Originally Posted by
757_Driver
for those that want to know why you can multiply knots (nautical miles per hour) by the gradient and come up with feet per minute. its because there are give or take 6000 ft in a nm and there are 60 minutes in an hour.
The six's cancel out. so you can just to %grad x ground speed.
i,e 140 kt approach times 5% gradient = 700 fpm
FWIW
the genuine answer for a 3 degree approach (5.2%) is 140*5.2% = 7.28 nm / hr * 6080 ft = 44262 ft / hr. divided by 60 mins per hour gives 737 ft /min
I think 700 is close enough for government work.
Or for Descent
gradient =ROD/GS or for Climb
gradient= ROC/GS to find the FPM you need to make the gradient required.....