United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued March 17, 2017 Decided August 29, 2017

Reissued February 7, 2018

No. 15-1158

CITY OF PHOENIX, ARIZONA,

PETITIONER

v.

MICHAEL P. HUERTA AND FEDERAL AVIATION 

ADMINISTRATION,

RESPONDENTS

Consolidated with 15-1247

On Petitions for Review of a Decision 

by the Federal Aviation Administration

John E. Putnam argued the cause for petitioner City of 

Phoenix, Arizona. With him on the briefs was Peter J. Kirsch.

Matthew G. Adams, pro hac vice, argued the cause for 

petitioners Story Preservation Association, et al. With him on 

the briefs was Peter L. Gray.

Lane N. McFadden, Attorney, U.S. Department of Justice, 

argued the cause for respondents. With him on the brief was 
2

John C. Cruden, Assistant Attorney General at the time the 

brief was filed. 

Before: ROGERS and GRIFFITH, Circuit Judges, and 

SENTELLE, Senior Circuit Judge.

Opinion for the Court filed by Circuit Judge GRIFFITH.

Dissenting opinion filed by Senior Circuit Judge

SENTELLE.

GRIFFITH, Circuit Judge: In September 2014, the Federal 

Aviation Administration changed longstanding flight routes in 

and out of Phoenix Sky Harbor International Airport. The city 

of Phoenix and a historic neighborhood association both 

petitioned for review, alleging that the FAA’s action was 

arbitrary and capricious. We agree.

I

Phoenix Sky Harbor International Airport is one of the 

nation’s busiest airports. To minimize the impact of the sound 

of aircraft on residents, the FAA historically has routed flights 

over industrial and agricultural parts of the City, and the City 

has used zoning to minimize impact on residential areas and 

either purchased or furnished with sound insulation the homes 

most affected by flight paths, at a cost of hundreds of millions 

of dollars.

In response to a mandate from Congress to modernize the 

nation’s air-traffic control system, see FAA Modernization and 

Reform Act of 2012, Pub. L. No. 112-95, 

§§ 101(a), 213(a)(1)(A), 126 Stat. 11, 47, the FAA sought to 

alter the flight routes in and out of Sky Harbor and to employ 

satellite technology to guide planes. For consultation on its 
3

developing plans, the FAA formed the Phoenix Airspace Users 

Work Group with the City and others.

One of the new flight paths the FAA devised would route 

planes over a major avenue and various public parks and 

historic neighborhoods. The new route would increase air 

traffic over these areas by 300%, with 85% of the increase 

coming from jets. The FAA consulted on the environmental 

impact of this and other proposed changes primarily with a 

low-level employee in Phoenix’s Aviation Department, who 

warned the FAA that he lacked the expertise and authority to 

discuss environmental matters on the City’s behalf. The FAA 

never conveyed the proposed route changes to senior officials 

in the City’s Aviation Department, local officials responsible 

for affected parks or historic districts, or elected city officials.

As plans progressed, the FAA used computer software to 

model the noise impact of the proposed route changes. This 

modeling predicted that two areas in Phoenix, which included 

twenty-five historic properties and nineteen public parks, 

would experience an increase in noise large enough to be 

“potentially controversial.” But the agency concluded that 

these projected noise levels would not have a “[s]ignificant 

[environmental] impact” under FAA criteria. Joint Appendix 

333, 334. Based on this conclusion, the FAA issued a 

declaration categorically excluding the new flight routes from 

further environmental review. The FAA shared these 

conclusions with the State Historic Preservation Officer, 

predicting that the new noise levels would not disrupt 

conversation at a distance of three feet and would be no louder 

than the background noise of a commercial area. The State 

Officer concurred in this prediction.

The FAA presented the finalized flight routes in an April 

2013 meeting attended by a low-level project manager of the 
4

City’s Aviation Department. The agency also sent the proposed 

routes and maps showing affected areas to the other low-level 

Aviation Department employee, with the caveat that plans were 

“subject to change.” J.A. 302. In May 2014, the FAA notified 

the Phoenix Airspace Users Work Group that the new routes 

would take effect in September. The FAA did not share its 

environmental conclusions with Airport management until the 

day before the routes were to go into effect. Management asked 

the FAA to delay implementation so the public could be 

informed. The FAA refused.

