 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued March 10, 2017                 Decided July 28, 2017

                        No. 16-1101

       FLYERS RIGHTS EDUCATION FUND, INC., D/B/A
         FLYERSRIGHTS.ORG, AND PAUL HUDSON,
                     PETITIONERS

                             v.

        FEDERAL AVIATION ADMINISTRATION, ET AL.,
                     RESPONDENTS


           On Petition for Review of an Order of
            the Federal Aviation Administration


     Joseph E. Sandler argued the cause and filed the briefs
for petitioner.

     Karen Schoen, Attorney, U.S. Department of Justice,
argued the cause for respondents. With her on the brief were
Benjamin C. Mizer, Principal Deputy Assistant Attorney at
the time the brief was filed, and Mark B. Stern, Attorney.

    Before: ROGERS, MILLETT, and PILLARD, Circuit Judges.

    Opinion for the Court filed by Circuit Judge MILLETT.
                                2

    Opinion concurring in part and concurring in the
judgment filed by Circuit Judge ROGERS.

     MILLETT, Circuit Judge: This is the Case of the
Incredible Shrinking Airline Seat. As many have no doubt
noticed, aircraft seats and the spacing between them have
been getting smaller and smaller, while American passengers
have been growing in size. Paul Hudson and the Flyers
Rights group became concerned that this sharp contraction in
passenger seating space was endangering the safety, health,
and comfort of airline passengers. So they petitioned the
Federal Aviation Administration to promulgate rules
governing size limitations for aircraft seats to ensure, among
other things, that passengers can safely and quickly evacuate a
plane in an emergency. The Administration denied the
petition, asserting that seat spacing did not affect the safety or
speed of passenger evacuations. To support that conclusion,
the Administration pointed to (at best) off-point studies and
undisclosed tests using unknown parameters. That type of
vaporous record will not do—the Administrative Procedure
Act requires reasoned decisionmaking grounded in actual
evidence. Accordingly, we grant the petition for review in
part and remand to the Administration.

                                I

                                A

    Congress has charged the Federal Aviation
Administration with ensuring the safety and security of
commercial airline passengers.          See 49 U.S.C.
§§ 44701, 40101(d); see also Wallaesa v. Federal Aviation
Admin., 824 F.3d 1071, 1079 (D.C. Cir. 2016). In fulfilling
that role, the Administration has “‘plenary authority to
[m]ake and enforce safety regulations governing the design
                                3

and operation of civil aircraft’ in order to ensure the
‘maximum possible safety.’” Bargmann v. Helms, 715 F.2d
638, 642 (D.C. Cir. 1983) (alteration in original) (quoting
H.R. REP. NO. 2360, 85th Cong., 2d Sess. 2, 7 (1958)).

     As relevant here, the Federal Aviation Act charges the
Administration with “promot[ing] safe flight of civil aircraft
in air commerce by prescribing * * * minimum standards
required in the interest of safety for * * * the design, material,
construction, quality of work, and performance of aircraft,” as
well as “regulations and minimum safety standards for other
practices, methods, and procedure[s] * * * necessary for
safety in air commerce[.]” 49 U.S.C. § 44701(a)(1), (5).
When issuing such minimum safety standards and regulations,
the Administration must consider “the duty of an air carrier to
provide service with the highest possible degree of safety in
the public interest[.]” Id. § 44701(d)(1)(A). In addition, the
Administration “shall consider the following matters, among
others, as being in the public interest: (1) assigning,
maintaining, and enhancing safety and security as the highest
priorities in air commerce[, and] (2) regulating air commerce
in a way that best promotes safety and fulfills national defense
requirements.” Id. § 40101(d)(1), (2). The Administration
thus has broad authority to promulgate regulations
“reasonably related to safety in flight.” Wallaesa, 824 F.3d at
1079 (internal quotation marks and citation omitted).

     Members of the public may petition the Administration to
promulgate, amend, or repeal regulations. See 49 U.S.C.
§ 106(f)(3)(A); 14 C.F.R. § 11.61(a). Such a petition must
include, among other things, the purpose of the proposed
action, an “explanation of why [the] proposed action would be
in the public interest,” and “[a]ny specific facts or
circumstances that support” the proposed action.           14
C.F.R. § 11.71(a).     Once it receives a petition, the
                              4

Administration has six months to respond either “by
dismissing such petition[], by informing the petitioner of an
intention to dismiss, or by issuing a notice of proposed
rulemaking or advanced notice of proposed rulemaking.” 49
U.S.C. § 106(f)(3)(A); see 14 C.F.R. § 11.73(a), (e).

