58

For travel hacking (and interest) value, colleagues and I have been trying to work out which routes worldwide might have the highest number of required legs.

That is, for a one-way flight from airport A to B, how many legs minimum are required to fly to B from A?

Eg: CHC to SYD, while you can go CHC->AKL->SYD (2), there are direct flights to SYD, so the minimum number of legs is 1.

Note: there is a practical flight hacking and novelty purpose. Evidently in 1939 KLM listed 26 stops from AMS to SYD, and I'd love to go on the 'most number of stops' flight without stupidly just hopping around random airports.

I've done CHC->AKL->MEL->HKG->LHR (4) but you can do CHC->AKL->DXB->LHR, so minimum legs there is 3.

  • 6
    Out of all possible city pairs, you're looking for the one(s) with the largest number of stops on the shortest possible itinerary between the two cities? – Michael Hampton Nov 1 '16 at 5:20
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    I was just yesterday reading a presentation that the ITA Matrix people did a decade back about the mathematics of airline ticketing, claiming that the minimum journey from a remote airport in Alaska to another in Africa took 20 separate flights over four days, but the claim was unsourced and unexplained. – Malvolio Nov 1 '16 at 5:20
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    Does it have to be bookable on a single ticket? I suspect the definitions get a bit weird at the edges when you're dealing with charter airlines to remote airports. – Zach Lipton Nov 1 '16 at 5:52
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    Or entire countries with no IATA member airlines, so you can't book single tickets to or from some places there anyway. – Michael Hampton Nov 1 '16 at 5:53
  • 8
    If you are interested in doing this properly, Open Flights does maintain a more-or-less up-to-date list of airline routes at openflights.org/data.html. It should not be too difficult to compute the diameter of the graph directly, although with 3209 nodes (airports), it may take some time. – Calchas Nov 1 '16 at 12:48
59

As with many questions about extremes, the answer depends on the precise rules you impose.

Hops count as multiple flights: 13 flights. It's reasonable to argue that one should be very permissive when finding record itineraries. As such, the following 13-flight itinerary from SVR to SRV (a dyslexic's nightmare?) is one of the best single answers I know:

SVR THU NAQ JUV JAV SFJ KEF ANC ANI CHU CKD RDV SLQ SRV
  1. Fly from SVR Savissivik Heliport to THU Thule Air Base/Pituffik Airport on Air Greenland 9002 (Bell 212)
  2. Fly to NAQ Qaanaaq on Air Greenland 9003 (Bell 212)
  3. Fly to JUV Upernavik on Air Greenland 629 (DHC-8)
  4. Fly to JAV Ilulissat on Air Greenland 205 (DHC-8)
  5. Fly to SFJ Kangerlussuaq on Air Greenland 571 (DHC-8)
  6. Fly to KEF Keflavík on Air Iceland 5492 (DHC-8) [seasonal]
  7. Fly to ANC Anchorage on Icelandair 679 (Boeing 757) [seasonal]
  8. Fly to ANI Aniak on Ravn Alaska 816 (DHC-8)
  9. Fly to CHU Chuathbaluk on Ravn Alaska 3402 (Cessna)
  10. Fly to CKD Crooked Creek on Ravn Alaska 3402 (Cessna)
  11. Fly to RDV Red Devil on Ravn Alaska 3402 (Cessna)
  12. Fly to SLQ Sleetmute on Ravn Alaska 3402 (Cessna)
  13. Finally fly to SRV Stony River on Ravn Alaska 3402 (Cessna)

Note that many of these flights are only offered one or two days a week, so the entire route is not particularly achievable together. Google Flights is aware of all but the first flight, but doesn't let you book many of them; nonetheless, all of the flights can be booked online individually. Note that this itinerary was shortened in the comments from 14 legs by using the seasonal flights in the middle; outside of the summer, it likely takes three legs to get from SFJ to ANC (eg, via CPH and LAX).

A quirk of this example is passing through Thule Air Base, which requires an access permit. An alternative is to fly from QUV Aappilattoq Heliport near the southern tip of Greenland, though now Google Flights is unaware of the initial four flights (all on helicopters):

QUV QFN JNN JJU UAK GOH KEF ANC ANI CHU CKD RDV SLQ SRV

Another quirk is its sensitivity to the direction of travel. An alternative is KBW Chignik Bay, a five-hop trip on Grant Aviation either way:

KBW KCL KCQ KPV PTH AKN ANC KEF SFJ UAK JJU JNN QFN QUV
KBW KCL KCQ KPV PTH AKN ANC KEF SFJ JAV JUV NAQ THU SVR
QUV QFN JNN JJU UAK GOH KEF ANC AKN PTH KPV KCQ KCL KBW
SVR THU NAQ JUV JAV SFJ KEF ANC AKN PTH KPV KCQ KCL KBW

