A partial shutdown of the FAA began on July 23. Congress failed to pass a short-term funding extension. This furloughed 4,000 FAA employees and tens of thousands of airport construction workers. Planes are still flying, but the federal government is losing more than $30 million dollars a day from uncollected passenger ticket taxes. Republicans in the House and Senate Democrats disagree about union-forming rules and rural airport subsidies. As lawmakers leave for summer vacation, the stalemate threatens to stretch past Labor Day. What’s behind the impasse, and the consequences for the nation’s air system and the traveling public.