Pilots from major U.S. airlines are suing to stop the federal mask mandate for public transportation.

A group of 10 individuals who fly for JetBlue, Southwest Airlines, and American Airlines filed a lawsuit on Tuesday that argues the Federal Transportation Mask Mandate is “an illegal and unconstitutional exercise of executive authority” because the defendants — the Centers for Disease Control and Prevention and its parent agency, the Health and Human Services Department — “acted without” authorization or following the rulemaking process outlined by the Administrative Procedure Act.