Fuel tank access question

Flying Scotsman · #1 11-27-2007, 12:55 AM

Okay, another dumb question...

There's a big ol' access plate that goes on the inboard side of the fuel tank, covering a big ol' hole that you cut in the rib. Our question, dumb as it may be...why? Do you really *need* to cut that sucker out, or could one just mount the fuel pickup to the rib? When would you ever need to get into the tank, anyway? You can't repair a leak other than on the inboard bay via that access. To repair or replace the fuel pickup, perhaps? How often would one need to do that?

Or is there some other reason for this access hole that we're missing?

asav8tor · #2 11-27-2007, 01:21 AM

Excellent point. My covers are prosealed on so tight I can't get them off. If I need to get in there I'm going to have to cut a new hole in the rear baffle, so might as well not have it.

I'm trying to think. You might need it in final assembly of the tank?

rzbill · #3 11-27-2007, 03:56 AM

I'm not flying yet, so my tanks are pressure tested but not flight experienced.

I elected capacitive gages and I custom designed a conventional fuel inlet in the bottom rear corner of the tank to accept an externally removable finger screen. This was before the fuel fitting SB and before seeing the RV-10 tank which is basically the same idea. With no moving parts inside, I deleted the access panel. It is not needed for tank assembly.

I would have left the panel in place in any other tank configuration (ie: std pickup, flop tube, float gages)

If I run into trouble, I have saved the panel parts and will install in the back baffle adjacent to the problem needing to be fixed.

Jeff R · #4 11-27-2007, 05:52 AM

I think it is there to make it easier to service the fuel pickup and and sender unit should there ever be a problem. Without it, you will have to cut into the plate, and that is a lot harder to do after the tank is built. The cork gasket is there to make gaining access easier though, if you prosealed both sides, it will still be a pain (it will be a super pain if you didn't use the gasket). The only thing I would do differently over what the plans say is to add an extra fitting for a possible, future fuel return line needed by some fuel injection systems.

Mel · #5 11-27-2007, 06:33 AM

Many of us have used proseal and NO gasket on the access plate. No leaks and it's not all that difficult to remove when needed.

Rick6a · #6 11-27-2007, 06:55 AM

Quote:

Originally Posted by Flying Scotsman

....There's a big ol' access plate that goes on the inboard side of the fuel tank, covering a big ol' hole that you cut in the rib. Our question, dumb as it may be...why? Do you really *need* to cut that sucker out....

Interesting question...and not so dumb! Last summer I did a repair on a friend's Piper Cherokee fuel tank which is similiar in design to an RV fuel tank. To gain access to and replace the badly rusted fuel filler flange, I had to cut in an access panel on a 40 year old fuel tank. Obviously, Piper did not build the tank with future access in mind.

Flying Scotsman · #7 11-27-2007, 11:09 AM

Re: fuel injection return line...can you elaborate? I intend to run an XPIO-360...

Re: fuel filler repair...this wouldn't help that, as the access panel is on the inboard end of the fuel tank (don't have plans in front of me at the office, but there is no access plate on the outboard end, IIRC).

And lastly...if I had to repair or replace the flop tube or fuel pickup, couldn't I just cut the access hole at that time and retrofit it if/when it ever needed to be done? How often does a fuel pickup "go bad" or need servicing, anyway? I haven't any idea, just asking.

More and more I'm thinking screw the access panel...just another messy job w/ sealant and a potential leak and a bunch of work for not much, if any, gain...unless I'm missing something really critical here...

erich weaver · #8 11-27-2007, 11:30 AM

Its possible to remove the plans-built access plate even with the wings attached. I dont think you could cut an access plate after the fact with the wings attached however.

erich

Flying Scotsman · #9 11-27-2007, 11:36 AM

All you have to do is pull the fuel tank off, though...not that big of a job. Not fun, but not like taking the wings off.

The one thought I had was that the access plate allows you to put your fuel pickup tube(s) in after sealing all the ribs and the rear baffle, thus avoiding the possibility of somehow getting sealant on the pickup end of the tube during assembly. I suppose that might be a very good reason to have an access plate...

chaskuss · #10 02-21-2023, 07:37 AM

Quote:

Originally Posted by Flying Scotsman

Okay, another dumb question...

There's a big ol' access plate that goes on the inboard side of the fuel tank, covering a big ol' hole that you cut in the rib. Our question, dumb as it may be...why? Do you really *need* to cut that sucker out, or could one just mount the fuel pickup to the rib? When would you ever need to get into the tank, anyway? You can't repair a leak other than on the inboard bay via that access. To repair or replace the fuel pickup, perhaps? How often would one need to do that?

Or is there some other reason for this access hole that we're missing?

I realize this is an old thread. That said, now you could set up your float style gauge as is done on the RV-10 & 14. No access cover installed.

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