Bye-bye, 747s: Check out Delta's new flagship aircraft, the Airbus A350

It's the end of an era for American aviation. At the end of the year, Delta Air Lines will retire its Boeing 747s, the double-decker, humpbacked jumbo jets that made air travel more affordable for millions over the past 50 years.

Meet its successor: The sleek, two-engine Airbus A350.

Delta will have five of the twin-aisle workhorses by the end of the year and its inaugural commercial route will travel from Detroit to Tokyo on Oct. 30. Other destinations from Detroit include Seoul, Shanghai, Beijing and Amsterdam, which all be flying by next spring, according to Delta. The airline is the first U.S. carrier to operate the A350.

CNBC got a look inside. But it wasn't just the plane Delta debuted. The airline also showed off its new Delta One business class cabin, which features suites with — very heavy — sliding doors, and the airline's first-ever premium economy cabin.

Here's a look at the inside and exterior of the plane:

The Airbus A350 uses less fuel than a Boeing 747. The twin turbofan engine jet has a range of 8,000 miles.

Delta debuted its new business class suites aboard the Airbus A350. The theme is privacy. Prices vary but for flights in December, about $6,000 will buy a ticket that gets travelers a seat in the suite, which features a lie-flat bed, and heavy door for added alone time. There's also a "do not disturb" button, but travelers might want to wake up for an ice cream sundae.

The seats in the Delta One suites convert to lie-flat beds but passengers can get comfortable using controls if they want to just recline while they watch new releases on the 18-inch monitors.

The lie-flat beds are made of memory foam for added comfort. The 32 suites also feature ample space to work and store laptops. There's so much, in fact, that jetlagged travelers will want to spend a few minutes checking the seat like a hotel room for any documents and devices they may have stored. Travelers also get a Tumi amenities kit and can preorder their meals.

Delta also unveiled a first for the carrier: Premium economy. Delta calls the step-up from regular, old coach Delta Premium Select. For about 50 percent more than the cost of an economy class ticket, passengers in one of the 48 seats in the new cabin get 38 inches of legroom (about six inches more than regular economy), a seat that's a half-inch wider than economy, a larger screen and a footrest. They also receive a small amenities kit for the ride.

The Airbus A350 has 226 economy class seats. The seats are also made of memory foam but understandably, it's a bit of a tighter squeeze than the more expensive classes. The seat is 18 inches wide and has a pitch of 31-32 inches. One perk: slippers.