Why so many Shamrock "Lifeguards" out of KORD?


I listen to KORD ATC almost every evening on my commute, and I happen to be passing by right as the Aer Lingus flight is leaving. It seems that at least once a week, if not more, the callsign is “Shamrock xyz Lifeguard”. Why does this flight have this designation so frequently? I seem to hear the Lifeguard designation very rarely for other flights/airlines. Thanks much.


Jason can correct me if I’m wrong, There are several ways to add lifeguard to the flight number. I’m guessing for an airline flight that is just departing they would be carrying organs for transplant. Maybe there is a high leprechaun population in the Chicago area… :smiley: