The labor union that represents American Airlines‘ pilots said Tuesday that it is making plans to picket at the carrier’s major hubs this fall to protest overscheduling, fatigue and a lack of hotels for crews over the summer.

American and Southwest Airlines‘ flight attendants’ unions have complained about similar issues.

The pilots’ union’s plans are the latest sign of rising tension between some labor groups and airlines’ management, which have scrambled to keep up with travel demand during the peak vacation months, to capture revenue after the pandemic sparked a prolonged slump for the industry.

The Southwest Airlines Pilots Association, which represents Southwest‘s roughly 9,000 pilots, last month said it is considering picketing at U.S. airports during end-of-year holidays over similar issues. Those plans are still under considering, the union’s president Casey Murray told CNBC on Tuesday.

The Allied Pilots Association, the union that represents American’s 15,000 pilots, is in the middle of contract negotiations with the airline, as is the carrier’s flight attendant union.

The union said it was planning to picket at American’s hubs in Miami International Airport, Dallas/Fort Worth International Airport and others “in the coming weeks.”

“Our airline needs scheduling practices that support the safety margin, respect pilots’ and passengers’ needs, and de-risk American Airlines to protect and improve revenue,” the union said in a note to members.

American didn’t immediately comment.