How do pilots calculate their rate of descent so that they’re at ground level when the reach the runway?

Question

How do pilots calculate their rate of descent so that they’re at ground level when the reach the runway?

In: Other

Answer 1

Since nobody else has mentioned it. When planning for when you should be starting your descent, a general rule of thumb is the “3 to 1” rule. For every 1,000ft you need to loose, you need 3 miles. So if I’m at 30,000 ft and I want to be at 3,000ft 10 miles from the airport, I will need 81 miles to descend. + the 10 from the airport so 91 miles from the airport I want to descend. (30,000-3,000= 27,000) (27×3= 81) (81+10= 91)

So if ATC hasn’t started me down by then, I’ll go ahead and request lower.