. First, the hub solidity of
`
`0.98 is reported in the general design philosophy section, which as described
`
`above, discloses parameters for a design FPR of 1.27 (i.e. not the design FPR of
`
`3 Dr. Mathioudakis cites no evidence to support his assertion that a POSITA would
`
`not consider a hub solidity of 0.91 to be near 1.
`
`8
`
`

`

`
`
`the M45SD-02). GE-1005.008. Second, the only requirement for hub solidity
`
`disclosed in Davies is that it be less than 1 for reverse thrust. GE-1005.007
`
`(“[R]everse thrust…implies that the blade solidity must be less than unity….”).
`
`The statement that hub solidity is near 1 is made in the context of simplifying an
`
`equation, and not in a list of required features of the M45SD-02:
`
`
`
`GE-1005.007 (annotations in yellow)
`
`
`
`Third, Dr. Mathioudakis contends that the tip solidity of 0.83 must be
`
`utilized because Davies discloses only one fan design. UTC-2015, ¶ 62. This
`
`argument is inconsistent with Davies, which discloses two different design FPRs,
`
`as described above, and therefore two different fan designs.
`
`III. CLAIM CONSTRUCTION OF BFPPR
`
`Claim 1 requires “a bypass flow passage having a pressure ratio that is
`
`
`
`between 1.1 and 1.35 with regard to an inlet pressure and an outlet pressure of said
`
`bypass flow passage.” GE-1001 at claim 1. As described in the Petition, a
`
`POSITA would understand that the inlet pressure of the bypass flow passage is
`
`measured at the inlet to the fan. Petition at 18. Petitioner’s construction is
`
`consistent with the claims and specification, which both describe the bypass flow
`
`9
`
`

`

`
`
`passage inlet as co-extensive with the propulsor (i.e., fan). GE-1001 at claim 1
`
`(“propulsor is located at an inlet of a bypass flow passage”); see also GE-1001 at
`
`2:49-50. Furthermore, Figure 1 of the 412 Patent illustrates that the inlet to the
`
`bypass flow passage 60 is co-extensive with the fan inlet (shown below).
`
`
`
`UTC’s position that the inlet to the bypass flow passage is at the front of the
`
`fan nacelle has no support in the 412 Patent. UTC-2015, ¶ 48. The specification
`
`never refers to or illustrates the front of the fan nacelle, let alone describe that as
`
`the inlet to the bypass flow passage. GE-1034, ¶ 17. A POSITA would understand
`
`that Figure 1 illustrates that the inlet 60 is co-extensive with the fan case (not the
`
`fan nacelle), which circumscribes the fan blades. Id.
`
`GE-1001.002, Figure 1 (annotations in red); GE-1034, ¶ 16
`
`
`
`10
`
`

`

`
`
`In contrast, a fan nacelle extends forward of the fan case and blades, as shown
`
`below. GE-1034, ¶ 17.
`
`
`
`GE-1024.002, Figure 1A (annotations in red); GE-1034, ¶ 17
`
`
`
`Under the proper construction—i.e., inlet pressure for measuring BFPPR is
`
`at the fan inlet—pressure losses associated with structures located upstream of the
`
`fan do not contribute to any difference between FPR and BFPPR. Under Patent
`
`Owner’s construction—i.e., inlet pressure for measuring BFPPR is at the front of
`
`the fan nacelle—those losses would contribute to the difference. As described
`
`below, Davies anticipates and renders obvious the claimed BFPPR ranges under
`
`either construction.
`
`IV. DAVIES ANTICIPATES THE CLAIMED BFPPR RANGE
`
`
`
`The claimed BFPPR is equal to FPR minus the pressure losses in the bypass
`
`flow passage. Accordingly, a POSITA would understand that for a given FPR, the
`
`11
`
`

