  United States Court of Appeals
      for the Federal Circuit
                ______________________

                   AIRBUS S.A.S.,
                      Appellant

                           v.

            FIREPASS CORPORATION,
                      Appellee
               ______________________

                      2014-1808
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/001,555.
                  ______________________

                Decided: July 17, 2015
                ______________________

   MATTHEW BERKOWITZ, Kenyon & Kenyon LLP, New
York, NY, argued for appellant. Also represented by
WALTER E. HANLEY, JR., ALOYSIUS ANTONY PFEFFER.

   ERIC SHUMSKY, Orrick, Herrington & Sutcliffe LLP,
Washington, DC, argued for appellee. Also represented by
ANDREW S. ONG, Menlo Park, CA; ROBERT M. ISACKSON,
New York, NY.
               ______________________

    Before LOURIE, DYK, and MOORE, Circuit Judges.
2                     AIRBUS S.A.S.   v. FIREPASS CORPORATION



LOURIE, Circuit Judge.
    Airbus S.A.S. (“Airbus”) appeals from the decision of
the United States Patent and Trademark Office (“PTO”)
Patent Trial and Appeal Board (“Board”) in an inter
partes reexamination dismissing Airbus’s cross-appeal for
lack of jurisdiction. * See Airbus S.A.S. v. Firepass Corp.,
No. 95/001,555, 2013 WL 5866589 (P.T.A.B. Oct. 29, 2013)
(“Board Decision”), reh’g denied, 2014 WL 2121080
(P.T.A.B. May 19, 2014) (“Rehearing Decision”). Because
the Board erred in dismissing the appeal, we vacate its
decision and remand.
                       BACKGROUND
    Firepass Corporation (“Firepass”) owns U.S. Patent
6,418,752 (the “’752 patent”), which is directed to using
hypoxic compositions for preventing and extinguishing
fires. In October 2009, Firepass brought suit against
Airbus in the District Court for the Eastern District of
New York alleging infringement of, inter alia, several
claims of the ’752 patent. In February 2011, Airbus filed
a request for inter partes reexamination of the ’752 pa-
tent. In its request, Airbus proposed that each of original
claims 1, 2, 4, 7, and 8 was anticipated under 35 U.S.C.
§ 102 by U.S. Patent 5,799,652 (“Kotliar”). J.A. 171.
Airbus also proposed that claims 1, 2, 4, and 7 were
anticipated under § 102 by (1) Boeing Military Airplane



    *    The Leahy-Smith America Invents Act amended
the inter partes reexamination provisions of the Patent
Act. See Leahy-Smith America Invents Act, Pub. L. No.
112-29, § 6, 125 Stat. 284, 299–305 (2011) (“AIA”). As
those amendments do not apply here because the request
for inter partes reexamination in this case was filed before
the date of enactment, September 16, 2011, id., we ex-
press no opinion on the applicability of the AIA provisions
to the current case.
AIRBUS S.A.S.   v. FIREPASS CORPORATION                    3



Co., “Vulnerability Methodology and Protective Measures
for Aircraft Fire and Explosion Hazards,” Final Report
AFWALTR-85-2060 (1986) (“AFWAL 2060”); and (2) T.C.
Knight et al., “The AH-64A Nitrogen Inerting System,”
AIAA-84-2480 (1991) (“Knight”). J.A. 174, 178. The PTO
granted Airbus’s request in part, finding that Kotliar
presented a substantial new question of patentability, but
also found that Knight and AFWAL 2060 did not present
a substantial new question of patentability. In July 2011,
the district court in the meantime stayed its litigation
pending resolution of Airbus’s reexamination request.
    During reexamination, Firepass added independent
claim 91 and dependent claims 92–94. Claim 91 was
based on original claim 1, and “includes both the limita-
tions set forth in [c]laim 1 . . . , as well as additional
narrowing limitations.” Appellee’s Br. 11. In response to
the new claims, Airbus proposed the following obvious-
ness rejections under 35 U.S.C. § 103: (1) claims 91–93
over Kotliar in view of AFWAL 2060; (2) claim 94 over
Kotliar in view of AFWAL 2060 and Knight; and (3) claim
94 over Kotliar in view of AFWAL 2060 and the
knowledge of one of ordinary skill in the art. The Exam-
iner, however, found that the proposed rejections based on
AFWAL 2060 and Knight did not present a substantial
new question of patentability. Nevertheless, the Examin-
er ultimately rejected claims 91–94 under 35 U.S.C. § 112,
¶ 1 for lack of written description.
    Firepass appealed from the rejection of claims 91–94
under § 112, ¶ 1, and Airbus cross-appealed from the
Examiner’s refusal to adopt the proposed obviousness
rejections of claims 91–94. Board Decision at *1. The
Board first reversed the Examiner’s rejection of claims
91–94 under § 112, ¶ 1, finding that the claims were
supported by an adequate written description. Id. at *11.
But the Board then dismissed Airbus’s cross-appeal
relating to the same claims, finding that “the statutory
authority for third-party requester appeals is . . . express-
4                     AIRBUS S.A.S.   v. FIREPASS CORPORATION



