Not long after jet-powered aircraft entered the skies in the second half of the twentieth century, manufacturers were hard at work developing executive aircraft that could efficiently whisk the rich and famous across the globe, without having to interact with commercial airline passengers anywhere along the way. private jets offered a level of convenience that most could never even imagine, as they allow one to walk directly onto their own aircraft without ever clearing security after arriving just seconds before takeoff and touch down in a new city as quickly as the plane can get you there.