Are the numbers on a runway true or magnetic?

Airport runways are perhaps the most visible example of a navigation aid updated to match shifts in Earth’s magnetic field. By FAA rules, runways are numbered according to the points on a compass, from 1–36, reflecting the magnetic compass reading to the nearest 10 degrees and dropping the last digit.

How is a runway numbered?

All runways are numbered based on the magnetic azimuth (compass bearing) in which a runway is oriented. There are 360 degrees on a compass rose. The opposite end of the runway always differs by 180 degrees, so it’s numbered 18 higher or lower. For example, Runway 9-27 is oriented east-west.

What is magnetic north and true north?

True north is a fixed point on the globe. Magnetic north is the direction that a compass needle points to as it aligns with the Earth’s magnetic field. What is interesting is that the magnetic North Pole shifts and changes over time in response to changes in the Earth’s magnetic core. It is not a fixed point.

Are runways in magnetic north?

The numbers in runway names refer to the angle a runway sits from magnetic north. In Austin’s case, runway 17L used to be around 170 degrees clockwise from magnetic north at one end, and 350 degrees away if you’re approaching from the other end.

What do the numbers on a runway map mean?

The number indicates the runway’s heading. On a compass North is 360°, East is 90° South is 180° and West is 270°. You cannot have a runway zero. The two digit number is essentially 1/10th of the magnetic heading of the runway ±5° i.e. one digit per ten degrees.

What is the direction of a 36 degree runway?

A runway pointing to the north with a heading from 355° to 004° will be generally given the number 36 (1/10th of 360° ±5°), similarly runway 09 points east (85°~94°), runway 18 is south (175°~184°), and runway 27 points west (265°~274°).

What is the heading of the centerline of Runway 34?

Here, the heading of the centerline could be 342 degrees and the runway will be labeled Runway 34. A compass, and all 360 degrees of it. On the compass above, find approximately 342 degrees.

How do I find the leading zero on a runway?

If there is a giant 19 painted on one end of the runway, there is a giant number 1 painted on the other side. (Just remember that you’re facing outward from the compass.) In the US, our runways omit the leading zero for runway 01, which is not the case in much of the world. So, at London Heathrow (LHR) you’ll spot runway 09L.