1 in 60 rule
Encyclopedia
The 1 in 60 rule is used in air navigation
, and states that if a pilot has travelled sixty miles then an error in track of one mile is approximately a 1° error. It is based on the small-angle approximation. In reality the error is 0.96° but this difference is trivial in air navigation. It is hard to fly more accurately than within about 2° of tolerance. The error increases with the angle but again remains within flying tolerances for any error that is likely to occur in the air. Because this rule is used by single pilots with many other tasks to perform, often in a basic aircraft without the aid of an autopilot
, it must be a simple process that can be performed in their heads. This rule is also used by air traffic controller
s to quickly determine how much to turn an aircraft for separation purposes.
If a pilot is flying a 120 mile leg and finds after 30 miles that they are two miles left of track then they have flown 4° left of their intended track, i.e.
left of track. Changing the heading four degrees right will now bring them to parallel the intended track. At that point they still have 90 miles to their next waypoint. They are thus two miles to the left of that and thus the waypoint is 4/3 of a degree (2 × 60/90) to the right or approximately 1° right. The pilot then adds these two to get 5° and flies 5° right of their previous heading.
You can also use the 1 in 60 rule to approximate your distance from a VOR
by flying 90 degrees to a radial and timing how long it takes to fly 10 degrees. The time in seconds divided by 10 is roughly equal to the time in minutes from the station at your current speed.
Air navigation
The basic principles of air navigation are identical to general navigation, which includes the process of planning, recording, and controlling the movement of a craft from one place to another....
, and states that if a pilot has travelled sixty miles then an error in track of one mile is approximately a 1° error. It is based on the small-angle approximation. In reality the error is 0.96° but this difference is trivial in air navigation. It is hard to fly more accurately than within about 2° of tolerance. The error increases with the angle but again remains within flying tolerances for any error that is likely to occur in the air. Because this rule is used by single pilots with many other tasks to perform, often in a basic aircraft without the aid of an autopilot
Autopilot
An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...
, it must be a simple process that can be performed in their heads. This rule is also used by air traffic controller
Air traffic controller
Air traffic controllers are the people who expedite and maintain a safe and orderly flow of air traffic in the global air traffic control system. The position of the air traffic controller is one that requires highly specialized skills...
s to quickly determine how much to turn an aircraft for separation purposes.
Examples
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.If a pilot is flying a 120 mile leg and finds after 30 miles that they are two miles left of track then they have flown 4° left of their intended track, i.e.
- 2 × 60/30
left of track. Changing the heading four degrees right will now bring them to parallel the intended track. At that point they still have 90 miles to their next waypoint. They are thus two miles to the left of that and thus the waypoint is 4/3 of a degree (2 × 60/90) to the right or approximately 1° right. The pilot then adds these two to get 5° and flies 5° right of their previous heading.
You can also use the 1 in 60 rule to approximate your distance from a VOR
VHF omnidirectional range
VOR, short for VHF omnidirectional radio range, is a type of radio navigation system for aircraft. A VOR ground station broadcasts a VHF radio composite signal including the station's identifier, voice , and navigation signal. The identifier is typically a two- or three-letter string in Morse code...
by flying 90 degrees to a radial and timing how long it takes to fly 10 degrees. The time in seconds divided by 10 is roughly equal to the time in minutes from the station at your current speed.