# Centralmost world airport?

Given that there are 1,281 international airports in the world (according to Wikipedia), there must be an airport that is ‘centralmost’ depending upon some definition - maybe it has the smallest sum of distances to all the other international airports. Or maybe it is the airport that is closest to the geometric center (projected to the Earth’s surface) of all the other international airports. Or maybe it has the smallest sum of squares of distances to all other airports. Or maybe you want to weight airports based on the population in their catchment; if we’re evacuating the world to a single location, it might make sense to try to minimize man-miles flown, not just airport-to-airport miles for single flights. Whatever; you may choose your definition. I guess we can assume that magic planes can fly nonstop great-circle routes from airport to airport, and that if an airport can provide flights across one national border it can provide flights across all borders, in order to simplify the problem.

So, does this problem have a known solution(s) based on whatever particular definition(s) you choose for ‘centralmost’? Looking at a map of international airports, I would guess maybe Diori Hamani in Niger, but that’s just a WAG.

My inclination for this problem is to minimize the length of the longest distance from the airport: That is to say, the Central Airport is within X miles or less of all other airports, and no other airport has a smaller X. Since all airports are on the surface of the Earth, which is (to good approximation) a sphere, this is equivalent to finding the airport whose antipode is the most isolated. So we’d want to find a big circle (probably in the middle of the ocean) with no airports in it, and then look at the point opposite the center of that circle, and look for an airport near there.

One complication is that there are a lot of tiny flyspeck islands in the middle of the ocean, and if such an island has any civilized development at all, an airport is the first thing it’s going to have.

I feel like you should take the schedule of available flights into account. A lot of aviation uses a hub-and-spoke topology, so tiny islands probably wouldn’t change things much, insofar as you would anyway need to get to a major airport on the way to your destination. Here is a possible list of hub airports to consider.

I feel a better method would be to take every airport and find the distance between it and the other 1280 airports in the world. Then figure out the average length of those 1280 routes.

Do this for every airport and whichever one has the lowest average length would be the “centralmost”. It’s the airport that is, on average, closest to every other airport in the world.

This method focuses on all of the connections an airport has rather than just its longest one. That would avoid the flyspeck island issue you raised.

The islands in the southern Indian Ocean are without airports. They’re uninhabited; at most they have scientific teams on them and those get to their islands by boat. The antipodes of that area is North America. Eyeballing it, I’d say the center of that area is east of Kerguelen Island. Antipodal to that is Alberta and Montana. So Calgary or Great Falls.

There’s similar regions in the south Atlantic and South Pacific, but I don’t think they’re larger.

Per Chronos’ notion, the international airport closest to the antipode of Point Nemo in the South Pacific is probably Orenburg in Russia.

Let me clarify my OP a bit: there are multiple ways to define this problem, but I’m looking for airports that actually meet one these definitions. So, for example, maybe Heathrow purports to have the shortest sum-of-distances to all other airports, while Kathmandu Airport can be reached by all humans in the shortest time, or whatever?

Maybe nobody has worked out this type of problem, but it seems like the sort of thing that a PR flack at some international airport would like to be able to claim.

If you want to evacuate the world to a single location, you’re going to end up with everyone connecting in Atlanta anyway.

Ah, but in at least one formulation there are no connections, just nonstop great circle flights.

I wonder what the practical difference would be between the least-sum-of distances and Chronos’ shortest-distance-to farthest formulations. Or from the least-sum-of-squares-of -distances, since we are limited to picking an airport that already exists, not planning a theoretical pykrete carrier base in the Arctic.

If you’re asking which airport is closest to the most people in the world, the answer seems to be either Dubai or Istanbul. Both airports have built huge international hub operations as a result.

No airports in the Americas would qualify; they are all way too far from Asia.

By that standard, I would actually expect St. Petersburg to be better than either of those cities. North America might not have the population of Asia, but it’s not nothing, either, and a far-north city would have better access to North America, across the pole. On the other hand, it’s a lot further than the Middle East from Africa.

Assuming you follow a criterion similar to Chronos’, but ignore airports like Honolulu or Tahiti which serve small populations, and not going too far south to approach big cities like Sydney or Santiago then … you might find a point of “maximal isolation” near the antipode of Cairo, Egypt.

This is slightly startling since, long before the Pacific Ocean was even discovered, there were mystic traditions which placed Cairo at the center of the world!

How about this, then: is there a database of coordinates of international airports, such that the actual least-sum or least-sum-of-squares or whatever can be calculated?

You would not ignore any existing international airports, although you might not weight them very much if you are doing a population-based calculation

OK, as a crude rule of thumb.

I took the co-ordinates of the 50 largest airports in the world by 2017 traffic volume.

Plotted them on an X-Y graph as Mercator projection (S&W values negative) and find the median point is 18.2006N 31.6697W which is in the north Atlantic and Cape Verde your nearest international airport.

Weighting by traffic volume make a minimal adjustment to be 18.8468N 32.0705W.

If you want to use a different projection or take into account substantial factors like great circle navigation etc, be my guest.

Hey! Do I post the location of your secret underwater lair?

penultima thule, that method depends not only on your choice of projection (which is highly significant), but also on your choice of eastern and western boundaries. You can put the center on pretty much any longitude line you want just by shifting the map.

I compulsively hack out code the way some people compulsively eat potato chips. (Unfortunately I sometimes compulsively eat potato chips while I’m compulsively hacking out code. :smack: ) So I said “Why not?” By approximating the Earth as a sphere, great circle distances are easy to compute; why not find the centralmost major airport? In the interest of bipartisanship I’d even minimize both total distance and total distance-squared (and any other suggested norms).

But where to find the longis and latis? And how to decide which airports to use? There’s aviationfanatic.kml at aviationfanatic.com, but it has 41,000+ airports (and annoyingly has only ICAO code, not IATA code).

15 out of 50 are in U.S.A., which biases relative to OP’s criterion — he wants to save everyone, not just frequent fliers. BTW, penultima thule: Am I missing something? Did you need 150 clicks or more to get all the coordinates or is there some shortcut?

Anyway, you guys pick an airport list, and I’ll volunteer to hack out the centralmost.

The age old question of the reference point for longitude.
Sure you can define the prime meridian anywhere you like, but that’s not going to change the weighted average of the data points.

No shortcut, just cut&paste the table and airport co-ordinates into a workbook and determine the degrees as decimals.
If you want something sophisticated, well that’s precisely why the SD has people like your goodself, Chronos and Colibri et al.

Slightly off topic, but I wonder which airport with non-international status is the biggest on this planet? Somewhere China?

Believe that title goes to Van Nuys Airport