MIAMI — American Airlines launched its much vaunted Airbus A321 Transcontinental aircraft Tuesday as the carrier began rolling out a plethora of customer facing changes following the merger.

The first A321 flight, American 118, took off Tuesday morning from Los Angeles LAX at 0722PT bound for New York JFK. The inaugural flight was reportedly low-key (we are on board, look for a review later today!), with no gate ceremony and only a quick reference by the crew aboard. Passengers aboard will be treated to a fresh interior, reflecting the carrier’s push to renovate its product. As such the airplane comes complete with a first, business, premium economy, and coach cabin.

Curiously American is the only airline offering a first class cabin on one of the most lucrative markets on the planet. While other full service carriers, such as United, have ditched first class, American instead opted to keep it. It contends that the product, which looks awfully similar to its heavily praised Boeing 777-300 business class seat, is desired by discerning passengers looking for a seamless experience. And with only ten of the seats on board, likely a highly sought after one.

The airplane will gradually begin to displace the carrier’s fleet of aging Boeing 767-200 airplanes on the route, eventually operating all thirteen daily roundtrips by June of 2014. San Francisco (SFO) will begin receiving the same airplane in March. Like LAX, SFO will receive the airplane exclusively on all five daily flights by June.

The airline received its first A321T in November, and the company unveiled the airplane to the press and high-value customers in LAX and JFK late last month. Before even taking to the skies the airplane has received high praise for its low-density configuration and significant upgrades across all cabins. As the aircraft enters service today we will quickly discover whether it lives up to the hype.

American also unleashed a handful of customer-facing experiences following the merger with US Airways in December, most of which apply to premium passengers. The combined carriers now allow customer miles and points to be equally earned in spent in both of their loyalty programs (AAdvantage, and Dividends). Members of each program receive reciprocal benefits, such as access to preferred seats, priority bag delivery, and premium cabin check-in. Members of the carrier’s respective lounge clubs will be able to access either Admirals Club or US Airways Clubs, and boarding announcements will accommodate the elite passengers of both.

For non elite passengers, check-in timeframes have been aligned beginning today, and ticket counters and gates are now co-located at New York JFK.

These first steps come less than one month after American and US Airways merged, creating the world’s largest airline. A long road faces both as they work to merge and streamline experiences, covering everything from reservations and operations to napkins and drink mixers.