What are the maximum number of layovers/plane changes required between any two airports?

[robert_columbia]

Consider all the airports of the world that have regularly scheduled passenger service. What are the maximum number of stops/layovers/plane changes required to travel between any two, assuming that you are traveling on regular passenger service, not on charter flights, private planes, or military planes. That is is there a pair of airports, or set of pairs of airports, where you cannot get between one to the other without a minimum of x stops.

My guess is that it would be between two small airports in opposite corners of the world, such as trying to get from a small regional airport in the US to a small regional airport in Africa or something, especially ones that don’t get a lot of traffic.

[MikeS]

@robert_columbia

My guess is that it would be between two small airports in opposite corners of the world, such as trying to get from a small regional airport in the US to a small regional airport in Africa or something, especially ones that don’t get a lot of traffic.

Interesting question. I don’t have a definitive answer, but I suspect that neither of your termini will be in the U.S., except perhaps as a transit country. Given the hub-and-spoke model that most U.S. airlines use, I would be surprised if there’s any airport in the continental U.S. (with scheduled service) that is more than one hop away from a major international airport. You’d do “better” trying to go from, say, South America to Africa, which if I’m not mistaken requires transit via either the USA or Europe.

Also, if you view the world’s airline network as a graph (with cities as points and scheduled flights as edges), you’re asking about the diameter of the graph.

ETA: Apparently my factoid about scheduled service between S. America and Africa is out of date; according to this page, there’s now service from São Paulo & Buenos Aires to Johannesburg, and from Luanda to Rio de Janeiro.

[MikeS]

This paper, which used data on the airline network from 2000-2001, found two airports separated by 15 (!) flights:

The farthest cities in the network are Mount Pleasant in the Falkland Islands and Wasu, Papua New Guinea: To get from one city to the other, one needs to take 15 different flights. From Mount Pleasant, one can fly to Punta Arenas, Chile, and from there fly to some hubs in Latin America. At the other end of the path, from Wasu one needs to fly to Port Moresby (Papua New Guinea), which requires a unique sequence of eight flights. In the center of the path, between Punta Arenas and Port Moresby, six different flights are needed. In contrast to what happens the ends of the path, in the central region of the path there are hundreds of different flight combinations, all of them connecting Punta Arenas and Port Moresby in six steps.

No idea whether this answer would be the same today, but I would suspect that the answer would be in the same ballpark.

[fifty-six]

I will be leaving March 3 to Akutan, Alaska from Homer, Alaska.

It will take me three planes and a boat. One plane a 1939 Grumons Goose as it is the only plane that can land in the harbor and drive up to the small pad they call an airport.

I do not even leave the state or go through any security at all.

If I lived in one of the villages across Kachemak Bay just 15 miles away it would be one additional plane. So in Alaska to Alaska travel 4 separate planes is not unheard of 3 is common.

Some of the guys I work with live in the lower 48. To get to a major airport in Oregon they take up to 4 separate planes if they needed to go to another small airport it could be 5.

[Giles]

OK, let’s try this: Colonsay (CSA) in Scotland to Obo (OBX) in Papua New Guinea:

(1) Oban (OBN) – only choice.
(2) Islay (ILY) – only way to get to the global network of airports.
(3) Glasgow (GLA)
(4) London Heathrow (LHR)
(5) Hong Kong (HKG)
(6) Cairns (CNS)
(7) Port Moresby (POM)
(8) Obo (OBX)

I don’t think you can do it in less than 8 flights.

ETA: I posted before I saw MikeS’s post: if you change the destination to Wasu, I think this looks better.

[Onomatopoeia]

I don’t know what the maximum number of changes there are, but the maximum I’ve experienced, entirely within the US, was for my trip last September from Hawaii to New Jersey.

My itinerary

Sat SEP24 DELTA 596 - LV HONOLULU OAHU 0816P - AR KAHULUI MAUI 0853P
Sat SEP24 DELTA 1212 - LV KAHULUI MAUI 1015P - AR LOS ANGELES 0623A#
Sun SEP25 DELTA 16 - LV LOS ANGELES 0900A - AR ATLANTA 0425P
Sun SEP25 DELTA 2242 - LV ATLANTA 0543P - AR NEWARK 812P

Needless to say, it was a horribly long day, the pain of which was offset by an amazing fare.

