Southwest Airlines’ aircraft maintenance workers voted overwhelmingly Tuesday morning to approve a new labor contract that would increase wages by 20% and provide $160 million in back pay, according to the union that represents them.

In a statement, the Aircraft Mechanics Fraternal Association said 94% of its 2,400 workers voted for the pact, which provides what it called “long overdue” raises and additional benefits.

“The increases are earned as compensation for their daily responsibilities … during a time of economic growth, experience and knowledge on the (Boeing) 737, and record profits for this radically changing airline industry,” said Bret Oestreich, the union’s national director.

The union said its work will now shift to “restoring the safety culture Southwest Airlines has traditionally been known for.”

Southwest Airlines said the new contract benefits all parties and is key to preserving the airline’s long-term health.

“Our mechanics will receive well-deserved pay increases, and the company will realize additional flexibilities necessary to compete in today’s airline industry,” Russell McCrady, vice president of labor relations, said in a statement Tuesday.

Details weren’t immediately available regarding one of the most controversial items in the contract — how much maintenance work the airline would be able to outsource.

The contract’s approval followed a disruptive start to the year that saw mechanics ground flights for maintenance issues, resulting in hundreds of flight delays and cancellations and ending with Southwest going to court to stop what it called an unlawful job action.

Then, after the Boeing 737 Max was grounded worldwide, the two parties came to an agreement.