That's a good question, but yes, I do think you are missing something.
Most medical conditions can be treated with the proper medicine. And it is the medicine, not the medical condition, that the FAA is concerned about.
Most medicines for the most common conditions do not impede the person from operating a car. After all, if a drug company put out a medicine that makes a person dizzy, uncoordinated, or sleepy, then the drug company would have a hard time selling that medicine. Instead, they design drugs that overcome the problem (high blood pressure, perhaps) that does not lead to dangerous side effects. And if a person can drive a car filled with passengers in heavy traffic, that is hardly different from flying a light plane with a passenger.
AOPA has a list of medicines that are commonly prescribed for a vast number of medical conditions and whether the FAA would disqualify a person from taking that medicine. Very few of them are disqualifying.
But many do carry the requirement for the pilot to submit an EKG, X-ray, stress test, echo test, blood work, etc., with the medical. So the pilot goes to his doctor, says he needs the test, the doctor says it is not a medical necessity so the pilot must pay out of his own pocket for the tests (his insurance will not pay.) The extra medical test will cost $500 to $2,000.
Now he submits all of this paper work, waits three months for FAA Oklahoma City to get back to him (in the meantime he cannot fly), and is finally given his medical -- perhaps with a requirement that he must submit to another medical within one year rather than two years, or a new one if his doctor prescribes a different medicine.
The real problem with the medical is that most pilots will pass the medical -- eventually. Even pilots with heart transplants have regained their medical. The problem is the hoops they must jump through.
So, what is the best course? For pilots who only fly for enjoyment, the sport pilot allows them to continue to fly without the extra headache of jumping through the hoops.
A sport pilot or one with PPL must self certify before each flight that he or she is capable of flying safely. So each pilot must make the right decision. If they are ethical they will do so.
