Imagine you’re one of the many American workers subject to random tests for the presence of drugs or alcohol in your system, and a test turns up high levels of heroin and cocaine. If you contend that the lab must have mixed up your urine sample with someone else’s should you be able to demand a DNA test to prove your innocence? If you’re a pilot, the answer is no.

Federal law mandates random drug and alcohol screening for pilots and certain other airline and airport employees. And federal regulations spell out just about every step of the procedure for these testing programs, and what happens to samples after they’ve been tested.

However, a now-former pilot for Spirit Airlines claims that something must have broken down in this rigid system and, just like all the hopeful non-fathers on Maury, he needs a DNA test to prove his innocence.

In 2007, after landing at the airport in Ft. Lauderdale, FL, the pilot was selected for a random drug test. He provided his urine, signed off that “each specimen bottle used was sealed with a tamper-evident seal in my presence; and that the information provided on this form and on the label affixed to each specimen bottle is correct.”

The sample was then sent to Quest Diagnostics, a third-party testing firm that subsequently notified Spirit the pilot’s sample tested positive for high levels of morphine and metabolites of heroin and cocaine.

Following a protest from the pilot, a second lab — Diagnostic Sciences, Inc. — tested the sample and came up with the same positive (for drugs; not for the pilot) results, leading the FAA to issue an emergency order revoking his license and certifications.

The pilot appealed this decision to the National Transportation Safety Board, where an administrative law judge presided over a two-day hearing on the matter.

In spite of the pilot’s protestations that he did not use any drugs and that his samples must have been mishandled, the judge found in 2008 that there was “no reason to doubt” the validity of the two tests of his urine. Both the full board of the NTSB and the 11th Circuit Court of Appeals subsequently affirmed the administrative law judge’s decision, holding that “it was not arbitrary and capricious for the Board to conclude that the FAA had made a prima facie showing,” and that the pilot had failed to rebut that case.

The pilot, still maintaining he’d done nothing wrong, eventually filed a lawsuit against Concentra, the company responsible for actually gathering the urine sample. As part of that case, he tried to compel Quest to provide some of his original urine sample for further testing.

Quest objected and was eventually successful in quashing the court order to turn over the sample, with the court agreeing that federal regulations prohibit Quest and other labs from turning over samples without approval from the Dept. of Transportation.

So in 2014, the pilot’s attorney filed formal requests with the DOT seeking approval to have the sample released by Quest.

Problem is, one of those many federal regulations on drug testing procedures explicitly states that a testing laboratory is “prohibited from making a DOT urine specimen available for a DNA test.”

Since the pilot was specifically looking to test this sample for DNA, lawyers for the DOT denied his request.

And so the pilot appealed to the D.C. Circuit Court of Appeals, arguing that the DOT’s reasoning for the refusal is “arbitrary and capricious,” that the DOT was misreading its own rules, that the anti-DNA testing rules are inconsistent with the law that established the testing program, and that his constitutional rights are being violated by being denied access to his own urine sample.

The appeals panel response? In short: “None of these arguments is persuasive.”

In an opinion [PDF] released earlier today, the court found that there was no ambiguity about the regulation preventing the release of samples for the purpose of DNA testing.

Yes, there is a later requirement in the regulations mandating that labs must keep samples on hand for the purpose of “preserving evidence for litigation,” but the court said this rule says nothing about the actual conditions for release.

Moreover, the court concluded that the pilot could not demonstrate that the “no DNA testing” rule is “irrational or inconsistent” with existing law.

First, concluded the court, the strict chain of custody for these samples renders the likelihood of a mixup “very unlikely.”

Second, even if a DNA test were to prove that the urine in the sample does not belong to the pilot, it doesn’t prove when or where the mix-up occurred.

And because of the previously mentioned strict chain of custody involved, the court concluded that the presence of a third party’s DNA would only indicate that “a guilty employee was trying to defeat the test,” presumably by using someone else’s urine.

“[T]he DoT quite reasonably – in view of the risk to airline safety – wants to avoid reinstating a pilot’s license on the basis of a DNA mismatch,” wrote the court.

The pilot had argued that it would be downright silly and stupid for him to have substituted a drug-user’s urine for his own if he was trying to fool a drug test. Again, the court was not swayed, agreeing with the DOT that “one might substitute a tainted sample unwittingly, believing the source was clean.”

Finally, the pilot argued that DNA technology has become more accurate in the 16 years since the DOT first explained its rationale against allowing DNA tests of samples. The court countered that accuracy was never the issue for the DOT: “rather, the Department is concerned that a mismatch could not rule out manipulation by substitution.”

Given that pilots have ample other methods to appeal and argue their case for a false-positive, the appeals court found no reason to set aside the DNA testing rule.

As for the pilot’s claim that his constitutional right to due process was being violated by not having access to the sample, the court concluded that “He offers no legal support for his position that the Constitution entitles him to such discovery,” pointing to a 2009 Supreme Court ruling , in which SCOTUS denied a prisoner’s petition to obtain postconviction access to the State’s evidence for DNA testing.’

“If postconviction incarceration is an insufficient deprivation of liberty to create a right to DNA testing,” concluded the court, “then… [the pilot’s] liberty interest in being free of a government-imposed stigma on [his] professional reputation is likewise insufficient.”

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