7ECA stringers and bulkheads

[Bill Vickland]

HI to all Citabria lovers. I am a new member just getting into a complete rebuild of my basket case1967 ECA. I have two immediate issues.
1. The #2 plywood bulkhead 4-555 is not identical to the old ones that I have removed. The old ones have a notch cut on the lower edge where it would make contact with the upper central longeron. I hate to modify a new item. Is this possibly a bulkhead that is used with other planes?

2. I am installing new stingers and formers and do not want to use the nails to attach the stingers to the bulkheads that were apparently used when this plane was new. I am told I can safety wire the stringers, presumably using brass wire, to the formers. However, I am also told it is unnecessary to fasten them al all, as the fabric will keep them in place. If I use safety wire, should merely drill thru the leg of the mushroom stringer on both sides of bulkhead and pull the wire thru a hole in the bulkhead? Or there a recommended approach here. Your help will be greatly appreciated. Many thanks, Bill.

 

[aftCG]

Can't help you but welcome. Great questions that I'm sure someone here can answer

 

[Bartman]

Welcome Bill!

Who did you buy your parts from? Is there a mounting option where the lines from one bulkhead to another look better or worse? Do the outlines of the new bulkhead parts match the outline of the old parts?

if you cut anything be sure to seal it somehow so moisture can't get in.

don't forget, ccdforums.com is a shortcut to get here.

 

[Bruce]

Welcome to the club, always happy to have another project join up, where are you from? What is time frame for project? I allowed 1 year but looks like it will be considerably longer.

 

[Bartman]

Bill, I was thinking, is it possible the formers you removed were damaged at the bottom and trimmed so that good wood would be in the mounting tabs and the new ones are the shape that the olds ones should have been? not likely but thought I'd throw it out there

rainbow page listing with photo
https://rainbowflyingservice.godaddysites.com/shop?olsPage=products/former-set

 

[Bruce]

I ran across another site back country I think and there was a comment about Rainbow bulkheads not having the stiffening supports like factory any body have any experience with this?

 

[Bill Vickland]

Wow, I am gratified by the responses to my issue. My old bulkheads were intact but badly warped, so I am replacing all 5. From front to rear, ,of the new formers from Wag Aero, #s 1,4 and 5 are perfect replicas of my old ones. Numbers 2 and 3 are both different from my old ones. The new ones come pre drilled for the two mounting locations and are different in that the mounting at the upper longeron is shorter in the horizontal dimension so that the two stingers on the side will not make contact with the Bulkhead. Tomorrow, I will contact Wag and send those four back and make four new ones by copying the old ones. Many thanks for all of your contribution.

I still need to determine the proper means of attaching the stringers to the bulkheads with safety wire. Any help there would be greatly appreciated.
Thanks again to all,
Bill V

 

[Bruce]

I am no authority like you I’m just attempting to recover my aircraft correctly. With saying this the wire I have are brass, also the nails are small like same ones used to secure the ribs in the wings, this is probably for the covering process to keep them from coming loose wile placing the fabric and shrinking other than this I see no reason for them. I guess you can glue them in place to avoid nails, I was planning to go back like factory unless something turns up hear to change my mind, please send some pictures of the new bulkheads as I have yet to purchase mine. I am looking to see if they have the stiffeners.

 

[Bartman]

that aluminum panel in the first photo, i've got two of them with the project I brought home but had no idea what they were! thanks for educating me! lol

 

[Bartman]

I am no authority like you I’m just attempting to recover my aircraft correctly. With saying this the wire I have are brass, also the nails are small like same ones used to secure the ribs in the wings, this is probably for the covering process to keep them from coming loose wile placing the fabric and shrinking other than this I see no reason for them. I guess you can glue them in place to avoid nails, I was planning to go back like factory unless something turns up hear to change my mind, please send some pictures of the new bulkheads as I have yet to purchase mine. I am looking to see if they have the stiffeners.

Bruce, I'm no expert either but those "stiffeners" look like repairs, imho. have you seen them referred to as stiffeners on parts made anywhere else?

the RC builder in me thinks those bulkhead attach points should be hardened with penetrating CA glue, they always seem to go to crap, especially the bottoms

 

[Bruce]

I think pictures help sometimes more then words, as for stiffness being a repair or factory is unknown to me but it would appear that they are factory all the bulkheads are dated 1979 which is when this aircraft was built. And there’s no entries in the logbooks for any repair in this area, but there has been repairs and the landing gear in the front and from ground loop. If they are from a repair there is no Evidence of other damage and these two sections are the only ones without distortion. Good question though as only these 2 bulkheads have that.

 

[Bartman]

was the fabric on the fuselage original or redone at some point?

my wild-ass-guess for today is that the fabric was redone and the person doing the work tried to reuse the formers by reinforcing them like that. or they were beginning to bow and they were reinforced with the old fabric still on there. one of my stringers has a patch where someone must have pushed on the fabric and cracked it.

 

[Bartman]

i was wild ass wrong! @Bruce ; from the factory;

 

[Bruce]

Ahhh the fun of discovery! Which is why we enjoy this site. Plus I will say the bulkheads with this are not distorted but all the rest are.

 

[Bill Vickland]

I think pictures help sometimes more then words, as for stiffness being a repair or factory is unknown to me but it would appear that they are factory all the bulkheads are dated 1979 which is when this aircraft was built. And there’s no entries in the logbooks for any repair in this area, but there has been repairs and the landing gear in the front and from ground loop. If they are from a repair there is no Evidence of other damage and these two sections are the only ones without distortion. Good question though as only these 2 bulkheads have that.

 

[Bill Vickland]

Bruce, I'm no expert either but those "stiffeners" look like repairs, imho. have you seen them referred to as stiffeners on parts made anywhere else?

the RC builder in me thinks those bulkhead attach points should be hardened with penetrating CA glue, they always seem to go to crap, especially the bottoms

I think pictures help sometimes more then words, as for stiffness being a repair or factory is unknown to me but it would appear that they are factory all the bulkheads are dated 1979 which is when this aircraft was built. And there’s no entries in the logbooks for any repair in this area, but there has been repairs and the landing gear in the front and from ground loop. If they are from a repair there is no Evidence of other damage and these two sections are the only ones without distortion. Good question though as only these 2 bulkheads have that.

Bruce, could you phonograph the top half of the #2 and @3 bulkhead. Those are the ones that don't seem to fit. And for what its worth, these two came from Wag Aero and came with the stiffeners. It looks like that is the way theyre suppose to be.
Thanks

 

[Bill Vickland]

Bruce is the aluminum plate in your photos a baseplate for the radio antenna. Is there an accepted installation design for that. Since the VOR is going the way of the buggie whip, I am also trying to determine if we can use the VOR antennas in the vertical fin. But that is a whole different thread.
Bill V

 

[Bruce]

Hope this helps, the plate is radio and VOR was it tail from factory. Last photo let’s you know my priority’s, thought I should show that because it was kicked out for higher priorities

 

[Bartman]

Thanks for the photos Bruce! I still have your t-shirt here for your photos from Oshkosh way back when! I'll get it out this week.

Bart
(nice Porsche)

 

[Bruce]

You could just bring the shirt to Sun and fun