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

🇺🇸 N821AN - Boeing 787 9 - American Airlines AAL9794/AA9794, Washington Dulles (IAD) to Dallas-Fort Worth (DFW) - 4.7 mi away @ 40075 ft, heading SW at 533 mph. Spotted 24x before! [02:38:18 PM CST] #AB349F #N821AN #B789 #AMERICAN #AAL9794 #AA9794 #autopilot #ADSB #ADSBbot