Looking at tickets for, say, a flight from Melbourne (MEL) to Cape Town (CPT) I found none without an airport stop - i.e. at Doha (DOH).

I understand that the "direct" route (great circle) is perhaps too close to the southern pole, but what is the reason to make such a long route?

The ideal paths are:

MEL-DOH = 7,426 mi
DOH-CPT = 4,615 mi
TOTAL   = 12,041 mi

while the direct route is:

MEL-CPT = 6,416 mi

The half of the distance! Even if you don't follow the great circle (for the reason above) the "single hop" route will be very close to the first part of the trip (MEL-DOH).

A second thought might be about the lands below: of course MEL-DOH-CPT is for most of the path above lands. But as I learn here it is not unusual to have long paths over the seas.

So, what are the reasons to avoid the shortest path in this example?


4 Answers 4


It's not just a stop, it's a change (picking a random date a couple of week in the future you'd be in Doha for about 23 hours). This is how airlines operate - they serve multiple routes form one or more bases or hubs (at which maintenance and many other services may be concentrated). In Qatar's case their base is Doha. So they fly from Doha to anywhere they can make a profit, e.g. MEL and CPT (other airlines use Hong Kong or Dubai for this connection).

Qantas use Melbourne as a base, so it wouldn't be too hard for them to fly to Cape Town - or for South African Airways to do the same (Cape Town is a hub for them). The fact that neither do suggests they don't think they could sell enough seats to make money on the route, as there are unlikely to be regulatory hurdles that completely block this route.

  • 5
    Sorry to say that just because the original poster and a handful of other people may want a direct route, that small number does not justify the airlines maintaining a direct route.
    – Dean F.
    Nov 12, 2020 at 20:03
  • 15
    This answer is correct, but just a note that there are direct flights between Australia and South Africa, even during the current pandemic. But apparently the airlines feel that they can profitably operate flights between the large cities SYD-JNB, but not MEL-CPT, and something like MEL-SYD-JNB-CPT may be more hassle than a one-stop journey with a change of planes at a hub like Doha or Hong Kong.
    – mlc
    Nov 12, 2020 at 20:51
  • 3
    @mlc not surprising really as Johannesburg's area population is twice Cape Town's. Although Sydney is only a little bigger than Melbourne its airport looks like it should serve a much larger population - anywhere from Canberra to Newcastle (at least) Nov 12, 2020 at 21:04
  • 9
    Silly fun fact: Some people say this proves the Earth is flat. The north pole is in the middle of the disc, and Antarctica is all around the outside edge, so the shortest paths between places in the southern hemisphere usually go via the northern hemisphere... Nov 13, 2020 at 14:21
  • 3
    @user253751 - and on such a map the distance from Auckland to Sydney is the same as London to New York. Which given the flight time of 3 hours means that it's the best value flight in the world: a trans-Tasman Concorde for just a few hundred bucks. Why all the other Airbus + Boeing operators don't exploit the supersonic capabilities of their airliners is quite the puzzle... Nov 14, 2020 at 11:01

There is already a very good and accepted answer, so mine is just for added fun.

A very interesting way to visualize this is www.flightconnections.com. It's an interactive map that shows all regularly scheduled direct flights. If you click on Capetown, you can see that nothing goes to Australia and the farthest west you can get is Hong Kong.

Now why is that?

Almost all airlines operate a "hub and spoke" system. That means their is one (or a few) "central" airport that's home to the airline and that serves individual flights to all other destinations. So almost all routes from A B to will have a layover at a hub, so you fly A->Hub->B (unless A or B are a Hub itself). The reason for that is easy: it allows the airline to serve a large numbers of city combination with relatively small number of direct flights. If you want to serve 100 cities with all possible combinations you would need 4950 different flights. With a hub and spoke system you only need 99. The hub also allows the airline to put all infrastructure in a single location since every plane shows up at the hub after every second flight.

