The 1-in-60 rules is a basic rule of thumb used in air navigation. It states:
One degree offset equals one nautical mile when sixty nautical miles from the origin
|Distance from VOR||1 degree = ?nm|
If a pilot is flying a leg of 120 miles and finds after travelling 60 miles that they are two miles to the right of track then a correction of 4° to the left (2° to fly parallel to the intended track and another 2° to bring them to their target) will bring them to their destination.
To calculate the distance on a DME arc, use these basic calculations.
10nm Arc = Divide radials by 6
12nm Arc = Divide radials by 5
15nm Arc = Divide radials by 4
E.g. 30 degrees of a 10nm arc is 30/6 = 5nm