Airbus officially opened its third, final assembly line in Mobile on Monday, cementing the Alabama city's status as the world's fourth largest aircraft manufacturing hub behind Seattle, Toulouse, and Hamburg.

The new facility will produce A320-series aircraft, a single-aisle jetliner that earlier this month surpassed the Boeing 737 as the best-selling commercial airplane in history. The expansion doubles Mobile's A320 output to 16 planes annually and brings total production at the campus to about 20 aircraft per year, including four A220-series jets.

"The growth to this final assembly line has been made in record time," said Robin Hayes, chairman and CEO of Airbus in North America. "That is incredible."

The project was supported by more than $51 million in state and local tax incentives. Workers are currently assembling an A320 aircraft scheduled for delivery to United Airlines early next year.

Christian Scherer, CEO of Airbus Commercial Aircraft, said the Mobile site plays a key role in the company's global production strategy. Airbus is expanding in both Mobile and Tianjin, China, aiming to build 75 aircraft per month to help clear a backlog of about 7,100 pending orders for A320-family jets.

"It's a big contribution to the overall production of Airbus," Scherer said.

Despite lingering supply chain issues, which Scherer called "noise of disturbance" from the COVID-19 pandemic, the company is targeting 820 airplane deliveries in 2025. In September, Airbus delivered 73 planes to 41 customers, the company's strongest monthly output this year.

Scherer said that "98 percent of our suppliers are working at the rhythm we are asking them." However, he acknowledged there "are still some hiccups. There is, by some definitions, a weak link in the chain. But it's a whole lot better than it was a year ago, or two years ago."

The expansion is also driving job growth in Mobile.

Daryl Taylor, senior vice president of Commercial Aircraft Operations for Airbus in the U.S., said the new assembly line adds 1,000 jobs, bringing total employment at the site to more than 2,000. Airbus expects to employ up to 3,100 workers in Mobile by the end of its current ramp-up phase, with an additional 300 to 400 jobs anticipated once the new line reaches full capacity.

The opening of the new assembly plant comes one month after the company celebrated its 10th anniversary in Mobile, and about 14 months after it manufactured the 500th Alabama-made airplane from Mobile.

The Airbus relationship to Alabama has come with generous economic and tax incentives from both the state and local governments. The latest assembly plant includes the following:

Scherer declined to say how much the new final assembly line costs, other than to say. "it stings" and "is a big number" compared to the $600 million investment the company spent to build the first A320 assembly plant over a decade ago.

"It's a very meaningful number in this capital-intensive industry of ours," he said.

The presence in Alabama is described by Airbus officials as "partnership," that goes beyond buildings and manufacturing plants.

Republican U.S. Senator Katie Britt credited the Mobile-based workforce that continues to grow, while fellow Senator Tommy Tuberville praised the company's focus of hiring veterans. He said that close to 30 percent of the Airbus workforce in Mobile has a military background.

U.S. Rep. Shomari Figures, D-Mobile, said the presence of Airbus also helped erase decades of struggle that the Mobile Aeroplex at Brookley had come to represent since the complex's workforce dwindled during the 1960s. Brookley's apex was during World War II when more than 16,000 civilians were employed at the military base.

"When Airbus made a decision to come (to Mobile), the outlook in this city and this region and state changed," Figures said, thanking the company for deciding to make its initial $600 million investment in opening a manufacturing plant a decade ago. He called it "restoring a sense of twinkle in downtown Mobile's eye."

The expansion also brought about a bit of city pride and thumbing at past critics who claimed that Mobile did not have the capacity to build airplanes.

Mobile Mayor Sandy Stimpson, who is retiring on November 3, acknowledged the past criticism from Washington Democratic U.S. Senator Patty Murray without naming her. Murray made the comments in 2009, at a time that Boeing and Airbus were in competition for a military tanker refueling contract.

"Ever since I heard her say that," Stimpson said, "I knew she was underestimating us."

Stimpson also echoed past comments from Airbus chief executive Tom Enders, who had previously said the "sky is not the limit" for what the company could do in Mobile. However, for the time being, there appears to be no major large growth projects on the Airbus horizon within the Brookley complex.

"This field has growth capacity," said Scherer about the property surrounding the Airbus plant that is about six miles south of downtown Mobile. "We have to be patient. The good news is our industry remains a growth industry ... air transportation is bound to grow. We are cultivating a very fertile ground here in Mobile."

Mobile celebrates Airbus facility expansion, and cements its global aviation status