Formula for Descent Rate

What formula is best for calculating rate of descent?

This is a pretty good thread.


For the rate of descent in feet per minute; i use Ground Speed*5… Always check the indicator on the map as it gives you an idea when you’re going to reach your specified altitude

Use VirtualHub to calculate TOD :)

watch this Swiss001 will show you

Cruising altitude - 3000 + altitude of airport DIVIDED BY descent speed = minutes out you need to descend

Actually…I don’t believe in a formula for descent.

I like to think of descent at the “correct” TOD as more of a sweet spot. So the more you fly, the more you know roughly when you need to descent and at what phases of the descent to slow down, reduce vs, etc.

You also have winds to take into account. tailwinds mean you should descend earlier while headwinds for a later descent.

Of course, you shouldn’t expect yourself to master this on the first time (unless you do, then good for you). It’s a trial and error thing, but you can learn a great deal from things that went wrong during descent.

watch this video!!

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Top of descent (TOD) is how far out you should start descent for a desired rate of descent (ROD)
TOD= (Alt/Rod)*(Gs/60)
Pick a rate of descent you like
Alt= Altitude
Rod= Rate of descent
Gs= Ground speed

For a random distance to determine rate of descent
If you want to know how fast to descend from a certain distance then;
Rod= (Gs/60)*(Ft/Nm)
Ft/Nm= Altitude loss needed divided by the distance to destination.

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