As Learjet (along with Cessna, Hawker/Beechcraft and major operations of Boeing, Airbus, and Spirit Aerosystem) is based in Wichita, this story of Frank Sinatra, the Rat Pack, and a Learjet has special meaning. For everyone else, it is a neat story.
And, yes, the “FS” in the tail number = Frank Sinatra.
Hat tip: D.J. LaChapelle