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

🇺🇸 N899UA - Airbus A319 132 - United Airlines UAL8218/UA8218, Ronald Reagan Washington Ntl (DCA) to Chicago O'Hare (ORD) - 3.6 mi away @ 15850 ft, heading WNW at 374 mph. Spotted 22x before! [05:55:39 PM CDT] #AC6886 #N899UA #A319 #UNITED #UAL8218 #UA8218 #ADSB #ADSBbot