D&E Wings?! Help!!

[Steve Morgan]

I have recently purchased a Clipwing project with a modified D&E (all aluminum) wing. The ailerons are longer than normal (109") and the spars are already clipped to 12' 2". I have plenty of stamped ribs to make the wing but according to Eric it will be way too heavy as is. I just set myself up on here and need ideas how to lighten the wing. I am thinking of an 11ft wing section plus wingtip and fuse attach brace to get my entire length to 27ft. What rib spacing (+/- 12"?), nose rib doubler spacing(+/- 6"?), how many sets of drag/anti-drag wires (2 bays and a fuel tank diagonal brace?) do you guys think would be lightest?
I will be putting a 160+ hp engine in it.

[Vasey fan]

Re: D&E Wings?! Help!!

Have you got a set of Swick plans? Mike included drawings for both the wood and metal spar versions, though off the top of my head the spars are listed at 12'6''.

If you're really commited to the all metal wing, you could probably save some ounces by going with pre-war ribs vs. stamped, other than that, pretty much everything in there needs to be.

I remember reading that while building Voyager, Dick Rutan joked that they'd performed the gravity test on all the potential components. They held the item at arms length and let go of it, if it hit the floor it was deemed too heavy and didn't get installed. I think Eric uses the same technique.

[Steve Morgan]

Re: D&E Wings?! Help!!

I think you are right, there are not many ways to lighten the wing without sacrificing strength. I am planning on having 13 main ribs with 10" spacing... but what I really need to know is what nose rib spacing to use? Since it will be a sheet metal leading edge I want to avoid crushing it at 180 mph! I was thinking of 6" spacing. Swick plans call for roughly 4.5" spacing, is that correct or a little overkill?... Anyone with experience with a crushed LE want to weigh in on the subject?

[Forrest Barber]

Re: D&E Wings?! Help!!

I blew one in, actually the top of the leading edge came loose under the fabric with a 150mph push and 170 out the bottom . We then attached the leading edge after bending it 90 degrees and putting the nails into shear. This was a Swick " Leisa Marie" Standard Category with 180 hp Lyc.
She had the .020 leading edge and we put back to back false ribs up front with an extra false rib attached to each main rib. Based in Akron, Oh will be at the Fly-In this week-end.

[Steve Morgan]

Re: D&E Wings?! Help!!

Here is my latest drawing for the all aluminum wing with 10" rib spacing and 5" nose rib spacing. This design only has one more rib than my previous 12" spacing set up and 6" nose rib spacing but gives me that comforting piece of mind of additional strength. The other photos are of the ribs, aileron hinges, aileron bellcranks, and the sheet metal leading edges with the 90 degree bends on each end

[Acroeric]

Re: D&E Wings?! Help!!

Steve- I worked this original design with Ernie Heald when he owned D&E. In fact those are the first set of wings I originally owned. . . . . they are really nice but way heavy. I think all the components for one wing weighed over 100 pounds. For comparison-I weighed my all wood wing ready to cover this weekend with an aileron, cables, 10 gallon tank, pitot tube etc and it was heavier than I had planned but still was only 68 pounds. I'm thinking when covered it will be under 80 pounds which is less than a stock wing weighs.

Anyway- In your drawing you show 2 bays of drag wires- you really need to add the third bay that goes through the tank. Adding a fuel tank cover on top and bottom may suffice but I do not remember the ribs being strong enough to handle it. DEFINATELY add the 3rd bay.

Your leading edges are .025 if I remember correctly-best way to aviod collapsing the leading edge is to stay within a reasonable speed and G range. I collapsed one but mine was not built correctly from the start- there is no reason one built with .020 edges and the correct placement of false ribs should ever give a problem.At .025 and 10" you'd be ok without the false ribs. Personally- I'd trash the .025 set and build a set out of .020 because of the weight penality.

Love seeing the progress- hopefully mine will fly in 2010.

[Steve Morgan]

Re: D&E Wings?! Help!!

Actually in the area where that third bay is supposed to be I planned to use a 3/4" dia. .049 steel tube cross brace like the American Champion does their all Aluminum wings. I just sold my Super D project to get this T-craft. The cross brace design would just be easier than the 2 wires because I was thinking of the less modifying I would need to do to the fuel tank and the one less compression I-beam at the root rib.

Does this plan seem strong enough? I think it will be as light as a pair of wires and fittings, and certainly lighter than the tank plates covers in the original design. What do you guys think?

[Steve Morgan]

Re: D&E Wings?! Help!!

they are really nice but way heavy. I think all the components for one wing weighed over 100 pounds.

Eric, do you remember any of the wing components being overbuilt? From what I can see the ribs shouldn't weigh any significant amount more than any other stamped ribs, and the aluminum I-beam compression struts are impressively light. Do you think the spars are the cause of the high weight?

Also, I measured the thickness of the leading edges and they are .020".... what would you suggest the nose rib spacing be with .020 leading edge? if I can get away with 8" spacing that would be great, and save a decent amount of weight

[Acroeric]

Re: D&E Wings?! Help!!

I remember the weight coming from the oversize spars, cast drag wire fittings, cast wing fittings, oversize drag wires, ailerons- especially the leading edge, and aileron hinges. The ribs are not a source of much added weight. The fuel tanks were really overbuilt as well if I remember correctly. I think that you will gain 20-30 pounds total which is not a huge deal- they are really strong wings and should work really well. Just keep the weight to a minimum on the fuselage and you will be fine. The guys at D&E had a Cub with their Tcraft full length wings on it- they said the airplane gained 75 pounds from the stock cub wings. . . .

If you are using a Continental I'd recommend leaving out the wing tanks- with the Lycoming you'll need them!

As for rib spacing- if you are going with everything on 8" centers I would install the leading edge without any false ribs- the leading edge like you have with the 90 degree bend that attaches to the spar is extremely tough- isn't it 2024-T3? On my all wood wings I use a spacing of 12" but that is with wood leading edges.