United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued February 16, 2018 Decided May 25, 2018

No. 17-1043

ERIC FRIEDMAN,

PETITIONER

v.

FEDERAL AVIATION ADMINISTRATION,

RESPONDENT

On Petition for Review of an Order 

of the Federal Aviation Administration

Z.W. Julius Chen argued the cause for petitioner. With him 

on the briefs was Gregory S. Walden. Pratik A. Shah entered 

an appearance. 

Peter G. Dickos and Allison Jones Rushing were on the 

brief for amicus curiae American Diabetes Association in 

support of petitioner.

Casey E. Gardner, Attorney, Federal Aviation 

Administration, argued the cause and filed the brief for 

respondent. 

Before: HENDERSON and TATEL, Circuit Judges, and 

WILLIAMS, Senior Circuit Judge.
2

Opinion for the Court filed by Circuit Judge TATEL.

TATEL, Circuit Judge: For the second time, Eric Friedman, 

a type-one diabetic and aspiring commercial pilot, challenges 

the Federal Aviation Administration’s refusal to grant him a 

medical certificate required for commercial flight. Because 

Friedman uses insulin to manage his blood sugar, the FAA 

required him to submit data from a relatively new method of 

blood-glucose testing known as continuous glucose monitoring

(CGM), which Friedman declined to provide. In a prior

decision, our court held that the FAA “ha[d] not borne its 

burden of justification” for requiring CGM data. Friedman v. 

FAA (Friedman I), 841 F.3d 537, 544 (D.C. Cir. 2016). On 

remand, the FAA explained that it needed the data because 

CGM is able to detect hypoglycemic episodes often missed by

more traditional monitoring, and it supported that explanation 

with medical studies in the administrative record. Because that 

explanation satisfies our remand order, we deny the petition for 

review. 

I. 

The opinion in Friedman I describes the background of 

this case. Friedman I, 841 F.3d at 539–41. Here, we provide a 

brief summary and then describe the FAA’s actions on remand.

Congress has directed the FAA to promulgate regulations 

that “promote safe flight of civil aircraft,” 49 U.S.C. 

§ 44701(a), and to discharge this obligation “in a way that best 

tends to reduce or eliminate . . . accidents in air transportation,”

id. § 44701(c). Specifically, Congress has instructed the FAA 

to ensure that pilots are “physically able to perform the duties 

related to[] [their] position.” Id. § 44703(a). To implement this 

directive, the FAA requires pilots to hold medical certificates 

of one of three classes: pilots who fly commercial airliners
3

must have first-class medical certificates, 14 C.F.R. 

§ 61.23(a)(1), pilots who otherwise fly commercially must 

have second-class certificates, id. § 61.23(a)(2), and pilots who 

fly privately must have third-class certificates, id.

§ 61.23(a)(3). In keeping with Congress’s instruction that the 

FAA consider “the duty of [a commercial] air carrier to provide 

service with the highest possible degree of safety in the public 

interest,” 49 U.S.C. § 44701(d)(1), the Federal Air Surgeon, to 

whom the FAA Administrator has delegated his medical 

certification authority, 14 C.F.R. § 67.407, has adopted more 

rigorous medical standards for pilots who fly commercially 

(first- and second-class) than for those who fly privately (thirdclass), see id. §§ 61.23(a), 67.101–67.315.

Under FAA regulations, some medical conditions,

including diabetes treated with insulin, are presumptively 

disqualifying for any class of medical certificate. Id.

§§ 67.113(a) (first-class), 67.213(a) (second-class), 67.313(a) 

(third-class). The primary danger of flying with insulin-treated

diabetes, the FAA has explained, is the risk of hypoglycemia, 

a state of abnormally low blood-glucose levels, which is 

common among diabetics, especially those who use insulin, 

and which can impair a range of cognitive functions, including 

reaction time, memory, problem solving, and spatial reasoning. 

Special Issuance of Third-Class Airman Medical Certificates 

to Insulin-Treated Diabetic Airman Applicants, 61 Fed. Reg. 

59,282, 59,282 (Nov. 21, 1996) (explaining that the FAA’s 

disqualification policy was based in large part on concerns 

about hypoglycemia). 

Notwithstanding this presumptive disqualification, FAA 

regulations provide that, “[a]t the discretion of the Federal Air 

Surgeon,” the agency may grant a “Special Issuance” medical 

certificate to any applicant who shows an ability to safely 

perform all authorized duties “to the satisfaction of the . . . Air 
4

Surgeon.” 14 C.F.R. § 67.401(a). Pursuant to this authority, the 

Air Surgeon has awarded special-issuance third-class medical 

certificates to some insulin-treated diabetics—a practice that

has led to “no medically related accident, incident, or inflight 

incapacitation, from any cause.” Friedman I, 841 F.3d at 540. 

