On Aug 20, 4:13 am, PMSC Member wrote:
On Aug 19, 9:15 pm, Uncle Fuzzy wrote:



On Aug 2, 3:25 am, Derek Copeland

wrote:
In that case, I suppose you would have to go onto oxygen a little bit lower
down with thefuselageextractionventfitted!

At 16:40 31 July 2008, Jim White wrote:

Now there is a thought.... Open the airventif you are close to
airspace
to make the logger think you are lower, and fit an extractionventif
you
want that height record.

jim- Hide quoted text -

- Show quoted text -

I made this vent to replace the access hatch for connecting my
controlshttp://griderpirate.smugmug.com/gallery/3702283_9hEKD#355235771_pv8zu
Next weekend I will fly with a manometer to compare static to cabin
pressure with the 'normal' hatch, then the 'Mandl Extractor' hatch. I
can report subjectively that I was MUCH more comfortable in the
cockpit.

Nice work.

Now DB is a pretty smart guy, so chances are he has this figured out.
But I sure don't. I can't see how exhausting air into the low
pressure area that's responsible for producing aerodynamic lift is a
good thing. Perhaps the mass flow is trivial and doesn't matter as
long as the flow isn't spoiled. But we sure go to a lot of effort to
eliminate air leaks in this area and sealing surely does help....

Ahhh, another victim of the all too common "equal path length theory".
Although a wing does generate a certain amount of reduced pressure on
it's upper surface and that does contribute to the lift, the
dominating force of lift rather comes from the thrust generated by the
air being flung down off the trailing edge for the wing. To account
for the actual physics of flight, one must also rely on Newtonian
physics coupled with Coanda Effect (http://en.wikipedia.org/wiki/Coand
%C4%83_effect ), since if you rely on Bernoulli alone a plane can not
fly inverted! See: http://www.eskimo.com/%7Ebillb/wing/airfoil.html
for much better explanation.

-Paul