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David Paule

Well Known Member
I'm building an RV-3B, and there's not really any standardized way of getting fresh air to the cockpit, so I'm considering a NACA vent in the bottom of the wing like RV-8s have. My RV-8 preview plans dates to 2004, and doesn't seem to cover that installation, although it does show a picture of the hole in the wing skin.

1. How well does it work?

2. Is the wing pressurized by the vent, or is there a duct to the fuselage?

3. What's the wing/cabin interface? Any chance of a photo?

Thanks!

Dave
Still building wings, RV-3B, one hole at a time
 
Hi Dave

It works well. Bottom skin comes with NACA vent cutout, 2" tube through a hole in the fus side (like the Aileron pushrod holes), vent by aft stick.

Problem for an RV-3 is it bringing the air out aft of the spar, when most would want the vent forward of it.

I am looking at a NACA vent in the fus fwd stbd skin under the cowling cheek (like RV-8 front seat), or taking the air from the aft baffle.
 
Paul's solution?

Gents,

At Osh this year, I peered inside Paul Dye's 3 and saw that he used little hinged doors on the fuse sides, right near the canopy skirt. Seemed like a simple solution for the tight quarters of the 3. No scat, no NACA cuts, just open and close. Perhaps he'll post a picture of them.

P.S. I'm flying out tonight to pick up my partially completed 3B kit tomorrow. Soooooo excited!
 
If I was building a non-QB wing, I'd most assuredly try to fit a NACA scoop similar to the one on the RV-8 Dave. It works well on the Valkyrie.

I'm not sure what Mike is remembering, but we have round inlets in Tsam's skirts, and they really don't do much. I think that RV-10 scoops just behind the throttle area would work well - we just didn't get to it before going to paint, and I'd hate to do it now.
 
The rear seat vents for the -10 are small doors - about 3x1.5". Avery Tools also sell some neat handles to operate them. Could work.......
 
I had a chance to see an RV-3 fuselage today (for the first time...) and the structure's tight in the area that would be needed to get the vent hose into the cockpit. The photo shows the area. There's even a vent hose lying there.

2mcc4k0.jpg


The hose would need to enter the fuselage just aft of the existing holes under the seat pan (that attaches to those curved flanges you see). Then it would need to go past the aileron pushrod that goes through the big hole and somehow get to the other side of the spar bulkhead at the left in this photo.

Hate to say it, but this part of the idea doesn't seem practical at the moment.

Thanks, everyone for your comments.

Dave
 
Ironflight said:
I'm not sure what Mike is remembering, but we have round inlets in Tsam's skirts, and they really don't do much.
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Paul,

That's what I remember seeing. I guess I didn't describe it too well. Are you saying your solution doesn't deliver enough cooling air?

P.S. I picked up my partially completed RV-3B project this weekend. Looks like I'll have my work cut out for me. There are many rivets that, in my eyes, don't make the grade and will need to be replaced. Still ought to save me a bunch of time though. I'm a happy camper.
 
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ppilotmike said:
Paul,

That's what I remember seeing. I guess I didn't describe it too well. Are you saying your solution doesn't deliver enough cooling air?
Click to expand...

The make lots of nose - very little air flow. Try the RV-10 back-seat vents below the longerons - my guess (no data) is that they will be much more effective. Another alternative is to use ram air from the back of the engine baffle and run a SCAT tube - several folks have done that very successfully. There are pros and cons relative to taking your cabin air from the engine compartment, and I don't have a strong feeling on the risk trades of that.

Paul
 
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