The chine is a fuselage wing, in as it gives lift and control to the aircraft, a brilliant thought by Kelly that was extended on the SR-71 after testing the A-12.
BTW, Slide rules are great, but I gave those up years ago, I program all my CNC equipment in my head, I only use an editor to tell my machines what I want it to do. I'm sure all those cam programs are nice for people who don't really understand what a machine does but I know exactly what its doing.
Yeah...old timer....who knows what the....
My dad made me go program his Acroloc on Saturday's in the 80's because I typed faster than he did. He mostly stood behind me and told me what to do, but he used a hand calculator and cheated a bunch because he was usually hungover.