Although the Air Surgeon has never granted a specialissuance first- or second-class medical certificate to an insulintreated diabetic, the FAA announced in 2013 that it “hope[d]

that in the future [it] may be able to . . . safely certificate . . . a 

subset of [insulin-treated diabetics]” at the first- and secondclass level, and asked the American Diabetes Association 

(ADA) to form an expert panel “to investigate the possibility 

of identifying” such diabetics. Letter from Michael P. Huerta, 

Administrator, FAA, to Robert Ratner, Chief Scientific & 

Medical Officer, ADA (July 15, 2013), Joint Appendix (J.A) 

416. In its report, the panel recommended a protocol for 

identifying low-risk insulin-treated diabetics and concluded

that for such pilots “there is no incremental risk of permitting 

[them] to fly.” ADA, Expert Panel Recommendationsfor Pilots 

with Insulin-Treated Diabetes 6 (2015), J.A. 368. 

The FAA declined to adopt the recommended protocol,

explaining that it found the panel’s recommendations lacking 

in “evidentiary support” and neither “operationally feasible”

nor sensitive to commercial pilots’ “real-world challenges.”

Letter from James R. Fraser, Federal Air Surgeon, FAA, to 

Robert Ratner, Chief Scientific & Medical Officer, ADA (Apr.

9, 2015), J.A. 447. The FAA also believed that the panel’s 

protocol was too lax, as it would have allowed certification of 

pilots with blood-glucose levels “outside the normal glycemic 

range at least 20 percent of the time.” Id. Despite declining to 

adopt this (or any) protocol for special issuance of first- or 

second-class medical certificates to insulin-treated diabetics, 

the FAA emphasized that it did not have a “blanket ban,”
5

stating it was open to issuing certificates on an ad hoc basis.

Letter from James R. Fraser, Federal Air Surgeon, FAA, to Eric 

Friedman (Mar. 9, 2015), J.A. 361.

In April 2015, Petitioner, Eric Friedman, an insulin-treated 

diabetic who currently holds a special-issuance third-class 

medical certificate, applied to upgrade his certificate to first 

class. After receiving Friedman’s application, the FAA 

requested blood-glucose testing results either from finger-stick 

testing, which involves pricking a finger and using a 

glucometer to test extracted blood, or “if applicable,” from

CGM, a newer and less commonly used method of bloodglucose testing that measures glucose levels continuously using 

a subcutaneously inserted sensor and a small, wearable device.

Letter from James R. De Voll, Medical Appeals Manager, 

FAA, to Eric Friedman (Apr. 30, 2015), J.A. 73. 

In response, Friedman provided only finger-stick data, 

explaining that he does not use CGM. Over the next several 

months, the FAA again suggested—and later demanded—that 

Friedman provide CGM data for a minimum of 90 days, 

eventually warning that failure to do so would result in denial 

of his application. Friedman reiterated that he does not use a 

CGM device “because neither of [his] treating physicians . . .

has found . . . [the device] is clinically indicated or medically 

necessary.” Letter from Eric Friedman to James R. De Voll, 

Medical Appeals Manager, FAA (Nov. 6, 2015), J.A. 42. 

Friedman also pointed out that the ADA expert panel had 

recommended against CGM’s use due to its tendency to 

“record transient postprandial spikes in glucose levels,” which 

are “of no clinical significance.” ADA, Expert Panel 

Recommendations for Pilots with Insulin-Treated Diabetes 7

n.ii, J.A. 369. The panel itself wrote in support of Friedman’s 

application, stating that although CGM is “useful in identifying 

trends” in blood-glucose levels, it is less accurate than finger-
6

stick monitoring and thus neither necessary nor appropriate for 

medical certification decisions. Letter from Daniel Lorber, on 

behalf of ADA Expert Panel, to James Fraser, Federal Air 

Surgeon, FAA (Nov. 6, 2015), J.A. 65–66. Unconvinced, the 

FAA informed Friedman that it was “unable to proceed with”

his application “until [it] receive[d] the information previously 

requested.” Letter from James R. De Voll, Medical Appeals 

Manager, FAA, to Eric Friedman (Dec. 1, 2015), J.A. 53.

Friedman then filed a petition for review in this court, in 

which he claimed that the FAA’s denial violated the 

Administrative Procedure Act (APA), 5 U.S.C. § 706(2)(A), 

and the Pilot’s Bill of Rights, Pub. L. No. 112-153, 126 Stat. 