                              B

     On August 26, 2015, Paul Hudson and the non-profit
organization Flyers Rights Education Fund of which he is
president (collectively, “Flyers Rights”) petitioned the
Administration to promulgate rules governing the minimum
requirements for seat sizes and spacing on commercial
passenger airlines. In its petition, Flyers Rights provided
evidence that commercial airline seat and spacing dimensions
have steadily decreased in size over the last several decades.
The petition noted that economy-class “seat pitch”—the
distance between a point on one seat and the same point on
the seat directly in front of it—has decreased from an average
of 35 inches to 31 inches, and in some airplanes has fallen as
low as 28 inches. Evidence in the petition further indicated
that average seat width has narrowed from approximately
18.5 inches in the early-2000s to 17 inches in the early- to
mid-2010s. The petition also noted that, since the 1960s, the
average American flyer had grown steadily larger in both
height and girth. Flyers Rights expressed concern that the
decrease in seat size, coupled with the increase in passenger
size, imperiled passengers’ health and safety by slowing
emergency egress and by causing deep vein thrombosis (a
potentially fatal condition involving blood clots in the legs),
                                 5

as well as “soreness, stiffness, [and] other joint and muscle
problems.” Pet. for Rulemaking 6. 1

     Accordingly, Flyers Rights asked the Administration to:
promulgate regulations that would (i) “set[] maintenance
standards and limit[] the extent of seat size changes [on
commercial airlines] in order to ensure consumer safety,
health, and comfort”; (ii) “plac[e] a moratorium on any
further reductions in seat size, width, pitch, padding, and aisle
width until a final rule is issued”; and (iii) “[a]ppoint an
advisory committee or task force to assist and advise the
[Administration] in proposing seat and passenger space rules
and standards[.]” Pet. for Rulemaking 3.

    On February 1, 2016, the Administration denied Flyers
Rights’ petition for rulemaking.          The Administration
explained that, in addressing petitions for rulemaking, it
weighs: “(1) [t]he immediacy of the safety or security
concerns * * * raise[d], (2) [t]he priority of other issues the
[Administration] must deal with, and (3) [t]he resources we
have available to address these issues.” Denial of Pet. for
Rulemaking 1; see also 14 C.F.R. § 11.73(a).               The
Administration then concluded that Flyers Rights’ concerns

    1
       Flyers Rights is not alone in its concerns. See Press Release,
Office of the Hon. Steve Cohen, Tenn. 9th Dist., Reps. Cohen and
Kinzinger, Senators Blumenthal, Schumer, Markey, Menendez and
Feinstein Introduce Bipartisan, Bicameral SEAT Act (March 9,
2017),     https://cohen.house.gov/media-center/press-releases/reps-
cohen-and-kinzinger-senators-blumenthal-schumer-markey-
menendez-and [https://perma.cc/KL7J-GE62] (last accessed July
21, 2017) (“The average distance between rows of seats has
dropped from 35 inches before airline deregulation in the 1970s to
about 31 inches today. The average width of an airline seat has also
shrunk from 18 inches to about 16½.”).
                               6

did not warrant action because the issues raised “relate[d] to
passenger health and comfort, and d[id] not raise an
immediate safety or security concern.” Denial of Pet. for
Rulemaking 2. The Administration reasoned that it already
“require[s] full-scale evacuation demonstrations and analysis
that set the limit for the maximum number of passengers for
any given airplane model,” including for aircraft with
“interior configurations that are more critical (less seat pitch
and higher number of passengers) than most configurations
operated by the airlines,” and that emergency egress tests
“have been successfully conducted at 28- and 29-inch
pitch[.]” Id. The Administration added that “[s]eat pitch
alone does not determine the amount of space available
between seats * * * [because] modern, thinner seats at lower
seat pitch provide more space than older seats did at higher
pitch.” Id. The Administration further noted that the medical
concerns identified in the petition exist “irrespective of the
seat pitch[.]” Id. With respect to Flyers Rights’ concerns
about deep vein thrombosis, the Administration concluded
that the condition was “rare”; it can occur with “any long-
duration seated activity”; and its risks are “the same for
economy-class and business-class.” Id.

     The Administration’s denial of the petition for
rulemaking did not cite any studies or tests to corroborate its
representations.     Nor did it challenge Flyers Rights’
characterization of seat dimension decreases or passenger size
increases.

