Jenilee Harrison appears (in a speaking role) as one of a group of L.A. Rams cheerleaders. She actually was a Rams cheerleader at the time.
Ponch didn't seem to have a fear of flying in the episode "Career Day " the 5th episode of S1. He begged to go up the the chopper to avoid desk duty. Furthermore he seemed to enjoy the ride.
Both Jon's apartment and Carol and Kim's apartment appear to share the very same layout and style,as well as the same hallway.