Hatz Biplane Association

Dear friends, I am about to build the rib jig and do not understand some details on the plan for the aileron ribs. It appears that the aft end of the shorter wing rib has a separate beveled spruce spar in the span-wise direction? The aileron rib appears to have three span-wise spars in the front, middle and trailing edge (wedge) of the rib. Is this correct? When making the ribs for the aileron section, it appears to be simplest to make a full-length rib with the different layout shown in the lower RH corner of the rib plan, then remove the cap strips on the top and bottom where the aileron separates from the wing? These additional spars are then added when the wings are assembled? I hope this makes sense. I keep searching for the guide "Hatz Construction for Dummies" that describes such things but until now No Joy.

There are three pieces of spruce that make up the aileron opening/aileron in the original design.
One at the front and one at the rear of the opening and the third is the small piece halfway back. I used the wedge as a filler, for strength, and it is the same width as the rib. I had plenty of small pieces of plywood left over so I used that, covered by a gusset, instead of spruce. My trailing edge is aluminum.
How you construct them is up to you. Some builders made all of the ribs full length, assembled them to the spar, added the three pieces of spruce and then cut away what was not needed. That way you know everything will match up later.

Jeff Moore

Thank you Jeff! I like the idea of cutting away the ailerons during wing assembly. This sounds similar to the way some composite wings are made. Kent