     Flyers Rights sent a follow-up letter to the
Administration’s Director of the Aircraft Certification Service
asking the Administration to “formally cite the study(ies) [it]
* * * rel[ied] on” in denying the petition. J.A. 173. In
response, the Administration identified a series of its own
reports on airplane emergency egress and links to medical
                               7

websites that discussed deep vein thrombosis. The studies
cited in the letter did not address the impact of smaller seat
dimensions or increased passenger size on the ability of
passengers to expeditiously leave their seats and reach the
emergency exits.

    Dissatisfied with the Administration’s unsubstantiated
representations about matters of passenger health and safety,
Flyers Rights timely petitioned this court for review.

                              II

     We review the Administration’s actions to determine
whether they were “arbitrary, capricious, an abuse of
discretion, or otherwise not in accordance with law.” Safe
Extensions, Inc. v. Federal Aviation Admin., 509 F.3d 593,
604 (D.C. Cir. 2007) (quoting 5 U.S.C. § 706(2)(A)). Under
that standard, we will reverse “only if the agency’s decision is
not supported by substantial evidence, or the agency has made
a clear error in judgment.” Id. (citation omitted). Upon
review, we may “affirm, amend, modify, or set aside any part
of the order and may order the * * * Administrat[ion] to
conduct further proceedings.” 49 U.S.C. § 46110(c).

     Because Flyers Rights challenges the Administration’s
decision not to engage in rulemaking—the Administration’s
inaction—our review is “extremely limited.” WildEarth
Guardians v. EPA, 751 F.3d 649, 651 (D.C. Cir. 2014)
(citation omitted); see Massachusetts v. EPA, 549 U.S. 497,
527 (2007) (“narrow” review of agency decision not to act).
That is because an agency has “broad discretion to choose
how best to marshal its limited resources and personnel to
carry out its delegated responsibilities.” Massachusetts, 549
U.S. at 527; see also Defenders of Wildlife v. Gutierrez, 532
F.3d 913, 919 (D.C. Cir. 2008) (“[A]n agency’s refusal to
                               8

institute rulemaking proceedings is at the high end of the
range of levels of deference we give to agency action under
our ‘arbitrary and capricious’ review.”) (internal quotation
marks and citation omitted).

     In reviewing such decisions, we ask “whether the agency
employed reasoned decisionmaking in rejecting the petition,”
Defenders of Wildlife, 532 F.3d at 919, and we will overturn
the agency’s decision “only for compelling cause, such as
plain error of law or a fundamental change in the factual
premises previously considered by the agency,” WildEarth
Guardians, 751 F.3d at 653 (internal quotation marks and
citation omitted). Our review turns, more specifically, on
whether the agency “adequately explained the facts and policy
concerns it relied on and [whether] * * * those facts have
some basis in the record.” Id. (alterations in original; citation
omitted).

                              III

    Flyers Rights challenges two aspects of the
Administration’s denial of its petition for rulemaking: (1) its
conclusion that current seat pitch and width, as well as
passenger size, do not negatively impact emergency egress,
and (2) its denial of authority to consider matters related to
passenger health and comfort. We agree with Flyers Rights
that the Administration failed to provide a plausible
evidentiary basis for concluding that decreased seat sizes
combined with increased passenger sizes have no effect on
emergency egress. But we disagree with Flyers Rights’
challenge to the Administration’s declination to regulate
matters of physical comfort and routine health.
                               9

                      Emergency egress

     Flyers Rights’ petition for rulemaking reasonably
identified a safety concern arising from the commercial
airlines’ documented pattern of placing ever larger passengers
in ever smaller seats with still less space between them. The
petition explained why such seating constrictions could make
it more difficult for passengers to quickly leave their seats and
escape an aircraft in the event of an emergency. Specifically,
the petition asserted that, in an emergency, decreased seat
spacing would increase panic, delay access to the center aisle,
and impede the escape of injured passengers. The petition
also included multiple comments from airline passengers
expressing safety concerns. One commenter stated that
current seat spacing made it “necessary to climb onto [her]
seat to get out.” J.A. 167. Another commenter asserted that,
given current seat spacing, “[i]n an emergency, there is no
way we would have been able to get to an exit row in less
than three or four minutes[.]” J.A. 169.

     The Administration has a broad mandate to protect and
promote passenger safety. Ensuring that all passengers can
rapidly evacuate an airplane is of central importance to that
safety mission. See 14 C.F.R. § 25.803(c) (requiring that
aircraft with a capacity of more than forty-four passengers be
capable of evacuation within ninety seconds, and that actual
egress demonstrations be undertaken to ensure compliance
with Administration regulations). The Administration does
not dispute that. Accordingly, when the Administration
responds to a petition for rulemaking that exposes a plausible
life-and-death safety concern, the Administration must
reasonably address that risk in its response.

    The Administration failed that task here. In asserting that
decreasing seat size and pitch had no effect on emergency
                               10

egress, the Administration pointed to certain studies and
demonstration tests. But the cited studies say nothing about
and do not appear to control for seat pitch, width, or any other
seat dimension. Nor do they address or control for how
increased passenger size interacts with the current seat
dimensions to affect emergency egress. Studies cannot
corroborate or demonstrate something that they never mention
or even indirectly address.

     The Administration argues that the omission of
information about seat dimensions from the tests means that
seat dimensions are categorically unimportant to emergency
egress. That makes no sense. Tests generally require a
limited number of variables to be workable and verifiable.
The omission of other variables says nothing about such
variables’ relevance to what is being tested; it says only that
they were not recorded, measured, or altered for that
particular test. Take, for example, a study on tooth decay that
only recorded participants’ sugar consumption. The study’s
silence on the question of brushing and flossing would surely
not imply that brushing and flossing have no effect on the risk
of getting a cavity.

     The Administration’s rationale also blinks reality. As a
matter of basic physics, at some point seat and passenger
dimensions would become so squeezed as to impede the
ability of passengers to extricate themselves from their seats
and get over to an aisle. The question is not whether seat
dimensions matter, but when.

     Indeed, an Administration study that addressed passenger
size in a slightly different context actually corroborates Flyers
Rights’ point. The study considered, among other things, the
ability of wider passengers to pass through the emergency exit
row and door. Importantly, this test found that increased
                                11

passenger width had the greatest effect on exit speed of all the
variables tested. See J.A. 89 (chart indicating “[w]aist [s]ize”
had the largest “[r]elative [m]agnitude of [e]ffect[]” of the ten
variables tested). Yet nowhere did the Administration explain
why passenger size would impede progress through the
relatively wide emergency exit rows, yet have no impact on
passenger movement through the far more cramped (seat-
pitch-decreased) seating rows. 2

     The Administration also overlooks that its studies are
outdated. They were conducted in the 2000s when, according
to the petition, seat dimensions were larger. Agency
reasoning, however, must adapt as the critical facts change.
See American Horse Prot. Ass’n v. Lyng, 812 F.2d 1, 5 (D.C.
Cir. 1987) (“[A] refusal to initiate a rulemaking naturally sets
off a special alert when a petition has sought modification of a
rule on the basis of a radical change in its factual premises.”).

     The Administration points out that evacuation tests must
be run with the maximum allowable passenger occupancy for
any given aircraft model.        See 14 C.F.R. § 25.807(g)
(regulating the number of passengers allowed in each
specified aircraft model to promote emergency egress); id.
§ 25.803(c) (tests must be run with maximum allowable
occupancy). The problem for the Administration is that
maximum occupancy is not an adequate proxy for cabin-seat
or passenger dimensions. Because planes commonly include
different seating classes like first class, business class, and

    2
       A second study in part examined the impact of passenger
size on injuries sustained when traveling through the emergency
exit door.       Notably, that study observed that “physical
characteristics (gender, age, waist size, height) [were] previously
shown to significantly affect emergency egress[.]” J.A. 39.
                               12

economy plus, limiting the number of seats in an aircraft does
not limit seat pitch and width in all of the seats, and especially
in the ordinary economy-class seats. That means that
economy-seating pitch could decrease to levels that could
impede emergency egress, while the pitch and width in the
first class and business class seats would not.

     Finally, the Administration stated in its decision that
emergency evacuation tests have been successfully run with
seat dimensions as small as those being used by commercial
airlines. The problem is that not one of those tests is in the
record.    So they provide no evident support for the
Administration’s conclusion.

     The Administration says they were omitted because the
tests are “proprietary.” Administration’s Br. 13. Of course,
an agency may decline to include confidential business
information in the public administrative record in certain
narrow situations, as long as it discloses as much information
publicly as it can. See MD Pharm., Inc. v. Drug Enforcement
Admin., 133 F.3d 8, 13 (D.C. Cir. 1998) (upholding an
agency’s decision not to include confidential business
information in the public record of a licensing hearing); cf.
Mead Data Central, Inc. v. United States Dep’t of the Air
Force, 566 F.2d 242, 260 (D.C. Cir. 1977) (Under the
Freedom of Information Act, “[i]t has long been a rule in this
Circuit that non-exempt portions of a document must be
disclosed unless they are inextricably intertwined with exempt
portions.”).

