There’s already a vast amount of empty space at the 7-million-square-foot aviation maintenance complex at Kansas City International Airport.

Come September, despite the efforts of the city to find another tenant, the overhaul base may be completely vacated. That’s when American Airlines plans to shut down its operations there, laying off nearly 500 mechanics, workers and managers.

The airline industry continues to lose money and airlines are trying to downsize to profitability. At one time, American had 900 planes. Now it’s operating 600 planes and no longer thinks it needs a third maintenance base in Kansas City.

The company made its official announcement Wednesday. In a letter to employees, Carmine Romano, senior vice president of maintenance and engineering, called the closing a “difficult but important step.”

For Gordon Clark and others who have worked many years at the base, it will end an era in Kansas City aviation that began when Trans World Airlines opened the facility in 1956.

“This is our legacy of 50-plus years,” said Clark, president of Transport Workers Union Local 530. “Our reputation for quality with TWA and then American Airlines is unprecedented. We’ve always been professionals, and we’ve taken on every challenge asked of us by the airlines through the years.”

American said it will also close secondary maintenance operations at airports in Detroit, Minneapolis and San Jose, Calif. A big maintenance department at San Francisco International Airport will be reduced to a secondary operation. St. Louis also will face a maintenance reduction.

In all, the company will eliminate 700 jobs.

But like last year, when American downsized its maintenance operations, the brunt of the cutbacks will be felt here. American’s decision will mean about 490 employees, including about 420 hourly workers, will be gone. That will leave American with two overhaul bases, one near its headquarters in Fort Worth, Texas, and its biggest base, in Tulsa, Okla.

When American bought the financially troubled TWA in 2001, there were 3,500 TWA employees in Kansas City, including 2,600 at the overhaul base. After the facility is closed, the company said, 100 American employees will remain at KCI.

American was one of the few major airlines that managed to avoid a bankruptcy reorganization after the September 2001 terrorist attacks. However, it has had to go through a series of downsizings and reach concessionary wage agreements with its unions.

Employment at the Kansas City base continued falling through the years as work shifted to American’s base in Tulsa, which employs about 7,000.

Before this week, the biggest setback occurred last year, when half of the Kansas City facility’s 1,000 employees were let go through voluntary separations, early retirements and involuntary layoffs.

In the current cutback, management and union employees will be offered standard severance packages, and many hourly workers in Kansas City and St. Louis will be eligible for a $12,500 payout if they leave before next September.

According to Clark, the company said more than 80 percent of hourly workers are eligible for the special payout. He estimated that 40 percent to 50 percent of 420 remaining union employees will apply for that buyout and retire from the company. Nearly 360 of the base’s workers remaining are 50 or older, he said.

Others may have a chance to transfer to another airport if they have enough seniority. At the time of the TWA buyout, the unions reached an agreement to allow Kansas City mechanics to keep 25 percent of their TWA seniority at nine other airports, Clark said.

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