On Tuesday, August 25, 2015 at 1:41:15 AM UTC-5, Tango Whisky wrote:
Am Montag, 24. August 2015 23:53:39 UTC+2 schrieb Jonathan St. Cloud:
On Monday, August 24, 2015 at 12:43:49 PM UTC-7, wrote:


Look at the Jonker Sailplanes website for one example


The poster was looking for solutions that would work in gliders with fuel tank in baggage compartment. The JS-1 has a take on the Buttler/Murray/Nixon vent which would not work with a gas tank were the vent would be.

I have put extractor vents into the small engine bay doors on my Ventus cM. Needed to put two 5 cm dia holes into the bulkhead separating the cockpit from the engine bay (Schempp-Hirth confirmed me that this bulkhead is not structural and that I could put any holes I'd like).

Aside from the questionable Mandl report on the DG website and anecdotal evidence from those who had air extractors installed - are there measurable effects? While I believe that venting of the cockpit is improved, I doubt this is making for better performance until someone shows me data. Until then, I would call this snake oil.
Herb