Southwest Airlines flights are returning back to normal after about a fifth of the fleet was grounded Tuesday. Most travelers at Sky Harbor shouldn’t be affected.

But if you’re flying Southwest, it’s probably a good bet to double-check your flight status. The airline grounded 128 planes after discovering they had missed inspections of backup rudder systems. Now, federal officials have agreed to let those planes keep flying, if they’re checked within a five-day deadline. The missed inspections involve hydraulic systems used to control the rudder if the main system fails.

About 80 flights nationwide were canceled Tuesday, but a Southwest spokesperson said flights should only be “minimally” affected in the next few days.