United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued December 13, 2021 Decided May 10, 2022 

No. 21-1062 

YDIL W. PHAM, 

PETITIONER

v. 

NATIONAL TRANSPORTATION SAFETY BOARD AND FEDERAL 

AVIATION ADMINISTRATION, 

RESPONDENTS

Consolidated with No. 21-1083 

On Petitions for Review of a Decision 

of the National Transportation Safety Board 

Alan Armstrong argued the cause and filed the briefs for 

petitioner/cross-respondent. 

Joshua M. Koppel, Attorney, U.S. Department of Justice, 

argued the cause for respondents/cross-petitioners. With him 

on the briefs were Brian M. Boynton, Acting Assistant 

Attorney General, Abby C. Wright, Attorney, Cynthia A. 

Dominik, Assistant Chief Counsel for Enforcement, Federal 
2 

Aviation Administration, and Agnes M. Rodriguez and Casey 

Gardner, Attorneys. 

Before: SRINIVASAN, Chief Judge, ROGERS and JACKSON*

, 

Circuit Judges. 

Opinion for the Court by Circuit Judge ROGERS. 

ROGERS, Circuit Judge: Ydil Pham and the Federal 

Aviation Administration both petition for review of the 

National Transportation Safety Board’s suspension of Pham’s 

pilot and medical certificates for 180 days. Pham contends that 

the Board erred in concluding that he refused a drug test when 

he left the test center before providing the requisite amount of 

urine because (1) he was not told he could drink water (a “shybladder” warning), as required by regulation, (2) he was given 

permission to leave, and (3) his urine sample was unlawfully 

discarded. He also contends that the Board impermissibly 

applied a strict-liability standard. The FAA objects by crosspetition to the Board’s decision to suspend rather than revoke 

Pham’s certificates as the FAA ordered, contending that (1) the 

Board is obligated to defer to the FAA’s guidance and 

interpretations of its regulations, (2) those regulations require 

revocation of medical certificates for at least 2 years after a 

refusal to test, and (3) the Board deviated from its precedent 

without explanation. For the following reasons, the court 

denies Pham’s petition and grants the FAA’s cross-petition. 

I. 

The FAA is authorized to issue “airman certificates,” 

which permit individuals to engage in a range of activities 

related to aviation. 49 U.S.C. §§ 44702(a), 40102(a)(8), 

*

 Circuit Judge Jackson was a member of the panel at the time the 

case was argued but did not participate in this opinion. 
3 

44711(a). Pursuant to this authority, it issues six types of pilot 

certificates. 14 C.F.R. § 61.5(a). Among other requirements, 

pilots must be “physically able” to perform their duties, 49 

U.S.C. § 44703(a), and must obtain a “medical certificate” 

certifying their physical fitness to pilot planes as measured 

against specific criteria, see 14 C.F.R. § 61.23 and pt. 67. 

The FAA is also required to establish a program for 

“preemployment, reasonable suspicion, random, and postaccident testing of airmen . . . for use of a controlled 

substance.” 49 U.S.C. § 45102. FAA regulations require that 

each test subject provide at least 45 milliliters of urine for a 

drug test. 49 C.F.R. § 40.65(a). If the test subject fails to do 

so, the collector must follow “shy-bladder” procedures, under 

which the collector must discard the specimen and “[u]rge the 

[subject] to drink up to 40 ounces of fluid.” Id. § 40.193(b). If 

the subject leaves the test center before the collection is 

completed, the departure is deemed a refusal to test. Id.

§ 40.191(a)(2). 

Further, the FAA may revoke certificates if it “decides . . . 

that safety in air commerce or air transportation and the public 

interest require that action.” 49 U.S.C. § 44709(b)(1)(A). 

