IT IS RECOMMENDED THAT YOUR AIRPORT BE CONSTRUCTED TO THE STANDARDS IDENTIFIED IN FAA ADVISORY CIRCULAR (AC) 150/5300-13, AIRPORT DESIGN (CURRENT VERSION). ALSO, A CLEAR APPROACH SLOPE, AS IDENTIFIED IN (AC) 150/5300-13 TABLE 3-2 APPROACH/DEPARTURE STANDARDS, SHOULD BE ESTABLISHED AT EACH RUNWAY END. IF THERE ARE OTHER OBSTRUCTIONS THAT PENETRATE THE APPROACH SURFACE, THEY SHOULD BE REMOVED OR LOWERED. IF THE PENETRATING OBSTRUCTIONS CANNOT BE REMOVED OR LOWERED, WE RECOMMEND THAT THE THRESHOLDS BE DISPLACED AND APPROPRIATELY MARKED, SO AS TO PROVIDE A CLEAR APPROACH SLOPE SURFACE TO EACH RUNWAY END. PLEASE NOTE THAT ROADS ARE DEFINED AS OBSTRUCTIONS BY 14 CFR PART 77. PRIVATE ROADS ARE THE GREATER OF A 10 FOOT VERTICAL OBSTRUCTION OR THE HIGHEST MOBILE OBJECT THAT NORMALLY TRAVERSES THE ROAD. PUBLIC ROADS ARE CONSIDERED A 15 FOOT OBSTRUCTION, INTERSTATE HIGHWAYS ARE A 17 FOOT OBSTRUCTION, RAILROADS ARE 23 FOOT OBSTRUCTIONS AND WATERWAYS ARE THE HIGHEST MOBILE OBJECT THAT TRAVERSES THE WATERWAY. BE ADVISED, IN ACCORDANCE WITH 14 CFR PART 157, ANY CONSTRUCTION, ALTERATION TO OR ABANDONMENT OF THE SUBJECT AIRPORT REQUIRES NOTICE TO THE FAA FOR AERONAUTICAL REVIEW. NOTICE FOR THESE ACTIONS CAN BE GIVEN USING FAA FORM 7480-1, "NOTICE FOR CONSTRUCTION, ALTERATION AND DEACTIVATION OF AIRPORTS". PLEASE REFER TO FORM 7480-1 FOR TRIGGERING EVENTS THAT WILL REQUIRE NOTICE.