3:1 Rule
altitude to lose (in thousands) x 3 = dme to start down
G/S divided by 2, add a 0 = FPM required for 3:1 calculation. (also works for FPM required for glideslopes)
example: you are 24000 need to cross nesto at 10000. Groundspeed is 420
14 x 3 = 42nm
420 / 2 = 210 add zero 2,100 FPM
start down at 42nm and use 2100 fpm
make sure to increase descent rate when GS increases
Last edited by propjunkie; 04-28-2011 at 11:48 AM.