GroundLoop.
Not disagreeing with you but isn't there a couple of other factors?
I seem to remember that you can take an extra 10% on top of the PCN for limited operations and also above that the airfield can elect to allow operations with A/C with a higher ACN if they have 'procedure' in place- like regualr runway/pavement checks.
I recall many years ago a 747 operations ex BHX that required a full runway inspection after every landing/departure....usually to pick up bits of runway!!!!
I amy be wrong but seem to recall there are further 'allowances' to be made.