Magnum CG - ?????
Okay guys, help me out here. I have read the comments from Magnum fliers about CG placement, and from the what I saw it seemed the range of 135 - 145mm from the LE at the root was a good spot.
I was sitting over tea at lunch, fiddling with the last details on my Magnum hoping to put it up on Monday. So, wondering about the CG in relation to the MAC I grabbed a sheet of paper from our plotter and laid out a wing panel. I then looked at the tip and decided to extrapolate the LE outward, and intersect a line that seemed to bisect the swept tip area about in half. So now I have what I considered a good representation of the wing planform with a straight cut tip.
Now.. I used the standard method of determining MAC, drawing lines forward and rearward from the root and tip, equal to the other's chord length respectively. I then drew the lines that intersect at the MAC. So far it looked like it made sense. Then, I calculated the 25% and 30% locations on the MAC, and extended them back to the root. Here's what I got:
25% MAC: 188mm from LE at root
30% MAC: 200mm from LE at root
So - either I did something wrong here, or you guys are all flying with way forward CG's... but you'd think someone would notice that.
Anyone have thoughts on this?
MJD