I flew from CBR - Canberra [35.2809° S, 149.1300° E] to ADL - Adelaide [34.9285° S, 138.6007° E] on Tuesday and noticed on the inflight map that it was very close to being perfectly west. As you can see from the lat/long pairs, it's not far off.

I was wondering if there were other airports closer to 'straight' east-west that actually have flights between them?

To clarify, the difference between Canberra and Adelaide is 0.3524 deg latitude. The 'straightest east-west (or west-east) would have the smallest difference in degrees latitude.

To avoid same-city airports or terminals, the pair should be at least 50km apart.

Partner question: What's the straightest north-south flight?

  • 1
    Openflights.org has a database of airports with latitude and longitude, so one could easily find the closest pair among their data. Of course, this probably includes lots of tiny airports with little or no service, so maybe you want some criteria as to which airports should count. Dec 14, 2017 at 1:07
  • @NateEldredge thanks, and as from other comments on the other question, I've adjusted to IATA airports in different cities.
    – Mark Mayo
    Dec 14, 2017 at 1:17
  • 2
    This isn't really very meaningful since shorter routes will be dominated by ATC routing requirements and longer routes will be dominated by great circle routes. Unless your endpoints are on the equator neither will appear straight on any popular projection.
    – user67901
    Dec 14, 2017 at 1:49
  • Openflights also has a database of routes (last updated in February, it appears). So this might be a fun SQL exercise for somebody with a little more spare time than me. Dec 14, 2017 at 3:43
  • As others have pointed out there are two different questions and it's not completely clear which one you're asking. Do you want a pair of cities such that the flight between them travels along the same latitude (this is the question in the title and forces us to look either for very short flights or for flights close to the equator) or a pair of cities with flights between them which lie on the same latitude (this appears to be the question you want to ask from the question body)? In the second case, just by looking at a map: Vienna-Munich, Berlin Schönefeld-Amsterdam-Warsaw, Prague-Krakow. Dec 14, 2017 at 5:07

1 Answer 1


Following the same procedure as the longitude question and the same elimination of nonsense and duplicates:

SELECT ST_Y(source_geom) as src_y, ST_Y(destination_geom) as dst_y, abs(ST_Y(source_geom)-ST_Y(destination_geom)) as delta, name, destination_airport, source_airport from flights order by delta limit 25;

'35.4213981628418','35.4213981628','4.17941237174091e-11','Olympic Airlines','KSJ','AOK' '43.3021011352539','43.3011016845703','0.00099945068359375','Iberia Airlines','BIO','LCG' '59.3502998352','59.3516998291','0.00139999390000867','Linhas A','PPW','WRY' '32.89860153','32.896800994873','0.00180053512695366','American Airlines','DFW','CHS' '-0.894','-0.891833007335663','0.00216699266433718','Garuda Indonesia','MKW','SOQ'

Our first result, between Kasos Island Public Airport and Karpathos Island National Airport, two Greek islands, is shockingly, incredibly straight, but the airports are only 22km apart, failing the distance test.

Excluding that gives us a new candidate: flights between Bilbao Airport and A Coruña Airport in northern Spain, a distance of 444km and a difference in latitude of just .001. However, nobody seems to be operating that route at present. FlightAware and FlightRadar24 list no such flights, and the OneWorld route map shows only an Iberia flight from A Coruña to Madrid.

Next is PPW-WRY in Scotland, home to the shortest scheduled passenger flight in the world. Certainly fun, but less than 3km.

Which brings us to our actual winner: Dallas/Fort Worth-Charleston, United States. This provides an impressive distance of 1,589km between the two US cities with a latitude difference of 0.0018. The route is served by twice-daily nonstops on American Airlines, AAL2762/AAL2763/AAL2764 (for whatever reason, 2764 is used for both directions).

Update: Going by azimuth, PostGIS tells me the winner is TAS-UGC, a bearing of 90.007, assuming WGS84 geography.

  • You should also calculate the azimuth for this one :)
    – JonathanReez
    Dec 14, 2017 at 8:56
  • This is the sort of one I wanted - DFW to Charleston - that's awesome - basically directly east!
    – Mark Mayo
    Dec 14, 2017 at 10:04
  • Hmm, re TAS-UGC....back to Uzbekistan!!
    – Mark Mayo
    Dec 14, 2017 at 10:05
  • The azimuth answer depends on the direction of flight as it assumes a great circle flight so the bearing changes during flight (except if you are at the equator). Perhaps better to divide latitude delta by distance to get a sense of "how close to due west" you are.
    – Floris
    Dec 15, 2017 at 12:49

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .