I go to a high school in the suburbs of Philly that has what seems like every turboprop, small jet and the occasional 737 being vectored into philly flying over it. Good for me, I could look at em all day

. But I was thinking about why it was only the smaller aircraft. I'm thinking that it's becasue the smaller guys use the shorter runway 26/8 and runways 9L/27R abd 9R/27L are reserved for the bigger jets. So maybe the smaller aircraft are using a different STAR(I honestly don't have a clue as to how STARs work, who assigns them, whether or no they are arrival runway dependent, etc.). Can anyone shed some light on this?