The National Air Traffic Controllers Association filed a lawsuit against the federal government Friday, in an attempt to force the government to pay its members the wages they’ve accrued during the 21-day government shutdown. Bloomberg news reports that this is the third time since the government shutdown began that workers have sued over their lack of wages. As The Daily Beast previously reported, this isn’t the only action airport workers are taking, either: TSA agents are calling out sick in protest, and some are already quitting over their lack of pay. Nearly 800,000 federal workers lack paying jobs as a result of the shutdown.