United Airlines has applied to the U.S. Department of Transportation for permission to operate a new daily roundtrip flight between Ronald Reagan Washington National Airport (DCA) and San Francisco International Airport (SFO). This proposed route aims to provide additional nonstop options for travelers and connect them to various destinations within the Western U.S. and internationally. The airline emphasizes that this new service would offer convenient morning and afternoon departures, avoiding peak congestion times at both airports.