MARANA, Ariz. — There may be no airliner as recognizable as the Boeing 747, the world’s first jumbo jet, with its iconic hump of an upper deck. For aviation fans, the introduction of the “Queen of the Skies” was a triumph of engineering and grace: unprecedented size and speed with spiral-staircase international glamour.

But the airline business has changed, and the giant plane has become more expensive to operate. A couple of weeks ago, the final 747 flight by any commercial United States airline took to the sky.

Like so many others before it, the plane was heading to the Southwest to retire.