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

🇺🇸 N851UA - Airbus A319 131 - United Airlines UAL8120/UA8120 (MSN-ORD-SLC) - 3.3 mi away @ 2525 ft, heading NNE at 254 mph. Spotted 41x before! [10:29:33 PM CDT] #ABACD2 #N851UA #A319 #UNITED #UAL8120 #UA8120 #Landing #ADSB #ADSBbot