Random or Rational Runways?

Last week was my 40th post. Some readers have noted my posts are heavy and they require a certain mood to read and digest. Others voiced a different opinion: “...so do you actually have any positive posts without a trace of didactic prose?🤔”

Unapologetically, no. I don’t. Hence the name of the blog: WITAWOPS. But on the occasion of 41, here is a slightly lighter one.

What Other People Say (or don't think):

I’ve worked on airport projects for about 5 years and I have flown in and out of airports across the globe: Anchorage, Bogota, Cairo, Gandor, Gilgit, Johannesburg, Kinshasa, Lubbock, Phuket, and Singapore. What struck me across the globe was the number of airport staff, consultants, and passengers who don't know how runways are numbered. 

Why is Boston’s newest runway 14/32, while Giglit has 7/25. Why does Singapore have 2R/20L but also 2C/20C and 2L/20R? Look at a satellite image of any airport and you will see the runway number at the end. For example, here are the runway maps for Boston Logan (BOS) and for Chicago’s O’Hare Airport (ORD). ORD actually has the most in the world (8) while BOS has 6.

Sources: Massport.com and flychicago.com

How It Works:

Planes must take off and land into the wind. ORD’s main runways lie in east-west orientation, accounting for the prevailing winds. Each runway has two names (e.g., 14/32 for BOS). The assigned runway is the one on which the airplane’s wheels first touch. A plane taking off from Boston’s southernmost runway in a southwesterly direction is using Runway 14. A plane landing the other way (towards the northwest) is using Runway 32. 

Add a zero to the runway number and you get the compass heading. Runway 14 is 140 degrees which is southeast between 90 and 180. Runway 32 is 320 degrees which is northwest between 270 and 360 degrees. That’s it! 

If you are flying into Boston for the first time and the air traffic control tells you to use Runway 22, you know you have to approach the airport heading in that direction. Therefore, you approach the City from 220 minus 180 or 40 degrees which translates an approach from the northeast.

Complex Runway Systems:

But both Logan and O’Hare have two or more runways on the same orientation. That’s where Left and Right come into play. As you approach Logan, you are told to land on 4L or 4R. Pick the one to the left or the right! But  O’Hare has three runways on the same orientation (actually 6 but we will get there). So 10L and 10R are jointed by a 10C for Center in the middle. Pretty simple. This is a universal numbering system that any pilot should know how to use.

So what happens when there are 6? Fake it. Assign one compass bearing to the first three 3 (10 left, center, and right at ORD south of the terminal buildings) and assign the next point on the compass to the next three (9L, 9C, and 9R to the north). You would still approach the airport from the same general side (both 90 and 100 are basically approaching from the west and heading east).

What Do I Think?

Ingenious. Universal. Logical. Whoever invented it should be credited but whoever decided to adopt it globally should also get kudos. The fact that no country has decided not to play by the same rules demonstrates its success.

Why Should You Care?

I'll borrow the London Underground’s safety slogan - “See it, Say it, Sorted”. But I will morph it to “See it, Solve it, Satisfied”. My mind doesn’t like mysteries. I have to solve them. If I see something that should make sense and I can’t figure it out, I will find out!