Marc Ramsey wrote:

It is precisely this sort of situation, a conflict between aircraft
legally present in the same airspace, that sometimes leads to
undesirable (from our perspective) changes in airspace classification
and rules. What is truly fortunate was that it was not an airliner...

A couple of years ago, there was a midair over the French alps (possibly
the best known (as well as the best) glider area in Europe), between an
airliner which approached Lyon (France) and a glider. (I forgot further
details.) Luckily, both aircraft landed safely. It was clearly the
airliners fault, as the collision occured in airspace class E and the
glider had the right of way. Problem was, the airliner pilots thought
they were in class D, because the Jeppesen map which they used was wrong.

Anyway, before this accident, all airspace over the French alps was
class E up to FL195, i.e. freely usable by everyone without a clearance.
As a consequence of this accident, it's no more.

Stefan