1 in 60 rule

This rule is also used by air traffic controllers to quickly determine how much to turn an aircraft for separation purposes.

But since even a skilled pilot cannot manually fly with better than about 2° accuracy, and winds are constantly varying, the rule remains useful for most realistic situations.

The math behind this shows that this method is not entirely accurate, with roughly a 5% error, but the rule's objective is to get workable numbers in a dynamic environment, and it fits this purpose quite well.

Here is the breakdown: A circle of 60 NM radius has a circumference of: 376.99 divided by 360° produces: This rule is therefore very good approximation.

This becomes very useful for estimating or correcting vertical speed settings and flight path angles (FPA) during climb, descent, or approaches.