Preparing the Wing Ribs

I saved time by preparing all the ribs for both wings at the same time.

I began the preparation of the ribs by deburring the edges of the flanges and lightening holes.

I adjusted the rib flanges 90 degrees to the web using a special flange bender.

Incorrect flange angle.

Using the custom tool to adjust the flange angle.

Verifying corrected flange angle.

The forming process leaves ribs bowed, particularly the leading edge ribs. I straightened the webs with fluting pliers. I placed the center of each flute at the midpoint between the prepunched holes and used a straightedge or holes in a wing skin to check for straightness of the line of rivet holes. The straighter the parts, the better they fit.

Comparing the rib straightness with a straightedge.

Using the fluting pliers to straighten the rib.

Verification of straightness after adjustment.

I made provision for running stall warning system wires and wingtip position lights, strobes or landing lights by drilling holes in the ribs for the installation of 3/4″ conduits. I installed plastic grommets in the 7/16″ holes in the inboard ribs of the left wing for routing the pitot tube line.

Time: 6 hours.