     The problem here is that the Administration has given no
reasoned explanation for withholding the tests in their
entirety, and it has declined to file them under seal or in
redacted form. Yet the Administration explicitly relied on
those missing studies in reaching its decision to deny the
                                 13

petition for rulemaking. See Denial of Pet. for Rulemaking 2
(“Full scale evacuation tests on widely used airplanes have
been successfully conducted at 28- and 29-inch pitch[.]”);
J.A. 178. And the Administration asks the court to trust those
studies in reviewing the Administration’s decision. See Oral
Arg. Tr. 29–33; Administration’s Br. 11–13.

     But that is not how judicial review works. We cannot
affirm the sufficiency of what we cannot see. “[A]n agency
decision based on ‘reliable data reposing in the [agency’s]
files’” but hidden from judicial view “simply cannot
withstand scrutiny.” United States Lines, Inc. v. Federal
Maritime Comm’n, 584 F.2d 519, 535 (D.C. Cir. 1978).

     Indeed, we have long held that, when “the data relied on
by [an agency] in reaching its decision is not included in the
administrative record and is not disclosed to the court[,]” we
cannot “determine whether the final agency decision reflects
the rational outcome of the agency’s consideration of all
relevant factors[.]” United States Lines, 584 F.2d at 533
(footnote omitted). Whatever deference we generally accord
to administrative agencies, “we will not defer to a declaration
of fact that is ‘capable of exact proof’ but is unsupported by
any evidence.” McDonnell Douglas Corp. v. United States
Dep’t of the Air Force, 375 F.3d 1182, 1190 n.4 (D.C. Cir.
2004) (citation omitted). 3


     3
        See also Safe Extensions, 509 F.3d at 605 (“[A]n agency’s
‘declaration of fact that is capable of exact proof but is unsupported
by any evidence’ is insufficient to make the agency’s decision non-
arbitrary.”) (citation omitted); cf. Chamber of Commerce of U.S. v.
SEC, 443 F.3d 890, 899 (D.C. Cir. 2006) (for an informal
rulemaking, “[a]mong the information that must be revealed for
                                14

     The problems with the Administration’s position do not
stop there. Even with respect to its unseen tests, the agency
cannot say whether those tests accounted for increased
passenger size, which is a critical component of the egress
problem raised by Flyers Rights’ petition. When questioned
at oral argument, counsel for the Administration was unaware
whether such tests take into account larger passengers. See
Oral Arg. Tr. 29, 33–34.

     To be sure, the record needed to support an agency’s
decision not to engage in rulemaking can be sparser than that
needed to support rulemaking. Normally, it “need only
include the petition for rulemaking, comments pro and con
where deemed appropriate, and the agency’s explanation of
its decision to reject the petition.” WWHT, Inc. v. FCC, 656
F.2d 807, 818 (D.C. Cir. 1981).

     But this case is different because the Administration
admits it relied materially on information it has not disclosed,
and the Administration has pointed this court to that
information as a basis for affirmance. Having invited the
court into its record, the Administration cannot hide the
evidentiary ball. Cf. CTS Corp. v. EPA, 759 F.3d 52, 64
(D.C. Cir. 2014) (“It is black-letter administrative law that in
an [Administrative Procedure Act] case, a reviewing court
should have before it neither more nor less information than
did the agency when it made its decision.”) (alteration in




public evaluation are the technical studies and data upon which the
agency relies”) (internal quotation marks and citation omitted).
                                 15

original; internal quotation marks and citation omitted). To
do otherwise would reduce judicial review to a rubber stamp. 4

     In short, when an agency denies a petition for
rulemaking, the record can be slim, but it cannot be vacuous.
Especially so when, as here, the petition identifies an
important issue that falls smack-dab within the agency’s
regulatory ambit. While we do not require much of the
agency at this juncture, we do require something. And
information critically relied upon by the agency that no one
can see does not count. We accordingly remand to the
Administration to adequately address the petition and the
emergency egress concerns it raises. If the petition for
rulemaking is again denied, the Administration must provide
appropriate record support for its decision. 5

