The modern airplane-making business features a lot of players, but only two that actually matter: Boeing and Airbus. Naturally, instead of sharing the global market, they spent a lot of their time and resources on a never-ending battle of one-upmanship.

In its eternal quest to outmaneuver Boeing in the skies, Airbus' launched its latest riposte to Boeing's successful, (if initially troubled,) 787 Dreamliner. Thursday morning, the A330-900neo completed its maiden flight, a four-hour, 13-minute jaunt out of and into Toulouse-Blagnac airport in southwestern France, where the planemaker is based.

Airbus claims this new variant of the A330-900 will burn 14 percent less fuel than its predecessor, thanks to new and more efficient Rolls-Royce engines ("neo" stands for new engine option), the use of drag-reducing winglets, and minor improvements to the way the wings slice through the air. (As a bonus for those without noise-canceling headphones, Airbus pledges the new engines will make half as much noise as the units they're replacing.)

The twin-aisle, wide-bodied jet will hold up to 287 passengers in a standard layout, 10 more than could cram into the outgoing model. Somehow, the plane-maker has maximized capacity without making life in the air a waking nightmare (though it has considered that). Rather, it squeezed in the extra seats by rejiggering its cabin design, reorienting and shrinking the crew rest quarters and lavatories. That means every economy seat is a plausible 18 inches wide. So, not quite a palace—but no dungeon, either.

This improved efficiency and increased seating is a big deal for Airbus. The airline industry operates on profit margins tighter than a middle seat on a Ryanair flight, and the key to wooing customers is burning less fuel and packing in passengers.

It's also a small but crucial step in the plane's long march to certification. Airbus plans to have the A330-900neo fully certified for service by mid-2018, but first it must complete a rigorous testing regime that includes 1,100 hours in the air. Thursday's first flight was a calm affair, but things are about to get rough. Before any paying passengers can climb aboard, Airbus' test pilots will torture the new jet every way they know how. They'll fly through the planet's harshest climates, at temperature and altitude extremes. They'll push it as high and fast as it can go. They'll pilot it through brutal turbulence and see how it handles aborted takeoffs and landings.

And once they're sure this plane is ready to take off for real, they'll get back to developing the next answer to whatever Boeing's cooking up.

Life Aloft