Originally Posted by
freezingflyboy
Wow, good luck with that! Whats so hard about estimating to make the mental math easy? Look folks 13DME is pretty close to 12DME, right? At 12 DME each degree of arc is roughly 1/5 of a mile (60/12). Divide the number of degrees to arc by 5 (70/5=14) and boom, i just flew 14 miles along the arc. No paper or calculator required. Sheesh, yall like to make things complicated, dontcha!
And no, they wouldn't be impressed. If a kid whipped that out when I used to give checkrides (Not that I would, its a stupid question. Who cares how many miles you flew along an arc?) I'd tell him thats how a mathematician would figure it out, now how would a pilot do it?
I'm not freaking out I'm just curious about the math. I used 2*pi*r where r=13dme and I keep getting an answer of 20.42miles
90/360=.25 Therefore after plugging in my numbers to the above equation and making sure to add the (90/360) for the dme degrees it looks something like this. [2(3.14159)][13(.25)]=20.42nm. We are about 6miles difference is a lot. 42% off.