On September 18, 2014, the FAA published the new 

routes, and related procedures, and made them effective 

immediately. The public’s reaction was swift and severe: the 

planes supplied the sound, the public provided the fury. In the 

next two weeks, the Airport received more noise complaints 

than it had received in all of the previous year. 1 Residents 

complained that the flights overhead were too loud and 

frequent and rattled windows and doors in their homes. Some 

claimed that they had trouble sleeping uninterrupted, carrying 

on conversations outdoors, or feeling comfortable indoors 

without earmuffs to mute the noise.2

In response to the uproar, the FAA held a public meeting 

the next month that drew 400 attendees and hundreds of 

 1 See Brittany Hargrave, Phoenix Neighbors Protest Sky 

Harbor Flight-Path Change, THE ARIZONA REPUBLIC, Sept. 30, 

2014 (updated Oct. 1, 2014), http://azc.cc/YQlwu5.

2 See Ashley Thompson, Neighbors Upset at FAA’s New Flight 

Patterns Hold Day of Protest, KNXV, Oct. 24, 2015, 

http://www.abc15.com/news/region-phoenix-metro/centralphoenix/neighbors-upset-at-faas-new-flight-patterns-hold-day-ofprotest.
5

comments.3 There the agency promised to review the noise 

issue and update the City’s Aviation Department. The FAA 

later claimed to have identified and corrected the problem: 

aircraft had been straying from the new routes. The agency said 

it was “teaming with the airport staff and industry experts” to 

see what more could be done about the noise levels. J.A. 609. 

But despite the FAA’s assurances, the City continued to receive 

record numbers of noise complaints. In early December, the 

City told the FAA that public concern remained high.

That month the State Historic Preservation Officer also 

asked the FAA to reconsider the new routes in light of their 

impact on historic properties, which he said was far worse than 

he had been led to believe. He said he had originally concurred 

with the agency’s optimistic projections only out of deference 

to the FAA’s technical expertise.

Around the same time, the FAA’s Regional Administrator 

met with Phoenix’s City Council and publicly admitted, “I 

think it’s clear that . . . [our pre-implementation procedures 

were] probably not enough because we didn’t anticipate this 

being as significant an impact as it has been, so I’m certainly 

not here to tell you that we’ve done everything right and 

everything we should have done.” J.A. 773.

A week after this concession, the City asked the agency to 

reopen consultation and restore the old routes until the City and 

 3 See Miriam Wasser, Sound and Fury: Frustrated Phoenix 

Residents Are Roaring Ever Since the FAA Changed Sky Harbor

Flight Paths, PHOENIX NEW TIMES, Mar. 4, 2015, 

http://www.phoenixnewtimes.com/news/sound-and-fury-frustratedphoenix-residents-are-roaring-ever-since-the-faa-changed-skyharbor-flight-paths-6654056; Caitlin McGlade, FAA Will Study 

Solution to Flight-Path Noise, THE ARIZONA REPUBLIC, Oct. 16, 

2014 (updated Oct. 17, 2014), http://azc.cc/1waaUm9.
6

the agency could engage the public in discussions. In response, 

the FAA said it would work with the airport and airlines to 

investigate additional changes to the flight paths. To that end, 

the FAA promised to reconvene the original Working Group, 

assuring the City that it was “an important player in this 

process.” J.A. 750-51. But the agency also said it could not 

reinstate the routes in place before September 18, 2014, 

because that would require a time-consuming series of related 

changes to air-traffic control and aircraft automation systems, 

as well as additional safety and environmental reviews. The 

FAA also declined the Preservation Officer’s request to reopen environmental review of the new routes.

In mid-February and again in early April the following 

year, the City submitted data to the FAA purporting to show 

that the agency’s assertions to the Preservation Officer 

regarding the noise impact of the new routes were “massive[ly] 

and material[ly]” incorrect. J.A. 814. The City also alleged that 

computer modeling the FAA was required to use under its own 

regulations showed that 40,000 additional residents would be 

exposed to noise loud enough to disrupt speech compared to 

before the new routes were implemented. And the City 

renewed its request that the FAA reopen a statutorily mandated 

consultation process with the State Preservation Office, in 

order to provide the City with data from the FAA’s modeling, 

conduct an environmental review of the route changes, and find 

ways to either minimize the noise impact of those changes or 

restore the old routes.

In mid-April the FAA responded with a letter to the City 

that included the Working Group’s final report. The report 

evaluated alternative routes and amended some existing routes 

but reaffirmed the agency’s decision not to conduct further 

review of the new flight paths’ environmental impact. And 

though the accompanying letter expressed the FAA’s 
7

frustration that the City had offered no alternative route 

proposals, the letter also conveyed the agency’s promise to 

consider further modifications as it “continue[d] to support a 

collaborative approach towards addressing the community’s 

concerns.” J.A. 1036. The letter did not address the City’s data, 

modeling, or requests. In fact, the accompanying documents 

disclosed that noise level reduction was not among the 

Working Group’s stated objectives.