“Refusal . . . to take a [required] drug or alcohol test . . . is 

grounds for . . . [s]uspension or revocation” of a pilot 

certificate, 14 C.F.R. § 120.11, and disqualifies the pilot from 

holding any of the three classes of medical certificate for two 

years from the refusal to test, id. §§ 67.107(b)(2), 67.207(b)(2), 

67.307(b)(2). Adversely affected individuals may appeal an 

FAA order to the National Transportation Safety Board 

(hereinafter, the “Board”). 49 U.S.C. § 44709(d). 
4 

II. 

In August 2020, Pham, an experienced airline pilot, 

interviewed for a job with Private Jets. As a condition of 

employment, he was required to take a pre-employment drug 

test. Upon arrival at the test center, the test collector, Lois 

West, explained the testing procedures, including that he would 

need to produce a urine sample. Pham began the testing 

procedures but did not provide the required 45-milliliter urine 

sample, see 49 C.F.R. § 40.65(a), and left the test center. West 

reported Pham’s refusal to test to Private Jets’ drug testing 

manager, Cindy Boone, who, pursuant to FAA guidance, see

FAA Drug and Alcohol Compliance Enforcement Inspector 

Handbook, FAA Order 9120.1D, at 43 (Aug. 9, 2018), notified 

the FAA that Pham had refused a drug test. 

On November 5, 2020, the FAA issued an emergency 

order revoking Pham’s airline transport pilot certificate and his 

airman medical certificates. Emergency Order of Revocation, 

FAA Case No. 2020 WA 910339 (Nov. 5, 2020) (hereinafter, 

the “Revocation Order”). The Revocation Order stated that 

Pham’s failure to remain at the test center until the collection 

process was completed constituted, pursuant to 49 C.F.R. 

§ 40.191(a)(2), a refusal to submit to a required drug test, 

Revocation Order at 2, and that Pham, therefore, “lack[ed] the 

qualifications necessary to hold [an airline transport pilot 

certificate] and any class of airman medical certificate,” id. at 

3. The revocations were made effective immediately, id. at 3, 

because Pham’s “refusal to submit to FAA-required drug 

testing demonstrates that [he] . . . lack[s] the degree of care, 

judgment, and responsibility required of the holder of a pilot 

certificate and any class of airman medical certificate,” id. at 4. 

Pham appealed to the Board. 
5 

Before an administrative law judge (“ALJ”) for the Board, 

West testified that Pham had provided an insufficient urine 

sample and had told her that he was unable to stay at the test 

center any longer. See NTSB Hearing Tr. (Nov. 23–24, 2020) 

at 19–20. West also testified that she informed Pham that 

leaving before the test collection process was completed would 

be considered a refusal to take a test. Id. at 20. West denied 

giving Pham permission to leave the test center and testified 

that she had told Pham that “he would have to get a whole new 

form from [his] job” after leaving because, once she indicated 

a refusal on his testing form, she could not use that form again. 

Id. at 21. Although West could not recall whether she informed 

Pham about the shy-bladder procedure, she noted that she was 

trained to do so. Id. at 20, 39. West further testified that after 

Pham left, she contacted Boone to notify her of Pham’s failure 

to complete the test. Id. at 33–34. Boone’s testimony 

confirmed that West told her that Pham left the test center 

before completing his drug test, although West had warned him 

that leaving would be considered a refusal. Id. at 61. Boone 

reported Pham to the FAA, she explained, because she is 

required to report any refusal of a drug test. Id. at 62–63. 

Pham admitted in his testimony that the urine sample he 

produced was deemed insufficient, id. at 111, and claimed that 

when he asked West if he could go to lunch and come back to 

finish the test, she granted him permission to do so, stating that 

Private Jets could send a new application if Pham returned, id.

at 112. Pham testified that West neither gave him shy-bladder 

instructions nor told him that leaving the test center would be 

deemed a refusal, claiming that he would not have left the 

center had he been so informed. Id. at 113–14. 

The ALJ found that West’s testimony was “very credible 

as to advising [Pham] that” leaving the test center before 

completing the testing process “was a refusal,” id. at 158, 
6 

noting that her testimony was corroborated by paperwork she 

had filled out the day the test began, id. at 157, Exh. A-2. By 

contrast, the ALJ found Pham’s testimony was unpersuasive, 

because as an air transport pilot, Pham was held to a “higher 

standard” and should have known the relevant regulations. Id.

at 158. The ALJ specifically found that Pham (1) had provided 

a urine sample that was “insufficient” in volume; (2) “was 

advised that [leaving the test center] constituted a refusal”; and 

(3) “was advised that, if he left, he would have to have another 

confirmation form when he returned.” Id. at 159. Therefore, 

the ALJ concluded that the FAA had proven a violation of its 

drug-testing regulations and affirmed the FAA’s revocation of 

Pham’s certificates. Id. at 159–61. 

 

Pham appealed the ALJ’s initial decision to the Board. 

The Board deferred to the ALJ’s credibility determinations, 

Opinion and Order, NTSB Order No. EA-5889, at 17–21 (Jan. 

4, 2021) (hereinafter, the “NTSB Order”), and affirmed the 

ALJ’s determination that Pham had refused a drug test, id. at 

21–25. In response to Pham’s argument that he did not receive 

a shy-bladder warning as 49 C.F.R. § 40.193(b) required, the 

Board observed that “West explained the most important part: 

leaving before providing an adequate sample constitutes a 

refusal.” Id. at 25. The Board also rejected Pham’s argument 

that the ALJ had improperly applied a strict-liability standard, 

finding that the ALJ “considered the witnesses’ testimonies, 

assessed the witnesses’ credibility, reviewed the exhibits, and 

weighed the parties’ arguments.” Id. at 28. Further, it rejected 

Pham’s argument that discarding his sample constituted 

spoliation of evidence, inasmuch as Pham was sanctioned 

because he left the test center, not because his sample tested 

positive. Id. at 29. The Board sua sponte reviewed the FAA’s 

revocation sanction and reduced it to a 180-day suspension, 

identifying two “mitigating factors.” Id. at 31–32. First, there 

was no clear evidence that Pham was informed he could drink 
7 

water to produce another sample. Id. at 31. Second, Pham 

could have been confused by West’s statement that he would 

need a new form if he returned, because Pham may have 

interpreted that as a suggestion that a new test was possible. Id.

at 32. 

 

 Pham petitioned for review, and the FAA filed a crosspetition for review. 

III. 

The court must uphold the Board’s decision “unless it is 

‘arbitrary, capricious, an abuse of discretion, or otherwise not 

in accordance with law,’ or ‘unsupported by substantial 

evidence.’” Huerta v. Ducote, 792 F.3d 144, 153 (D.C. Cir. 

2013) (quoting 5 U.S.C. § 706(2)(A), (E)) (internal citations 

omitted). This court will “‘defer to the wisdom of the agency, 

provided its decision is reasoned and rational . . . .’” Dillmon 

v. NTSB, 588 F.3d 1085, 1089 (D.C. Cir. 2009) (quoting 

Chritton v. NTSB, 888 F.2d 854, 856 (D.C. Cir. 1989)). 

A. 

Pham principally contends that the Board lacked 

substantial evidence to conclude that he refused a drug test 

because he was not given a shy-bladder warning and was 

allegedly given permission to leave. He also contends that the 

sample collector “spoliated” evidence, Pham Br. 41, and that 

the Board applied a strict-liability standard, both of which 

violated his constitutional rights. None of these challenges is 

persuasive. 

Substantial evidence “is such relevant evidence as a 

reasonable mind might accept as adequate to support a 

conclusion.” Chritton, 888 F.2d at 856 (internal citation and 
8 

quotation marks omitted). The court must accept all 

“reasonable credibility determinations” made by the ALJ and 

approved by the Board. Dickson v. NTSB, 639 F.3d 539, 542 

(D.C. Cir. 2011) (internal citation and quotation marks 

omitted). Here, the ALJ evaluated the entire record as well as 

various inconsistencies in testimony. The ALJ reasonably 

found that West was more credible than Pham and concluded 

that, in violation of 49 C.F.R. § 40.191(a)(2), Pham had refused 

a drug test by failing to remain at the test center until the testing 

process was complete. NTSB Hearing Tr. (Nov. 23–24, 2020) 

at 156–61. The Board stated that it deferred to the ALJ’s 

credibility findings and agreed that Pham had refused a drug 

test. See NTSB Order at 1–2, 21. In addition to West’s 

testimony, other evidence adequately supports this finding. For 

example, the Custody and Control Form stated that Pham 

refused a drug test, id. at Exh. A-2, and West testified that the 

form reflected her recollection of events, id. at 28–29. Private 

Jets’ drug testing manager, Cindy Boone, testified about her 

telephone call with West as reflected in Boone’s email to the 

FAA. Id. at 61, 64, Exh. R-6. And Pham admitted that he left 

the test center without providing a sufficient urine sample. Id.

at 117–18. 

Undeterred, Pham contends that the Board had no factual 

basis for its refusal finding because he did not receive the shybladder instructions required by 49 C.F.R. § 40.193(b)(2). The 

Board acknowledged that the record was unclear but found that 

the test collector “explained the most important part: leaving 

before providing an adequate sample constitutes a refusal.” 

NTSB Order at 25. The Board reasonably concluded that 

because the sanction was premised on Pham leaving the test 

center before completing the testing process, see NTSB 

Hearing Tr. (Nov. 23–24, 2020) at 159–60 (citing 

49 C.F.R. § 40.191(a)(2)), the collector’s failure to mention 

shy-bladder procedures was “not fatal to the [ALJ’s] 
9 

determination” that Pham had refused a drug test, NTSB Order 

at 24. As to Pham’s testimony that the test collector gave him 

permission to leave when she said he would need a new form 

to return, the Board acknowledged that this statement might 

confuse a “reasonable person” by suggesting that a “new test 

was possible.” Id. at 25. But that confusion did not alter the 

fact that Pham was “notified [] that if he left the facility, it 

would be a refusal,” id. at 22–23, yet still “left the testing 

facility without providing an adequate specimen and[,] 

therefore, violated the applicable regulation,” id. at 25. And 

contrary to Pham’s contention, there is no inconsistency 

between the ALJ’s finding that Pham was advised that his 

leaving the facility would constitute a refusal to test and the 

finding that Pham was advised he would need a new 

confirmation form if he returned: the need for a new 

confirmation form for a future test is fully consistent with 

treating a departure from the facility as a refusal to complete 

the current test. 

Pham contends that the claims against him should have 

been dismissed because the test collector disposed of his 

sample in violation of 49 C.F.R. § 821.19(c), and that although 

49 C.F.R. § 40.193(b)(1) requires disposal of insufficient 

specimens, the provision is unconstitutional because it destroys 

exonerating evidence in violation of the Due Process Clause of 

the Fifth Amendment. The Board reasonably concluded there 

was no violation of 49 C.F.R. § 821.19(c); the regulation 

prohibits disposal of specimens only when a judge orders 

production of the specimen or there is a timely request to 

preserve the sample, neither of which occurred here. NTSB 

Order at 29. Pham’s constitutional objection is meritless; the 

urine sample could not have been exculpatory because the issue 

is not whether the sample was positive but whether Pham 

refused a test by leaving the test center before the process was 
10 

complete. Id. In any event, Pham cites no precedent holding 

that disposal of an insufficient sample is unconstitutional. 

Nor, contrary to Pham’s view, did the Board apply a strictliability rule in violation of its own precedent and the Due 

Process Clause. Rather, the Board noted that the ALJ 

“considered the witnesses’ testimonies, assessed the witnesses’ 

credibility, reviewed the exhibits, and weighed the parties’ 

arguments,” id. at 28, and relied on evidence that Pham was 

warned that leaving the test center before providing an 

adequate sample would constitute a refusal to test, id. at 25. 

The court therefore denies Pham’s petition for review. 

B.

In its cross-petition, the FAA contends that the Board 

acted contrary to law by reducing Pham’s sanction from 

revocation of his certificates to a 180-day suspension. In 

particular, the Board is required to defer to the FAA’s sanction 

determination if it is reasonable, but the Board did not exercise 

deference. Further, the FAA contends that the Board acted 

contrary to law by suspending Pham’s medical certificates for 

180 days because FAA regulations make Pham ineligible to 

hold such certificates for two years. The FAA contends that 

the Board’s choice of sanction was also arbitrary and 

capricious because it deviated from Board precedent. 

1. 

The Federal Aviation Act, 49 U.S.C. §§ 40101 et seq., 

creates a “‘split-enforcement’” regime in which the FAA has 

regulatory and enforcement authority, and the Board has 

adjudicatory authority. Garvey v. NTSB, 190 F.3d 571, 573 

(D.C. Cir. 1999) (quoting Hinton v. NTSB, 57 F.3d 1144, 1147 

n.1 (D.C. Cir. 1995)). In Martin v. Occupational Safety & 
11 

Health Review Commission, 499 U.S. 144 (1991), the Supreme 

Court held that the agency with adjudicative power in a splitenforcement regime would play a role similar to a “court in the 

agency-review context” and review the rulemaking agency’s 

interpretations of its rules “only for consistency with the 

regulatory language and for reasonableness.” Id. at 154–55. 

This court has similarly held that the Board and the court “must 

defer to the FAA’s interpretations of its own aviation 

regulations.” Garvey, 190 F.3d at 577 (citing Martin, 499 U.S. 

at 147, 150–57). FAA guidance provides that revocation is an 

appropriate sanction for refusal to test. U.S. Department of 

Transportation, FAA Order 2150.3C, at 9-14, Fig. 9-5(11) 

(Sept. 18, 2018). So, the FAA contends that the Board 

improperly “substituted its own judgment for the [FAA’s]” in 

adjusting the sanction, exceeding its role in the splitenforcement regime. FAA Br. 38. 

Pham’s case, however, differs from Martin to the extent 

the FAA seeks deference to its application of a policy statement 

that guides its enforcement discretion rather than an 

interpretation of its rule as in Martin, 499 U.S. at 148–49. 

Further, the rulemaking agency’s interpretation in Martin was 

issued as part of a formal citation against an employer. Id. at 

157. “[L]ess formal means of interpreting regulations,” such 

as “enforcement guidelines,” are “entitled to some weight on 

judicial review” but “not entitled to the same deference” as a 

formal citation. Id. As such, the approach in Martin instructs 

deference to FAA’s enforcement guidelines and sanction 

determination but does not specify the level of deference the 

Board owes. Still, the Supreme Court has held that courts 

should overturn an agency’s choice of remedy only if it “is 

unwarranted in law or is without justification in fact.” 

American Power & Light Co. v. SEC, 329 U.S. 90, 112–13 

(1946). Because the Board essentially acts as a court in the 

split-enforcement regime with the FAA, Martin, 499 U.S. at 
12 

154, this standard guides the court’s review of the Board’s 

sanction decision. 

Although the Board states it deferred to the FAA’s choice 

of sanction, see NTSB Order at 31, and lists two mitigating 

factors that may cast doubt on the FAA’s sanction, id. at 31–

32, it adjusted the sanction without finding that the sanction is 

unwarranted in law or without justification in fact. 14 C.F.R. 

§ 120.11 provides that a refusal to test is grounds for 

“revocation of any [airman] certificate,” and 14 C.F.R. 

§§ 67.107(b)(2), 67.207(b)(2), 67.307(b)(2) provide that a 

refusal to test in the prior two years disqualifies a pilot from 

holding medical certificates. The FAA’s sanction had 

justification in fact, as the FAA found that Pham had been 

warned that leaving the test center before providing a sufficient 

urine specimen would be considered a refusal to test but he left 

anyway. Revocation Order at 2. The FAA concluded this 

demonstrated that Pham lacked “the degree of care, judgment, 

and responsibility required of a certificate holder.” Id. at 4. 

