There’s a short little section that go “some airlines are allowed to do this strange thing, especially if a fuel stop is involved”. But it doesn’t explicitly say what the fifth freedom is, just alludes to it.
This paragraph is worded a bit confusingly, but it was pretty clear to me: the fifth freedom is the fifth of nine aviation freedoms from a treaty signed in 1944.
Airline 1 from Country A
Airline 2 from Country B
Airline 1 is allowed to fly from A to B, refuel in B, and then fly from B to C. But the fifth freedom allows Airline 1 to pick up people in country B and provide them cheap flights to country C, thus competing with Airline 2, which is native to country B.
It could be entirely possible that my understanding is incorrect, though... but that's what I got from their explanation.
I do completely agree with other posters that this is thinly-veiled advertising, though. This stands out with their Japan flights for me, since I live in Japan and occasionally look for tickets.
It's interesting that they point the price for Osaka-Honolulu because it's surprisingly low (~80% cheaper), but they conveniently neglect to mention that the Tokyo-LA flight is only 10-15% cheaper than a domestic airline.
Sometimes this means a better deal than shorter haul flights so the airline can fill seats on their less popular leg, sometimes it's actually worse (especially if you're a frequent flyer more likely to have miles or offers with your local carrier). As the article points out, stopping flights also getting rarer as aircraft range increases and passenger demand increases because most people would prefer to fly London to Sydney without an hour in Singapore, and airlines find it much easier to fill flights to individual international destinations.
1) The right to fly over a foreign country without landing.
2) The right to refuel or carry out maintenance in a foreign country without embarking or disembarking passengers or cargo.
3) The right to fly from one's own country to another country.
4) The right to fly from another country to one's own.
5) The right to fly between two foreign countries on a flight originating or ending in one's own country.
This video has a lot of good info on it: https://www.youtube.com/watch?v=thqbjA2DC-E
And wikipedia page: https://en.wikipedia.org/wiki/Freedoms_of_the_air
Not all countries/stops allow 5th freedom rights in all cases.
Sounds like just journalistic exaggeration
They are famous among aviation enthusiasts simply as a way to get access to airlines that one might otherwise have to travel great distances to try.
If an airline based in A is running a flight A>B>C, they can’t feed any pax to B except from A, or carry pax further than C (without interlining). So there’s a bit more of an incentive to sell tickets B>C while other airlines flying that route can sell tickets to a much wider array of passengers (coming from pre-B (but not A) or going post-C).
https://en.wikipedia.org/wiki/Great_circle
as opposed to loxodromic:
http://www.gcmap.com/mapui?P=ADD-LAX
I have to say its still unintuitive, I need a globe :/
http://www.gcmap.com/mapui?P=ADD-DUB-LAX
to see how close Dublin is to the theorical route you just posted.
To be more exact (if not pedantic) the 5th freedom would apply if Air India could sell tickets and take passengers only for the ORD-FRA and FRA-ORD legs and Frankfurt is not merely a fuel stop.
Anyway, I had very little money so I took a flight that was an option to fly from the "west coast of the US" to "western Europe". I waited for a nearby US departure since, our ground transportation is difficult, but flew into Paris, then took an overnight train to Bologna.
When I left, I departed from Milan. The difficult part was that the shady company organizing the tickets told me the wrong Milan airport, but getting to Milan is easy. You could even take a train from Messina, since the train itself gets on the ferry from Sicily to the Italian peninsula. From Rome, Milan is only a three hour train ride with spacious seating and large windows to watch the scenery roll by. If you're on a tight budget with a flexible schedule, you can go a pretty long distance by train before it seems like any inconvenience at all.