The City’s response expressed frustration that despite 

initial promises, the FAA had organized the Working Group so 

that it would not address the noise issue, and had even excluded 

the City from meetings for fear of confrontation between the 

City and the airlines. Indeed, the City was not listed as a 

Working Group member. The City also protested that it had

provided an alternative plan to the FAA—namely, reinstating 

the original routes but continuing to use satellite technology—

which the City claimed would eliminate the 69% increase in 

residents exposed to higher noise levels and cost airlines only 

$700,000 more per year in fuel compared to the new routes.

In late May, the City met with the FAA and the airlines to 

again discuss ways to fix the noise issues. The FAA 

characterized these discussions as “productive” in a follow-up 

letter sent on June 1. J.A. 1109. The letter also listed short-term 

adjustments the agency could make within six months, as well 

as some “longer term” possibilities, which the agency could 

implement within a year following additional environmental 

review. Id. The letter said nothing about the City’s data 

submissions, previous requests to reopen consultation and 

environmental review, proposal to return to the old routes while 

still using satellite technology, or exclusion from the Working 

Group. 
8

Also on June 1, the City sought review in our court, 

characterizing the FAA’s last letter as a final order. The 

Historic Neighborhoods filed their own petition for review in 

late July. The FAA moved to dismiss these petitions as 

untimely.

II

We must first determine whether these petitions are 

untimely. A petition for review of an FAA order must be filed 

in the Court of Appeals “not later than 60 days after the order 

is issued.” 49 U.S.C. § 46110(a). The parties disagree over 

when this sixty-day clock began to run—i.e., when the FAA’s 

decision regarding the new flight routes crystallized into final 

agency action. The answer is relevant because only a final 

action can be a reviewable “order” within the meaning of 

section 46110’s sixty-day deadline. See Flytenow, Inc. v. FAA, 

808 F.3d 882, 888-89 (D.C. Cir. 2015). A final order is one that 

“mark[s] the consummation of the agency’s decisionmaking 

process” and that either determines “rights or obligations” or is 

a source of “legal consequences.” Friedman v. FAA, 841 F.3d 

537, 541 (D.C. Cir. 2016) (quoting Bennett v. Spear, 520 U.S. 

154, 177-78 (1997)).

The FAA contends that its final “order” regarding the new 

routes issued on September 18, 2014, when the routes were 

formally published and put into effect. We agree. The 

September 2014 publication was a final order because it 

satisfies both prongs of the finality test. 

First, the September publication marked “the 

consummation of the agency’s decisionmaking process,” id., 

because it put the new routes into effect following extensive 

testing and evaluation intended to ensure that those routes 

would be safe and consistent with air traffic requirements, see
9

Fed. Aviation Admin., Order No. 7100.41, Performance Based 

Navigation Implementation Process §§ 2-3 to 2-6 (2014).

Petitioners respond that although the new routes went into 

effect in September, the agency’s decisionmaking process 

regarding those routes had not yet concluded. See Friedman, 

841 F.3d at 541. Petitioners note that the FAA’s process for 

developing new routes actually has five steps, of which 

publication of the new routes was only the fourth. The fifth step 

provides for post-implementation monitoring and review, 

which, petitioners contend, could have led to further route 

changes.

But this final step is not part of the agency’s 

“decisionmaking process.” Id. (emphasis added). Rather, it 

consists of “Monitoring and Evaluation” of decisions already 

“[i]mplement[ed],” see Order 7100.41, supra, § 2-7, “to 

ensure” that those decisions play out “as expected,” id. To be 

sure, that monitoring might lead to adjustments to the new 

routes, but by then the primary development of those routes has 

already happened. Cf. Friedman, 841 F.3d at 543 (explaining 

that “a vague prospect of reconsideration” does not defeat a 

finding of finality).

As for the second prong of the finality test, it was the 

September publication, and not the June 1 letter or any of the 

agency’s other reports or communications, that determined 

“rights [and] obligations” and produced “legal consequences.” 

Id. at 541. And it was the September publication that led to the 

effects petitioners now seek to reverse: increased noise in 

certain areas of Phoenix. We also note that the relief requested 

by petitioners is “vacat[ur] and remand [of the] FAA’s decision 

to implement the [new flight] routes”—that is, of the 

September order. Phoenix Br. 61. Thus, petitioners implicitly 

recognize that the September publication, and only that 
10

publication, determined the legal consequences they wish to 

challenge. We therefore conclude that the September 18, 2014 

publication of the new flight routes was the relevant final 

“order.” 

The petitions thus came more than half a year too late. The 

review statute, however, provides that a court may allow a 

petition to be filed after the usual deadline “if there are 

reasonable grounds for not filing by the 60th day.” 49 U.S.C. 