1159 (2012) (codified at 49 U.S.C. § 44703 note). Our court 

granted the petition, explaining that “[t]he FAA’s letters 

communicating its demand for CGM data to Friedman . . . 

fail[ed] to articulate any rationale for consideration of the 

additional information.” Friedman I, 841 F.3d at 544. 

Although, in its brief before the court, the FAA relied on the 

expert panel’s acknowledgment of CGM’s value, we found this 

argument unconvincing given the panel’s unequivocal 

opposition to the use of CGM for medical-certification 

decisions. Id. The agency, we emphasized, was unable to 

“identify any FAA statements that could be construed as 

explaining its denial of Friedman’s application.” Id. at 545.

Because the FAA had “not borne its burden of justification,”

id. at 544, we remanded for it to “offer reasons for its denial of 

Friedman’s application,” id. at 545.

Two months later, on January 27, 2017, the FAA sent

Friedman a letter “in response to the D.C. Circuit’s decision.”

Letter from Michael A. Berry, Federal Air Surgeon, FAA, to 

Eric Friedman (Jan. 27, 2017), J.A. 439 (“January 27 Letter”). 

The FAA began by explaining that although it “ha[s] not 

allowed special issuance first- or second-class medical 
7

certification for [insulin-treated diabetics],” its “goal” was to 

change that, and “[t]o that end,” it was “working to develop an 

evidence-based framework.” Id. Turning to Friedman’s 

application, the FAA acknowledged his “assertion, supported 

by [his] treating physicians, that [he] demonstrate[s] excellent 

glycemic management as evidenced by self-monitoring with a 

traditional ‘finger-stick’ recording glucometer.” Id. That said, 

the FAA went on to explain why it nonetheless demanded that 

Friedman submit CGM data in order to obtain a medical 

certificate. Because the adequacy of that explanation is central 

to this appeal, we quote it in full:

Current studies of the safety and efficacy of CGM 

devices . . . show . . . that . . . hypoglycemia remains 

common and frequently goes unrecognized by 

traditional finger-stick testing. Thus, self-monitoring 

using finger-stick testing alone is not an adequate 

mitigation strategy for operations requiring a first- or 

second-class medical certificate.

Because it is impossible to know the true extent 

of glycemic variability through self-monitoring with 

traditional “finger-stick” tests, we have determined 

that a fixed period (90 days) of CGM is necessary in 

order to consider your eligibility for an Authorization 

for special issuance of a first-class medical certificate. 

The CGM data that we have requested will be 

reviewed for evidence of glycemic control and 

stability, as well as to evaluate the potential use of 

CGM as risk mitigation during operations requiring a 

first- or second-class medical certificate.

Id., J.A. 439–40. Since Friedman had “not provided the 

requested CGM report and related data,” the FAA concluded, 
8

it was “unable to consider [him] for a special issuance firstclass medical certificate.” Id., J.A. 440.

In this petition for review, Friedman argues that the FAA

“still fails to articulate a defensible rationale for denying [his] 

application.” Pet’r’s Br. 2. Again arguing that the FAA has 

violated both the APA and the Pilot’s Bill of Rights, Friedman

urges us to “remand for the FAA to (finally) grant [him] a firstclass medical certificate.” Id. at 3. The ADA has filed an 

amicus brief in support of Friedman.

II.

At the outset, we emphasize the narrowness of the issue 

before us. Because the FAA sent its January 27 letter in 

response to this court’s remand, the only question we must 

answer is whether it has “fill[ed] the analytical gap identified 

in [our] opinion.” Heartland Regional Medical Center v. 

Leavitt, 415 F.3d 24, 29 (D.C. Cir. 2005). Here, that gap is the 

FAA’s failure to “offer reasons for its denial of Friedman’s 

application.” Friedman I, 841 F.3d at 545. In determining 

whether the FAA has satisfactorily provided such reasons, we 

are guided by well-settled principles of administrative law. We 

look to see whether the agency has “examine[d] the relevant 

data and articulate[d] a satisfactory explanation for its action,”

which may not neglect any “important aspect of the problem,”

“run[] counter to the evidence,” or be “so implausible that it 

could not be ascribed to a difference in view or the product of 

agency expertise.” Motor Vehicle Manufacturers Ass’n of the 

United States, Inc. v. State Farm Mutual Automobile Insurance

Co., 463 U.S. 29, 43 (1983). Although we will not, as in 

Friedman I, “supply a reasoned basis for the agency’s action 

that the agency itself has not given,” id. at 43 (citing SEC v. 

