. I can't see O'hare, which I believe is the third busiest airport in the world, letting a small Cessna or something disrupt what must be an extremely complicated ballet of movement. So they have one runway that is no where near the routes of the big planes just for the little guys...
I think we're playing Tennis with TWO questions now.
-Yes you can Legally land a small, low cruise speed, single engine aircraft at ANY civil airport in the U.S.(with the exception of two previously mentioned).
-Will ATC allow you to do so? Workload permitting, and the prevailing attitude at the controlling authority involved are the only two factors that may dictate otherwise. Remember, in a Class B, authorization must first be given to enter the airspace, and in Class C radio communication must be established, BUT it's not uncommon to hear " REMAIN CLEAR OF THE CLASS CHARLIE AIRSPACE".
.....so I loaded up the plane and moved to Middle-EEEE..........OIL..that is......