"Al Gerharter" wrote in message ws.com...
1083 fps @ 59F, Sea Level, hypothetically dry atmosphere. STP, Standard
Temperature & Pressure. In std water, about 4800 fps. Al

SNIP
For quick and dirty (in one's head) cruise calculations I always used
1.0 Mach = 600 kts. (It's closer to 610 at -57F) but that let me, for
example, say .8M was 8 miles a minute. On the deck, about 670 (11
m/min). That and using fuel flow per minute (3000pph - 50ppm) gave me
rough figures. Of course, if things looked tight, then I used the
whiz-wheel. BTW, on the deck 760 mph is close to .1M (STP), so when
your car is showing 76 mph, you're buzzing along at about .1M. (For
interstate travel, 75 mph is 12.5 miles in 10 minutes . . . we just
completed about 6000 miles of driving where I used this sort of mental
T=D/R to predict ETAs thus boggling my better half. Same sort of calcs
can be used ina light plane such as C152 . . . 6gph = 1 gal in 10 min,
90KTS = 1.5 nm/min; 120(tailwind)=2 nm/min. As above, use the
calculator if things look tight. (If they do you've screwed up.)
Walt BJ