The ribs are clecoed onto the spar, and all apart from the outer three ribs have bolts top & bottom of the flange. This is the hardware removed from the spars as supplied. Some people have replaced this hardware, but I inspected the bolts and couldn’t see the point, and the MS21042-3 nuts seemed to have the same residual torque as new ones from the pot … so back in they went! 

As usual I applied JC5A to the flanges.

Also I smeared JC5A on the bolts to prevent possible corrosion due to dissimilar metals.

Torque Wrench

My CDI Torque Wrench from Cleaveland is great for setting the correct torques, seen in the top picture. But it is not so good for determining the residual torque value … needed so you can add this to the required setting torque, and then set the wrench to this total value. So on one of my trips to the USA I purchased a dial torque wrench, again by CDI. This is perfect for measuring the residual torque of the nuts prior to final torquing.

Ribs

The inner two ribs are left off at this stage, to allow easier access to set their rivets. They are closer together in this section due to the walkway.

Also you have to be careful to install the bolts the right way round … these inner ribs have some of the bolt heads the other way round from the rest of the wing. I’m guessing it’s to ensure clearance for the wing tanks.

Next job is the riveting, and I’m waiting for Tim to to help!