Specifications include, but are not limited to: Runway:A defined rectangular maneuvering area on an airport prepared and maintained for the landing or takeoff operations of aircraft. The runway is the only portion of an airport that should be used for aircraft landing and takeoffs. The runway is distinct and should be distinguished from other surfaces such as taxiways or safety areas and maintained accordingly. The dimensions of a runway are defined on the Airport Layout Plan (ALP) or, where an ALP does not exist, is outdated or is incorrect, the dimensions should be determined after consultation with the FAA. After the runway’s length or width isestablished, these dimensions must be published in the Airports Facility Directory (Alaska Supplement)and the Airport Master Record (Form 5010). Subsequent changes to the runway length or width also must be promptly noted in these publications. Guidelines criteria used for determining runway dimensions on the different classes of airports may be found in FAA Advisory Circulars No. 150/5300-12 and 150/5300-4B.Runway Safety Area:A rectangular area, centered on the runway centerline, which includes the runway (and stop way, in present) and runway shoulders. Safety areas are not intended for normal aircraft operations but enhance the safety for airplanes which undershoot, overrun, or veer off the runway and it provides accessibility for fire fighting and rescue equipment during such incidents. The safety area is cleared, drained, graded, and may be turfed, and must not have any potentially hazardous ruts, depressions, humps, or other surface variations. Safety areas are designed and maintained to support the movement of any aircraft allowed to use the airport without causing substantial damage. If a safety area cannot be maintained to this standard, the unusual and hazardous condition must be noted or the dimensions of the safety area must be reduced to include only the area that can be maintained free of conditions that might cause substantial damage to an aircraft. On airports which provide snow removal services the FAA regulations and advisory circulars required that snow be removed from safety areas only to the extent that aircraft on the runway do not make contact with snow banks. However, it is advisable to maintain the safety areas off the thresholds clear of significantly large snow banks and assure that all lights are markers are visible. Guideline criteria used for determining safety area dimensions on the different classes of airports may be found in the FAA Advisory Circulars No. 150-5300-12 and 150-5300-4B. As is often the case in Alaska, it sometimes is impractical to construct an airport in accordance with these particular standards. In those instances, the FAA will work with airport operations on a case-by-case basis in order to establish alternative dimensions.Threshold Marker Panels: Thresholds shall be marked with panels 2’ high by 8’ long. The panels shall consist of a while reflectorized background with orange reflectorized chevrons as illustrated in Figure 4. The panels shall be placed perpendicular to the runway centerline and in line with the runway threshold cone markers. If the runway has no lights/cone markers in place, threshold marker panels should be installed so that they will not have to be relocated whenever come markers are added.The inside edge of the panel shall be 15” from the extended designated edge of the runway. As illustrated in figures 1 and 2, at most airports the inside edge of the panels will normally be 5’ outside of the outermost threshold light/ or cone marker. More than 5’ distance should separate the inside edge of the panel and the outermost threshold light/cones if these lights/cones are placed closer than 10’ to the designated runway edge.On runways with narrow safety areas, it may be necessary to position the panel on supports or wing ramps outside of the safety area in order to maintain a 15’ clearance from the runway edge (Figures 1 and 2).Threshold cone markers shall be placed “outboard” only when the threshold is displaced or a taxiway exits the threshold (see “Threshold Cone Markers”). In these instances the marker panels may be placed more than 15’ from the extended edge of the runway. Figure 3 illustrates where marker panels should be placed if threshold or cones are “outboarded”.If marker panels are mounted in a manner that allows for removal while maintenance upon the runway is being performed, care should be taken to assure that other fixed points of reference are available to guide crews relocating the panels and/or cone markers. The permanent fixed mounting of markers panels produces an additional benefit for maintenance crews by providing them with easily recognizable reference points which they can use to locate the designated boundaries of the usable runway and reference when relocating cone markers.