Series 5 Vixen partial (second) rib

**FoxBob** · 11-29-2023, 07:49 PM

When installing partial rib #2 PN 27023 (mine were stamped 27022) under the fuel tank, instruction says to trim to fit around aft edge of fuel tank, fabricate shims from scrap stringer material (wood) so that the the bottom cap strip of partial rib conforms to airfoil profile of #1 and #3 ribs. Bond partial rib to rear spar and shims to fuel tank. The instructions say nothing about attaching partial rib #2 to the front spar (too short to reach) nor to the shims. The illustrations do not show any such attachment. Is the front of the bottom cap strip of partial rib #2 intended to free-float? Should it be bonded to the shims? Should the shims be applied at more than one location along the bottom cap strip?

**alexM** · 11-29-2023, 08:16 PM

I've slept since I did this job, so I might need a picture of how it is too short to reach the front spar. I recall trimming it to fit, but I do not recall it being too short.

To answer the rest of your questions, you will likely need at least a few shims between the tank and that floppy lower cap strip in order to get it to be "fair" with ribs #1 and #3. You will absolutely be bonding that cap strip to the shims, which in turn will be bonded to the bottom of the tank.

My mother would be the first to tell you "don't do what Alex did", but here are some pics from that job
PXL_20211017_210157653.jpg
PXL_20211021_041153878.jpg
PXL_20211021_041206025.jpg

**Jerrytex** · 11-30-2023, 10:48 AM

Also take note of your rib stitching pattern. Make sure you don't glue your spacers where your rib stitching needs to be in order to be lined up with the rest of the rib stitching on the wing.