"Freedom flights" refers to a program that allowed people living under communist regimes to leave their countries and live in freedom elsewhere. Full definition
You might elect to use a fifth freedom flight simply because it offers a better seat and service, especially in business. (rewardexpert.com)
A fifth - freedom flight connects the airline's home country with another country by means of a third country. (rewardexpert.com)
For a revenue ticket, fifth freedom flights are often cheaper than buying tickets for a regular route because airlines often treat them as auxiliary service on the way to their main destination. (rewardexpert.com)