A chapter of aviation history has closed, as commercial U.S. passenger airlines bid farewell to the Boeing 747, the jumbo jet that made air travel affordable for millions of people around the world because it could carry hundreds of passengers inside. The double decker aircraft with the humped fuselage is one of the world’s most recognizable planes. But after flying the four engine, fuel-thirsty plane for decades, Delta Air Lines and United Airlines are retiring the so-called Queen of the Skies in favor of sleeker, more fuel efficient models that are cheaper to operate. Pan American Airways debuted the enormous twin deck airliner in January 1970, and flights by US passenger airlines have been flying uninterrupted ever since. The 747 was a marvel of engineering when it first flew months before the first moon landing in 1969. Affectionately known as ”queen of the skies,” the 747 was postage stamp famous, an icon of pop culture, and the backdrop of movies, television and a flying emblem of the US presidency as Air Force One.