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For those that wonder why it's impossible... Runway numeric designators are the compass heading of the runway, divided by 10. So, Runway 27 would be a runway

by brk 12y ago

For those that wonder why it's impossible... Runway numeric designators are the compass heading of the runway, divided by 10. So, Runway 27 would be a runway oriented at 270 degrees. The other end of that runway would be runway 9 (It's 180 degrees the opposite direction, 18 lower). Therefore, a runway 60 would indicate 600 degrees, on a 360 degree arc ... :)

falcolas 12y ago
More compass and runway fun - magnetic north moves over time, so a runway's number may change over time, despite not moving.
- sokoloff 12y ago
  More random trivia. Runways are not strictly named by their magnetic headings. Chicago O'Hare has so many east-west runways that they have "mis-named" some of them: (see 10L/28R and 10C/28C, both of which are on magnetic headings of 93/273. And yes, they have a 10-Left and 10-Center, but no 10-Right. :)) http://airnav.com/airport/ORD http://airnav.com/airport/ORD
  - falcolas 12y ago
    Sounds like a side effect of the magnetic north movement. It has drifted east (in relation to the US) about 6° in the last 30 or so years, so if Chicago hasn't re-named them since laying them down, a compass alignment of ~100° becoming 93° makes sense.
    - sokoloff 12y ago
      No, it's the effect of having more than 3 east-west runways. 9L, 9R, 10L, and 10C. The sub-names (left, center, right) only go up to 3. Detroit Metro has the same issue with their SW/NE runways (21L, 21R, 22L, and 22R are all mutually parallel.) http://airnav.com/airport/dtw http://airnav.com/airport/dtw Atlanta Hartsfield has 5 runways, all aligned on 94.4*, named 8L, 8R, 9L, 9R, and 10: http://155.178.201.160/d-tpp/1405/00026AD.PDF http://155.178.201.160/d-tpp/1405/00026AD.PDF
  - joezydeco 12y ago
    10R is actually under construction and will be open around October 2015. =)
- mikeash 12y ago
  When I started flying, my home airport had runway 09/27. A few years ago, it got repainted as 10/28 because of drift. Some people still slip up and call it 09/27 by accident.

by brk 12y ago

falcolas 12y ago

More compass and runway fun - magnetic north moves over time, so a runway's number may change over time, despite not moving.

sokoloff 12y ago
More random trivia. Runways are not strictly named by their magnetic headings. Chicago O'Hare has so many east-west runways that they have "mis-named" some of them: (see 10L/28R and 10C/28C, both of which are on magnetic headings of 93/273. And yes, they have a 10-Left and 10-Center, but no 10-Right. :)) http://airnav.com/airport/ORD http://airnav.com/airport/ORD
- falcolas 12y ago
  Sounds like a side effect of the magnetic north movement. It has drifted east (in relation to the US) about 6° in the last 30 or so years, so if Chicago hasn't re-named them since laying them down, a compass alignment of ~100° becoming 93° makes sense.
  - sokoloff 12y ago
    No, it's the effect of having more than 3 east-west runways. 9L, 9R, 10L, and 10C. The sub-names (left, center, right) only go up to 3. Detroit Metro has the same issue with their SW/NE runways (21L, 21R, 22L, and 22R are all mutually parallel.) http://airnav.com/airport/dtw http://airnav.com/airport/dtw Atlanta Hartsfield has 5 runways, all aligned on 94.4*, named 8L, 8R, 9L, 9R, and 10: http://155.178.201.160/d-tpp/1405/00026AD.PDF http://155.178.201.160/d-tpp/1405/00026AD.PDF
- joezydeco 12y ago
  10R is actually under construction and will be open around October 2015. =)
mikeash 12y ago
When I started flying, my home airport had runway 09/27. A few years ago, it got repainted as 10/28 because of drift. Some people still slip up and call it 09/27 by accident.