Yes they can fly over that fence easily ...because mine do it all the time and then when its getting dark they come back...mine come back but some other peoples says theirs dont .
Mine will fly straight up 40 feet to land in the top of the oak trees. They are extremely adept fliers even if their first choice for moving is running. The first few times mine flew at me in the field I'd duck because I didn't realize they had such control and would turn enough to miss me.
Mine fly to the top of the house 3 story, so i would have to Yeah they will fly over the fence. If in the same run as your chickens you can put a landing board on top of fence for them to stop at on way into and out of run. They should return each night to roost in the coop.