The cost per seat-mile is being driven by the fact that Airbus sold the seat-mile efficiencies assuming a larger number of seats then the airlines have actually

The cost per seat-mile is being driven by the fact that Airbus sold the seat-mile efficiencies assuming a larger number of seats then the airlines have actually outfitted. The 747 and the 707 are _the_ airframes that changed the world. Boeing is still releasing planes that are directly derived from the 707s (the 737-MAX) while the 747s where not only the first double deck jet, they were the first widebody. Their times are coming to a end though..