At any given moment, a million people are in flight, claims a new three-part PBS/BBC documentary series. Its title, City in the Sky, is derived from that notion. The first hour-long installment, which airs on PBS tonight at 10 p.m. (check local listings), is called “Departure.” It attempts to impart a sense of wonder about a place we’re usually too stressed out to really notice, much less enjoy, when we visit it firsthand: the airport.

“If you want to visit the city in the sky, the first step involves getting off the ground,” a narrator intones, and he’ll spend the remainder of the hour reestablishing and re-re-restablishing his stating-the-obvious bonafides. But the time still glides by, driven by some glossy cinematography and a genuinely absorbing look beneath the tarmac of two of the world’s busiest airports.

Atlanta’s Hartsfield-Jackson Airport is presented as the United States’ most advanced in terms of crowd management. We get a walkthrough from Jim Harding, whose firm, Gresham Smith and Partners, designed ATL’s international terminal. He talks about the subtle cues intended to keep travelers flowing through terminals efficiently. Meanwhile, ATL’s transportation director, Christopher Smith, asserts that its underground “plane train” is “the busiest train system in the United States,” moving 94 to 100 million people across its 4,700-acre expanse annually.

The episode then takes us to Dubai International Airport, the world’s busiest. Some of the statistics used to emphasize the facility’s girth are just silly, as when we’re told that stacked on end, the 57 million pieces of luggage DXB processes each year would reach as high as 1,100 Burj Khalifas. (The 828-meter-high tower is the world’s tallest, which would make the luggage only a centimeter high. Hmm.) But the glimpse into the “bizarre subterranean world” 80 feet underground where DXB’s $700 million luggage system hums away is fascinating.

The show also takes us through the assembly of an Airbus A380, the world’s largest passenger aircraft. We follow its various components on their fortnightly parade through the streets of Gimont, France, “like some kind of hushed industrial carnival” to Airbus’s sprawling Final Assembly Plant outside of Toulouse, where some 20,000 rivets are driven in by hand to hold the aircraft together throughout its anticipated 60 million mile operational life. Fueling its 25,000-gallon tanks takes half an hour and $28,000 dollars, we learn. In Europe, that avgas is supplied by the Central European Pipeline System, a 3,000-mile long pipeline that pumps 2.4 billion gallons per year.

So when the narrator says, “Every takeoff is an act of gravity-defying brilliance,” it may not be artful. But it’s not wrong.

Episodes 2 and 3, “Airborne” and “Arrival,” air Feb. 15 and 22, respectively.