🇺🇸 N77543 - Boeing 737MAX 9 - United Airlines UAL2664/UA2664, San Francisco (SFO) to Baltimore/Washington Thurgood Marshall (BWI) - 5.7 mi away @ 35150 ft, heading E at 578 mph. Spotted 13x before. [02:51:40 PM CDT] #AA7E9A #N77543 #B39M #UNITED #UAL2664 #UA2664 #ADSB #ADSBbot