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

🇺🇸 N648FR - Airbus A321 271NXSL - Frontier Airlines FFT3587/F93587, Philadelphia (PHL) to Los Angeles (LAX) - 4.5 mi away @ 37850 ft, heading W at 499 mph. Spotted 6x before! [06:30:12 PM CDT] #A88380 #N648FR #A21N #FRONTIER_FLIGHT #FFT3587 #F93587 #ADSB #ADSBbot