Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N476UA - Airbus A320 232 - United Airlines UAL2421/UA2421, Denver (DEN) to Indianapolis (IND) - 4.5 mi away @ 36775 ft, heading E at 593 mph. Spotted 34x before! [04:06:49 PM CDT] #A5D927 #N476UA #A320 #UNITED #UAL2421 #UA2421 #ADSB #ADSBbot

Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N434UA - Airbus A320 232 - United Airlines UAL2421/UA2421, Denver (DEN) to Indianapolis (IND) - 4.0 mi away @ 36325 ft, heading E at 536 mph. Spotted 25x before! [04:03:16 PM CDT] #A533BD #N434UA #A320 #UNITED #UAL2421 #UA2421 #ADSB #ADSBbot

Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N17322 - Boeing 737MAX 8 - United Airlines UAL2421/UA2421, Baltimore/Washington Thurgood Marshall (BWI) to San Francisco (SFO) - 4.5 mi away @ 37175 ft, heading W at 440 mph. Spotted 5x before! [07:32:36 PM CDT] #A1270B #N17322 #B38M #UNITED #UAL2421 #UA2421 #ADSB #ADSBbot

Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N77537 - Boeing 737NG 800/W - United Airlines UAL2421/UA2421, Phoenix Sky Harbor (PHX) to Washington Dulles (IAD) - 4.5 mi away @ 37050 ft, heading E at 606 mph. Spotted 17x before! [03:23:45 AM CST] #AA7E7B #N77537 #B738 #UNITED #UAL2421 #UA2421 #ADSB #ADSBbot