     4
        See WildEarth Guardians, 751 F.3d at 653 (a reviewing
court must determine “whether the agency adequately explained the
facts and policy concerns it relied on and [whether] * * * those
facts have some basis in the record”) (alterations in original;
emphasis added; internal quotation marks and citation omitted);
American Radio Relay League, Inc. v. FCC, 524 F.3d 227, 238
(D.C. Cir. 2008) (“Allowing such omissions in data and
methodology may ma[ke] it impossible to reproduce an agency’s
results or assess its reliance upon them.”) (alteration in original;
internal quotation marks and citation omitted); Air Prods. &
Chems., Inc. v. FERC, 650 F.2d 687, 699 (5th Cir. 1981) (noting
that “official notice of unspecified information in the files of an
agency precludes effective judicial review”).
     5
        See generally Florida Power & Light Co. v. Lorion, 470
U.S. 729, 744 (1985) (“If the record before the agency does not
support the agency action, if the agency has not considered all
relevant factors, or if the reviewing court simply cannot evaluate
the challenged agency action on the basis of the record before it, the
                              16


     Flyers Rights asks the court to go further and order the
Administration to institute rulemaking. That we will not do.
“Our cases make clear * * * that such a remedy is appropriate
only ‘in the rarest and most compelling of circumstances.’”
American Horse Prot., 812 F.2d at 7 (quoting WWHT, 656
F.2d at 818). Rather, remand is the presumptive remedy
when the agency record is insufficient “to permit [the court]
to engage in meaningful review.” See id. (internal quotation
marks and citation omitted). Because the Administration
claims to have access to the information that would fully
justify its denial of the petition for rulemaking, an order to
engage in rulemaking is unwarranted at this point.

                Health and comfort concerns

     Flyers Rights also objects to the Administration’s failure
to address its concerns regarding passenger health and
comfort. More specifically, Flyers Rights’ petition worried
that cramped seat conditions cause deep vein thrombosis,
“soreness, stiffness, [and] other joint and muscle problems[.]”
Pet. for Rulemaking at 6. The Administration rejected such
concerns partly on the ground that they “relate to passenger
health and comfort, and do not raise an immediate safety or
security concern.” Denial of Pet. for Rulemaking 2.

    Flyers Rights argues that the Administration’s failure to
consider matters of passenger health and comfort is a
misinterpretation of its statutory authority, pointing to
assorted statutory provisions that purportedly require
consideration of “the availability of a variety of adequate,

proper course, except in rare circumstances, is to remand to the
agency for additional investigation or explanation.”).
                              17

economic, efficient[,] and low-priced services” and the
“develop[ment] and maint[enance of] a sound regulatory
system that is responsive to the needs of the public.” Flyers
Rights’ Opening Br. 26 (emphasis omitted) (quoting 49
U.S.C. § 40101(a)(4), (7)). The problem for Flyers Rights is
that the cited statutory provisions apply only to the Secretary
of Transportation, not to the Administration. See 49 U.S.C.
§ 40101(a).

     Flyers Rights also points out that “health” is a component
of “safety”—a criterion the Administration without a doubt
must consider under applicable statutory provisions. Flyers
Rights’ Reply Br. 7–9; see Flyers Rights’ Opening Br. 26–27.
See also 49 U.S.C. §§ 44701, 40101(d). We agree. We have
held that the Administration’s statutory authority “embod[ies]
a comprehensive scheme for the regulation of the safety
aspect[s] of aviation[.]” Bargmann, 715 F.2d at 642 (internal
quotation marks and citation omitted).            That includes
protecting passengers’ physical health in flight, even from
harms that are not occasioned by the flight. Indeed, in
Bargmann, we rejected the Administration’s position that its
authority was confined to addressing only those health issues
that were “caused or induced by flight.” Id. at 640 (emphasis
and internal quotation marks omitted). We held instead that
the Administration has the authority to regulate first aid kits
for treating conditions that occur during the flight, whether or
not those conditions are caused by flight conditions or
operations. Id. at 642; see also Wallaesa, 824 F.3d at 1080
(reaffirming the Administration’s power to regulate “care for
ill passengers”).

