Hatz Biplane Association

Sorry for the barrage of questions lately.

The end rib on page 8...that's only for the bottom wings, correct? The end rib associated with the center section is all I'll have for the upper wings then.

Thanks for all your patience with me.

John

I don't have my plans handy at the moment, but if I understand your question correctly, it's safe to say that each wing section & C/S have end ribs. The C/S has end ribs and the top & bottom wings have end ribs at the root. All of them are solid plywood as specified on the plans.

I am looking forward to your answer as I have not been able to find the upper wing end rib on the plans either. The lower wing end rib is on an angle so I would assume that it would be too wide/tall for the upper wing. The center section rib is also a little different since it sits on the plywood floor and the mounting plates will be in a slightly different location. I would probably use the center section rib from the plans but I glued it to my center section plywood when I made the center section ribs and now it is gone. I was just going to trace a wing rib and "wing" it.

It seems to me, the sheet 8 end rib applies only to the lower wings. The CS end rib is a little different; it won't match up with the lower wing end rib and sheet 8 rib seems to have notches unique to the bottom wing walk area. I don't see how or why there'd be two end ribs together up there. I'm about to gamble on that as I submit my wood order.

John,
There is defiantly an end rib for the top wings it is just a question of whether or not it is on the plans. There are two end ribs at the center section wing union with about 1/8 of an inch between them. I can't find it on the plans but I am sure that it is there.

I should have checked these before posting. Oh well. The photo's are from Scotts site.

This shows center section behind the wing root. Guess I'll update my order.

These plans are known for some inconsistencies where a part may appear on one drawing and not appear on a related drawing. When analyzing a particular component or assembly, you need to take a good look at the plans and make sure you review any and all drawings (probably spread across multiple pages) that may document the part you are interested in.

In the case of the top wing root rib I'm pretty sure it appears on the drawing that shows the connection of the top wing and center section as it specifies the required gap at that location. I'll get the page # tonight when I get home. I think it is also shown on the top wing drawing as well.

The only difference between top and bottom wing end ribs is that the lower wing end ribs need to be canted a little to make clearance for the fuselage side if you are building as per the Classic. In other words, the Classic fuselage sides bow outward and cause the wing end ribs to poke into the fuselage skin just above the lower longeron unless the end rib is canted outward to prevent this.

I specifically pulled those plans (sheet 10) when this started, and no help there. All I can say is, thank goodness for the builders posting photos, otherwise, I wouldn't have a chance at this. I literally have a hole in my pants (right knee) from being on the floor looking at all the pages. That mechanical drawing class from college is not helping