There isn't a K-29 at ORD
, so I think the above post refers to K-19 which is indeed a pretty good place to spot. It's the last gate on one of AA
's several concourses. If you'll be flying out of the H concourse you can also head to the end of that concourse for a pretty good view. If you have some extra time and are willing to walk a bit the end of the L concourse (near the Delta gates and some AA
gates are there also) you'll have good views of the international terminal across the ramp.
Assuming you'll be arriving internationally, the train that you'll need to take from terminal 5 to terminal 3 has some pretty good views out the window. If you have extra time to kill you can ride the train all around the airport...it runs between each of the terminals and the remote parking lots.
Technically spotting and photography is perfectly acceptable at the airports according to the Chicago police, however some uninformed security guards have been known to harass spotters. I've never had any problems though. If you do get hassled ORD
is such a big airport you can just head off to another concourse and chances are you wouldn't run into the same person twice.