I'll go down with Airborne Artist then, because I think that 1:1,000,000 is the nearest likely aviation map scale applicable. There are 1760 yds to a mile, 3 feet to a yard, 12 inches to a foot. So a mile is 1760*3*12 which thanks to Danny's permission to use a calculator is 63360 inches. So on a 1,000,000 map 20 miles (the distance Danny flew in 8 mins at 150 mph) is 20*63360/1000000 = 1.27", which in good old air force parlance is close enough for Government work to Danny's thumb tip to knuckle length.
Oh, edited to add that all the above holds true for statute miles only in speed and distance. As Danny was flying a US aircraft I'm assuming the ASI was calibrated as such, otherwise I make'a the big mistake.
Last edited by Chugalug2; 24th Oct 2012 at 22:36.