ly limited to the review of examiner final decisions that
are ‘favorable to the patentability’ of a claim.” Id. at *12
(quoting 35 U.S.C. §§ 134(c), 315(b) (2002)). The Board
concluded that the “determination of a ‘[l]ack of a sub-
stantial new question of patentability is not a favorable
decision on patentability.’” Id. (quoting Belkin Int’l, Inc.
v. Kappos, 696 F.3d 1379, 1383 (Fed. Cir. 2012)). Accord-
ingly, the Board dismissed Airbus’s cross-appeal for lack
of jurisdiction. Id.
    Airbus requested rehearing, but the Board denied the
request. Rehearing Decision at *1. The Board wrote that
§§ 134(c) and 315(b) and 37 C.F.R. § 41.61(a)(2) only
provide for the Board to review a decision favorable to the
patentability of any claim, including new claims. Id. at
*2. The Board again concluded that the Examiner’s
finding of no substantial new question of patentability
was not a decision favorable to patentability. Id. (citing
Belkin, 696 F.3d at 1383). The Board also confirmed that
it did not dismiss the cross-appeal because the Examiner
had found no substantial new question of patentability
with respect to the original claims, but it did so based on
the Examiner’s subsequent, independent determination
that Airbus’s proposed rejections of new claims 91–94
raised no substantial new question of patentability. Id.
    Airbus timely appealed to this court. We have juris-
diction pursuant to 28 U.S.C. § 1295(a)(4)(A).
                        DISCUSSION
     We review the Board’s legal determinations, including
whether the Board possessed jurisdiction in a case before
it, de novo. In re Gartside, 203 F.3d 1305, 1315 (Fed. Cir.
2000). Statutory interpretation is a question of law that
we likewise review de novo. In re Kathawala, 9 F.3d 942,
945 (Fed. Cir. 1993).
    Inter partes reexamination is a two-step process.
First, “after the filing of a request for inter partes reexam-
AIRBUS S.A.S.   v. FIREPASS CORPORATION                     5



ination under section 311, the Director shall determine
whether a substantial new question of patentability
affecting any claim of the patent concerned is raised by
the request.” 35 U.S.C. § 312(a) (2006). After the Direc-
tor has determined that there is a substantial new ques-
tion of patentability affecting a claim, the Director orders
“inter partes reexamination of the patent for resolution of
the question.” Id. § 313.
    After institution, § 314(a) provides that “reexamina-
tion shall be conducted according to the procedures estab-
lished for initial examination under the provisions of
sections 132 and 133.” Id. § 314(a). The patentee is
“permitted to propose any amendment to the patent and a
new claim or claims, except that no proposed amended or
new claim enlarging the scope of the claims of the patent
shall be permitted.” Id. In addition, after institution, a
third-party requester is limited to citing certain addition-
al prior art:
    (1) which is necessary to rebut a finding of fact by
    the examiner;
    (2) which is necessary to rebut a response of the pa-
    tent owner; or
    (3) which for the first time became known or
    available to the third party requester after the fil-
    ing of the request for inter partes reexamination
    proceeding. Prior art submitted under paragraph
    (a)(3) of this section must be accompanied by a
    statement as to when the prior art first became
    known or available to the third party requester
    and must include a discussion of the pertinency of
    each reference to the patentability of at least one
    claim.
37 C.F.R. § 1.948(a) (emphasis added).
    Airbus argues that the Board erred in dismissing the
cross-appeal relating to the Examiner’s refusal to consider
6                    AIRBUS S.A.S.   v. FIREPASS CORPORATION



