[Wills_9A]

I have a quick question for the experts out here....I am riveting skins on my wings and I am probably going to leave the bottoms off, but according to my manual (RV-9) I am only to screw and bolt about half of the tank attachment bolts and screws (presumably because it would have to come off later). I can not find anywhere in the manual where the tanks have to come off again, looked at wing attachment with no joy.

My question is, should I go ahead and final attach my tank now, as it looks like it would be much more difficult to do with the bottom skins riveted on? OR, is it really easier to leave them out as I may need to pull my tanks off later.

As always, thanks for the help!

 

[ClayR_9A]

prepare to remove the tanks

I've had mine off... twice... to fix minor leaks.

Prepare for the eventual job while the bottom skins are still off. Make SURE the pitot tube (or any wire) routing doesn't interfere with your ability to get a socket on each of the bolts.

Countersink the aluminum z brackets leading into the platenuts to help the bolt find the platenut.

Make sure you spend the time to smooth the inside of those large lightening holes on each side of the wing access panels. (a 1-2" scotchbrite wheel in a die grinder works well for this)

Make sure all the bolts fit easily through the spar into the tank attach brackets. Enlarge the holes (slightly) in the spar if necessary so the bolts can go through and engage the platenuts easily without any trouble.

Just imagine yourself, under the wing, reaching up inside the access panels with an air rachet trying to get at those bolts - with the aileron pushrod in there to make things harder. Do anything you can now to make that job easier later.

Once you're satisfied, attach the tank with all the bolts before you rivet on the bottom skin... and HOPE you never have to take the tank off.

 

[hoskinsb]

Van's Response

I had the exact same question a couple of weeks ago. I have attached Ken Scott's response. Hope this helps.

"It is often easier to work on the fuse/wing -- especially in the panel
area -- combination if the tanks are off. The tanks need to be on for
some initial fitting work, though, so we specify using just enough
fasteners to do that." Ken Scott


Brent