§ 46110(a). While we “rarely [find] ‘reasonable grounds’ 

under section 46110(a),” Elec. Privacy Info. Ctr. v. FAA, 821 

F.3d 39, 43 (D.C. Cir. 2016), we have done so in cases quite 

similar to this one. 

For instance, in Paralyzed Veterans of America v. Civil 

Aeronautics Board, the Board promulgated a final rule but 

“explicitly left its rulemaking docket open in order to receive 

additional comments from the public.” 752 F.2d 694, 705 n.82 

(D.C. Cir. 1985), rev’d on other grounds sub nom. U.S. Dep’t 

of Transp. v. Paralyzed Veterans of Am., 477 U.S. 597 (1986). 

“Aware that the rule might be undergoing modification, and 

unable to predict how extensive any modifications would be, 

petitioners elected to wait until the regulation was in final form 

before seeking review,” six months after the final rule had been 

published. Id. We found that petitioners had shown “reasonable 

grounds” for late filing under a review statute materially the 

same as the one at issue here. 4 See id. (citing 49 U.S.C. 

§ 1486(a) (1976)). In doing so, we observed that “[a]ny delay 

simply served properly to exhaust petitioners’ administrative 

 4 In Paralyzed Veterans, the petitioners had filed a petition for 

review within sixty days of an amended final order. But the 

Paralyzed Veterans court treated that fact as a distinct reason to 

review the petition, considering “[m]ore important[]” the fact that 

petitioners had shown reasonable grounds for delaying their petition 

for review of the original order. See 752 F.2d at 705 n.82.
11

remedies, and to conserve the resources of both the litigants 

and this court.” Id.

Similarly, in Safe Extensions, Inc. v. FAA, after the FAA’s 

publication of an advisory circular establishing certain 

requirements for manufacturing products provoked a 

“significant uproar in the industry,” the FAA told the industry 

to ignore the existing order pending a revision. 509 F.3d 593, 

603 (D.C. Cir. 2007). The petitioner, “[b]ased on these 

representations, and hoping to avoid litigation,” decided to wait 

and see if the agency would address the petitioner’s concerns 

voluntarily. Id. As a result, we found reasonable grounds for 

the petitioner’s late filing. Id. at 604. 

To be sure, in Safe Extensions the FAA had expressly 

directed the petitioner to ignore the final order, whereas here 

the FAA merely promised to look into possible modifications. 

But the key in Safe Extensions was that the agency left parties 

“with the impression that [it] would address their concerns” by 

replacing its original order with a revised one. Id. at 596. There 

we were concerned that the agency’s comments “could have 

confused the petitioner and others.” Id. at 603.

Those same concerns are present here. The FAA 

repeatedly communicated—in an October public meeting, in a 

November letter, in a December public meeting, in a January 

letter, in a February decision to reconvene the Working Group, 

in an April letter, and in a May meeting with city officials—

that the agency was looking into the noise problem, was open 

to fixing the issue, and wanted to work with the City and others 

to find a solution. This pattern would certainly have led 

reasonable observers to think the FAA might fix the noise 

problem without being forced to do so by a court. And given 

the FAA’s serial promises, petitioning for review soon after the 

September order might have shut down dialogue between the 
12

petitioners and the agency. See Oral Arg. Tr. 58:8-13. We do 

not punish the petitioners for treating litigation as a last rather 

than a first resort when an agency behaves as the FAA did here. 

See Paralyzed Veterans, 752 F.2d at 705 n.82.

While we rarely find a reasonable-grounds exception, this 

is such a rare case. We hold that petitioners had reasonable 

grounds for their delay in filing. To conclude otherwise would 

encourage the FAA to promise to fix a problem just long 

enough for sixty days to lapse and then to argue that the 

resulting petitions were untimely. We therefore reach the 

merits of the petitions.

III

The petitioners argue that the FAA’s approval of the new 

flight routes was arbitrary and capricious and violated the 

National Historic Preservation Act, the National 

Environmental Policy Act, the Department of Transportation 

Act, and the FAA’s Order 1050.1E. We agree.5

A

Under the National Historic Preservation Act, federal 

agencies must “account [for] the effect of their actions on 

structures eligible for inclusion in the National Register of 

Historic Places.” Ill. Commerce Comm’n v. ICC, 848 F.2d 

1246, 1261 (D.C. Cir. 1988). In fulfilling this obligation, 

agencies must consult with certain stakeholders in the 

potentially affected areas, including representatives of local 

 5 Petitioners also claim that the FAA violated the agency’s own 

Order 7100.41 by excluding the City from the Working Group reconvened in the wake of the controversy over the new routes. We do 

not reach that argument, however, because our review is limited to 

the agency’s September order.
13

governments. See 36 C.F.R. § 800.2(a)(4), (c)(3). If an agency 

determines that no historic structures will be adversely 

affected, it still has to “notify all consulting parties”—

including a representative of the local government—and give 

them any relevant documentation. Id. § 800.5(c).

Here the FAA failed to fulfill these obligations because it 

consulted only low-level employees in the City’s Aviation 

Department, whom the City had never designated as its 

representatives. True, the City never informed the FAA that 

low-level Aviation Department employees were inadequate 

points of contact, but that is irrelevant. Neither statute nor 

regulation imposes a duty on local governments to 

affirmatively inform the agency of their chosen representatives. 

Just the opposite: the agency must ask local governments who 

their authorized representatives are. See id. § 800.3(f), (f)(1). 

The FAA never took that step here. And the FAA’s failure to 

notify and provide documentation to the City of the agency’s 

finding of no adverse impact violated regulations under the 

Preservation Act, and denied the City its right to participate in 

the process and object to the FAA’s findings. See id.

§§ 800.2(c)(3), 800.5(c)(2).

Additionally, unless confidential information is involved, 

agencies must “provide the public with information about an 

undertaking and its effects on historic properties and seek 

public comment and input.” Id. § 800.2(d)(2) (emphasis 

added). The FAA admits, however, that it did not make “local 

citizens and community leaders” aware of the proposed new 

routes and procedures, J.A. 364, and it does not claim that any 

confidentiality concerns applied. 

Further, by keeping the public in the dark, the agency 

made it impossible for the public to submit views on the 

project’s potential effects—views that the FAA is required to 
14

consider. See 36 C.F.R. § 800.5(a); see also Am. Bird 

Conservancy v. FCC, 516 F.3d 1027, 1035 (D.C. Cir. 2008) 

(“Interested persons cannot request an [environmental 

assessment] for actions they do not know about, much less for 

actions already completed.”).

B

Under the National Environmental Policy Act (NEPA), 

federal agencies must assess and disclose the environmental 

impacts of “major” actions prior to taking those actions. 42 

U.S.C. § 4332(2)(C); 40 C.F.R. § 1502.1. This process 

“ensures” that before an agency acts, it will “have available” 

and “carefully consider[] detailed information concerning 

significant environmental impacts.” Robertson v. Methow 

Valley Citizens Council, 490 U.S. 332, 349 (1989). The process 

also “guarantees that the relevant information will be made 

available to the larger audience that may also play a role in both 

the decision-making process and the implementation of [the] 

decision.” Id.

NEPA’s requirements vary based on the type of agency 

action in question. Actions with significant environmental 

effects require a full environmental-impact statement. Actions 

with impacts that are not significant or are unknown require a 

briefer environmental assessment. And actions “which do not 

individually or cumulatively have a significant effect on the 

human environment” can be categorically excluded from any 

environmental review. 40 C.F.R. § 1508.4. 

However, the FAA may not categorically exclude an 

action from environmental review if “the Administrator 

determines that extraordinary circumstances” would counsel 

otherwise. FAA Modernization and Reform Act of 2012, Pub. 

L. No. 112-95, § 213(c)(1), 126 Stat. 11, 49. Under the FAA’s 
15

own regulations, extraordinary circumstances exist when an 

action’s effects “are likely to be highly controversial on 

environmental grounds.” Fed. Aviation Admin., Order No. 

1050.1E, Environmental Impacts: Policies and Procedures 

¶ 304i (2004). Here, the FAA found that the new routes were 

“not likely to be highly controversial on environmental 

grounds,” and thus determined that no extraordinary 

circumstances existed. That determination was arbitrary and 

capricious.

The FAA’s determination was arbitrary in light of the 

agency’s admitted failure to notify “local citizens and 

community leaders” of the proposed new routes before they 

went into effect. J.A. 364, 367. This failure made it impossible 

for the FAA to take into account “[o]pposition on 

environmental grounds by a . . . State, or local government 

agency or by . . . a substantial number of the persons affected 

by the [FAA’s] action.” Order 1050.1E, supra, ¶ 304i; cf. Am. 

Bird Conservancy, 516 F.3d at 1035 (faulting the agency for its 

lack of diligence in informing and involving the public since 

“[i]nterested persons cannot request an [environmental 

assessment] for actions they do not know about, much less for 

actions already completed”).

The FAA argues that it was reasonable simply to assume 

that its proposal would not be controversial on environmental 

grounds, given that the agency had “confirmed that no 

significant noise impacts were anticipated at all, received the 

concurrence of the State Historic Preservation Officer[,] who 

expressed no concerns, and then further discussed the finding 

with the Airport Authority[,] [which] also expressed no 

concerns.” FAA Br. 80. Common sense reveals otherwise. As 

noted, the FAA’s proposal would increase by 300% the number 

of aircraft flying over twenty-five historic neighborhoods and 

buildings and nineteen public parks, with 85% of the new flight 
16

traffic coming from jets. The idea that a change with these 

effects would not be highly controversial is “so implausible” 

that it could not reflect reasoned decisionmaking. See Motor 

Vehicle Mfrs. Ass’n of U.S. v. State Farm Mut. Auto. Ins. Co., 

463 U.S. 29, 43 (1983).

The FAA also erred by deviating from its usual practice in 

assessing when new flight routes are likely to be highly 

controversial, without giving a “reasoned explanation for . . . 

treating similar situations differently.” W. Deptford Energy, 

LLC v. FERC, 766 F.3d 10, 20 (D.C. Cir. 2014). In assessing 

proposed route changes at airports in Boston, Northern 

California, Charlotte, and Atlanta, the FAA has relied on its 

general observation that a proposal is likely to be highly 

controversial if it would increase sound levels by five or more 

decibels in an area already experiencing average levels of 45-

60 decibels. But here the agency said exactly the opposite and 

never explained its about-face. The FAA replies that “[e]ach 

airport is different and the potential effects of any changes at 

those airports will differ as well.” FAA Br. 81. But that does 

not explain how the Phoenix plan could be less likely to stir 

controversy than other plans that had the same projected 

impact. Thus, the agency acted arbitrarily in departing from its 

usual determinations regarding when a projected noise increase 

is likely to be highly controversial. 

In short, the FAA had several reasons to anticipate that the 

new flight routes would be highly controversial: The agency 

was changing routes that had been in place for a long time, on 

which the City had relied in setting its zoning policy and 

buying affected homes. The air traffic over some areas would 

increase by 300%—with 85% of that increase attributed to 

jets—when before only prop aircraft flew overhead. The FAA 

found a “potential [for] controversy” but did not notify local 

citizens and community leaders of the proposed changes as the 
17

agency was obligated to, much less allow citizens and leaders 

to weigh in.6 And the agency departed from its determinations 

in materially identical cases. Thus, the FAA acted arbitrarily in 

finding under Order 1050.1E that the new routes were unlikely 

to be highly controversial and could thus be categorically 

excluded from further environmental review.

C

Petitioners also raise two claims related to the 

Transportation Act’s section 4(f). First, they argue that the 

FAA violated its duty to consult with the City in assessing 

whether the new routes would substantially impair the City’s 

parks and historic sites. Second, petitioners claim that the FAA 

was wrong to find that the routes would not substantially impair 

these protected areas. We agree on both points. 

i

Section 4(f) of the Transportation Act calls for “special 

effort[s] to preserve the natural beauty of . . . public park and 

recreation lands . . . and historic sites.” 49 U.S.C. § 303(a). To 

that end, the FAA’s regulations require it to consult “all

appropriate . . . State[] and local officials having jurisdiction

over the affected section 4(f)” areas when assessing whether a 

noise increase might substantially impair these areas. Order 

1050.1E, supra, ¶ 6.2e (emphases added). According to the 

 6 Although at times it may be difficult to identify precisely who 

must be notified, the FAA’s regulatory acknowledgment of its 

obligation has narrowed the field. Here, given the changes about to 

occur, it was unreasonable to ignore elected local officials once the 

FAA was on notice that the Aviation Department employee lacked 

authorization to speak for the City of Phoenix. See infra Part III.C 

(discussing FAA regulations under section 4(f) of the Transportation 

Act). 
18

City, the agency violated this requirement by not consulting the 

proper city officials about the proposed flight routes in 

Phoenix. Cf. Nat’l Conservative Political Action Comm. v. 

FEC, 626 F.2d 953, 959 (D.C. Cir. 1980) (“Agencies are under 

an obligation to follow their own regulations, procedures, and 

precedents, or provide a rational explanation for their 

departures.”).

The FAA responds that it did consult employees in the 

City’s Aviation Department, and that at the time the City didn’t 

tell the agency what the City now asserts: that those employees 

lacked authority to speak for the City regarding the new flight

routes. Thus, the FAA contends, its failure to consult other 

local officials was not arbitrary.

