This applies to all travelers over the age of two.
Passengers at SFO Friday morning say they are fine with tighter restrictions.
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"I think it's a good safety precaution," said Julia Vita of Saratoga. "Especially right now, because I believe there is a second wave going on. I think, even though it is a strict rule, it is good they are taking these precautions."
"I think it is important, obviously, for your safety, for other people's safety. Especially when the airplane is packed and you're side to side with the other person. I definitely think it is important for adults. I don't know about 2-year-olds because they can just take it off," said Celine Gabr of Portland.
United says if you have an extraordinary circumstance you can contact the airline and ask for an exception. But Southwest and American say the rules apply to everyone: If you can't wear a mask, those airlines say you should stay home.
"I mean if it keeps us safe, you know, that's the key right?" said Ron Foster of Manteca. "It's all about safety, so I don't mind wearing it as long as it is going to make us safe. But it's gotta be for everybody, not just some people."
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The new rules come at a time when the majority of Americans are hesitant to fly. A new ABCNews poll found 33% of Americans are willing to board a plane. 23% of those willing to fly are Democrats- 58% are Republican.
United's policy goes into effect Friday July 24th. Southwest's starts Monday July 27th and American's starts Wednesday July 29.
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