What is a “5th freedom” flight?

The “freedoms of the air” are a set of nine commercial aviation rights granting a country’s airlines the privilege to enter and land in another country’s airspace.

1st – right to fly over a foreign country without landing
2nd – right to refuel or carry out maintenance in a foreign country without embarking or disembarking passengers or cargo
3rd – right to fly from one’s own country to another
4th – right to fly from another country to one’s own
5th – right to fly between two foreign countries on a flight originating or ending in one’s own country
6th – right to fly from a foreign country to another while stopping in one’s own country for non-technical reasons
7th – right to fly between two foreign countries while not offering flights to one’s own country
8th – right to fly inside a foreign country, continuing to one’s own country
9th – right to fly inside a foreign country without continuing to one’s own country

Numbers 5, 7, and 9 are related and are sometimes all termed “5th freedom” by the general public. Each grants the airline in question the right to fly either within a foreign country or between two foreign countries. For example, the 5th freedom might grant Lufthansa the right to carry passengers from New York to London only without continuing on to Germany while the 9th freedom might grant Lufthansa the right to carry passengers between San Francisco and Chicago only without continuing on to Germany. 5th freedom flights are increasingly common though 7th and 9th freedom flights remained largely restricted to the European Union.