proposed rejections to new claims because of a deemed
lack of a substantial new question of patentability. Ac-
cording to Airbus, Knight and AFWAL 2060 were proper-
ly cited under § 1.948(a)(2), and the determination of a
substantial new question of patentability is irrelevant to
new claims proposed by a patentee during the course of
an inter partes reexamination. Airbus contends that the
determination of a substantial new question of patentabil-
ity is only applicable to arguments made by a requester in
an inter partes reexamination request prior to institution.
Airbus also argues that, in the alternative, an examiner’s
decision that a proposed rejection raises no substantial
new question of patentability is appealable because it is a
decision favorable to patentability.
    Firepass responds that the Board correctly dismissed
Airbus’s cross-appeal because Airbus may not appeal from
an examiner’s decision that a proposed rejection raises no
substantial new question of patentability.       Firepass
asserts that § 312(a) obligates the Director to determine
whether a substantial new question of patentability has
been raised with respect to “any claim of the patent” that
a third-party requester asks the PTO to review. Firepass
argues that the relevant statutory framework, PTO
regulations, and the Manual of Patent Examining Proce-
dure (“MPEP”) do not distinguish between original and
added claims. Therefore, Firepass contends that the
substantial new question of patentability test was proper-
ly applied to new claims 91–94.
    We agree with Firepass that a party may not appeal
from an examiner’s decision that a proposed rejection fails
to raise a substantial new question of patentability on the
ground that such a decision is one favorable to patentabil-
ity. Belkin, 696 F.3d at 1383. Such a decision is not a
patentability decision, favorable or otherwise; it is a
substantial new question decision. Thus, that argument
of Airbus’s fails.
AIRBUS S.A.S.   v. FIREPASS CORPORATION                   7



    However, the provision requiring a determination of a
substantial new question of patentability was not appli-
cable to the case once the Director already had ordered
reexamination on the ground that other prior art raised a
substantial new question of patentability. We therefore
agree with Airbus that the Board erred in dismissing the
cross-appeal for lack of jurisdiction because the Examiner
incorrectly refused to consider proposed rejections to
newly-added claims after reexamination had been insti-
tuted.
    Once reexamination has been instituted, it is only 37
C.F.R. § 1.948(a)(2) that limits the prior art that can be
raised by the third-party requester in proposed rejections
to newly-added or amended claims. Although § 312(a)
requires the Director to “determine whether a substantial
new question of patentability affecting any claim of the
patent concerned is raised by the request,” the statute
notably does not contain the same requirement for pro-
posed rejections to claims added or amended after institu-
tion of the reexamination. 35 U.S.C. § 312(a) (2006).
Section 312 is expressly limited to the pre-institution
request from the third party. Id.
     Section 314 governs the conduct of inter partes reex-
amination proceedings, and it provides that “reexamina-
tion shall be conducted according to the procedures
established for initial examination under the provisions of
sections 132 and 133.” Id. § 314(a). Sections 132 and 133,
in turn, discuss the initial prosecution of an application.
See id. § 132 (titled “Notice of rejection; reexamination”);
id. § 133 (titled “Time for prosecuting application”). None
of those sections requires an examiner to evaluate pro-
posed rejections to new claims added during reexamina-
tion for a substantial new question of patentability;
instead, the statute only directs the examiner to follow
“the procedures established for initial examination.” Id.
§ 314(a).
8                     AIRBUS S.A.S.   v. FIREPASS CORPORATION



