Wing spar replacement options

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kayakalex

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My 7ECA had its annual at the end of June, and we found two cracks in the starboard front spar. The larger crack is maybe 4" long. A .005" feeler gauge can be wedged in about 1/8". Both cracks are on the rear face of the spar between the fuel tank and the strut attachment. Both cracks run with the grain, near the center of the spar. Neither crack goes thru a bolt or nail hole. There is no evidence of compression failure on any spar.

I've had this plane 6 months. My A&P IA also performed the pre-buy inspection, and we did not see these cracks. They're pretty small, but he’s meticulous so I think they’re new. Also, the pre-buy inspection was done in the winter in a moist region of Washington state. Now it's June, and it's been warm and dry for a couple months here in Oregon. The plane used to live in Phoenix, so it has seen some big humidity changes.

I got second and third opinions from A&P IAs with experience inspecting Champs. Neither expect the cracks to be an immediate safety issue. Both agreed that the spar fails the wing spar AD.

I’m exploring options, and here’s what I’ve found so far.

Option 1. Replace just the one defective wood spar. I got an estimate of $4k to have it done. It’s the least expensive option, but it might be false economy. Something caused one spar to crack. Others may follow.

Option 2. Buy new aluminum sparred wings from the factory. Add shipping (about $1250 to Oregon) to the prices on ACA’s web site and it totals about $20k with some time for my mechanic to install them.

Option 3. Buy and install Milman aluminum spars. The spar kit is $4k. The leading edge kit sounds like a good idea, so add $1100. The myriad Polyfiber products listed to cover two Citabria wings plus miscellaneous stuff I could identify added up to $2700. I’d need a HVLP sprayer… Pretty soon, it’s looking like $8-12k+, depending on what surprises I find and how much I hire out. (The goal is to finish the project before losing my wife, so I may end up hiring out a bunch of this.)

I welcome advice, comments, recommendations, etc. Are my cost estimates in line with your experience? Are there other options I should consider? Am I a wimp not to do all the work myself? Do you know someone in the Willamette Valley who needs a project more than I do? Thanks in advance!
 
I found cracks like that on a rear spar of my Decathlon. Plan A was to repair them - the SL calls for repair or replacement however splashing ink over the spar revealed that the defect extended over several feet instead of several inches.
Similar history with inspections and climatic changes when I bought the airplane 18 months previously.
But - when we stripped it we saw that it had a wingtip strike - many years ago. Hit so hard that the fuselage fitting had put a half inch deep impression in the butt end of the spar - couldn't be seen until the wing was taken off the airplane. So we replaced the front spar as well.
That cost of $4K to replace one spar - that include recover, paint and instal?
Pix of my Decathlon at http://www.airplanecards.com/gallery/djpacr
 
Dave,

The spar replacement estimate was done over the phone based on info I supplied. My level of involvement was to include drop-off, pick-up, and writing the check. I assume they'd find other stuff that needed to be fixed once it got opened up.

It sounds like I should remove the fabric and inspect everything before committing to any plan of action.

Nice looking Decathalons! Which one is yours?

-Alex
 
I had both wings rebuilt with new wood spars on my Citabria for $14K including recover. It flies great, and once you fly the wood in slight turbulence you will never want aluminum.
 
A number of posts mention the harsher feel of aluminum spars in turbulence. I've only flown wood sparred Citabrias, so I don't know what I should expect with aluminum. Would it be harsher than a C-152? A little? A lot? Is it like hitting potholes in a pickup truck? This is a consideration.

Then there's the question of whether to bother rebuilding with wood at all. The AD is written so broadly, anything that looks like a crack will ground me. And the 3-4 months of flying I'm missing this year are the most turbulent ones. By the time summer bumps arrive next year, I could be so accustomed to aluminum spars I might not notice a difference. What do you think?
 
I am new to this site and pretty new to Citrabias, flew one years ago, late 60's or early 70s. Anyway, is there information available for me to sort out the different models,(BCA,ECA, etc) with info on engines, spars and such. I'd like to buy an airplane to be able to put on floats during the summers and wheels or skis in the winter. Does anyone have info on how these airplanes do on floats?
Thanks
StPat
 
We replaced ours with Milman spars. The price for the spar kit was $3,100. The parts fit great the plane flies great. I don't notice a rougher ride at all. The total for both wings was about $12,500.

This compares to $18,000 for American Champion to do the job and also they want to charge a $4,000 core charge that you may or may not get back all of. Also, we feel the Polyfiber process with aerothane is standing the test of time compared to some of the cracking problems mentioned with the AC process.
 
I'm not to sure but I'll check in the morning I think there is a company that makes the same spar as millmen cheaper....
 
charlie hensley said:
This compares to $18,000 for American Champion to do the job and also they want to charge a $4,000 core charge that you may or may not get back all of.
Click to expand...

Actually we have never failed to give the entire $4k back. Its just a clause 'in case". Also, since the AD we basically just plain stopped worrying about the core charge. Its still posted, again, 'just in case' but we have not actually done a core charge for a few years.

Wood spars dampen turbulence? Thats a new one.
 
I flew my airplane (7gcaa) to the factory last year from California and had the wings replaced. I haven't noticed any difference in ride in or out of turbulence. Only difference I noticed was a more confident feeling looking at that larger strut holding the wing. Also everyone remarks about the excellent finish on the wings.
Ray
 
I bought the new wings from ACA uncovered, and covered them myself, saved some $. Exelent wings, no wory.
Bill Becker
 
globe,
Care to elaborate on how much you saved? When my wings need a rebuild I will be using a metal spar. My Champ is a 7AC-CONV with an O-235 and I have 13 gallon tanks in each wing.
 
I don't remember the exact savings for buying the wings without cover, but I think it was around $2000. The price I payed in 2002 was $16000.
Bill Becker
 
Dumb question, with a metal spar conversion do you get a higher licenced empty weight? I have a 78 7gcbc, I'd love to get a legal increase rather than push the envelope on 1650 when taking a passenger.
 
With a 7GCBC and ACA wings you get a higher Gross Weight. 1800 lbs to be exact.
This does not apply to Milman's
 
Wood spars dampen turbulence? Thats a new one

Thats not a new one if you fly wood wing wonders. Wood flexs more in turbalance. I have 2 wood wing wounders and when friends are flying next to me and start to complane about turbalance I take another drink from my open contaner( non acholic) :lol: :lol: :lol:
 
I flew the wood for years in my 79 GCBC and now have metal in my new American Champion GCAA . If you could feel a differnce you will soon forget about it. Plus I am happy not to have to worry about seeing little nails on the hangar floor! If you have the money go for the new metal wings they are worth every penny. You can safely put "the feel of the wood" off your reasons list .
 
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