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

🇺🇸 N744NK - Spirit Airlines NKS2150/NK2150, General Edward Lawrence Logan (BOS) to Dallas-Fort Worth (DFW) - 4.2 mi away @ 37400 ft, heading WSW at 439 mph. Spotted for first time! [11:47:49 AM CDT] #AA029C #N744NK #SPIRIT_WINGS #NKS2150 #NK2150 #ADSB #ADSBbot