United Airlines has added a health self-assessment for passengers during the check-in process. In order to be permitted to fly, passengers must confirm that they have not been diagnosed with Covid-19 over the prior three weeks, are not experiencing a list of Covid-19 symptoms and have not been in contact over the prior two weeks with someone who has tested positive for the virus. They also must confirm that they will wear a face covering while on board. The assessment will appear to passengers checking in digitally, and those checking in with agents at the airport will have to confirm their responses verbally.