`

`
`
`corresponding BFPPR depends on the magnitude of the bypass flow passage
`
`pressure losses. Based on the fan inner pressure ratio of 1.18 and fan outer
`
`pressure ratio of 1.27 for the M45SD-02, the corresponding BFPPR would fall
`
`within the ranges of claims 1, 2, and 4 if the pressure losses are less than 5.5% of
`
`FPR. Even if the pressure losses were 13% of FPR, the fan outer pressure ratio of
`
`1.27 would have a corresponding BFPPR (i.e., 1.27 x .87 = 1.10) within the ranges
`
`of claim 1 (1.1-1.35) and claim 4 (1.1-1.2).
`
`A. UTC Overstates the Pressure Losses in the Bypass Flow Passage
`
`Dr. Mathioudakis contends that the pressure losses in the bypass flow
`
`
`
`passage disclosed in Davies “could” create a difference between FPR and BFPPR
`
`that exceeds 7%. UTC-2015, ¶ 84. Dr. Mathioudakis, however, only reaches this
`
`conclusion by (1) considering many structures that do not contribute to the
`
`difference between FPR and BFPPR; (2) categorizing many conventional
`
`components of a bypass flow passage as unconventional; and (3) mischaracterizing
`
`several structures located in the Davies bypass flow passage.
`
`1.
`
`Dr. Mathioudakis Considered Irrelevant Structures
`
`FPR and BFPPR differ based on the outlet pressure measurement location.
`
`
`
`GE-1003, ¶ 62. The outlet pressure for FPR is measured just downstream of the
`
`fan stators (P4 below), while the outlet pressure for BFPPR is measured at the
`
`outlet of the bypass flow passage (P2 below). Id.
`
`12
`
`

`

`
`
`GE-1003, ¶ 76
`
`
`
`
`
`While the difference between FPR and a corresponding BFPPR is due only
`
`to pressure losses associated with structures that are located between P4 and P2,
`
`Dr. Mathioudakis included many structures that are not between those points. GE-
`
`1034, ¶¶ 20-23. First, Dr. Mathioudakis incorporated structures associated with the
`
`engine inlet (i.e., upstream of the bypass flow passage inlet), including an
`
`“elongated and divergent inlet cowl, an annular inlet constriction on the inlet cowl,
`
`an open-nose fan hub, [and] acoustic treatments….” UTC-2015, ¶ 94; GE-1034, ¶
`
`20. Second, Dr. Mathioudakis included an “elongated core cowl,” which is
`
`downstream of the bypass flow passage outlet. UTC-2015, ¶¶ 86, 94; GE-1034, ¶
`
`21. Third, Dr. Mathioudakis analyzed losses associated with the fan stators,4
`
`including their shape, quantity, and a constriction in the bypass flow passage
`
`
`4 Stator losses are encompassed in the FPR reported in Davies, and do not
`
`contribute to a difference between FPR and BFPPR. GE-1034, ¶ 22.
`
`13
`
`

`

`
`
`located at the stators. UTC-2015, ¶¶ 82-83, 87; GE-1034, ¶ 22. The figure below
`
`shows the structures that Dr. Mathioudakis erroneously included in his analysis:
`
`GE-1005.019, Figure 1 (annotations in red); GE-1034, ¶ 23
`
`2. Many Structures in Davies Are Conventional for a
`Turbofan Engine
`
`
`
`Dr. Mathioudakis also erroneously categorized many structures of the
`
`
`
`Davies bypass flow passage as “unconventional,” including a compressor bleed
`
`valve, acoustic linings, constricting outlet nozzle, and the length of the bypass flow
`
`passage UTC-2015, ¶ 82.
`
`
`
`Compressor bleed valves and acoustic linings are typical structures in
`
`turbofan engines. GE-1034, ¶¶ 25-26; GE-1025 at 2:50-55 (“air supplied by
`
`intermediate compressor 2 can be bled off….”); GE-1026.007 (“Currently,
`
`14
`
`

`

`
`
`acoustic liners are used in the inlet, fan case, aft bypass duct….”). Both of these
`
`standard structures are described in an exhibit relied on by Dr. Mathioudakis.
`
`UTC-2007.006.
`
`
`
`Moreover, Dr. Mathioudakis asserts, without any supporting analysis, that
`
`the constricting outlet nozzle and length of the Davies bypass flow passage make it
`
`unconventional. A POSITA would understand, however, that all turbofan engine
`
`bypass duct nozzles constrict. GE-1034, ¶ 28. Moreover, Dr. Mathioudakis
`
`provides no bases for his opinion that the length of the Davies bypass duct is
`
`unconventional. As an example, the M45SD-02 bypass duct is only slightly longer
`
`than the bypass duct of the GE-90 turbofan engine, which has been in commercial
`
`service since the 1990s. GE-1034, ¶ 27.
`
`3.
`
`UTC Mischaracterizes the Unconventional Structures in the
`Bypass Flow Passage
`
`Dr. Mathioudakis identified only two structures in the Davies bypass flow
`
`
`
`passage that are not typically present in a conventional turbofan engine: (1)
`
`auxiliary intakes for reverse thrust; and (2) a core inlet located downstream of the
`
`fan stators. GE-1034, ¶ 30. However, Dr. Mathioudakis mischaracterizes both of
`
`these structures to reach the conclusion that they could cause substantial pressure
`
`losses.
`
`15
`
`

