The five outboard W-1208-Rnose ribs which have had the aft flanges removed are now riveted onto the left wing's spar. Access was great so they were easily and quickly (relatively speaking) riveted onto the rib clips previously attached to the left spar.The five outboard W-1208-R nose ribs with the aft flanges removed riveted onto the spar assembly.
The sixth rib is one of three uncut W-1208-R ribs clecoed in place ready to be riveted next.
The next three ribs to be installed are the only three W-1208-R nose ribs which were uncut. These ribs receive more rivets the usual six on the web of the rib by way of an additional four rivets on the rear flange of the rib.
While removing the rear flanges of the W-1208 ribs I wondered why some aft flanges were left intact. It all makes sense now after really looking at how things go together. In a nut shell, the spar keeps getting thicker and thicker towards the root of the wing because of layer after layer of doubler plates added for strengthening. Because of this, the rib clips only have two large rivets attaching the clips to the spar which, all things considered, is not much support. Therefore, all the nose ribs in the area where there are doubler plates have their rear flanges riveted directly onto the spar. The photos below illustrate the need for the aft flanges on those nose ribs.
The gap behind the rib clip and spar can be easily seen here as well as the four holes
on the spar where the aft flanges of the W-1208-R nose ribs will be riveted.
In this photo of the root of the spar one can easily see the gap behind the
rib clips is considerable because of the many layers of doublers on the spar.
Photo of one of the W-1208-R nose ribs clecoed to a rib clip with the aft flange ready for riveting onto the left spar.
It was a 20 degree morning, so I only spent a couple of hours in the shop and did not begin riveting any of the ribs with the aft flanges. But will try to make progress tomorrow by first seeing how difficult it will be to buck the rivets attaching the aft flanges of the W-1208-R ribs to the spar. A quick check before quitting for the day revealed using solid rivets to rivet the aft flanges onto the spar appears doable at first glance … however the rivets will need to be bucked.