“Air safety depends on the willingness of certificate holders . . . 

[to submit] to drug tests,” and Pham’s refusal “betray[ed] the 

public trust.” Id. Pursuant to 49 U.S.C. § 44709(b)(1), the 

FAA can revoke certificates upon determining that “safety in 

air commerce or air transportation and the public interest” 

require revocation. 

The Board failed, however, to acknowledge the FAA’s 

policy rationale for revoking Pham’s license or to explain why 

those reasons were inapplicable or unjustified in Pham’s case. 

Pham’s reliance on the 2012 Pilot’s Bill of Rights, which 

removed a statutory provision requiring the Board to defer to 

the FAA’s interpretations of sanction guidance, Pub. L. 112-

153, § 2(c)(2), 126 Stat. 1159, 1161 (2012) (amending 49 

U.S.C. § 44709(d)(3)), does not advance his challenge to the 

FAA’s cross-petition. Removing a provision that provided for 
13 

deference is not the equivalent of enacting a contrary provision 

disallowing deference, and Pham identifies no reason the court 

should read the removal of the provision in this situation as an 

attempt to preclude deference by the Board. In fact, there is at 

least some indication in the legislative history that the 

provision was removed only because it was deemed 

superfluous in light of Martin. See 158 Cong. Rec. S4733 

(daily ed. June 29, 2012) (statement of Sen. Rockefeller and 

concurrence of Sen. Inhofe); id. at H5102 (daily ed. July 23, 

2012) (statement of Rep. Bucshon). 

Pham’s position that FAA Order 2150.3C is invalid 

because it is a legislative rule promulgated without notice and 

comment and the FAA’s “enforcement practice [is] to always 

seek a revocation,” Pham Reply Br. 37, misrepresents FAA 

Order 2150.3C, which provides that refusal to test “generally,” 

but not categorically, warrants revocation, FAA Order 2150.3C 

at 9-13, 9-14. This is a classic example of a policy statement 

that does not require notice and comment. 5 U.S.C. § 553(b); 

see Syncor Int’l Corp. v. Shalala, 127 F.3d 90, 93–94 (D.C. 

Cir. 1997). 

Because the Board’s decision did not accord appropriate 

deference, its modification of the FAA’s sanction, on the 

reasoning it offered, was contrary to law. 

2. 

The FAA’s challenge to the Board’s suspension of Pham’s 

medical certificates is persuasive. FAA regulations provide 

that an airman who has refused a drug test in the preceding two 

years is automatically ineligible to hold a medical certificate. 

14 C.F.R. §§ 67.107(b)(2), 67.207(b)(2), 67.307(b)(2); see also

id. §§ 67.101, 67.201, 67.301. Because the Board lacks the 

authority to invalidate FAA regulations, see Adm’r v. Ewing, 1 
14 

N.T.S.B. 1192, 1194 (1971); see also Garvey v. Kraley, NTSB 

Order No. EA-4581, 1996 WL 785071, at *1 n.3 (Aug. 18, 

1997) (citing Ewing, 1 N.T.S.B. at 1194), it was required to 

apply the FAA’s medical certificate eligibility requirements. 

The Board’s Order is contrary to law insofar as it allows Pham 

to hold medical certificates between 180 days and 2 years after 

he refused a drug test. 

 The court need not address whether the Board’s decision 

to adjust the sanction deviated from Board precedent, because 

the court is instructing the Board on remand to manifest proper 

deference to the FAA’s sanction choice and review it only for 

justification in law and fact. The Board’s role in the splitenforcement regime may require it to deviate from its own 

precedent if the FAA has taken a different but reasonable 

position. “[C]onsistency with the FAA’s position is more 

important than consistency with the Board’s own.” Garvey, 

190 F.3d at 584. 

Accordingly, the court denies Pham’s petition for review, 

grants the FAA’s cross-petition for review, and vacates the 

Board’s Order in part. The court remands this matter to the 

Board for further proceedings consistent with this opinion.