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One of my boys and my C build.

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Posted

Hi all. Hoping this is not too far off the beaten path to gain some info and suggestions along the way. My middle son and I picked up this wrecked C model fuselage and damaged wings. Nothing else to work/rework. I'll post a few more pictures later with other descriptions but here's a start. When done, I don't believe we can call it an Avid as we did not get the serial number. I guess we'll be needing to come up with a name somewhere.

This was a C model with 532 before it found that tree. (Not by any of us.)

After pulling the covering, we started cutting what was bent and needing to be replaced. Lots of work. From the get go, we decided to do a 16" extension as the lower longerons needed replacement anyway.

Attached is a couple pix. Again, this was a C model and much of what was done was done to match what was original materials.

So, for future reference, we are likely going to be putting a Corvair in. I know this is a heavy engine but also well convinced, the the engine installed and flying will be considerably lighter than a Sube instal. As I get more pictures up, perhaps someone will chime in with suggestions to beef up for these heavier loads.

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Posted

Yep, you guys got yourselves a project there. :)

I have to say I always admire guys with the skills to tackle the big jobs I would be scared of. This should be a fun rebuild to watch so please keep us posted on the progress, particularly the FWF.

Thanks!

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Posted (edited)

This post is/was meant as a teaser or at least to let everyone know where we started. I have more pics and will filter in more with some verbage as time permits. It started out as the owner of this plane had purchased another fuse and wing kits to replace that which was damaged. We came close to buying the whole plane plus this damaged stuff. In the end, we would have been flying the one plane then building a second plane from these parts. The owner changed his mind so guess what comes first. It will be an awesome day when this plane takes first flight. Hoping for this spring or early summer but guess what,,,,, LONG way to go.

Edited by C150L

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Posted (edited)

Here's a couple more build/rebuild pix. Not to mention all the bent tubing we started with, after cutting away all that which was bent, some squaring and alignment needed attention. Spar carry throughs were no longer in line or parallel to each other. Once the bent stuff was gone, it came back part way but still a lot of blocking, pushing, pulling etc was needed to part the good stuff back where it should have been.

Piece by piece, that's a lot of one at a time parts to cut and cope to fit.

If any comments or suggestions come to mind, we'd surely appreciate such. Thanks.

More pix to come.

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Edited by C150L

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Posted

I love to see the twisted metal replaced instead of the fuse being thrown away! I wish I would have stretched mine when it was down and being rebuilt!

Ahhh.. makes me think its time to get off my butt and start replacing tubes on my pacer fuse..

:BC:

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Posted

Its great to see an old bird getting rebuilt, great job keep us posted on the progress i will be watching very closely as Im just about to start putting my Model C kit together. I am wondering what the purpose is for extending the fuselodge? does this make for better in flight performance? i do have the larger tail feathers from the MKIV so that should already improve the perfomrance, would i gain a better cargo area i notice it doesn't really have one in its current configuration, this is my first build and since its such an old kit (1988) i know there are many upgrades that would be better done as we build rather than added i later,

Keep up the good work

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Posted

HC,

The reason for the fuse extension is due to heavier engines. The avid was originally designed around the Cayuna engine and even with a 582, they come out nose heavy. You can add weight to the tail, or just live with a plane that does not perfrom to its full potential. By extending the fuse, you get the CG back and some say it is not as "squirely".

They guy I bought my wreck from had put in an extended baggage in the back that I stuff full all the time! I have had over.. well.. lets just say I have had it um, full, and she still flys GREAT!

The one biggest thing I would do is not put all the twist in the wings when I build them, but that will also require shortening up the rear wing strut on the fixed side, or making both side ajustable with a simple weld on fitting you can get from Brett at airdale.

:BC:

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Posted

Why would you NOT do the full wing twist and if not how much should i do, it calls for a 2" difference frome tip to root end.

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Posted

Why would you NOT do the full wing twist and if not how much should i do, it calls for a 2" difference frome tip to root end.

Better cruise speeds with very little penalty to STOL performance. I can't think of the name of the thread but there was a lengthy discussion on this a while back. Leni??...

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Posted

Thank you, someone, for fixing the typo in my subject line. That has been annoying me and I found I could not edit that.

Less washout on the wings? What do you think, half? (1"?)

I also have had a number of aviation friends (builders/re-builders) tell me that the stretch will improve ground/landing. We're also widening the landing gear about 14".

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Posted

Few more pix.

Most of the cabin area structure rebuilt. Notice extra truss behind seat and additional vertical structure up back of door opening frame work. Why? Must have seen it somewhere.

Both front and read spare carry through tubes were removed and replace.

Tail reattached and new side stringers installed. Vertical fin was straightened during the tail work.

