The man's unwillingness to wear a mask triggered the assault, a witness said, and forced the cross-country flight to land in Denver. The female flight attendant was reportedly punched in the face.
The ripple effects of decisions made throughout the pandemic could mean disruptions for thousands of passengers throughout the busy summer travel season.
A new policy from American Airlines, the largest airline in the United States, put a limit on the weight of a wheelchair. Now, many power wheelchairs are too heavy to fly on smaller regional jets.
"To our departing 13,000 family members: thank you for your dedication and we look forward to welcoming you back," United told employees, as CARES Act payroll aid was set to expire.
The airlines will require all customers over the age of 2 to wear face coverings on board and at airports, with no exceptions. They say people who don't comply won't be allowed to fly as next week.
A spokesperson said American Airline's busiest flight out of LaGuardia Sunday only had 27 passengers and nine flights from JFK and LaGuardia had one passenger on each.
Southwest said its decision is "based on continued uncertainty" about when the FAA will allow the Max planes to return to service. Boeing's 737 Max fleet has been grounded worldwide since March.
The top official at the FAA says airline pilots had enough training to handle Boeing's flight control software linked to two deadly crashes. His statement has divided pilots in the U.S. and overseas.