     So there is no question that the Administration has the
statutory authority to address at least some passenger health
issues. See Wallaesa, 824 F.3d at 1079–1080 (Administration
may regulate medical equipment to ensure “‘the personal
                                 18

safety of the stricken passengers’ and crew”) (citation
omitted); Bargmann, 715 F.2d at 642–643 (“Not only are
inflight medical emergencies of immediate concern to the
personal safety of the stricken passengers, but they may also
be of concern to the safety of others.”) (citation omitted); 14
C.F.R. § 121, App. A (Administration regulation requiring
“automated external [heart] defibrillator[s]” on passenger
aircraft). 6

     The problem for Flyers Rights is that, in this case, the
Administration acknowledged its authority to protect the
health of passengers, stating that it would “continue to
monitor seat designs and effects on safety and health.” J.A.
175 (emphasis added). The Administration thus did not

    6
         The concurring opinion would hold that Flyers Rights
waived reliance on the Bargmann line of cases. Concurring Op. 1–
3. We respectfully disagree. Flyers Rights pressed the argument
that passenger health can be regulated in conjunction with safety in
its opening brief. See Flyers Rights’ Opening Br. 26–27; Flyers
Rights’ Reply Br. 7–9; Pet. for Rulemaking 3. To be sure, the
manner in which Flyers Rights substantiated that argument evolved
from its opening to reply brief. But that is not an uncommon
occurrence. What matters is that the core of Flyers Rights’
argument—that passenger health can be regulated in conjunction
with safety—remained the same. And once an argument is before
us, it is our job to get the relevant case law right. Cf. Elder v.
Holloway, 510 U.S. 510, 516 (1994) (when deciding a “question of
law,” a court “should * * * use its full knowledge of its own [and
other relevant] precedents”) (second alteration in original; internal
quotation marks and citation omitted); United States v. Rapone, 131
F.3d 188, 196–197 (D.C. Cir. 1997). Indeed, a party cannot forfeit
or waive recourse to a relevant case just by failing to cite it. See
Elder, 510 U.S. at 514–516; Metavante Corp. v. Emigrant Sav.
Bank, 619 F.3d 748, 773 n.20 (7th Cir. 2010).
                               19

decline to regulate the types of circulatory harms identified by
Flyers Rights because it thought it could not address such
matters. Rather, the Administration decided that it should not
address those issues at this time, making the very type of
regulatory-effort and resource-allocation judgments that fall
squarely within the agency’s province.

     Specifically, with respect to the risk of deep vein
thrombosis, the Administration cited evidence showing that it
rarely occurs and, regardless, is not caused by seat size or
spacing. See Denial of Pet. for Rulemaking 2; J.A. 176
(citing a study noting that guidelines issued by the American
College of Physicians indicate that deep vein thrombosis is
“extremely rare” and that risk of deep vein thrombosis is not
any higher in economy class than business class) (citation
omitted). Thus, the Administration reasonably declined to
initiate rulemaking to assess Flyers Rights’ concerns about
deep vein thrombosis.

     Flyers Rights also noted passenger problems with
“soreness, stiffness, [and] other joint and muscle problems” in
its petition for rulemaking. Pet. for Rulemaking 6. Given that
those conditions are commonplace, temporary, and non-life-
threatening discomforts, Flyers Rights’ petition failed to
demonstrate that the Administration erred in declining to
undertake immediate rulemaking. 7


    7
        Flyers Rights appears to have abandoned its argument that
the Administration must consider passenger comfort when issuing
regulations. In any event, the Administration reasonably concluded
that matters pertaining exclusively to passenger “comfort” are not
within its regulatory wheelhouse. See 49 U.S.C. §§ 44701(a),
40101(d).
                              20

                           *****

     We grant Flyers Rights’ petition for review in part, and
remand to the Administration for a properly reasoned
disposition of the petition’s safety concerns about the adverse
impact of decreased seat dimensions and increased passenger
size on aircraft emergency egress. We otherwise deny the
petition for review.

                                                   So ordered.
     ROGERS, Circuit Judge, concurring in part and concurring
in the judgment: I join the court in remanding this matter to the
Federal Aviation Administration (“FAA”) to address adequately
the petition for rulemaking filed by Paul Hudson and the Flyers
Rights Education Fund (“petitioners”) with respect to concerns
about emergency egress from airplanes in light of decreases in
seat size and pitch. See Op. 9–16. I also join the court in
rejecting petitioners’ argument that 49 U.S.C. § 40101(a)
required the FAA to consider matters of passenger health and
comfort. See Op. 16–17. Unlike the court, however, I would
decline to reach petitioners’ additional argument, first raised in
their reply brief, that the concept of “safety” in 49 U.S.C.
§ 44701(a), a term that is not statutorily defined, “inherently
includes and is intertwined with the health of passengers.”
Reply Br. 8. But see Op. 17–19.