Chenery Corp., 332 U.S. 194, 196 (1947)), we may—central to 

this petition—“‘uphold a decision of less than ideal clarity if 

the agency’s path may reasonably be discerned,’” id. (quoting 
9

Bowman Transportation, Inc. v. Arkansas-Best Freight System, 

Inc., 419 U.S. 281, 286 (1974)).

Friedman insists that the explanation the FAA provided in 

its January 27 letter is “no better” than that considered in 

Friedman I. Pet’r’s Br. 28. This is inaccurate. In Friedman I, 

the FAA had simply demanded, without explanation, that 

Friedman submit CGM data. Not until its brief before this court

did the FAA provide a reason, namely that the ADA panel had

acknowledged CGM’s value. But as we pointed out, the FAA

“overstate[d] the usefulness of this concession,” given the 

panel’s conclusion that CGM was inappropriate for this 

purpose. Friedman I, 841 F.3d at 544. The agency, in other 

words, “[did] not identify any FAA statements that could be 

construed as explaining its denial of Friedman’s application.” 

Id. at 545. 

By contrast, in its January 27 letter, the FAA provided its 

own, unequivocal medical explanation for requiring CGM

data: that such data is needed to detect hypoglycemic episodes 

that could well be missed by traditional finger-stick 

monitoring. “Current studies of the safety and efficacy of CGM 

devices,” the FAA explained, show that “hypoglycemia 

remains common and frequently goes unrecognized by 

traditional finger-stick testing.” January 27 Letter, J.A. 439–

40. As a result, “self-monitoring using finger-stick testing 

alone is not an adequate mitigation strategy for operations 

requiring a first- or second-class medical certificate.” Id., J.A. 

440. The FAA thus concluded that “CGM is necessary in order 

to consider [Friedman’s] eligibility for” a special-issuance

first-class medical certificate. Id.

This explanation, moreover, finds support in the 

administrative record. In contrast to Friedman I, where there 

was a “complete absence of a relevant administrative record to 
10

review,” Friedman I, 841 F.3d at 545, the administrative record

now before us includes “[c]urrent studies” finding that because 

finger-stick monitoring involves only static measurements, it 

often fails to detect hypoglycemic episodes occurring between 

tests, see, e.g., Bruce W. Bode et al., Glycemic Characteristics 

in Continuously Monitored Patients with Type 1 and Type 2 

Diabetes, 28 Diabetes Care 2361, 2361 (2005), J.A. 680 

(“Regardless of how often fingerstick blood glucose 

measurements are undertaken, discrete results offer only a 

static picture at any point and do not provide a sense of the 

number, intensity, and duration of glycemic excursions.”); 

Alberto Maran et al., Continuous Subcutaneous Glucose 

Monitoring in Diabetic Patients: A Multicenter Analysis, 25 

Diabetes Care 347, 347–352 (2002), J.A. 686–91 (noting that 

“glucose fluctuations during the day are often missed with”

finger-stick testing, id. at 347, J.A. 686, and concluding that a 

CGM device, tested on 70 diabetic patients, was accurate and 

well-tolerated); see also Timothy S. Bailey et al., American 

Association of Clinical Endocrinologists and American 

College of Endocrinology 2016 Outpatient Glucose 

Monitoring Consensus Statement, 22 Endocrine Practice 231, 

232 (2016), J.A. 645 (“[P]atients’ [finger-stick] monitoring 

may be infrequent or intermittent, their reports may be 

inaccurate, and overnight glucose levels are seldom measured. 

Given these limitations, episodes of hypo- and hyperglycemia 

may be missed . . . .”). CGM, on the other hand, “provides a 

much more rigorous measure of glycemic variability and 

glycemic exposure.” Lisa Gilliam & Irl B. Hirsch, Practical 

Aspects of Real-Time Continuous Glucose Monitoring, 11 

Diabetes Tech. & Therapeutics S-75, S-76 (2009), J.A. 721. 

Friedman argues that CGM is an “inappropriate” source of 

data because it records clinically insignificant spikes in blood 

glucose and tends to lag behind and differ from finger-stick 

values. Pet’r’s Br. 22; see also id. at 9–10. He fails, however, 
11

to explain how these limitations, acknowledged by the FAA, 

undermine the agency’s intended use of CGM data: to 

“augment” the finger-stick data that Friedman has already 

provided “to confirm his assertion that he can recognize and 

appropriately respond to hypoglycemic episodes.” Resp’t’s Br. 

