I’m told that this originally appeared in in something called CompuServe’s AVSIG (aviation special interest group), which predates the widespread use of the internet:
Its Christmas eve. Santa Claus has packed up the last of the toys, preflighted the sleigh, sumped the reindeer, and is getting ready to go when he sees a gentleman in a jacket and tie standing next to the sleigh, holding a clipboard. The fellow introduces himself: Hi, Im from the FAA, and Ill be riding jump seat for a check ride this evening. Well, Santa really doesnt need the aggravation on this busiest day of the year, but the FAA is the FAA, so he doesnt argue. They get in the sleigh, Santa tunes and copies the ATIS, and as hes guiding the sleigh to the runway, he glances over to the FAA guy and sees him breaking open a shotgun and inserting a pair of shells. What are you doing, he asks. The FAA guy replies Well, I shouldnt be telling this to you in advance, but youre gonna lose an engine on takeoff.