We are not persuaded. As noted, the FAA spoke mainly 

with one low-level employee in the City’s Aviation 

Department and occasionally with other low-ranking members 

of the department. But it was unreasonable for the agency 

simply to assume that low-level Aviation Department 

employees had jurisdiction over the historic sites and public 

parks protected by section 4(f), much less that these employees 

(along with the State Historic Preservation Officer) represented 

all the local officials with such jurisdiction, as the agency’s 

consultation duties required. Besides, the FAA cites no 

evidence that it consulted with these City officials on historic 

sites and public parks in particular. Thus, the FAA’s 

consultation process was arbitrarily confined.

ii

Section 4(f) also provides that a federal transportation 

project may “use” a public park or historic site only if “there is 

no prudent and feasible alternative to using that land.” 49 

U.S.C. § 303(c)(1). A project makes “constructive use” of a 
19

protected area if the project would “substantially impair” that 

area. Order 1050.1E, supra, ¶ 6.2e. And a project substantially 

impairs an area if it “substantially diminish[es]” the “activities, 

features, or attributes . . . that contribute to its enjoyment.” Id.

¶ 6.2f. For instance, a project would make constructive use of 

a park if it subjected the park to aircraft noise “at levels high 

enough to have negative consequences of a substantial nature 

that amount to a taking.” Id. In that case, the project could 

lawfully proceed only if there was no prudent and feasible 

alternative to using the park. 

In determining whether a transportation project would 

substantially impair an area protected under section 4(f), the 

FAA may rely on guidelines set forth in 14 C.F.R. pt. 150 (the 

Part 150 guidelines), including the directive “to evaluate 

impacts on historic properties that are in use as residences.” 

Order 1050.1E, supra, ¶ 6.2h. But the Part 150 guidelines “may 

not be sufficient to determine the noise impact” on historic 

residences if “a quiet setting is a generally recognized purpose 

and attribute” of those residences. Id. (emphasis added). Here 

the FAA found that a quiet setting was not a recognized 

purpose of the affected historic homes, neighborhoods, and 

sites, so the agency relied only on the Part 150 guidelines in 

assessing the noise impact on those sites. And on that basis, it 

concluded that the increased noise would not substantially 

impair the historic buildings and areas in question.

The City contends that it was unreasonable for the FAA to 

rely only on the Part 150 guidelines, because the agency didn’t 

have enough information to tell if the areas affected here were 

generally recognized as quiet settings. We agree. 

As evidence that these sites were not “generally 

recognized” as quiet settings, the FAA pointed to the sites’ 

urban location. Id. But that isn’t enough: even in the heart of a 
20

city, some neighborhoods might be recognized as quiet oases. 

The agency also observed that planes were flying over the 

affected historic sites even before the new routes took effect. 

But those earlier flights involved propeller aircraft that flew far 

less often, so the homes beneath them might still have been 

generally recognized as “quiet setting[s].” Id.

Thus, it was unreasonable for the agency to rely only on 

the Part 150 guidelines in concluding that noise from the new 

flight routes would not substantially impair the affected historic 

sites. As a result, that conclusion lacks substantial supporting 

evidence. For both these reasons, we find that the agency’s 

substantial-impairment analysis was arbitrary and capricious. 

See BFI Waste Sys. of N. Am. v. FAA, 293 F.3d 527, 532 (D.C. 

Cir. 2002) (observing that an agency’s action is arbitrary and 

capricious if it is “‘not supported by substantial evidence’ in 

the record as a whole” (quoting Motor Vehicle Mfrs. Ass’n of 

U.S. v. Ruckelshaus, 719 F.2d 1159, 1164 (D.C. Cir. 1989))); 

see also State Farm, 463 U.S. at 43 (“We may not supply a 

reasoned basis for the agency’s action that the agency itself has 

not given.” (quoting SEC v. Chenery Corp., 332 U.S. 194, 196 

(1947))).

IV

For the foregoing reasons, we grant the petitions, vacate 

the September 18, 2014 order implementing the new flight

departure routes at Sky Harbor International Airport, and 

remand the matter to the FAA for further proceedings 

consistent with this opinion.

So ordered.
SENTELLE, Senior Circuit Judge, dissenting:

I respectfully dissent from the majority’s opinion in this 

case, not because I disagree with the merits but because I 

believe the court should not reach them. I therefore express no 

opinion on the merits and instead disembark at the question of 

timeliness.

As the majority acknowledges, petitions for review of an 

FAA order must be filed “not later than 60 days after the order 

is issued.” 49 U.S.C. § 46110(a); see Maj. Op. at 8. 

Nevertheless, as my colleagues note, the petitions in this case 

were filed “more than half a year too late.” Maj. Op. at 10. 

Such late filing is excused “only if there are reasonable grounds 

for not filing” within the 60-day period. § 46110(a); see Maj.

Op. at 10. The majority relies on two cases, Paralyzed 

Veterans of America v. Civil Aeronautics Board, 752 F.2d 694 

(D.C. Cir. 1985), rev’d on other grounds sub nom. U.S. Dep’t 

of Transp. v. Paralyzed Veterans of Am., 477 U.S. 597 (1986), 

and Safe Extensions, Inc. v. FAA, 509 F.3d 593 (D.C. Cir. 

