The FAA aeromedical folks are on record as saying that insulin-dependent diabetes prevents one from safely acting as a required pilot crewmember unless the disease is evaluated and determined to be controlled. Here's the Federal Air Surgeon's position on the subject of LS pilots on this score:
Long-standing FAA regulation, § 61.53, prohibits all pilots--those who are required to hold airman medical certificates
and those who are not--from exercising privileges during periods of medical deficiency. The FAA revised § 61.53 to include under this prohibition sport pilots who use a current and valid U.S. driver’s license as medical qualification. The prohibition is also added under §§ 61.23 (c) (2) (iv) and 61.303 (b) (2) (4) for sport pilot operations. You should consult your private physician to determine whether you have a medical deficiency that would interfere with the safe performance of sport piloting duties. Certain medical information that may be helpful for pilots can be found in our
Pilot Safety Brochures.
If you follow that link, it will lead you to this:
Provided I otherwise qualify and have never sought FAA medical certification, am I authorized to exercise sport pilot privileges on the basis of a current and valid driver’s license if I have a chronic medical condition such as diabetes?
Response by the Federal Air Surgeon:
You should consult your private physician to determine whether you have a medical deficiency that would interfere with the safe performance of sport piloting duties. You may exercise sport pilot privileges provided you are in good health, your medical condition is under control, you adhere to your physician’s recommended treatment, and you feel satisfied that you are able to conduct safe flight operations.
However, it also leads you to this:
If my own physician thinks I’m okay to fly,
why do you have a problem with me?
Most physicians see their role as one of helping their patients by preventing medical problems when possible and treating medical problems if they do occur. This treatment may actually be a cure or it may be something that diminishes the impact of the medical condition on the person’s daily life. There are many conditions that can be cured, such as appendicitis, gall bladder disease, and pneumonia. There are other conditions that can be treated but are not cured, such as high blood pressure, heart disease, and diabetes.
In the case of this latter group, when a physician has done all that is possible to control the disease, the patient may be told that participation in any activity, including flying, is okay. To the treating physician, this means that there is nothing more to be done for the disease, and that activity will not make the disease worse. Unfortunately, the treating physician does not always realize that the medical condition
could make the activity worse (by making it less safe due to the medical condition). In addition, many physicians only fly as passengers on commercial aircraft. They do not realize the potential problems inherent in piloting aircraft, which may require more from the pilot than his or her medical condition will allow.
This sounds to me like the FAS is saying if you know you have a disqualifying condition like insulin-dependent diabetes, you can't use your DL as a medical to fly Light Sport unless you've been evaluated by an appropriately trained aeromedical specialist, not just any old physician. Now, they haven't explicitly said that in so many words, so I could be wrong, but that's the way I read the published FAS guidance.
