Pilots at Alaska Airlines voted to ratify a new four-year contract, the company and their union said on Tuesday.

The contract is effective on April 1, 2009, and covers 1,455 pilots at Alaska Airlines, a unit of Alaska Air Group Inc. The carrier and the Air Line Pilots Association said the deal includes pay raises and work rules that are more flexible for pilots and more productive for the company.

The company’s traditional pension plan will be closed to new pilots, who will get a 401(k) plan instead.

The deal won approval from 84 percent of pilots who voted. All but 5 percent of pilots voted, the company and union said.

The vote caps negotiations that began in January 2007; they reached a tentative agreement last month.

Pilots in general have seen pay erode and work rules get tougher in recent years.

“While this contract doesn’t restore everything, it does provide increases in pay and improvements in our work schedule and retirement flexibility while allowing our company to remain poised for success,” said Bill Shivers, chairman of the union’s Master Executive Council at Alaska. He called it “a positive step toward repairing the relationship between this pilot group and our management.”

Alaska Airlines President Brad Tilden said the deal “provides the right foundation for our pilots and airline to succeed long term.”