Folding Wings?

[BruceMe]

I found this from an old thread back in 2007 of a folding wing RV-4. I tried to contact Brian aka "N7034F" he didn't respond. The N-Number was cancelled, I presume it was sold internationally.

I'd like to make a fold mechanism on my RV-4 wing and anyone who has knowledge or wants to assist, I'd like to talk with. I took tons of pictures of every fold mechanism I could see at OSH17


Grumman Avenger (StoWing)


Obscure motorglider


Panther

I purchased a second wing for my RV-4 to chop up for this purpose.


Thanks!

-Bruce

[roadrunner20]

Bruce,
You may want to look at the Sonex Onex folding wing.
My friend has one locally here & it's a very interesting design.
http://www.sonexaircraft.com/onex/

[BruceMe]

Originally Posted by roadrunner20

Bruce,
You may want to look at the Sonex Onex folding wing.
My friend has one locally here & it's a very interesting design.
http://www.sonexaircraft.com/onex/

I have, but not in person. 100% agreed

[rv7charlie]

You might also look at the Bushby Mustang II. A proven design that flies at similar gross weight and speeds. The M-II wing is much thinner than the RV's, so the attach points should be much less stressed in the RV wing.

http://www.mustangaero.com/Mustang%20II/FoldingWing.html

How are you going to manage fuel? If you intend to trailer on public roads, you'd need wide load permits with the standard RV-4 tanks. Most folding-wing planes keep fuel in the fuselage, or inboard of the fold. Fuel weight in the outboard section will radically change the load on the hinge [edit] while folded.

Charlie

Just realized I inserted a broken link; hope this one actually works...

[Robert Anglin]

Or the PL-4A from Pazmany, it has push rod construction. The wings can be folded or removed as you wish at the 8 foot width for trailering. We have one but I don't do pictures well here. Yours, R.E.A. III # 80888

[BruceMe]

Found the folding wing RV-4 in Canada...

C-FEII

It's in Alberta

[BruceMe]

Originally Posted by rv7charlie

How are you going to manage fuel? If you intend to trailer on public roads, you'd need wide load permits with the standard RV-4 tanks. Most folding-wing planes keep fuel in the fuselage, or inboard of the fold. Fuel weight in the outboard section will radically change the load on the hinge [edit] while folded.

The folding wing RV-4 above moved the hinge, flap & fuel inboard two bays. If it worked for them... I may add an RV-3 header tank to fill for XC or extend the wing tanks behind the spar with a vent. Or... I'll live with ~14g a side.

-Bruce

[rv7charlie]

Originally Posted by BruceMe

The folding wing RV-4 above moved the hinge, flap & fuel inboard two bays. If it worked for them... I may add an RV-3 header tank to fill for XC or extend the wing tanks behind the spar with a vent. Or... I'll live with ~14g a side.

-Bruce

All about the 'mission'. I don't do a lot of cross country work, and I still find 32 gals to be somewhat limiting. I owned a 160 HP T-18 for a while that had less than 30 in the header, & it really was a pain.

[maniago]

I'm building a folding wing Mustang2. And I have fuel in the leading edge of the wings as well as two aux tanks, also in the wing area. None of my fuel is in the cabin.

By design, you shouldn't have but maybe 3 gal in the leading edges when folding, cause its very hard on the hinging hardware and the stowing cable, and it just makes the wing extra hard to maneuver. Its not a robust enough design for outside storage ala hellcat, corsair etc, but plenty fine for hangaring.

Fuel system design plumbing is interesting, but I'll not belabor that here. What I do want to touch on is the hot button issue "NO L,R,Both fuel selector in low wing a/c". That thread is closed for comments so I cant add my .02.

For a pair of folding wings that carry fuel, you need a way to balance fuel before you fold (for obvious reasons), and so I have said Andair valve in my Mustang2 for this purpose. "Both" is not a for flight item (I get the unporting arguments), but there is no lockout to prevent it. Just pilot management.