Tank cover

Joined
Jul 23, 2019
Messages
4
#1
Hello to all of you from the Netherlands,

Last year we've bought a 1967 Citabria 7GCAA and we decided to change the wooden spars for aluminum ones of the Milman kind.
We've got the spars in now, but our tank area is not like most pictures I can find on the forum.
When we took it apart the whole wing was covered with fabric. After removing it we could see threaded rivet nuts in both ribs
next to the tank and also on the 2 u-shaped alu parts on top of the front and rear spar.
That suggested to us that in the past it could have held an aluminum tank cover fastened with screws in the those holes.
Do any of you know such a construction ever existed on a Citabria?
It would make sencse, if something's wrong with the tank, just open the latch and lift it out, no fabric cutting.
I've seen it on the Piper cub, but could not find anything on the Citabria on the internet.
The tank is a welded 18 gallon version.
Hope someone can tell me something about this,

Thanks in advance, Simon
 

aftCG

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Apr 3, 2018
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#2
Welcome to the Asylum.

A removable skin over the tanks makes way too much sense. I have a hard time believing there isn't an STC to do the job.
 

Bartman

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#3
How many of those nut plates are there? I'd guess they would have to be every couple of inches or less to hold a large flat panel in place on the top of the wing.
 

Bob Turner

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#4
If it helps, my tanks are covered with fabric on all Cubs and the Decathlon. Aggregate total time without needing tank removal is approaching a half century. So - worth the effort? No, at least until a tank removal becomes necessary.
 

aftCG

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#5
Well my plane has had the surgery. They did a good job on the fabric repairs but the paint isn't a perfect match. And leaking tanks on a Citabria are not uncommon.

A C172 has covers that come off. If Cessna can do it...
 

Bob Turner

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#6
And Super Cubs. Yes, if you need to go in there every ten years, a cover will save you big bucks! I have done two Decathlon tanks (not mine) and it is a very expensive proposition. It seems uncommon, except for tanks welded up around 2002-2003.
 

MA Cantin

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#7
Hi November67, we have a 1959 7EC and it has the covers for the tanks. Not sure if it is original or changed through the years. We did the spar conversion too. For photos, look on the thread: ‘59 champion rebuild project on this forum. Hope this helps!

MA
 
Joined
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Messages
4
#9
Thank you all for the welcome (to the asylum...?) and your answers!
On the forum is a list of STC's but I can't find the right one.
There are quite a lot of nutplates with AN3 or AN4 holes just above the spars and in the ribs around the tank
area, the wings are away for spraying (primer) so I don't have pictures, but I guess the must be 3 or
four inches apart. Since this a big tank, we don't have the rib in the middle, but right next to the 3 tank holding straps
there are 3 omega shaped strips from the front to the rear spar, to which one could rivet or screw the panel.
We really want the panel, hope we never need it, but if we do..... Since she isn't wearing anything at the moment
this would be the right time. I've seen your pictures MA, thank you for pointing out to me, since I had not seen the
holes and the panel behind the wing.
Interesting question by mr Bartman, I don't know if MA Cantin wants to tell us, but since there is evidence of
something simular in the past in our plane there should be something in our log as well.
Last time she was covered was in 2012, but all fabric over the tanks.
Strange things can appear and disappear just like that........

Simon
 

MA Cantin

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#11
I had a look at the tech log. It only dates back to 1970. In 1993, the aircraft went through a major rebuild. I found an entry with a description of the work done. The tanks were replaced at that time. Here is a photo of that entry and the tank installation details. Not sure if the tank covers were part of this installation or if they were already on there. Btw, we are in Canada. I hope this info helps. It’s a start anyway! Let me know if you need anything else!

Best of luck,

MA
 

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Bob Turner

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#12
That DOT approval - is that a Canadian field approval?

Here’s my take: you do this with a field approval, because you are modifying a rib. You are also messing with the airfoil, but that should stay in the minor alteration category, because you will never notice the change.
 

Bartman

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#14
"Smith Aviation Products" doesn't return anything on google, was that for the tanks or the mods I wonder.

Talking about all of this stuff makes me want to bring home another project.........:unsure::unsure::unsure:
 

aftCG

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#16
Good question. I found this place which is here in ontario. The website mentions metal spar conversion for Champs as well. Might be the same guy for the tanks? @November67 maybe you could look into this. Here is a link:
http://bbiaviation.com/
Are you s****ing me? Kit built knock offs of Champs and Scouts?! The answer to my dreams
Where's my check book?
 
Joined
Jul 23, 2019
Messages
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#17
Thanks for looking up in your log, MA! A field approval is not what it once used to be, I read on the internet and
is not automaticly applicable to another plane , I'm afraid. I'm curious whats in our log, the co-owner is back today so
we'll have a look. Perhaps I can post some pictures of our wing tank opening.

There's a Canadian Smith family producing aircraft parts in Ontario, perhaps they used to be Smith aviation products in the past (?).
I can't find the D.O.T # on the net.
 
Joined
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#18
Something went wrong with timing, I'm afraid MA. I reacted on a not updated page of this thread.
Saw your comment after updating this mornnig, but at least we've found the same company.
Sorry for that, I'll try to contact them.
Im struggling finding anything in our log, I'm not very good at reading handwritten Italian......

Thanks again, Simon