More research for the Wing Leading Edge Mod

As I previously posted, I think I have made a decision to construct a removeable short nose section of the leading edge of each wing to make a completely modular, removeable section of the wing leading edge. Last night I decided to do some research on some P-51 web sites to try to find a drawing  or somthing that would show the internal wing structure, especially around the machine gun ports. I was pretty certain that there was an additional short spar in between one or two of the LE ribs to serve as a support for the gun barrels and provide some extra strength to the bay in which all the guns reside. I did this to tryto determine if I would need a similar short spar in between the two ribs that form the edges of the bay that I will use for my mod. Then it turns into an analysis to determine if I need a spar for the removeable section,or if I only need a spar in the location where the removeable section will detach from the ribs on either side and the wing skins on the top and bottom.

If I do decide to use a spar for the removeable section, then there is the question of what thickness of aluminum to use. This then led me down apath of taking a look at some builders that have modified their aircraft to incorporate some integral auxiliary fuel tanks into the leading edge of the wings. Ron Duren and Mike Rettig immediately came to mind. I had not visited Ron's site for long time, but I knew that he was still chipping away at finishing his RV-7. I was pleasantly surprised to find a recent post wherehe talked about finishing up his wiring and then being ready for a first engine start soon.

I was also able to dive into his blog to find all of the detail around the Tuckey-Duren Leading edge aux fuel tanks that he built. Hopefully my mod will be bit simpler, but I will most likely need to fabricate my own spars, and that means precise bending of the flanges on all 4 sides - yuck! This becomes even more complicated bythe fact that there are lightening holes on the ribs on both sides, and stiffener indentations that firther restrict where the flangesof the spars can attach to the ribs. I could replace the LE ribs with end ribs for the fuel tanks, which have no lightening holes. THis would make it easier to place the spars where I want to put them,but the problem with the tank ribs is that they are shorter than the LE ribs since a baffle plate is used to seal the back of each tank, and this baffle plate sits forward of the main wing spar by a couple of inches. I could probably modify those ribs by extending the length with another piece of aluminum, but that leads to more structural strength questions.No matter what I decide to do, I will always have to takeinto account the effect of this mod on the forces of shear, tension, and torsion that may be applied to the wing under a variety of different flight conditions.

I must continue to resist the urge, no matter how great, to experiement to the same great degree of trial and error engineering that the Wright brothers must have had to use. IOW,I don't want to just slapthis together and then go try it out, even though the Experimental Aircraft Certification category basically allows me to do just that. I value my life and the lives of others just a little to much to be that brave. (read stupid, bold, etc.-reminds meof the old saying:

"There are bold pilots, and there are old pilots, but there are no old, bold pilots" - I think you get the point.

Anyway, I am taking fine measurements of everything right now so that I at least I will know the dimensions of all the parts I am going to need for this little project. Even though I am not slamming rivets just yet, it feels good to get back into the businessof designing and building an airplane.