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

🇺🇸 N27509 - Boeing 737MAX 9 - United Airlines UAL1640/UA1640, Chicago O'Hare (ORD) to Phoenix Sky Harbor (PHX) - 4.0 mi away @ 32525 ft, heading W at 412 mph. Spotted 9x before. [01:29:53 PM CST] #A2BB89 #N27509 #B39M #UNITED #UAL1640 #UA1640 #ADSB #ADSBbot