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NACA Airfoil for RV-3 Empennage

R

rbregs

Active Member
Does anyone know the NACA (symmetrical) airfoil used by Van's for the RV-3 empennage. I have the airfoil for the wing. I'm looking for the airfoil used for the tail surfaces.

Van's didn't respond to my inquiry, and I've had no luck finding the information via the internet.

Thanks,

Bob
 
rbregs said:
Does anyone know the NACA (symmetrical) airfoil used by Van's for the RV-3 empennage. I have the airfoil for the wing. I'm looking for the airfoil used for the tail surfaces.

Van's didn't respond to my inquiry, and I've had no luck finding the information via the internet.
Click to expand...
It is a symetrical airfoil, and is probably one of the NACA 00XX series, where XX is the percent thickness. E.g., if you measure the chord and maximum thickness, and the thickness is 6% of the chord, it would be a NACA 0006.

Note that I have no hard info that Van used the NACA 00XX airfoils. I have heard that they are often used on tail surfaces, and the profile does look about right to my eyeball. Strictly an informed guess.
 
Thank You for Your Reply

Kevin,

Thank you for your reply. I too have read that the NACA 00xxs series are often used for empennage surfaces.

I have the RV-3B plans and therefore the airfoil coordinates listed for fabrication of the ribs. I will calculate the maximum airfoil thickness as a percent of the airfoil chord, and determine the associated NACA 00xx airfoil. That should get me in the neighborhood.

I'll then compare the airfoil coordinates listed on the plans against those generated using the determined NACA airfoil, and then go up or down the NACA 00xx airfoils until I get a good correlation between the calculated and plans identified coordinates.

Congratulations on your RV-8. I enjoyed following your build via your website.

Thanks for your reply,


Bob
 
Ok, have to ask....

as a fellow RV3 builder, I have to ask why you would want to know?
 
"I got's to know"

Nothing nefarious going on here.

I'm doing some model based definition (MBD) of the airplane using the plans and some CAD software. I?m creating what are called Master Dimension Surfaces or MDSs for the empennage surfaces.

Aren?t you glad you asked?
 
Not NACA 00xx

I'm pretty sure it's not a NACA 00xx anything. However, it's been 30 years since I looked at it.

As I remember, the leading edge radius doesn't match the thickness.

I finally decided it was just a "french curve" symmetrical surface that worked better than a round tube and fabric.

I can't complain about the performance at all on my RV-3 sn 50.
Even if the wing airfoil doesn't actually match the NACA 23012 airfoil data.
Harry Riblett says this is a good thing. :)

Jim Ayers
 
What you said " ", What I heard...

rbregs said:
Nothing nefarious going on here.

I'm doing some model based definition (MBD) of the airplane using the plans and some CAD software. I?m creating what are called Master Dimension Surfaces or MDSs for the empennage surfaces.

Aren?t you glad you asked?
Click to expand...

....blah, blah, blah blah blah, blah....
 
Empennage Surfaces Not a NACA 00XX Airfoil

Jim,

You are correct, the surfaces are not a NACA 00XX profile. I've run though the NACA 00XX airfoils and they don't match, at least not for the Vertical Stabilizer, which is the only surface for which the plans define a chord length (40.8").

I'm thinking a NACA 63009 but have been unable, as yet, to verify.
 
Are you looking at a plans cross section or a built cross section? Doubt seriously if the finished product is exactly as designed. Build leading edge radius is pretty much dependent on the pre-bend supplied in the kit. I'm sure it is not exact.
tm
 
Yes, Looking at the plans

Yes - I am looking at the Empanage (sic) Rib Patterns, sheet 13 of the
RV-3B plans.
 
Thank you

Tom,

Thanks for looking in your manual. I'm going to aks Van's Aircraft again for the information. I'm sure they are busy but it can't be that much effort to reply with the empennage airfoils?

Bob
 
Airfoil Mystery Solved

I received a very nice note from Mr. VanGrunsven who explained that he started with a NACA 0009 airfoil but modified it significantly.

He mentioned that he deepened the airfoil around the 50-60% chord to provide greater spar depth. He also explained his use of flat (straight) control surface ribs to enable the use of straight skin stiffeners.

He closed his note with "So, the end result is essentially a non- descript airfoil. It works well enough."
 
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