    In addition to the framework established by § 314 for
the conduct of reexamination proceedings, PTO regula-
tions explicitly restrict the prior art that can be raised by
the third-party requester once the Director has ordered
inter partes reexamination. 37 C.F.R. § 1.948(a)(2) limits
a third-party requester to use of additional prior art that,
inter alia, “is necessary to rebut a response of the patent
owner.” The language, “is necessary to rebut,” provides a
gatekeeping function to control the additional prior art
that a third-party requester may bring into the reexami-
nation. Section 1.948(a)(2) thus limits the third-party’s
ability to cite additional prior art against a newly-added
or amended claim with respect to limitations for which
the prior art has already been considered either during
original prosecution or in the request for reexamination.
    “The MPEP [is] commonly relied upon as a guide to
patent attorneys and patent examiners on procedural
matters . . . .” Litton Sys., Inc. v. Whirlpool Corp., 728
F.2d 1423, 1439 (Fed. Cir. 1984). Although the MPEP
does not have the force of law, it is entitled to judicial
notice “so far as it is an official interpretation of statutes
or regulations with which it is not in conflict.” Id. Here,
the MPEP is consistent with the statutory scheme and
§ 1.948(a)(2). MPEP § 2666.05, titled “Third Party Com-
ments After Patent Owner Response,” pertains to
§ 1.948(a)(2) and the limitations on submission of prior
art by the third-party requester after the order for inter
partes reexamination. According to § 2666.05, “any such
new proposed rejection stands on the same footing as a
proposed rejection presented with the request for reexam-
ination.” MPEP § 2666.05 (2008). Section 2666.05 con-
tinues, citing MPEP § 2617 for “the required discussion of
the pertinency of each reference,” and directing that “[a]n
explanation pursuant to the requirements of 35 U.S.C. [§]
311 of how the art applies is no less important at this
stage of the prosecution, than it is when filing the re-
quest.” Id.
AIRBUS S.A.S.   v. FIREPASS CORPORATION                   9



     Section 2617, in turn, provides guidelines for applying
prior art in the request for inter partes reexamination,
and states that the request “must ‘set forth the pertinency
and manner of applying cited prior art to every claim for
which reexamination is requested.’” Id. § 2617 (quoting
35 U.S.C. § 311(b)(2) (2006)). Citing PTO regulations,
§ 2617 requires a statement pointing out each substantial
new question of patentability, but that requirement only
extends to the request for reexamination. Id. (citing 37
C.F.R. § 1.915(b)(3)). Consequently, neither § 2617 nor
§ 2666.05 explicitly or implicitly directs an examiner to
determine whether a proposed rejection presents a sub-
stantial new question of patentability with respect to a
new or amended claim. Section 2617 only directs the
third-party requester to present an explanation of how
the proposed rejections apply to each of the claims, which,
in the case of a request, entails a discussion of a substan-
tial new question of patentability.
    In this case, Airbus’s proposed citation of prior art is
well within § 1.948(a)’s permission to cite prior art “which
is necessary to rebut a response of the patent owner.”
That response that Airbus is entitled to rebut was the
addition of new claims 91–94. Whether it rebuts those
claims is a question for the Examiner on remand.
    Firepass’s additional reliance on Belkin is misplaced.
In Belkin we considered whether the Board has jurisdic-
tion to decide if a substantial new question of patentabil-
ity exists with respect to a prior art reference before
institution of inter partes reexamination. Belkin, 696
F.3d at 1382. We concluded that the “Director’s determi-
nation that an issue does not raise a substantial new
question of patentability is not a decision favorable to
patentability.” Id. at 1383. We explicitly declined, how-
ever, to “reach the issue of what prior art references the
PTO may or may not consider during reexamination in
response to an amended or substituted claim.” Id. at 1384
n.2. Thus, Belkin does not inform our understanding of
10                      AIRBUS S.A.S.   v. FIREPASS CORPORATION



the availability of prior art in a proposed rejection after
reexamination has been instituted.
    The Board erred here because it premised its dismis-
sal of Airbus’s cross-appeal on the Examiner’s decision not
to consider Airbus’s proposed rejections because of a lack
of a substantial new question of patentability. But, once
the Director ordered inter partes reexamination it was
§ 1.948(a), not a determination of a substantial new
question of patentability, that governed the limitations on
Airbus’s submission of prior art. Thus, the Examiner
erred in evaluating Knight and AFWAL 2060 for a sub-
stantial new question of patentability, when his evalua-
tion should have been conducted under § 1.948(a)(2). We
have considered Firepass’s remaining arguments and find
them unpersuasive.
                         CONCLUSION
    Because the Board erred in dismissing Airbus’s cross-
appeal for lack of jurisdiction, we vacate and remand for
further proceedings consistent with this opinion.
              VACATED AND REMANDED
                             COSTS
     Costs to Airbus.