Going back to your specific example. Neither Capetown nor Melbourne are hubs, so you would need an airline that has a different hub and serves both airports. Again, flightconnections.com can easily illustrate that if you put in both airports. Turns out the only airlines that do this are Emirates (Dubai), Qatar (Doha) and Cathay Pacific (Hong Kong). So these are your only choices with a single layover.

It tends to be easier if you use a hub "in region", but unfortunately South African (Johannesburg) doesn't serve Melbourne and Qantas (Sydney) doesn't serve Cape Town.

Side note: Looking at the map also explains why some relatively small middle eastern countries have massively large airlines (Emirates, Qatar, Etihad, ..) It's basic geography: with a hub in the middle east, you can connect all continents and the vast majority of the major cities in the world with a single layover. Emirates for example only operates the largest planes: Boeing 777 and Airbus A380. Only a tiny fraction of their passengers are actually traveling from/to Dubai.

  • If your drive to a hub airport is not much longer than to your nearest airport, it is sensible to drive that bit further. In South Africa the distances may be too big though.
    – Willeke
    Nov 13, 2020 at 14:12
  • FWIW, it does show me a flight from Sydney to Johannesburg Nov 13, 2020 at 14:26
  • 1
    And my God, that site is full of ads. Including popups when you click on the map. Not a very nice site to explore. Nov 13, 2020 at 14:26
  • @user253751: Qantas flies JNB<->SYD. That doesn't help much with CPT<->MLE since it would be at least two layovers and the segments in South Africa would have to be on Qantas code share partnet (One World).
    – Hilmar
    Nov 13, 2020 at 16:23
  • @Hilmar Yeah, but I thought it was noteworthy that there are direct flights between Australia and South Africa, just not between those particular two cities. Nov 13, 2020 at 16:52

The economics of hub and spoke matter, but also the distance over open ocean matters. For the entire route from Melbourne to Doha to Cape Town there are other airports to land at in the event of an emergency. But for a direct flight from Australia to Cape Town there's nothing. There's only one uninhabited mountainous island with no airport. Shipping traffic doesn’t even go through there. It is very isolated. If a flight over that part of the world needs to come down it will have to ditch and rescuers will take weeks to arrive.

  • 7
    Except that direct flights between Johannesburg and Sydney do exist and this one happened just 2 days ago
    – Peter M
    Nov 13, 2020 at 20:30
  • ETOPS certificate applies to airplanes and crews for long flights over areas without suitable airports. (Engines Turn Or Passengers Swim or google it formal meaning :-) ). The longest twin-engine plane diversion is allowed by ETOPS-240 i.e. diversion time should not exceed 4 hours on a single engine to the nearest suitable airport. Which could be a military base with a hangar in the snowy North. 4-engines don't need ETOPS but they go extinct for financial reasons.
    – Jantar88
    Nov 14, 2020 at 13:25
  • This is completely wrong. It's completely commonplace to have very long flights over water. Note that cape town - Hong Kong is LONGER than CT - Melb, and is entirely water.
    – Fattie
    Nov 14, 2020 at 13:41
  • CT .. new york or atlanta is even longer, all water
    – Fattie
    Nov 14, 2020 at 13:41
  • 3
    @Fattie while those flights are mostly over water, there is still some land with airports somewhat nearby (reachable in an hour or such). That might be less of the case for the south indian ocean? Nov 14, 2020 at 22:55

The question is a bit nonsensical.

The answer to "Why do you have to go through another airport" is simply "there's no direct flight."

If there's no direct flight between two cities ............... you have to go through another city.

When you want to fly to (say) Cape Town, the first thing you do is simply bring up a map of all the direct flights of Cape Town:

enter image description here

As you can instantly see your easiest choices are HK, Dubai or Doha.

  • 4
    This is at best half an answer, the information in it is (mostly) already in the other answers.
    – Willeke
    Nov 14, 2020 at 13:59

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