2007), for its conclusion that reasonable grounds exist in the 

present case. See Maj. Op. at 10-12. Both cases, however, are 

distinguishable. 

As my colleagues in the majority acknowledge, in 

Paralyzed Veterans, “the Board promulgated a final rule but 

‘explicitly left its rulemaking docket open in order to receive 

additional comments from the public.’” Maj. Op. at 10 (citing 

Paralyzed Veterans, 752 F.2d at 705 n.82). This unusual 

circumstance, prompting the petitioners to wait for further 

changes to the rule before filing for review, constituted 

reasonable grounds within the meaning of § 46110(a). And, 

as the majority acknowledges in discussing Safe Extensions, 

that case involved the FAA instructing parties to ignore an 

order as it would be modified and revised. Safe Extensions, 

509 F.3d at 603; Maj. Op. at 10-11. The petitioner accordingly 

waited to file and, given that unique context, we concluded 
2

reasonable grounds existed for delayed filing. Safe Extensions, 

509 F.3d at 604. These factual contexts are distinguishable 

from the present case, in which the FAA never promised to 

suspend the existing order and explicitly had the new flight 

paths continue while it considered the possibility of future 

changes. Mere agency acknowledgment of the possibility of 

future modification is not a rare circumstance; Paralyzed 

Veterans and Safe Extensions are instead the truly rare 

circumstances of an agency explicitly inducing warranted 

delay by a putative petitioner. Agencies are often welcome to 

re-initiate the decision-making process at some future point and 

to follow the necessary procedures to change their minds —

this mere possibility, or even the mention of it, cannot be 

enough to excuse a petitioner’s failure to file within the 

statutorily mandated 60-day period. Otherwise, the statutory 

limit would cease to have meaning.

Instead, as we observed in Electronic Privacy Information 

Center v. FAA, 821 F.3d 39, 43 (D.C. Cir. 2016), “[w]e have 

rarely found ‘reasonable grounds’ under section 46110(a).” 

Safe Extensions (and, by comparison, Paralyzed Veterans) is 

the “rare instance[]” of such reasonable grounds, not the rule. 

Nat’l Fed’n of the Blind v. U.S. Dep’t of Transp., 827 F.3d 51, 

57 (D.C. Cir. 2016). Because reasonable grounds are so 

infrequent, the onus is almost always on the petitioners to 

protect themselves and file within the 60-day timeframe. The 

FAA’s failure to act with perfect clarity is not sufficient to 

remove petitioners’ duty to protect themselves. See, e.g., Nat’l 

Fed’n of the Blind, 827 F.3d at 57-58; Elec. Privacy Info. Ctr., 

821 F.3d at 42-43; Avia Dynamics, Inc. v. FAA, 641 F.3d 515, 

521 (D.C. Cir. 2011). Mere confusion over where or when to 

file, lack of clarity by the FAA in its communications, 

ignorance, and lack of notice do not suffice, at least 

independently, to qualify as reasonable grounds for delay under 

§ 46110(a) and our precedent. See Nat’l Fed’n of the Blind, 
3

827 F.3d at 57-58; Elec. Privacy Info. Ctr., 821 F.3d at 42-43; 

Avia Dynamics, 641 F.3d at 521. Such grounds are rare and 

found in unique circumstances, such as Safe Extensions and 

agency procurements of delay by promising a new order and 

instructing parties to ignore the prior one, or Paralyzed 

Veterans and an agency leaving its rulemaking docket open 

during the modification process, where delay “simply served 

properly to exhaust petitioners’ administrative remedies,” 752 

F.2d at 705 n.82. No such unusual facts are in the present case. 

I would determine that petitioners lacked reasonable grounds 

for untimely filing.

I note in passing the majority’s references to petitioners’

notice and knowledge of the FAA’s proceedings having come 

through “low-level” employees. See Maj. Op. at 3-4, 13. I do 

not see that this can help establish reasonable grounds for any 

delay, let alone one stretching six months beyond the 60-day

statutory provision. There was ample time for the higher-ups 

to gain and act on adequate knowledge.

In concluding that petitioners did not have reasonable 

grounds for waiting six months to file for review, I do not 

contend that the FAA acted with perfect clarity at all times. 

However, the record does not suggest to me that petitioners had 

a clear reason, akin to those rare instances present in Paralyzed 

Veterans and Safe Extensions, to forego at the very least a 

protective filing. For this reason, I would decide this case on 

the question of timeliness, deny the petitions for review, and 

decline to reach the merits of their arguments.