"Yeah, but as for 91.121 you're not maintaining any particular
cruising
altitude or flight level when operating a glider. "


The FAA legal department told me they recognize the problem /
confusion with the English language usage used in the regulation.
Gliders do not "cruise." However, the intent of the rule is clear.
Glider pilots must be aware of airspace altitude restrictions
including aircraft cruising.

Recognized exceptions to setting the altimeter to MSL include crop
dusting and aerobatics.

Yesterday, there was a very close near-miss with a glider and
commercial jet descending for a landing. The club where the glider
flies commonly uses and teaches using AGL altimeter settings.

It will only take a very few of these encounters for gliders to be
required to have ADS-B transponders and perhaps be banned from certain
airspace near airports where larger aircraft fly altogether.

A new, highly accurate GPS satellite was launched yesterday. First of
a series leading up to the new transponder technology.

Tom Knauff