Joshua's RV-9A Project

More work on the leading edges; I’d hoped to get them pretty much in the bag tonight, but the trouble with the fit of the left LE continues.  I searched last night and wasn’t able to find anything on this particular problem (though there is much said about the fit between the LE and the fuel tank…).  I’ve tried diassembling and reassembling it three times now, with identical results, so I’m thinking the problem isn’t a simple assembly issue, though I don’t know what to say it is.  Between each attempt, I re-checked the ribs for flange squareness and fluting straightness.  Made a couple minor tweaks here and there, but didn’t solve the problem.  Also tried different methods/orders of clecoing, including the Van’s method, to no avail.  After the second failed attempt, I put together the right LE to see if the problem existed there too; it didn’t.  The right assembly dropped onto the spar and clecoed beautifully into place.

The trouble is that, when set on the spar, the wing-bottom row of skin-spar holes lines up correctly, while the row on the top side of the wing doesn’t; the skin holes are about 1/2 diameter forward (up) of the holes in the spar, and the aft edge of the skin sits up from the main wing skin, leaving a noticeable gap.  The gap and hole misalignment is even down the entire length of the LE assembly.

After the third attempt, I tried clecoing the LE to the spar by letting it tip up enough to close the gap, then clecoing the top side along its length in every 3rd hole.  I then clecoed the bottom side, which required pulling down on the LE assembly; thinking that perhaps it would shift the ribs inside as necessary.  The gap stayed closed, but the ribs didn’t shift, their aft flanges just bowed up (on the top side, where the gap was forced closed); obviously not correct.

At this point, I’m not sure how to continue other than to keep taking it apart and reassembling it until it magically fits.  I measured the distance between the skin edge and the aft row of holes (top and bottom) on both the left and right skins, and the figures are identical.  I won’t be able to similarly measure the rib holes until I remove the assemblies and tear them down again.

This entry was posted on Sunday, January 4th, 2009 at 9:15 pm and is filed under Skin Panels. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.