Sun Country Airlines' pilots are stepping up pressure on the company to raise their wages.

The pilots union argues that no other sizable airline pays pilots less for flying Boeing 737s.

Federal records indicate the carrier has been consistently profitable since 2009. And pilots argue it's time for the carrier to share its good fortune with them.

"It's nearly doubled in size in the last few years," pilots union spokesman Jake Yockers said. "The industry is good. The charter business is strong. Fuel has never been cheaper."

The union, which would not disclose pay rates, said pilots haven't had a pay raise in 5 years. As of 2012, the median annual wage for all airline cockpit crew members was about $114,000, according to the Bureau of Labor Statistics.

The pilots have voted to authorize a strike and vow they would strike if necessary. But a walkout is not imminent.

Sun Country did not respond to a request for comment.