     The court does not usually address arguments first raised in
a reply brief, treating them as “waived,” in order to “prevent
sandbagging of appellees and respondents.” CTS Corp. v. EPA,
759 F.3d 52, 60 (D.C. Cir. 2014) (quoting Novak v. Capital
Mgmt. & Dev. Corp., 570 F.3d 305, 316 n.5 (D.C. Cir. 2009));
see United States v. Van Smith, 530 F.3d 967, 973– 74 (D.C. Cir.
2008) (citing cases and FED. R. APP. P. 28(c)). This, of course,
is not to say that the court should disregard refinements made in
a reply brief to an argument properly raised in an opening brief.
Here, however, petitioners have offered two distinct theories,
based on different statutory provisions, for how the FAA
misconstrued the scope of its statutory authority in dismissing
passenger health and comfort concerns in responding to the
petition for rulemaking — one in their opening brief and the
other in their reply brief.

    Petitioners contend in their opening brief that the FAA
misconstrued its authority by refusing to consider passenger
comfort and safety “because it interpreted its own statutory
mandate to be limited to safety concerns.” Pet’r Br. 26.
Although they acknowledge the FAA’s safety responsibilities
                                 2

under Section 44701(a), petitioners do not rely on this provision
for their argument and instead maintain that the FAA has
statutory duties distinct from its safety responsibilities that
require it to consider passenger health and comfort, citing
Sections 40101(a)(4) & (7). See id. at 26–27. Specifically,
petitioners state in their opening brief: “To be sure, the FAA
has a statutory responsibility to ‘promote safe flight of civil
aircraft in air commerce.’ 49 U.S.C. § 44701(a). But it also has
a responsibility, in regulating the industry, to consider a number
of other factors . . . .” Pet’r Br. 26 (emphasis added).
Petitioners then cite various obligations under Section 40101(a)
that require consideration of the needs and interests of the
public, and contend that these provisions create a “clear
statutory command” to consider passenger health and comfort
concerns. Id. at 26–27 (quoting Massachusetts v. EPA, 549 U.S.
497, 533 (2007)). In petitioners’ view, “the FAA believed,
incorrectly, that it was not legally obligated even to consider the
‘needs of the public’ with respect to passenger health and
safety,” id. at 27, quoting Section 40101(a)(7).

     Thus, it is evident that in their opening brief petitioners
conceived of health and safety as distinct factors, with the
FAA’s corresponding health obligations arising under different
statutory provisions than its safety responsibilities under Section
44701(a). Only after the FAA pointed out in its responsive brief
that Section 40101(a), on which petitioners relied in their
opening brief, applies to the Secretary of Transportation rather
than the FAA, see Resp’t Br. 19, did petitioners raise in their
reply brief the additional argument that “health” is a component
of “safety” under Section 44701(a), Reply Br. 8. As presented
by petitioners in their briefs to this court, one statutory theory is
not “baked into” the other. The FAA responded in its brief to
the only theory presented in petitioners’ opening brief and had
no opportunity to respond in its brief to petitioners’ second
theory presented for the first time in their reply brief. Stepping
                                  3

in, the court offers its own view on how the FAA construes its
own authority under Section 44701(a), without the benefit of
briefing from the FAA on this question. See Op. 18–19.

      Petitioners offer no explanation for their failure to raise both
arguments in their opening brief, none is apparent from the
record, and no extraordinary circumstances excuse their failure
to do so. The court seeks to avoid our precedent by suggesting
that petitioners’ statutory argument simply “evolved” in their
reply brief, Op. 18 n.6, but references to arguments presented in
the rulemaking petition to the FAA, see id., that petitioners did
not, in fact, raise in their opening brief does not eliminate the
“sandbagging” of the FAA that has occurred on appeal. After
all, litigants may have several reasons to think an agency has
erred, but they make choices about which arguments to present
on appeal; opposing parties in filing a responsive brief
legitimately confine their response to the arguments presented
in the opening brief. It is hardly common practice to ignore
whether the opposing party has notice of the other party’s
position, but see id., and this court has tended to take a strict
view of the obligation on appealing parties to set forth their
arguments in their opening briefs, see, e.g., Am. Wildlands v.
Kempthorne, 530 F.3d 991, 1001 (D.C. Cir. 2008); Van Smith,
530 F.3d at 973–74 (citing cases). Consequently, in accordance
with the court’s precedent, I would not reach the new statutory
theory presented only in petitioners’ reply brief.
