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

🇺🇸 N8939Q - Boeing 737MAX 8 - Southwest Airlines SWA3978/WN3978, St Louis Lambert (STL) to Denver (DEN) - 3.3 mi away @ 15350 ft, heading WNW at 379 mph. Spotted 2x before! [08:54:57 AM CDT] #AC541B #N8939Q #B38M #SOUTHWEST #SWA3978 #WN3978 #Departure #ADSB #ADSBbot

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

🇺🇸 N8692F - Boeing 737NG 8H4/W - Southwest Airlines SWA3978/WN3978, St Louis Lambert (STL) to Denver (DEN) - 5.5 mi away @ 15925 ft, heading WNW at 423 mph. Spotted 69x before! [08:59:22 AM CDT] #ABF2EA #N8692F #B738 #SOUTHWEST #SWA3978 #WN3978 #Departure #ADSB #ADSBbot