Fred Klein wrote:
> Did you use an after-market NACA vent? What size SCAT would you
> suggest? And how did you enter the plenum between the doors, given the
> reinforcement between the doors called for in the plans?
I made a small air door in the ceiling (between the doors), so it is
flush with the roof when closed, and forms a small forward scoop when
opened. It is directly connected to two eye-ball vents in the ceiling panel.
I have not yet been flying, but even with the engine on idle, the vents
already produce lots of air. I suspect that these things produce a real
blaze at cruise speed.
It is a simple solution, and I can't really see the advantage of taking
the air from the rear of the airplane and then transporting it all the
way to the intended place. Also, when taking air from the rear of the
plane, it might be mixed with some exhaust fumes (probably depending on
the amount of prop wash, speed and angle of attack). It is however very
unlikely that the exhaust fumes get to the roof of the airplane in any
normal flight configuration.
Of course if you make an opening in the roof, don't make it too big.
According to the air it produces with an engine on idle, you don't need
much of an opening there. I made a flange around the opening, doing
double duty as reinforcement around the opening, and forming a rain
proof seal when the scoop is closed.
--
Frans Veldman
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