I would ring the airport & ask them.
Excellent advice! Not all airports have turned to the "dark side" since 9/11. I flew out of KFLL for 20yrs and those guys have had a security program that rivals the Gestapo since well before 9/11.
....and with september 11, they dont seem to want to let anyone near the planes unless you are flying it
I had been hassled by security personell in vehicles many times, even when in a proper pilot's uniform! How this does anything other than providing additional motivation for future terrorist attacks should be explained for me! ::)
At any rate, I fly out of KBHM Birmingham now. I can walk around my own ramp at Birmingham in scruffy jeans, sneakers and a T-shirt and the only thing that the OP's guys have stopped me for is to ask if we had fresh coffee and donuts in the lobby! I am in a secure, fenced area which, for entry, requires either the standard, employee issued, remote gate control or a 12 foot ladder and a carpet. Point being, common sense prevails over knee jerk hysteria at Birmingham.
So, basically, all of this babble is to say that you should check with the airport authority or an FBO(fixed based operator) to gauge the level of acceptance for plane watching at your airport and if there are certain designated areas. BTW Birmingham has a very large, elevated viewing area with plenty of parking.

Executive Beechcraft(look for the Phillips 66 sign) is the FBO at MCI. It's located near the north side of the airport, between the main runways.
You may also want to try a smaller airport(usually they are more accomodating to plane spotters). At Downtown MKC, there is Aero Centre on the west side and Executive Beech on the east side. As a last resort, perhaps St Joseph. If the drive isn't too much. Good Luck!
.....so I loaded up the plane and moved to Middle-EEEE..........OIL..that is......