If you forbid helicopters, then it seems one can replace the Greenlandic side with airplane flights on Air Inuit to/from YZG Salluit (one of the northernmost Inuit communities) as suggested in another answer:

KBW KCL KCQ KPV PTH AKN ANC DEN YUL YGL YPX AKV YIK YZG
YZG YIK AKV YPX YGL YUL DEN ANC AKN PTH KPV KCQ KCL KBW
YZG YIK AKV YPX YGL YUL DEN ANC ANI CHU CKD RDV SLQ SRV

In other words, KBW ↔ YZG is the only pair I know of which requires 13 flights in either direction, all on fixed-wing aircraft and all individually known by Google flights. But KBW requires a seaplane and counting multiple hops as single flights, the trip can be done (with even more hopping) in a mere five flights! (YZG → SRV only works in one direction, but requires neither a helicopter nor a seaplane.)

Hops count as multiple flights, available together on Google Flights: 11 flights. I think there are many of these. Here's one from GTO Jalaluddin (Indonesia) to SRV, nearly 6000 miles geodesic distance:

GTO UPG DPS NRT SEA ANC ANI CHU CKD RDV SLQ SRV

Google Flights. $3,242. 64h 50m. 10 stops.

Hops count as one flight: 11 flights. If you allow helicopters, I think there are many such itineraries, although they all share one half:

AUY TAH VLI BNE BKK CPH SFJ JAV JUV NAQ THU SVR
SVR THU NAQ JUV JAV SFJ KEF YUL MIA LPB TDD RIB

If you forbid Thule Air Base specifically, then you drop down to 9 flights by switching to southern Greenland (you lose two flights because of "helicopter-hopping"):

AUY TAH VLI BNE BKK CPH SFJ UAK JNN QUV

If you forbid helicopters entirely, you can achieve the same result of 9 flights by chopping off the end of the SVR itineraries:

AUY TAH VLI BNE BKK CPH SFJ JAV JUV NAQ

Hops count as one flight, available on Google Flights: 8 flights. If you only demand that Google Flights be aware of the individual flights, then you can cut off SVR from the trips in the previous category to get 10 flights (9 if you forbid helicopters).

If you want to be able to book the flights, then I can't get any more than 8 flights ... and I can't even get them all at once. For example, for the following itineraries I can get a ticket for the first 7 flights, but I have to get the last segment separately:

AUY TAH VLI AKL IAH YYZ YYT YYR YDP
FTA TAH VLI NAN LAX YYZ YYT YYR YSO

Google Flights. $2,305. 58h 36m. 6 stops. Google Flights. $410. 1h 20m. Nonstop.

OpenFlights (August 6, 2014 data refresh): 14 flights. I also computed the answer according to the OpenFlights data suggested in the comments. There are 9 city pairs that require 14 flights, but none seem to hold up to inspection. I include them here for completeness:

KCG KCL KCQ KPV AKN ANC LAX CPH SFJ UAK JJU JNN XEQ QUV QFN
LPS WSX DHB RCE FBS LKE SEA KEF GOH UAK JJU JNN XEQ QUV QFN
XEQ QUV QFN JNN JJU UAK GOH KEF BRU FIH FKI GOM BNC BUX IRP
XEQ QUV QFN JNN JJU UAK GOH KEF DEN ANC AKN KCG KCL KCQ KPV
XEQ QUV QFN JNN JJU UAK GOH KEF DEN ANC ANI CHU CKD SLQ SRV
XEQ QUV QFN JNN JJU UAK GOH KEF YYZ YTS YMO YFA ZKE YAT YPO
XEQ QUV QFN JNN JJU UAK GOH KEF AMS YUL YGL YPX AKV YIK YZG
YPO YAT ZKE YFA YMO YTS YYZ CPH SFJ UAK JJU JNN XEQ QUV QFN
YZG YIK AKV YPX YGL YUL JFK CPH SFJ UAK JJU JNN XEQ QUV QFN

OpenFlights (November 3, 2016 live data): 12 flights. Using a computer (as I have) helps explore the search space quickly but is sensitive to peculiarities of the data. For example, if I use the live data from OpenFlights instead, the maximum distance is now two flights shorter. Here are some of the 19 such city pairs:

