Callie Kimball told CBS Little Rock affiliate KTVH-TV Carter Kimball "had a medical note from his physician stating that he's exempt from wearing masks because whenever he wears a mask he holds his breath or he starts freaking out and he will harm himself."

Callie said her family flew on Spirit to visit family in Las Vegas Friday without a problem. But Spirit wouldn't them stay on the return flight, which had a stopover in Dallas, even though her husband showed the plane's crew members the note.

She says they've always flown with Spirit and never had any issues until now. 

"He has a disability. It's protected under the American Disability Act and they go, 'No no no. Autism's not a disability. He has to wear a mask or he has to get off the plane.'"

Carter loves planes, and being removed from one upset him terribly.