Haydnc,
I am no expert in risk doctrine but the location, type and frequency of RPT / open charter operations would determine what type of fence you would require. If you can demonstrate your risk profile is such that say a 1.8m stock fence is sufficient then so be it. It has worked for major regional airports in WA with high frequency RPT jet operations.
In my experience, a 2m chain mesh with 3 x single strand barbed wire at the top, along the extent of the terminal precinct and apron would suffice with stock or other suitable fencing around the remainder of the perimeter. Normal signage requirements would apply.
Feel free to PM me.