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Posted

Interesting. I point at these pictures and it tells me how may downloads have been done for each picture. Hope our experience is able to help others in some way. Can hardly wait till it's flying.

One thought. We've made it no secret that this plane is going to have a heavy engine. (I still think the Corvair will come in less weight than the Subes could.) Somewhere I was reading about someone having some forward sweep on the wings. I'm wondering about adding maybe an inch or so forward sweep and if it would help the CG? Wouldn't want to go so much that the plane looks hideous when done but perhaps an inch or so might not even be noticeable? Any thoughts.

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Posted

Interesting. I point at these pictures and it tells me how may downloads have been done for each picture. Hope our experience is able to help others in some way. Can hardly wait till it's flying.

One thought. We've made it no secret that this plane is going to have a heavy engine. (I still think the Corvair will come in less weight than the Subes could.) Somewhere I was reading about someone having some forward sweep on the wings. I'm wondering about adding maybe an inch or so forward sweep and if it would help the CG? Wouldn't want to go so much that the plane looks hideous when done but perhaps an inch or so might not even be noticeable? Any thoughts.

The forward sweep does not look too bad, but it is noticeable if someone really looks at it. I dont think Randy swept his wings forwards on his subie install. When he gets back from hunting maybe he can chime in.

I fixed the title for ya :lol:

I am enjoying the pics, keep them coming, its all coming together !!

:BC:

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Posted

We bought the damaged fuse and wings last Nov, so what I'm working on posting is about a years worth work. It's sometimes hard to find time for both of us to get together to work on this. Been real slow the last few months.

More pix to come.

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Posted

Less washout on the wings? What do you think, half? (1"?)

All Avid models oficially called for 2" twist, although for years both Avid and Airdale had repeatedly and quite publicly advised builders that 1-1/2" was fine. I built my Mk-IV wings with the 1-1/2" twist and later wondered if I shouldn't have used even less. Reason I felt less might be better was three-fold: 1.) the Kitfox 1-3 models which are a darn near Avid C clone with an airfoil that is nearly identical in chord, under camber etc., albeit a slightly wider wingspan, use only 1" of twist per factory builder's manual and my KF-3 never fell out of the sky or exhibited any particularly nasty stall characteristics; 2.) the Kitfox IV (both 1050lb and 1200lb MTOW) uses only 1/2" of twist per factory builder's manual with a flatter bottom rib profile, which strikes me as inclined to offer a potentially more exciting stall characteristic, but stalls are still considered very docile; 3.) I have read and spoken to KF-IV owners who have built with slightly less twist than called for in the manual and, while the stalls require a bit more attention, they report it is far from dangerous and very manageable, with the added benefit that their plane does seem to cruise decidedly faster compared to other built-to-the-manual KF IV-1200's at the same empty weight with the same FWF. Personally, I would consider building a STOL or Heavy Hauler wing based on the Avid under cambered rib with only 1" of twist for all these reasons. However, as my very limited aeronautical design and engineering career extends to my garage only, that is only opinion not advice. In the least, I would further carefully compare internal wing construction to the KF-IV to see if it utilized additional drag tube bracing etc. before making a final decision.

Somewhere I was reading about someone having some forward sweep on the wings. I'm wondering about adding maybe an inch or so forward sweep and if it would help the CG?

I had some questions of my own and started a thread on the topic here >>> Setting wings to fuselage (a.k.a. calculating wing sweep). Some good discussion and info ensued that you may find helpful. Based on that info, I suspect 1" on your stretched fuse would be excessive for your planned engine. In fact, I personally would not build in much, if any, on the outside chance you ever sell the plane to someone interested in removing the alternative engine in favor of a 582 or 912ul FWF. If you refer to the link you will see I built my Avid+ (similar in fuse length to your stretched fuse) with 1/4" sweep, in large part because I was still undecided on my final FWF config. I felt that might provide a small benefit if I went with a heavier FWF but not shoot myself in the foot if I won the Lotto and installed a lighter 912ul, 912uls, UL260iS or even UL350iS (drool!).

If any comments or suggestions come to mind, we'd surely appreciate such. Thanks.

I have looked at your fuse and would offer the following suggestions:

1.) I am attaching a drawing I secured from somewhere that (I believe) was penned by one of the Euro aviation authorities to address on of their perceived fuselage weaknesses when evaluation for import. I have similar drawings for the KF 1-3 models that share some of the same fuse modifications. Whether it is simply a make work project to justify their existence, a huge safety issue or even holds any value is for you to decide. Regardless, you certainly have the capability to add the additional tubing at this stage of your build so why not?

2.) Later Avid Mk-IV's had reinforcing gussets added to the rear spar carry-through tube, one inboard and one outboard of the horiz. support post tube. Note, the outboard gusset had to be 'notched' to provide sufficient clearance for wing folding.

