A planimeter? ... A PLANIMETER?! Gee wiz, I don't think 2 people in a thousand know what one of those is, much less what it is for or how to use it! That said, you are probably right. We drafter, engineer types had a lot of tools available to us that have long since been replaced by the computer. A pitty. I've got mine stored somewhere with my sliderule. I think I will take it out and knock the dust off just for fun. For those who don't know, it is a tool for measuring the area of an irregular shape by tracing the nifty machine around the parimeter.

Wing area conventions are just that, conventions. They are a bit more useful than government gas mileage stickers on new cars, but serve the same purpose. Good for comparison to that which we know works.

All the best of luck to you on your project.

BP