The Transportation Security Administration (TSA) will not enforce the Covid-19 mask mandate on planes and other public transportation, after a federal judge in Florida on Monday struck down the requirement, ruling that the CDC had overstepped its authority. U.S. District Judge Kathryn Kimball Mizelle said the CDC had failed to adequately explain its reasons for the mandate and did not allow public comment in violation of federal procedures for issuing new rules.

The Association of Flight Attendants, the nation’s largest union of cabin crews, has recently taken a neutral position on the mask rule because its members are divided about the issue. On Monday, the union’s president appealed for calm on planes and in airports. “The last thing we need for workers on the front lines or passengers traveling today is confusion and chaos,” union leader Sara Nelson said. Nelson said it takes airlines 24 to 48 hours to put new procedures in place and tell employees about them. She said passengers should check with airlines for updates about travel requirements.

United Airlines said in a statement that, effective immediately, masks would no longer be required on domestic flights or certain international flights. “While this means that our employees are no longer required to wear a mask and no longer have to enforce a mask requirement for most of the flying public…they will be able to wear masks if they choose to do so, as the CDC continues to strongly recommend wearing a mask on public transit.”

The court’s ruling comes less than a week after the CDC extended the mask mandate for 15 days. The masking requirements applied to airplanes, trains, and other forms of public transportation. A Biden administration official says the order is no longer in effect. As of now masks are no longer required on any domestic flights.