New Member from Spanish Fork, Utah

[SammyD]

Hello, new member to the forum, been flying 7 and 8KCAB's for a few years, roughly 400 hours in ACA. looking for some guidance or leads on fuel tank repair/replacement that's not too much of a hike from Utah. I'm looking into Santa Paula, CA. Aswell as the ACA facility and many others. we use this plane for instruction and would like to see what we can do about getting this airplane flying sooner rather than later. Any advice would be greatly appreciated.

On another note, what is the general consensus on the causes of these tanks cracking/leaking... from the research I have done its generally snap rolls at high fuel levels, this is the 3rd tank I've personally known to crack in the 4 years I've been flying ACA's we intentionally don't do snaps or fly over 1/2 tanks. general lessons consist of UPRT, Spins, Primary and Sportsman competition maneuvers and tailwheel instruction. we never pull more than 4.5G's... First tank cracked along a baffle weld (common from what I know), second one we could not find using light air pressure and soapy water (just replaced the tank), and now this 3rd one (Still in the wing yet to know exactly what happened)

 

[Bob Turner]

Then you already know what a pain getting these things in and out really is.

Tanks manufactured early in the 2000s are known to be inferior. I don’t know if they stepped up their QC - others may know more.

No, I would never snap my own airplane, or a friend’s airplane. I do slow rolls, aileron rolls, inverted flight, and Immelmans. My 1977 tanks have never leaked, according to the logs. The aircraft was used for serious acro before I bought it two decades ago.

 

[Bartman]

Hello, new member to the forum, been flying 7 and 8KCAB's for a few years, roughly 400 hours in ACA. looking for some guidance or leads on fuel tank repair/replacement that's not too much of a hike from Utah. I'm looking into Santa Paula, CA. As well as the ACA facility and many others. we use this plane for instruction and would like to see what we can do about getting this airplane flying sooner rather than later. Any advice would be greatly appreciated.

On another note, what is the general consensus on the causes of these tanks cracking/leaking... from the research I have done its generally snap rolls at high fuel levels, this is the 3rd tank I've personally known to crack in the 4 years I've been flying ACA's we intentionally don't do snaps or fly over 1/2 tanks. general lessons consist of UPRT, Spins, Primary and Sportsman competition maneuvers and tailwheel instruction. we never pull more than 4.5G's... First tank cracked along a baffle weld (common from what I know), second one we could not find using light air pressure and soapy water (just replaced the tank), and now this 3rd one (Still in the wing yet to know exactly what happened)

Good morning Sammy D and welcome to our humble website. Which airplane is it that has a leak and what year is it? Generally speaking, if the tank is cracked somewhere, there isn't a short cut to fixing it. The only option is to open up the upper fabric of the wing and remove the tank to either repair it or replace it. There are a lot of hard tube and rubber hose intersections that are only held together with hose clamps leaving lots of opportunities for leaks to form but it can be challenging to chase down all of those spots.

You're right about snaps with too much gas in the tanks being a cause. The earlier ACA era tanks didn't have enough tabs on the baffles (they are welded into place through a series of slots on the exterior of the tank) but that's been changed so later tanks aren't as prone to leaking. I've never really heard of the 7 series Citabria tanks being leakers but I guess if you abuse them enough, they'll crack too.

If you have photos of the various cracks/leaks you've experienced, I'm always curious to see what they look like and where they happen.

Thanks and welcome!
Bart

 

[SammyD]

Good morning Sammy D and welcome to our humble website. Which airplane is it that has a leak and what year is it? Generally speaking, if the tank is cracked somewhere, there isn't a short cut to fixing it. The only option is to open up the upper fabric of the wing and remove the tank to either repair it or replace it. There are a lot of hard tube and rubber hose intersections that are only held together with hose clamps leaving lots of opportunities for leaks to form but it can be challenging to chase down all of those spots.

You're right about snaps with too much gas in the tanks being a cause. The earlier ACA era tanks didn't have enough tabs on the baffles (they are welded into place through a series of slots on the exterior of the tank) but that's been changed so later tanks aren't as prone to leaking. I've never really heard of the 7 series Citabria tanks being leakers but I guess if you abuse them enough, they'll crack too.

If you have photos of the various cracks/leaks you've experienced, I'm always curious to see what they look like and where they happen.

Thanks and welcome!
Bart

Hey Bart,

funny thing about that 7kcab someone put baffled tanks (like you described above) into the wing. After receiving the new tank we noticed it did not have baffles. Talking to ACA they informed us they never installed baffle tanks into 7kcab’s so that might be the reason for their lack of being leakers

current airplane in question is a 77’ super with rainbow wood spar wings built in 2013 with new tanks. Tank is still in the wing so no pictures of the physical issue but I’ll dig through my photos to see if I can find the first one I dealt with. It cracked just outside of a baffle weld. Was about a 1.5-2 In. crack if I remember right