Fliers Find an Old Friend on More Planes: Empty Seats

Jets are flying less full after airlines added capacity, delighting travelers and concerning investors

Air travelers’ odds of sitting next to an empty seat are improving.

U.S. airlines are adding larger jets to their fleets and more rows to existing aircraft. The result is more open seats on many flights even as demand for air travel grows.

That is good news for fliers who have grown accustomed to vying for desirable seats and bag space. It...