Fuselage repair help

[DMichaels]

I am working on a Champ for a fellow EAAer it was the plane he learned how to fly in many years ago. It has not flown in quite some time. It does have a 50 hour engine though that I have already checked out.

I would like to do a nice job on this as it may be his last chance at flying. I have most of it blasted and found quite a bit of corrosion.

What is the best way to fix the piece on the backbone?

The landing gear has been fixed before, just welded in. I would like to do a better job than the last person. A doubler maybe or replace the whole bracket?





Dan

[joea]

Dan,

First off, welcome onboard!

Where are you located? Might help as there might be someone with this experience in your area.

Not going to make it any easier, but I have been where you are right now and its going to be a bit of work ahead of you.

First, the photo with the tubing missing you will have to find out how far back you have to go to get good strong material, then replace the tubing from there on forward. Do you have a copy of the blueprint showing the size of tubing needed? If not then you need to get a copy to help.

Next photo on the landing gear mount. Many people just weld a backup plate or even washer to this tab, then use a longer bolt in this area.

Your photo of the rudder post is classic and they usually always rust here. If you cut out the tubing here, please look at the lower longerons from this area forward and make sure that they are not rusted as well.

Depending on where you live, Brian Safran in Ohio has a Chief fuselage jig that he lets others use, or does work with them to get the fuselage straight again. Might be worth looking at depending on the extent of the damage.

Good to see you helping the gent restore the airplane!

Joe A

[David Johnson]

Dan, The landing gear can be repaired using Aeronca Service Letter #6. It's available on www.aeronca.com. The upper longeron is a real tough area to fix.

I agree with Joe, you are really going to need a jig. Or build enough of one to keep the forward horizontal carrythru from moving. I have never replaced one of these but my friend Lloyd has. Much head scratching and foul language. The worst part is grinding the old tube out without damaging all the tubes that connect to it. I have always been told because of water settling there this is an area to always check out.

You also need to check the bottom of the diagonal tubes under the floor that meet at the forward stick control torque tube pillow block. Just make sure nothing moves while you cut the old out and put in the new.

AC 43.13 gives several options for splicing in, if you follow it the FAA won't give you any trouble. Bill Pancake advises to remove the door channel and check the tubes. All we have seen are rusted, some bad.

Good Luck! David J.

[DMichaels]

Thanks I have found much more rust since I took thos pictures. I had talked to Bill and he advised me to remove the door channel so I did.

KGTG Grantsburg, WI I have prints coming as well as the service amnual and service letters books. I also talked with Brian already. I think the backbone will be the hardest part I did not want to have to take the cluster apart. So much for thinking it could be easy.

Dan

[joea]

Dan,

Before you order blueprints from anywhere, let me know what you need. All of the NAA board of directors members have a DVD that has a massive collection of pre-war and some post-war Aeronca blueprints on it, and can email them to you directly for free.

All of the blueprints that John Houser in Middletown has, we have already, so let us know if we can help.

Joe A

[DMichaels]

Thanks Joe, I already sent out a check to John but if you want to email me the files I can get to work much faster.
nov32394 at yahoo
Dan

[joea]

Dan,

Need to know the number of the blueprints before I can send them.

Joe

[DMichaels]

7-450 according to Bill

Dan

[bsafran]

Please give us some information about your friend who needs his Champ repaired. He must be one heck of an individual to inspire someone to work that hard to preserve his airplane.

Maybe you can post a picture with him standing by his pride and joy. You do have an uphill battle as do so many others who have stripped off the fabric and found what 60 years of flying does to a plane. Rust is almost inevitable. These planes were never properly sealed and have spent so many years outdoors. Then there were the necessary repairs.

One splice here, another a few clusters down. Each time the mechanic did his best to keep things lined up properly, but how do you stay true to the blueprints when you are fixing things in the field? The rusted tube at the rear of what I call the spine of the fuselage is going to be your toughest repair.

There is nothing in the FAA's acceptable methods, techniques and practices that would permit a repair that does not carry through that very complicated cluster. It's not hard to do, it just takes time - lots of time. Replacing instead of repairing the cracked landing gear bracket in not a good option. Those brackets are not just welded to the longeron, they have a hole in them and slip over it. That way if the weld cracks, the fitting will not give way.

The repair in the tailpost area is the easiest of all and shouldn't take too much time or material. Thank goodness that Bill Pancake is around to advise you on how best to go about fixing your friend's plane. We have Bill's 7AC fuselage jig in Cleveland, OH and if it is not too far to travel, perhaps it would be best to bring it over and let us check it out to find out what else might be wrong with it.

Not only does Bill recommend removing the door channel to check for rust (every one we have checked has needed replacement) he wants you to check the measurement from the front wing attach point to the strut attach point on both sides. The measurements should be the same, but unfortunately the door side seems to settle somewhat and is substantially shorter that the left side.

We offer this jig to any Champ rebuilder to use for free to check their alignment. If repairing this plane might be a bit too much, please allow use to estimate what it might cost to repair it.

Feel free to talk to the people we have helped in the past. I can provide names and phone numbers if you like. I have to admit, while our welder is fantastic, he is slow. Don't expect a quick turn around - sorry!

[DMichaels]

Hi Brian,

I talked to you the other day on the phone. I want to try and get this thing to Oshkosh this year and I just talked to the owner about taking it down there just a few minutes ago. I hate to wait until March though. He thought that would be OK but he is not one to pay much if any for me to do it. I am basically doing this whole project for free (labor). I will also have to fight tooth and nail to get new parts (Instument panel ect). I did remove the door channels and there was rust there.

What I may do is start on the easier parts first and see how it goes. Right from the start I thought I would have to replace most of the backbone. He figured a small little patch over the area would suffice. I think if I took off the back cross piece I could get a piece inside up far enough to work. Then wrap a patch over the new back cross piece and the new backbone piece in a "T" configuration.



I almso cried when I first saw it.

Dan

[DMichaels]

I made a drawing from the plans in TurboCad so I can get any measurement I need.

I will work on 3D so I can get even more detailed.



Dan

[joea]

Assume you got the blueprint I sent?

[DMichaels]

I did thank you. It does not have the tail section measurements but I do not think that I will need them.

I will work on this in my spare time I should be able to reproduce the plans in Turbocad then anyone can just take it to Kinco and print it out fresh.

Dan

[Mikek]

7-450 according to Bill

Dan

Joe A,

Would you also send 7-450, 7-460, 4-547 & 4-562 to me at mknemeyer(at) dmtnet.com, have a print of 7-450 but not in great shape.

Also Dan, Brian and his Jig along with his Welder George can work wonders for your Frame and it will be RIGHT.

Mike K

[DMichaels]

Joe if it is not too much trouble could you forward the other three files that Mike mentioned.

Dan