Congress adjourned for the week without passing an extension of the FAA's operating authority, which means that as of midnight, the agency's non-essential functions shut down. Though air traffic controllers will stay on the job, there will be widespread effects. As the Democrats of the House Transportation and Infrastructure Committee
put it:
The House Republican leadership today will shut down major parts of the Federal Aviation Administration (FAA) at midnight to appease Tea Party extremists, a risky bet that will jeopardize $2.5 billion in construction projects, 87,000 American construction jobs, furlough 3,600 FAA aviation engineers, safety analysts, and other career professionals in 35 states, and cost $200 million per week in lost revenue.
“By senselessly shutting down the FAA tonight at midnight, the House Republican leadership is willing to lay off tens of thousands of middle class American construction workers and jeopardize billions of dollars in airport construction simply to score a few political points for Tea Party extremists,” said U.S. Representative Nick J. Rahall (D-WV), top Democrat on the House Transportation and Infrastructure Committee.
This does not fall in the "nobody could have foreseen" category: The House and Senate had 100 days (PDF) to come to an agreement. But House Republicans chose to hold the FAA hostage to their anti-worker agenda.