The application may look complicated at first, but it's actually quite simple. And if you're a beginner who doesn't know any of the terms, it'll teach you those aeronautical terms that seem so daunting.

All you actually need to do is fill in those blank boxes that are in that ugly light purple box. There are just 9 measurement you do with a yardstick.

Let's do the first one.
The big blue arrows point out the first measurement we need. The left blue arrow is pointing at the 'A' in the line, "Root Chord (A,AA)". The line includes two blank boxes. The first box is where we're going to fill in the measurement for the 'A'. If you look to the right and find the 'A' in the picture of the airplane, it's easy to see what to measure and where to measure. And obviously, you've just found out what and where the root chord of the wing is.

OK, the 'AA' is the root chord of the horizontal stabilizer. etc etc for just 9 easy to do measurements.

Each of the 9 measurements you need to do is shown on the picture of the airplane with a letter code like the 'A'. Just fill in the blanks. Find what to measure for each empty box by the code to the left of that box. Match the code from the left of the box by finding the code in the picture of the plane.

Simple. And you learn what some terms stand for.

Now all you have to do is run the application with a couple of different "Desired Static Margin" inputs. That's the bottom box in the light purple area. If you wanted the CG location for a "twitchy" aft CG location, you'd fillin the box with the number 5. If you wanted the airplane to have a "VERY safe forward CG" you'd plug in the value, 20. And the airplane would probably fly "mushy". So....... You've measured 9 things and plugged the measurements into the boxes and filled in a Desired Static Margin value. Just click the bar directly under the DSM input box and the application is so fast it looks like nothing happened. But if you scroll down the page, you'll see numbers have appeared in the blocks below the light purple block. Look in them and you'll find the location for the CG for your airplane if you want it to give the Desired Static Margin. That term too scientific for you? Then don't say it out loud in public.

BTW, run the application with a 10% and then a 15% and record the two CG locations, and you've got an extremely dependable CG range for that model.

Hope this helps reduce the mystery.