3.) Add a center plate for 4pt harness attach point, turtle deck anti-rattle support post, door lift cylinder attach plates, top deck antenna mounting plate for the next guy (hehe, inside joke folks!) and aft battery/ELT mounting provisions. I also recommend you add a 4th set of gear attach brackets now as well, like the KF models, in case the plane ever ends up near water (spreading out the 'pinched' float gear Z-struts looks better IMHO and adding a 4th rear strut makes sense for strength on the longer fuse). While the extra bracket on the KF is to the front, I would probably add the bracket aft under the first lower longeron tubing cluster behind your new rear seat truss (I like!)

4.) Have you made provisions for either manual or electric elevator trim?

There's more but I got to get back to work!

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Posted

Not what sure what happend yesterday cause I replied to the question on the 2" twist but I dont see the diatribe I spewed out, however, once again Doug comes through with a well layed out and thought out post!

Pretty much everything that Doug said, but I would go 1/2" max on the washout and then use more VG's on the tip section and less on the root section. I flew a MK IV that had VERY little washout (it was an extended speed wing) and it was gentle as a lamb on the stalls. I loved that plane! One day I wioll get around to building another set of wings, to HH specs but extended to the span of the kitfox. I want climb and STOL and dont care too much about cruise!

:BC:

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Posted

A little birdie has informed me that Airdale may be soon offering a new wing airfoil option, with up to a 32' span. One with very good STOL and reasonable speed characteristics.

One that's very similar to my wing (ahem)... :dunno:

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Posted

A little birdie has informed me that Airdale may be soon offering a new wing airfoil option, with up to a 32' span. One with very good STOL and reasonable speed characteristics.

One that's very similar to my wing (ahem)... dunno.gif

great... so now I am gonna end up with an Avikitfrankenstien :lol:

But it really sounds like Brett is on the right track! If he makes available what people want, he gets to sell stuff!! Now I get to modify my tail ski to fit the new 8" matco I just got hammerhead.gif

:BC:

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Posted

Talk to Brett again. He has the tailski for the 8" Matco wheel, too... :funnypostabove:

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Posted

Wide landing gear coming along. Possibly could have been a little taller but as is would be stock but one size larger tubing and about 13" wider with the pair. Rudder taking shape. Tail wheel in place. LOL. 4 new HH spar tubes on wall, waiting for wing rebuild.

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Posted

Wide landing gear coming along. Possibly could have been a little taller but as is would be stock but one size larger tubing and about 13" wider with the pair. Rudder taking shape. Tail wheel in place. LOL. 4 new HH spar tubes on wall, waiting for wing rebuild.

How much of a bitch would it be to make that gear taller?? You are going to want more angle of attack than stock! I have the tall gear and still drag the tail wheel every time with the mains 3' off the deck. I could get out ALOT shorter if I had even taller gear like Randy made for his!

You making tail wheel jokes mr :dunno::hammerhead:

:nutkick::lol:

:BC:

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Posted

I'm sssooooo glad I've found this site. So much good and pertinent info coming. I know we will be considering/using a lot from here which we may not have thought of on our own.

Have you made provisions for either manual or electric elevator trim?

Have not made provisions, but strongly considering a trimmable horizontal stabilizer, such as the Clipper (Pipers) have. What's going to make this a little tricky is getting the horiz stab struts braces to move with the horiz stab. I do have an idea on how to easily (ya, right) do it and not add much weight, although the tail would be the place to add a little USEFUL weight.

Ya, place for possible future owners antenna. (I get it.) Good idea.

Little unclear on that additional bracing sketch. Does look like some new bracing comes down to the longerons, where ones wheels would end up, if their gear was torn off after the hard landing after hitting a tree. Not sure where those braces end up on the top end.

Thanks for the info "friends".

Dale

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Posted

How much of a bitch would it be to make that gear taller?? You are going to want more angle of attack than stock! I have the tall gear and still drag the tail wheel every time with the mains 3' off the deck. I could get out ALOT shorter if I had even taller gear like Randy made for his!

You making tail wheel jokes mr :dunno::hammerhead:

:nutkick::lol:

:BC:

Would literally have to start over. Randy have sketches/drawings on his gear? How much taller is the tall gear and how much taller are Randy's?

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Posted

Had to try this.

I had this Koala from 1999 after I sold my 150 and just sold it this summer after getting my FAA medical back. Now I fly my friends 49 Clipper. Should be taking that out tomorrow for awhile.

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Posted

Little unclear on that additional bracing sketch. Does look like some new bracing comes down to the longerons, where ones wheels would end up, if their gear was torn off after the hard landing after hitting a tree. Not sure where those braces end up on the top end.

Top end of new tube goes to the center cluster behind the seat back.

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