Of course it applies. All of Part 91 applies as qualified for gliders.
91.17 covers alcohol and " substances (any drug) "that affects the person's
faculties in any way contrary to safety."
Since we know that illegal substances are included here, i.e., you may not
fly while under their influence, that leaves
us with OTC and prescription drugs that might have that affect.
The difference between piloting operations which require a medical and
piloting a glider which does not, is that the PILOT gets
to make the determination whether or not a legal drug affects his ability to
fly.
If you take antihistamines and they do not make you sleepy or interfere with
your ability to fly, you may fly.

It is a valuable and important distinction and I agree with every one who
suggests that we ought not to abuse it
or let it slip away.

Allan

"Andy Durbin" wrote in message
om...
"ADP" wrote in message
...


Let's assume we agree that Part 67 does not apply. How do you deny
the applicability of 91.17 a) 3). Don't you operate under part 91
when you fly? How is possible to operate a certificated glider in USA
without being subject to part 91?


Andy