On Saturday, October 21, 2017 at 2:58:33 AM UTC-4, krasw wrote:
Ok, probably all similarities are purely coincidental then.

But regarding air extractors, I find it surprising that mainly US audience of ras does not mention Will Schuemann's work, predating JS or DG, what 35-40 years?

Wil was certainly a pioneer. IIRC, his 301 Libelle captured ventilation air using the leading edges of the gear doors as a scoop (the belly just ahead of the doors was flattened a bit so the doors protruded--probably not the best idea in the event of a gear up landing).

Thus pressurized, the gear box fed ventilation air into the cockpit through two outlets over the shoulders of the pilot. I don't think these could be modulated, at least initially, which was a problem when it got cold.

Air exited the glider at the base of the rudder through an expanded opening and "splitter" at the bottom of the rudder based on Wil's experiments to find the ideal low-pressure location. Jim Indrebo had a really nice version of that exit vent on his 301 in the early 80s.

Chip Bearden