`

`
`
`
`
`First, Dr. Mathioudakis incorrectly states that auxiliary flow intakes for
`
`reverse thrust create gaps and have associated mechanical structures exposed to the
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`bypass flow passage. UTC-2015, ¶ 82. A POSITA would understand that
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`auxiliary flow intakes are aerodynamically designed to provide a continuous inner
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`surface, and would not include mechanical structures exposed to the bypass flow
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`passage, as shown below. GE-1034, ¶ 31; GE-1028 at 2:38-52.
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`GE-1028.003, Figure 2
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`
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`
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`Second, Dr. Mathioudakis ignores the clear disclosure in Davies that the
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`core inlet splitter nose is “relatively blunt.” Compare GE-1005.009 (“a relatively
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`blunt splitter nose…with minimum loss.”), with UTC-2015, ¶ 82 (“A blunt splitter
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`nose for the core inlet….”). A POSITA would understand that a typical splitter
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`nose has a sharp contour, while a relatively blunt splitter has a more curved shape
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`to aerodynamically interact with flow in both the forward and reverse thrust modes
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`of operation, thus incurring minimal pressure losses. GE-1034, ¶ 32; GE-
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`1029.004.
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`
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`16
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`

`

`B.
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`The Pressure Losses in the Davies Bypass Flow Passage Would Be
`No Greater than 7%
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`The only quantitative evidence of pressure losses cited by Dr. Mathioudakis
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`
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`
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`confirms Dr. Abhari’s analysis that the losses would not exceed 7%. As shown
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`below, UTC-2007 discloses a plot of thrust loss v. FPR. During his deposition, Dr.
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`Mathioudakis testified that a 1% thrust loss would correspond to a 1% pressure
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`loss. GE-1031 at 39:14-22; see also GE-1034, ¶ 33.
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`UTC-2007.006, Figure 10 (annotations in red)
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` 
`
`
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`Under the proper definition of BFPPR (i.e., inlet pressure measured at fan
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`inlet) the losses from the engine inlet, fan rotor (i.e., fan disk and blades), and fan
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`static structure (i.e., stators) shown above are irrelevant to determining the
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`17
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`

`

`
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`difference between FPR and a corresponding BFPPR because those structures are
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`not located between P4 and P2, as shown below. GE-1034, ¶ 34.
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` 
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`GE-1005.019, Figure 1 (annotations in red); GE-1034, ¶ 34
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`The relevant pressure losses are the duct/nozzle (~5%) and bleeds/leakage (< 2%),
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`which combined are less than 7%. GE-1034, ¶ 34. Thus, a POSITA would
`
`understand that based on the outer FPR of 1.27 for the M45SD-02 (GE-1005.005),
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`the corresponding BFPPR would be no less than 1.18 (i.e., 1.27 x 0.93 = 1.18). Id.
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`
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`Further, even if all losses disclosed in UTC-2007 were encompassed (i.e.,
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`using UTC’s construction for the measurement of the BFPPR), the corresponding
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`BFPPR for an outer FPR of 1.27 would still fall within the claimed ranges in claim
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`1 (1.1 to 1.35) and claim 4 (1.1 to 1.2). Specifically, assuming thrust loss to
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`pressure loss is correlated 1:1 as Dr. Mathioudakis testified, UTC-2007 discloses
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`18
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`

`

`
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`that the total pressure losses for all structures can reach approximately 9%,
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`yielding a BFPPR of 1.13 (i.e., 1.27 * 0.91 = 1.16). GE-1034, ¶ 35.
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`V. DAVIES RENDERS THE BFPPR RANGES OF CLAIMS 1, 2, AND 4
`OBVIOUS
`
`Petitioner set forth substantial evidence that it would have been obvious to a
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`
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`POSITA to optimize FPR (and thus BFPPR) for a high bypass ratio geared
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`turbofan engine (e.g., Davies). Petition at 35-38. UTC has not demonstrated any
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`criticality or unexpected results with respect to the claimed BFPPR ranges, and has
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`therefore failed to rebut Petitioner’s prima facie case of obviousness. In re
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`Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990) (“In the absence of adequate
`
`evidence showing that ranges of carbon monoxide concentration recited in claims
`
`27–34 are critical, the Board correctly affirmed the rejection….”).
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`A. Optimizing to a Low FPR Results in a Low BFPPR
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`UTC incorrectly asserts that the obviousness of the claimed BFPPR depends
`
`
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`on FPR and BFPPR being substantially equivalent. PO Response at 48 (“Petitioner
`
`contends that the ratio is ‘substantially equivalent’ to Davies’s ‘fan pressure ratio.’
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`(Petition at 16-17.) This is the foundation on which Petitioner’s obviousness case
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`rests.”). Petitioner made no such statement.5 Instead, the obviousness of the
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`5 Notably, UTC cites Petitioner’s claim construction section for this assertion
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`(Petition at 16-17), and not Petitioner’s obviousness analysis (Petition at 35-38).
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`19
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`

