I did all the turn tests used on DokGonzo's website
http://gonzoville.com/ahcharts/index.php , so I'll throw in a couple of notes for anyone interested in testing....
1) Be sure your tests are at the same altitude or comparisons will be meaningless. A difference of just a couple of hundred feet in altitude will throw off your comparisons. All my testing was done at 500 ft.
2) Keep your circles as level as possible. +/- 50 ft in any one circle was my miniumum on each of three turns. If I went up or down more than that I started over with three more circles. I started over a LOT!
3) The most subjective part of the test is calculating, really
guesstimating, your average speed. You will notice that your speed will vary slightly because it will be hard to keep within that +/- 50 ft altitude mentioned above. So you have to take a guesstimate of what your average speed was. You can see that being off just 1 mph in either direction can make a big difference in the size of your radius.
4) How do you know when you've completed an exact circle? Use the .target command to create a target. Start your timing as some part of your cockpit frame crosses the edge of the target, keep it up for three circles and end at the same point.
Divide your total time by 3 to get a one average circle time and use Badboy's formula to calculate your radius.
My formula is different from Badboy's. My formula calculates a slightly smaller radius than his does if I use the numbers he supplied.
I convert speed in MPH to speed in feet/sec (MPH x 1.46), then muliply that by the time to get distance covered in feet, I divide that distance by 3 (since I do three circles) (Circumfrence), then divide that distance by Pi (3.14) to get Diameter, then divide diameter by 2 to get Radius.
Using Badboy's speed and time, my formula calculates a turn radius of:
(170 x 1.46) = 248.2 ft/sec
248.2ft/sec x 18.3sec = 4542.06 ft
4502.06ft / 3.14 = 1446.5 ft (Diameter)
1446.5 / 2 = 723.2 ft Radius
The 2.8 ft difference is irrelevant. It's just the difference each of our formulas use for rounding. His is easier to use, because he's used a constant that takes out a lot of the calculations.
My formula sounds complicated, but since I had to figure it out myself a few years ago and you can see the logic I used, it's what I've got in my spreadsheet which does all the calculating for me automatically.
Warning, once you start testing it can burn up a lot of time. Because then you'll want to test at different fuel loads, different flaps settings, and different weapons configurations.....ect.