The US Supreme Court let stand a ruling that said the Transportation Security Administration could require airline passengers to wear masks during the height of the pandemic, keeping in place a precedent issued by a key federal appeals court.

The US Court of Appeals for the DC Circuit ruling said TSA has broad authority to maintain security and safety during national emergencies. TSA scrapped its mask mandate in April after a federal judge in a different case said the requirement exceeded the agency’s power.

The Supreme Court order is a defeat for Jonathan Corbett, a California lawyer and self-described frequent flier who sued to challenge the mask mandate. He asked the Supreme Court to either take up his appeal or declare the case legally moot and wipe away the DC Circuit opinion so it couldn’t serve as a precedent.

President Joe Biden put the mandate in place on his first full day in office, issuing an executive order requiring masks in airports and on planes, trains, intercity buses and other forms of transportation. His administration urged the Supreme Court to keep the DC Circuit opinion in force.

The DC Circuit handles an outsize share of cases involving the power of federal administrative agencies.

The case is Corbett v. TSA, 22-33.