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

🇺🇸 N14530 - AIRBUS A321neo - UNITED AIRLINES INC UAL520/UA520, George Bush Intcntl/Houston (IAH) to Chicago O'Hare (ORD) - 4.4 mi away @ 35200 ft, heading NNE at 546 mph. Spotted 2x before! [09:08:26 PM CDT] #A0B81D #N14530 #A21N #UAL520 #UA520 #ADSB #ADSBbot

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

🇺🇸 N14518 - Airbus A321 271NXSL - United Airlines UAL520/UA520, George Bush Intcntl/Houston (IAH) to Chicago O'Hare (ORD) - 4.3 mi away @ 36800 ft, heading NNE at 567 mph. Spotted once before! [08:14:36 PM CDT] #A0B7DF #N14518 #A21N #UNITED #UAL520 #UA520 #ADSB #ADSBbot