Get ready for the shutdown stuff to really hit the fan — or the jet turbine blades. A shortage of air-traffic control personnel prompted the FAA to halt flights into New York City’s LaGuardia Airport, a major international hub, CNBC reports this morning. The shortage apparently came from sickouts of unpaid workers caught up in the budget standoff:

A shortage of air traffic controllers prompted the Federal Aviation Administration to halt flights into New York’s LaGuardia Airport, as flights were delayed at several other major airports, including Newark.

The disruptions come a day after airline executives warned that the partial government shutdown, during which 420,000 federal workers, including Transportation Security Administration screeners and air traffic controllers, have been deemed essential and told to go to work, even though they aren’t receiving regular pay.

NBC reports that the FAA has also ordered a ground stop at LaGuardia as well as diverting inbound flights:

A ground stop has been ordered at LaGuardia Airport due to staffing issues, the Federal Aviation Administration said Friday.

The stop was ordered shortly before 10 a.m. Some arriving flights are also being delayed; the FAA reports an average of 41 minute delays for LaGuardia-bound flights out of Newark International Airport and Philadelphia International Airport.

At least one traveler tweeted that she was sitting on the tarmac for nearly an hour because of “staff shortages in air traffic control.” Making matters worse, her flight landed 45 minutes early, she said.

Scripps is reporting that delays are now taking place in Newark and Philadelphia as well. The FAA has announced that they’re trying to work around the problem, but that it also includes an air-traffic center in Florida:

Until now, the Trump administration put forth a significant effort to reassure travelers that flight operations remained smooth. Travelers are used to delays, but the suggestion that the FAA has insufficient numbers of flight controllers will get everyone’s attention, including the pilots’ union. The FAA’s statement explicitly acknowledges the sickout in its explanation:

“We have experienced a slight increase in sick leave at two air traffic control facilities affecting New York and Florida. As with severe storms, we will adjust operations to a safe rate to match available controller resources,” FAA spokesman Gregory Martin wrote ABC News in an email.

“We’ve mitigated the impact by augmenting staffing, rerouting traffic, and increasing spacing between aircraft as needed. The results have been minimal impacts to efficiency while maintaining consistent levels of safety in the national airspace system. The public can monitor air traffic at fly.faa.gov and they should check with airline carriers for more information,” Martin said.

Severe storms don’t last for 35 days, and they don’t result in disruptions in staffing over a long haul either. As the shutdown continues, the manpower shortages will get worse rather than better, and some of these workers might not come back when Congress and the White House finally agree on a funding package. They may have found other jobs with less instability and stress.

This will hike pressure for a short-term CR while both sides negotiate. Whether it’s enough pressure to actually negotiate or to remain in original bargaining positions remains to be seen. We have, however, finally hit the first real crisis of the shutdown.

Update: The shortages aren’t in New York, but at “en route” centers further south: