American Airlines has received a single operating certificate from the Federal Aviation Administration for American and US Airways, marking a major milestone in the integration of the two airlines.

The news is one step closer to the end for US Airways, with the brand expected to disappear from markets in the next year.

The FAA’s approval for American and US Airways to operate under one certificate is the culmination of more than 18 months of work aligning the carriers’ operating policies and procedures.

Beginning today, most flight operations, maintenance and dispatch procedures will be identical for all flights.

Air traffic control communications will refer to all American and US Airways flights with the call sign “American.”

“Achieving a single operating certificate is an important step toward becoming a fully integrated airline and the effort to reach today’s milestone touched nearly every area of our company,” said Robert Isom, American chief operating officer.

“For a project of this scope, many entities and people must come together and see it through to completion, but one person must ultimately oversee it in its entirety.

A team of more than 700 employees reviewed 465 manuals along with policies, procedures and programs from both carriers and selected best practices to implement for the merged airline.

More than 110,000 employees completed hundreds of thousands of hours of training in multiple phases and more than 115,000 pages on policies and procedures were published.

US Airways ticket counters until later this year when American moves to a single reservations system.

Since American and US Airways merged in December 2013, the airline has been making steady integration progress, including inducting US Airways into the oneworld alliance, merging separate frequent flyer programs into the single AAdvantage program and reaching five-year joint collective bargaining agreements with its pilots and flight attendants.

“The FAA’s Joint Transition Team, led by Skip Whitrock, helped guide us through a rigorous process designed to ensure that our airline is built on a solid foundation of regulatory compliance.

“We are extremely appreciative of the valuable direction that Skip, division managers Nick Reyes and Larry Fields and all at the FAA have provided us over the past year,” added Isom.