This is the wording of a Special Issuance Authorization letter, this one to a pilot with treated sleep apnea. The language is essentially the same for other conditions:
—————
We are please to inform you that after a review of your application … you have been granted an Authorization for Special Issuance of the enclosed third-class Airman Medical Certificate pursuant to 14 CFR §67.401.
The enclosed CERTIFICATE
Is valid until August 31, 2025
Requires your signature
Supersedes any previously issued certificates.
This AUTHORIZATION:
Shall be effective until it expires on August 31, 2030 or withdrawn
by the agency;
Supersedes any previously issued Authorization
Must be presented to your AME at the time you undergo an airman
medical examination.
You have been granted this Authorization for Special Issuance following the FAA’s determination that you do not meet the medical standards prescribed in 14 CFR Part 67 under Section(s) 67.113(b)(c), 67.213 (b)(c) and 67.313 (b)(c) for an unrestricted airman medical certification due to yuour established medical history or clinical diagnosis of ……
You must follow the Airman/AME Instructions set forth in this authorization for continued certification under this authorization.
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This makes it crystal clear what they are doing and what their authority is for doing it. It also makes it clear that this is a gift. “You are not qualified for medical certification, but instead of just telling you you are grounded, so go away, we have found a safe way for you to keep flying, provided you keep us up to date on your condition.” This is not any kind of unreasonable or oppressive intrusion on our rights. 50 years ago, most people with these Special Issuances would simply have been grounded forever.
The wording from an actual Special Issuance Authorization is above, but the point is that for the small percentage (maybe 5%) of applications for pilots who have some condition that might disqualify them, the specifics are reviewed on a case-by-case basis. Some are simply approved, with a caution to report deterioration in the condition. Some are given one of these SI authorizations. A very small fraction - consistently about 0.1% - are denied.
A few years ago several of us suggested to then-Federal Air Surgeon Dr Fred Tilton, that they give AMEs guidance for some conditions that would allow us simply to issue certificates for some conditions after verifying that all necessary data had been supplied and was within parameters. That led to the “CACI” (Conditions AMEs Can Issue) program. Those pilot don’t need a Special Issuance, don’t get a limitation on their medical certificate, and the AME is charged with documenting on the exam, “CACI qualified for [for example] hypothyroidism.”
For many others, even that isn’t necessary, but the burden is on the AME to be sure that whatever the condition is, it is adequately controlled, and simply annotate that when we submit the 8500-8 to FAA.
The standards for all of these are very clearly spelled out in the Guide for Aviation Medical Examiners, which is freely available on FAA’s website. Google it.