Airlines are an Americans with Disability Act-free zone:
It should be noted that all airlines mentioned recommend that any customers who cannot wear face coverings due to a medical condition or disability should postpone their travel until the temporary mask requirements are no longer in place.
Source: Airline rules for face masks | kgw.com
I have twice written to my elected representatives opposing further airline bailouts. Airlines want all taxpayers to bail them out while simultaneously restricting flights to healthy individuals only. Airlines are free perhaps, to restrict access on their own dime, but not on the taxpayers dime.
Recently, Delta kicked a hearing impaired person off a flight after his masked slip and he could not hear the flight attendant (nor see her mouth move because – masks!) who notified him of the mask falling down below his nose. The airline was notified of his hearing impairment and shown his two hearing aids but crew didn’t care and kicked him off the plane. The CEO later apologized to the customer (airlines have forgotten what “customer” means) but asked him to remove his video from social media.