`

`
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`claimed BFPPR is based on the undisputed fact that optimizing to a low FPR
`
`results in a low BFPPR. Petition at 36 (“[F]an pressure ratio, and thus the bypass
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`pressure ratio, is typically optimized…. [L]ow fan pressure ratio correlates with
`
`lower engine noise….”).
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`
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`It is undisputed that BFPPR is equal to FPR minus the pressure losses from
`
`the other structures in the bypass flow passage, which means for a given FPR the
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`corresponding BFPPR will be less. GE-1031 at 34:13-35:10; GE-1034, ¶ 19.
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`Moreover, for an engine to produce thrust, the BFPPR must be greater than 1. GE-
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`1031 at 32:13-17. Finally, Dr. Mathioudakis conceded that it was known in the art
`
`before the 412 Patent that it was desirable to minimize bypass flow passage
`
`pressure losses. GE-1031 at 19:2-20:1. For a given low FPR such as 1.27 (e.g.,
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`Davies), it was therefore known that the corresponding BFPPR would necessarily
`
`be between 1.0 and 1.27, and that it was desirable for BFPPR to be as close to 1.27
`
`as possible.
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`B. A POSITA Would Have Been Motivated to Optimize FPR and
`BFPPR
`
`As described in the Petition and Dr. Abhari’s initial declaration, a POSITA
`
`
`
`would have been motivated to optimize both FPR and bypass flow passage
`
`pressure losses (i.e., the variables that make up BFPPR). Optimizing to a low FPR
`
`20
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`

`

`
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`is desirable because it reduces engine noise,6 while optimizing pressure losses in
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`the bypass flow passage improves fuel efficiency. Petition at 36; GE-1003, ¶ 77.
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`At his deposition, Dr. Mathioudakis did not contest the well-known relationships
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`between (i) FPR and noise or (ii) pressure losses and fuel efficiency. GE-1031 at
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`18:13-16, 19:17-22.
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`
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`The examples of engines with FPRs that fall outside the claimed range cited
`
`by UTC do not negate the obviousness of the claimed BFPPR ranges.7 PO
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`Response at 65-66. As explained by Dr. Abhari and confirmed by UTC’s own
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`evidence, the ultimate selection of FPR (and thus BFPPR) depends on a variety of
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`factors, including noise, efficiency, weight, and installation concerns. GE-1003, ¶
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`78; UTC-2025.015 (“the optimum fan pressure ration has been found to be
`
`dependent on the metric of interest.”). The law of obviousness does not require
`
`that Petitioner demonstrate that a low FPR (and BFPPR) within the claimed range
`
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`6 An article published by a UTC executive in 2014 explains that noise “has been
`
`the bane of aviation from its inception over 100 years ago and continues to be so to
`
`this day.” UTC-2007.003-004.
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`7 UTC incorrectly asserts that UTC-2011 discloses an FPR of 1.45. PO Response
`
`at 66. UTC-2011 discloses an FPR ranging from 1.27-1.45. UTC-2011.005.
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`21
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`

`

`
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`is appropriate for all engine applications.8 In re Fulton, 391 F.3d 1195, 1200 (Fed.
`
`Cir. 2004).
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`C. UTC has Not Demonstrated Unexpected Results for the Claimed
`BFPPR Ranges
`
`UTC’s assertion that criticality is only relevant to the obviousness of a
`
`
`
`claimed range when prior art discloses a value within the range is incorrect. See
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`PO Response at 62-63. To the contrary, a prima facie case of obviousness exists
`
`where the prior art discloses a value within or close to a claimed range. Titanium
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`Metals Corp. v. Banner, 778 F.2d 775, 783 (Fed. Cir. 1985) (“The proportions are
`
`so close that prima facie one skilled in the art would have expected them to have
`
`the same properties. Appellee produced no evidence to rebut that prima facie
`
`case.”); MPEP § 2144.05 (“a prima facie case of obviousness exists where the
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`claimed ranges or amounts do not overlap with prior art but are merely close.”).
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`
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`Having set forth a prima facie case of obviousness, UTC must show that the
`
`claimed BFPPR ranges produce unexpected results. In re Woodruff, 919 F.2d at
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`1578 (“[T]he difference between the claimed invention and the prior art is some
`
`range or other variable within the cl