Hijack cargo plane; Fed Ex, UPS, DHL

Middle Eastern government works with terrorist group to purchase a 747 and replicates a US cargo jet like UPS, Fed Ex, DHL. Terrorist group hijacks real cargo plane in-flight, crashes over ocean and replaces with replica by using its transponder codes, flight pattern, etc. The terrorist plane is carrying nukes and or nerve gas. Terrorist plane flies into Memphis or Louisville or Chicago undetected and explodes over these cities.