Why there are almost no transoceanic flights in the Southern Hemisphere

Look at this map of world air traffic, taken this week from flight-tracking site FlightRadar24.

While the skies over the North Atlantic and Pacific Oceans are buzzing with aircraft, and busy air corridors link Latin America, Australia and Africa to points north, the Southern Hemisphere is pretty much a desert. Almost nobody is seen flying between the Earth's southern continents.

But why is intercontinental air traffic within the Southern Hemisphere so thin?

First of all, the Southern Hemisphere accounts for a much smaller share of the Earth’s landmass and population than the Northern one. And, historically, Latin America, Southern Africa and Australia and New Zealand have had closer cultural and political links with lands to the north than with places in the same hemisphere.

There are technical challenges too. It's true that today's long-haul jets can cross those vast oceans without refueling, but there's more to the story.

Take for example the reports, a couple of years ago, that Norwegian — back then in the midst of an international expansion — had been granted rights to fly nonstop between Buenos Aires and Perth, Western Australia, by way of the South Pole. It ended up not happening, not least because Norwegian has since scaled down its operations and divested from its Argentinian subsidiary.

The great circle distance between Buenos Aires and Perth is 7,800 miles. Long, but an easy hop for the Boeing 787-9, the longest-range aircraft in Norwegian’s fleet, and way shorter than Perth to London, which Qantas flies regularly with the same airplane. The real challenge on the route, which would pass right over the South Pole, isn't the distance, but the lack of diversion airports. There's nowhere to go if the plane needs to divert — for a medical emergency, say, or a technical issue.

Antarctica is also functionally the same as the open ocean when it comes to a very important technical issue: something called ETOPS, or "Extended Range Twin-engine Operational Performance Standards." Airplanes with two engines, i.e. most of them these days, must adhere to strict rules when flying over areas far away from potential diversion points, because they have just another engine to keep them in the air in the event that one fails. Crossing Antarctica on two engines under those rules is feasible, just barely, but there's still the issue of diversions. The continent has no airports where commercial jets can land.

Other flights across the Southern oceans aren't as challenging, but they are few and far between. Here's a list.

Africa to Latin America

Luanda - Sao Paulo on TAAG

The Portuguese empire is long gone, but somehow the links between these two Portuguese-speaking lands remains strong, even with the South Atlantic in between.

Angolan flag carrier TAAG recently discontinued its Luanda to Rio de Janeiro flight, but the route to Sao Paulo remains in place.

The 4,000-mile flight is operated by a Boeing 777-300ER with a three-class configuration. TAAG is one of the few airlines in the world that kept a true long-haul first class, a level above business, but it's not a member of any alliance or partnership with U.S. airlines, and its frequent-flyer program, named Umbi Umbi, is definitely not a major player.

Johannesburg - Sao Paulo on LATAM and South African Airways

The second-biggest economy in Africa after Nigeria and the biggest in South America are a natural choice for a nonstop connection, and both South African Airways and LATAM offer one.

South African Airways deploys an Airbus A330 on this route, while Delta's new South American partner LATAM has assigned one of its new Airbus A350-900s to it.

Flight time is 8h 45 min when flying eastward, and one hour longer in the opposite direction, because of jet stream winds.

Buenos Aires also enjoyed in the past direct links to South Africa, but both South African Airways, which flew out of Johannesburg, and Malaysia Airlines, which used to run the Kuala Lumpur - Cape Town - Buenos Aires route, eventually dropped the Argentinian capital from their route networks in recent years.

South America to Australia / New Zealand

Between South America and Australia and New Zealand, there are a few options to cross the Pacific.

Santiago to Easter Island and Papeete; Santiago to Auckland (LATAM)

Mataveri International airport on Easter Island (IPC) holds the record for the most isolated airport in the world, in terms of distance to the nearest other airport. LATAM serves it twice daily from Chile’s capital, Santiago, more than 2,000 miles away. Once a week, LATAM’s Boeing 787 Dreamliner continues to Papeete in French Polynesia, a further 2,600 miles of open ocean to the west.

LATAM operates a separate four-weekly nonstop between Santiago and Auckland, New Zealand. The 6,000-mile flight is also operated with a Boeing 787.

Santiago to Sydney and Melbourne

The flight between Chile's capital and Sydney by Australia's Qantas has the distinction of being the longest scheduled nonstop flight between cities in the Southern Hemisphere, at 7,060 miles. It's operated by one of the few Boeing 747s remaining in Qantas' fleet.

The one by LATAM, from Santiago to Melbourne in a 787-8, is just a bit shorter at 7,033 miles.

LATAM and Qantas are partners in the Oneworld alliance, with American Airlines. They codeshare on these routes and passengers can benefit from access to their respective regional networks at either end of their routes. That's going away at the end of this year, when LATAM plans to leave Oneworld.

Papeete to Auckland (Air Tahiti Nui) and Noumea (AirCalin)

LATAM’s island-hopper to Santiago is French Polynesia’s only regular link to South America, but the archipelago enjoys nonstop links to New Zealand.

Local carrier Air Tahiti Nui and Air New Zealand fly on alternate days nonstop between Auckland and Papeete, both using Boeing 787s.

Papeete also has one of the longest domestic flights in the world: the weekly nonstop AirCalin flight to Noumea, New Caledonia, another French territory. In this case, the aircraft of choice is one of AirCalin’s brand-new A330neos, covering almost 2,900 miles over the Pacific.

Buenos Aires to Auckland (Air New Zealand)

The Kiwi airline flies over the South Pacific and the Andes all the way to the Argentinian capital, 6,500 miles, in a Boeing 777-200ER – soon to be replaced by a 787-9.

Aerolineas Argentinas used to serve New Zealand from South America too, but dropped New Zealand years ago and subsequently stopped service to Australia as well, leaving Qantas, Air New Zealand and LATAM as the only carriers connecting South America to Australia and New Zealand.

Australia to Africa

Sydney to Johannesburg (Qantas); Perth to Johannesburg (South African Airways)

After the financially troubled South African Airways dropped Sydney and Melbourne from its schedule earlier this year, these are the only two nonstop regular flights linking Australia and South Africa.

These routes are also, for the time being, the preserve of four-engined jets. Qantas operates a Boeing 747 between Sydney and Johannesburg, while South African Airways uses an A340-300 on the Perth run.

Perth to Mauritius (Air Mauritius)

An alternative way to reach Southern Africa from Australia is via the island of Mauritius. Air Mauritius dropped its Sydney service but has kept a twice-weekly frequency to Perth, Western Australia, on an A330-200 and A330-900neo.

Once in Australia, passengers are able to connect with the domestic network of partner carrier Virgin Australia to Sydney, Melbourne, Brisbane and Adelaide.

At the other end of the route, besides the appeal of Mauritius as a holiday destination on its very own, Air Mauritius offers Australian passengers onward connections to a number of destinations in Africa.

Air Austral, an airline based in the island of Réunion, a French territory in the Indian Ocean just east of Madagascar, also tried to build a similar Australia-Africa link earlier this decade. After some time, though, flights linking Réunion's Roland Garros airport (RUN) to Sydney and Noumea were dropped. It held the distinction of being a domestic flight via an international city: from a French territory to another, with a stop in a foreign country.