[Tapioca_Dextrin]

@MikeS

The farthest cities in the network are Mount Pleasant in the Falkland Islands and Wasu, Papua New Guinea: To get from one city to the other, one needs to take 15 different flights. From Mount Pleasant, one can fly to Punta Arenas, Chile, and from there fly to some hubs in Latin America

I’ve done the Mount Pleasant -> Punta Arenas -> Santiago leg of that trip. It’s not too bad.

[Sicks_Ate]

Not answering the question, but sharing that I had to read the title a third time before I realized it didn’t say “What are the maximum number of gay lovers”.

[Bill_Door]

I once flew from Qingdao, China to Hong Kong, China to Bangkok, Thailand to Kolkata, India and then to Silchar Kumbhigram, India. And because of a document issue I had to clear customs, leave the international airport in Hong Kong and reclear security and customs on the way.

[MikeS]

@Tapioca_Dextrin

I’ve done the Mount Pleasant -> Punta Arenas -> Santiago leg of that trip. It’s not too bad.

According to Kayak, one can current fly Punta Arenas -> Santiago -> Sydney -> Port Moresby (for the low low price of about 7500 USD), which would knock three segments off of this longest path.

[suranyi]

@MikeS

According to Kayak, one can current fly Punta Arenas -> Santiago -> Sydney -> Port Moresby (for the low low price of about 7500 USD), which would knock three segments off of this longest path.

Who on earth flies Santiago->Sydney? That must be a pretty new route.

[JoelUpchurch]

@Onomatopoeia

I don’t know what the maximum number of changes there are, but the maximum I’ve experienced, entirely within the US, was for my trip last September from Hawaii to New Jersey.

My itinerary

Sat SEP24 DELTA 596 - LV HONOLULU OAHU 0816P - AR KAHULUI MAUI 0853P
Sat SEP24 DELTA 1212 - LV KAHULUI MAUI 1015P - AR LOS ANGELES 0623A#
Sun SEP25 DELTA 16 - LV LOS ANGELES 0900A - AR ATLANTA 0425P
Sun SEP25 DELTA 2242 - LV ATLANTA 0543P - AR NEWARK 812P

Needless to say, it was a horribly long day, the pain of which was offset by an amazing fare.

I don’t think it counts if you actually use a lousy routing. United has a non-stop from Honolulu to Newark.

[MikeS]

@suranyi

Who on earth flies Santiago->Sydney? That must be a pretty new route.

LAN Airlines (the Chliean flag carrier) does now. Apparently Qantas will start next month, while at the same time ending their non-stop Sydney-Buenos Aires service. (That latter route will still be covered by Aerolíneas Argentinas, though.)

[Onomatopoeia]

@Onomatopoeia

I don’t know what the maximum number of changes there are, but the maximum I’ve experienced, entirely within the US, was for my trip last September from Hawaii to New Jersey.

My itinerary

Sat SEP24 DELTA 596 - LV HONOLULU OAHU 0816P - AR KAHULUI MAUI 0853P
Sat SEP24 DELTA 1212 - LV KAHULUI MAUI 1015P - AR LOS ANGELES 0623A#
Sun SEP25 DELTA 16 - LV LOS ANGELES 0900A - AR ATLANTA 0425P
Sun SEP25 DELTA 2242 - LV ATLANTA 0543P - AR NEWARK 812P

Needless to say, it was a horribly long day, the pain of which was offset by an amazing fare.

@JoelUpchurch

I don’t think it counts if you actually use a lousy routing. United has a non-stop from Honolulu to Newark.

As does Continental, but that wasn’t my point.

[UltraVires]

@Onomatopoeia

As does Continental, but that wasn’t my point.

Right, but I think the poster’s point was that the answer to the OP’s question is “infinity” if you are allowed to include crazy itineraries where you deliberately take circuitous routes between destinations. I could hopscotch across the whole world before getting to a destination.

Implicit in the question is “minimum number of layovers which equal the maximum.”