BVI BEU BQL ISA BNE BKK FRA YHZ YYR YRG YMN YSO YHO
STZ SXO GRP MQH BSB ATL BOS YHZ YYR YRG YMN YSO YHO
THU NAQ JUV JAV GOH KEF AMS YUL YZV YNA YHR YIF ZLT
  • 3
    Just out of interest - which algorithm did you use? – JonathanReez Nov 2 '16 at 21:17
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    @JonathanReez: I computed all-pairs shortest paths in O(VE) time using breadth-first search. When I saw that there were less than 10k airports (V) and less than 100k routes (E), I realized it didn't even matter if I used a "slow" language. – A. Rex Nov 2 '16 at 21:22
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    Note that back in 2009 (seven years ago!), I asked on Stack Overflow whether there was any algorithm better than computing all-pairs shortest paths: stackoverflow.com/questions/1190543/… – A. Rex Nov 2 '16 at 21:41
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    I'd give you an extra +1 if I could, and not just because I maintain the OpenFlights data used to calculate this! – jpatokal Nov 3 '16 at 9:39
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    I think the really interesting thing here is that the two destinations are only just above 3.500 km away from each other and not as could be expected on opposite ends of the world (for the SVR to SRV route) – drat Nov 4 '16 at 1:34
43

The United Island Hopper is probably a good candidate for that. MLL (in Alaska) to KSA (in Micronesia) will require 7 stops (at least according to Google):

enter image description here

  • 3
    Google suggests another route with 7 stops google.com/flights/… (but that would still make it the current leader vis a vis this question, so +1) – Urbana Nov 1 '16 at 17:05
  • Hey, are stopovers allowed? – smci Nov 2 '16 at 11:59
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    I love the fact that Wi-Fi available during parts of the route :) – JonathanReez Nov 2 '16 at 13:26
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    Maybe as a single ticket, but one of the 7-stop routes (MLL → RSH → BET → ANC → SEA → HNL → MAJ → KWA → KSA) is sub-optimal, with an Anchorage → Seattle → Honolulu stretch that you can do directly. This makes the route six-segment as per the OP's clarification that it does not need to be on a single ticket. – E.P. Nov 2 '16 at 19:33
29

For a single ticket I'm going to go with six segments, with the caveat that you shouldn't book it:

PQS-AER or PQS-VOG

Pilot Station, Alaska, requires two flight segments just to get to Anchorage. The first, PQS-BET, is a half hour flight on a tiny little Cessna, and if you haven't flown one of these, it's a bit of an adventure. After ANC you've got two more segments to get to Heathrow, a fifth segment to Moscow, and finally you arrive in Sochi or Volgograd on your sixth flight two days later in desperate need of a shower.

But don't book this itinerary. You'll save about USD 2000 (!!!) by buying PQS-BET separately, and then flying BET-AER. You'll also get access to a shorter routing that isn't available when the PQS-BET segment is included, bringing you down to five flight segments.

There are numerous places in Africa where you might require six segments to go from the same starting point, with the caveats that they're entirely unbookable with the PQS-BET segment, and that your final segment might be unbookable through global travel agents; you might have to book directly with the airline or a local charter company. Such is the case if you travel to various places in Zambia, for instance; once you get to Livingston you're on your own.

From a few directed searches I wasn't able to come up with anything requiring seven or more segments that you can actually book, single ticket or separately, that I didn't eventually find a shorter routing. Perhaps someone else will...

  • 4
    @davidvc A segment is each time you get on the airplane, it takes off, lands, and you get back off. So it looks like you've found a seven segment itinerary. Congrats! Though, I see what you mean about the ZAG-ZAD-PUY segment(s). It's the same flight with a 30 minute stop. I suppose you could argue that one either way. On further consideration I suppose I would define a segment as each flight you need a separate boarding pass for. :) – Michael Hampton Nov 1 '16 at 6:21
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    @davidc Certainly don't need different flight numbers, I'm counting take-off and landings ie flights. Please do post as answer if you can demonstrate the link etc?? – Mark Mayo Nov 1 '16 at 7:46
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    You can fly from ANC to PKC in Russia, and then straight to Moscow, which would bring down the number of segments to Volgograd to 5. – JonathanReez Nov 1 '16 at 12:00
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    @JonathanReez That flight is seasonal, and apparently rather difficult to book even when it is flying. – Michael Hampton Nov 1 '16 at 15:47
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    @Tortoise you can do those in 6 if you choose a day with a direct Anchorage -> Chicago then Chicago -> London and London -> Riyadh. I've got one that can be viewed on flight booking sites and seems to need 9 stops, 10 flights - YRB -> SXK (far north of Canada to small Indonesian island) – user568458 Nov 1 '16 at 16:05
21

I could not find any flight search engine that indexes the Air Inuit airline, but given their destination map, getting from Salluit Airport, QC, Canada (YZG) (only served by Air Inuit), it would take at least 3 stops to get to Kuujjuaq.

Then, according to Google Flights, getting from Kuujjuaq, QC (YVP) to Taloyoak (YYH) takes a minimum of 4 stops. For example, one can stop in Montreal, Calgary, Yellowknife, Kugaaruk, to end in Taloyoak, NU, Canada.

So this makes a total of 8 stops from Salluit, QC to Taloyoak, NU, without even leaving Canada. There are probably even more remote communities in Canada that can be reached by even longer flights with many stops, the schedules are probably hard to find.

  • 1
    Using Air Inuit is a great idea; I should add it to my searches. Note that your itinerary can be shortened, however: Canadian North 478 flies Yellowknife--Taloyoak direct on Wednesdays according to both their printed schedules and booking searches on their website. (I know Google Flights thinks otherwise...) The reverse trip is direct on Thursdays. – A. Rex Nov 4 '16 at 21:05
  • Hi, Vince. Just now, you edited one of my answers to do nothing more than italicize some quotes that I already had in quotation marks. Please don't do that. Edits should only be made if they make a worthwhile change to the post; they shouldn't be used just to make posts look prettier to you, especially given that there is no need whatsoever to italicize text that is already in quotation marks. – David Richerby Dec 29 '16 at 18:23
16

If you just count takeoffs and landings, Papa Westray (PPW) in the Orkney islands would be a good destination, though Google Flights can't route you there.

Nearest I can get (via the current starting point, Pilot Station) via Google Flights is PQS to INV (Inverness) - 5 flights, 4 stops.

Then Loganair will get you to Kirkwall (6th flight) - operated as FlyBE at the moment, I think. Note that Edinburgh or Glasgow (EDI,GLA) would be alternatives to Inverness but Google Flights is reporting the same hops from PQS each way.

From Kirkwall you take Loganair's inter-island flights, which form a circular route (on the same plane), with Papa Westray being 4 further flights one way, or 5 the other add one further flight for a total of 7 flights.

Note that the Westray to Papa Westray flight has its own place in the record books, and can be viewed in its entirety if you have 2 minutes to spare.

EDIT : Either MLL (Marshall,AK) or KSA (Kosrae, Micronesia) from the other answer will push the route to INV up to 5 stops, getting to Papa Westray in a minimum of 11 8 flights.

EDIT again : I must apologise for an incorrect reading of the inter-island flight timetable (or hazy memory) - in fact it isn't a full circle route; each flight covers a subset of all the islands, you ran get to Papa Westray directly from Kirkwall, so this reduces to only 8 flights. My apologies for unintentionally misleading.

  • Indeed, on the Westray to Papa Westray, we have quite the information on that flight on this very site – Mark Mayo Nov 1 '16 at 13:27
  • @MarkMayo and made the news again today with its millionth passenger! theguardian.com/travel/2016/nov/01/… Which is a lot of passengers for an 8-seater... – Brian Drummond Nov 1 '16 at 14:27
  • From Kirkwall to Papa Westray is two hops (or at least used to be when I flew it). While there are longer circular, routes, twice a day there is a short circular route Kirkwal - Westray - Papa Westray - Kirkwall. – Aleks G Nov 3 '16 at 22:05
  • @AleksG Right, I think it used to be the circular route, apparently you remember a 2-hop to Papa Westray, but the current timetable shows 1 or 2 hops (depending which way you use it). Thanks for the confirmation. – Brian Drummond Nov 3 '16 at 22:41
  • FYI, I find seven flights using KSA KWA MAJ HNL EWR EDI KOI PPW or MLL PQS BET ANC KEF EDI KOI PPW (the latter using summers-only Icelandair). – A. Rex Nov 7 '16 at 18:10
-2

Not sure about the details but flights I've taken that are multistop: Iquitos: Some Military changover in the Amazon : Float plane to the TriFrontera with Colombia and Brazil To get to Iqitos you'd have to fly from Lima, so from somewhere obscure to get to Lima you'd up the count.

Island hopping you could look at the San Blas Islands chain on the caribbean side of Panama - we hopped a few islands/stops down before getting off and the plane was continuing; I'm not sure a brief stop on a strip of tarmac counts as a stop over?

-5

Believe it or not, the answer is pretty easy to find. There is a travel industry publication called the OAG. It comes in domestic and international editions. Between the two, at the back of each, there is a listing of each flight operated worldwide. Just scan the listings until you find the longest line(s) for a particular flight. That's it!

  • 3
    This doesn't in any way answer the question, as it doesn't include every possible route - just some of them. – Doc Nov 2 '16 at 6:53
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    This doesn't answer the question as the OAG dataset is a) not comprehensive (Missing some significant airlines) b) only covers flights, not routes requiring connections, which are essential to this problem c) Large enough to be effectively impractical to find the largest route involving connection manually. – user1937198 Nov 3 '16 at 2:09

protected by JonathanReez Nov 2 '16 at 22:45

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