31–32; see also January 27 Letter, J.A. 440 (“[S]elf-monitoring

using finger-stick testing alone is not an adequate mitigation 

strategy.” (emphasis added)).

Next, pointing out that “none [of the studies] addresses the 

medical evaluation of pilots with [insulin-treated diabetes],”

Pet’r’s Br. 22, Friedman maintains that the only word on the 

subject is that of the expert panel, which, he insists, was surely 

aware of the studies the FAA cites, yet concluded that “CGM 

data is unnecessary,” id. The FAA, however, was not bound by 

the expert panel’s assessment: “When specialists express 

conflicting views, an agency must have discretion to rely on the 

reasonable opinions of its own qualified experts.” Marsh v. 

Oregon Natural Resources Council, 490 U.S. 360, 378 (1989).

Moreover, the FAA did not, as Friedman asserts, ignore the 

expert panel. Quite to the contrary, it reviewed the panel’s 

recommendations and explained that it “require[d] more 

evidentiary support” than the panel had provided, January 27 

Letter, J.A. 440, given that the panel “did not ground its 

recommendations in any evidence-based medical literature,” 

Resp’t’s Br. 39. 

Finally, Friedman claims that there is no reason to believe 

that the FAA relied on the studies it cites, as it “did not identify 

any medical studies in its terse January 2017 Letter.” Pet’r’s 

Reply Br. 14. From our perspective, it certainly would have 

been helpful for the FAA to have elaborated on its generic 

reference to “current studies.” But aided by the FAA’s brief, 

which cites and explains the relevant studies, we can “discern”

the basis for its decision. BellSouth Corp. v. FCC, 162 F.3d 
12

1215, 1224 (D.C. Cir. 1999); see id. (“‘[T]he agency is not 

required to author an essay for the disposition of each 

application. It suffices, in the usual case, that we can discern 

the why and wherefore.’” (quoting ICBC Corp. v. FCC, 716 

F.2d 926, 929 (D.C. Cir. 1983))). Specifically, in response to 

our remand, the FAA “offer[ed] reasons for its denial of 

Friedman’s application.” Friedman I, 841 F.3d at 545. Put 

another way, it can no longer be said that the agency has “not 

identif[ied] any FAA statements” explaining why it needs 

CGM data. Id. (emphasis omitted). Equally important, the FAA 

offered its explanation in accordance with APA standards: it

“examine[d] the relevant data”—the medical studies and 

Friedman’s medical record—“and articulate[d] a satisfactory 

explanation for its action”—that CGM data is necessary to 

detect hypoglycemic events that finger-stick monitoring

misses. State Farm, 463 U.S. at 43. Friedman, moreover, has 

given us no basis for believing that the FAA either neglected 

an “important aspect of the problem,” or that its position is “so 

implausible that it could not be ascribed to a difference in view 

or the product of agency expertise.” Id.

We can easily dispose of Friedman’s claims under the

Pilot’s Bill of Rights. That statute provides, in part, that the 

“[g]oals of the [FAA]’s medical certification process are . . . to 

give medical standards greater meaning by ensuring the 

information requested aligns with present-day medical 

judgment and practices” and “to ensure that . . . the application 

of such medical standards provides an appropriate and fair 

evaluation of an individual’s qualifications.” Pilot’s Bill of 

Rights, Pub. L. No. 112-153, § 4(b), 126 Stat. 1159, 1163

(codified at 49 U.S.C. § 44703 note). According to Friedman, 

this provision requires the FAA to “align[]” its requests with 

“present-day medical judgment” and “provide[] an appropriate 

and fair evaluation.” See Pet’r’s Br. 5 (internal quotation marks 

omitted); see also id. at 21–22. That, of course, is precisely
13

what the FAA—asrequired both by our remand and the APA—

has now done, and we think it quite obvious that the Pilot’s Bill 

of Rights’ aspirational, goal-setting language creates no 

additional obligations. Cf. Rothe Development, Inc. v. United 

States Department of Defense, 836 F.3d 57, 65 (D.C. Cir. 2016) 

(describing a statute’s “goal[s]” as “aspirational”). 

III. 

For the foregoing reasons, we deny the petition for review.

In doing so, we have taken the FAA at its word: that it is 

“working to develop an evidence-based framework” to allow 

special issuance of first- and second-class medical certificates 

to certain insulin-treated diabetics, January 27 Letter, J.A. 439, 

and that “should Mr. Friedman’s CGM data corroborate his 

assertion” that he “does not pose a risk while he is in the 

cockpit,” he will receive a certificate, Oral Argument 31:55–

33:15, 38:32–40.

So ordered.