Metal SS Wing

[kenryan]

Has anyone considered not covering the SS wing and just making it all metal? Looks like it would add roughly 15 pounds to the overall weight. Are there considerations other than the weight penalty?

[danerazz]

Early ercoups are commonly "metalized" as you are suggesting. I don't know enough about the SS but don't see why it couldn't be done, and cannot think of any reasons other than weight not to do it.

[R Rinker]

really tempting idea...Some things I've "heard" is that, at the spacing of the ribs it will be 'wavy' and look bad. I guess you could go thicker and add stiffeners? If you have quick build wings you'd have to drill out a bunch of rivets to slide it under the leading edge, which is the main reason I quit thinking about it. So, adds 15 pounds at what gauge metal??

[kenryan]

85.75 square feet
X .228 (.016) = 19.5 lbs
X .285 (.020) = 24.4 lbs

It looks like the ribs are already set up for additional stringers, one top, one bottom. I can't imagine any problem with wavy-ness if stringers are added top and bottom. Using 1/2 X .035 round stringers would add another 2.6 pounds total. Using Oratex for figuring (because the weight is known) subtract about 6 pounds for fabric but then add back paint.

Bottom line: .016 with additional stringers, painted, probably about 20 pounds heavier than same two wings covered with Oratex.

[jak]

very first wings we buit were to have all metal sheeting the cad plans were drawn up for this as we built the wings we became very wary of the weight adding up. the sheet metal in the middle was omitted in the name of weight saving. Just to heavy. Jak

[kenryan]

Note, my figuring has been with regard to the main wing structure only, not including flaps or ailerons. I would now say that if you don't paint the wings, the result would be the addition of 15 pounds. That's using Oratex. If you are covering with some other, heavier fabric system, the difference would be less, depending upon the skill, or lack of skill of the person applying the coatings.

For those who like the idea of a metal wing, I think covering the main wing with .016 and leaving flaps and ailerons fabric makes a lot of sense. Incidentally, the Helio has metal wing and fabric ailerons (but metal flaps).

[danerazz]

Incidentally, the Helio has metal wing and fabric ailerons (but metal flaps).

So is the DC-3, B-17, and a whole bunch of others!

[Heliojoe]

New to this forum...but working on our 40th airplane build, the Just Aircraft "Super STOL".

Yes....the Helio Courier did have fabric ailerons with metal wing skins and flaps. I rebuilt 4 Helios and owned two myself...the premier STOL airplane bar none.

Yes....we are metalizing the wings on this Super STOL at the present time. It's a no brainer considering only about 20 - 23 inches remains to be covered. Those concerned about the weight should re-calculate the weight of fabric/tapes/several coats of Poly-Brush, 3 more coats of silver, possibly a coat of epoxy primer and finally 2-3 coats of 2 part urethane. The difference is negligible and I really don't think, the way this airplane is built, that it could care less. There are many other areas that weight can be saved........Heliojoe.

[jak]

heliojoe if you want to all metal the wing, please call troy he has some info you will want to know. Jak

[Heliojoe]

heliojoe if you want to all metal the wing, please call troy he has some info you will want to know. Jak

Hi Jak.........will call Troy on Monday...thanks.

[kenryan]

Well, if anyone is wondering what a metal SS wing looks like, here you are.

[Clark in AZ]

That's nice! What is the difference in weight compared to a fabric wing?

[z987k]

I would think that if you were going to go with an all metal wing, you might as well redesign the entire structure of it to take advantage of a stressed skin/semi-monocouque type. Metalizing an underlying structure meant for fabric does nothing but add weight. You could probably come up weight neutral with a proper metal wing with an internal structure more akin to a cessna.
There's quite a few metalized pa20/22 and 108's out there. All crap because of the weight it adds.

[danerazz]

I don’t know how much weight could be saved in a wing redesign. You could lighten the soars a bit, remove the drag tubes. But the ribs and everything else would have to stay. I suppose you could use lighter ribs as well.

The important question is “why” do you want the wings metal? That can only be answered by the builder. I am installing a much heavier engine in my highlander, simply “because I can.” I know it is heavier and am prepared for that. A lot of people put really nice (meaning heavy) interiors in theirs, or wheel pants, or crazy expensive panels. None of these do anything for their STOL performance, but that is what the builder wants.

Not everybody is a STOL superhero.

[danerazz]

85.75 square feet
X .228 (.016) = 19.5 lbs
X .285 (.020) = 24.4 lbs

It looks like the ribs are already set up for additional stringers, one top, one bottom. I can't imagine any problem with wavy-ness if stringers are added top and bottom. Using 1/2 X .035 round stringers would add another 2.6 pounds total. Using Oratex for figuring (because the weight is known) subtract about 6 pounds for fabric but then add back paint.

Bottom line: .016 with additional stringers, painted, probably about 20 pounds heavier than same two wings covered with Oratex.

I know this was a long time ago, but don’t forget that there is a top and bottom to be covered, I come up with about 80lbs to sheet a SS with .020 (both wings).

Of course this is based on me knowing virtually nothing about the SS wing, if I recall, the leading edge area is already metal, so it could take much less metal to fill in the remaining area.