A220.127.116.11. Fixed-Wing Layout. Static grounding points for fixed-wing aircraft will be located on
the parking apron as recommended by the aircraft manufacturer or as required by the facility.
Typically, one static grounding point is provided for every two parking spaces, and is located
between the parking spaces.
A18.104.22.168. Rotary-Wing Layout. One static grounding point will be provided at each rotary-wing
aircraft parking space, as shown in Figure A12.10.
A12.4.3. Installation. Static grounding points can be installed in new concrete or asphalt. New grounding
points placed in turf areas will be constructed in an 12,000-square-millimeter [18-square-inch] concrete pad
flush with existing ground. Static grounding points for turf areas are shown in Figure A12.11.
A12.4.4. Grounding Requirements. The maximum resistance measured, in accordance with IEEE
Standard 142, of new grounding points will not exceed 10,000 ohms under normal dry conditions. If this
resistance cannot be obtained, an alternative grounding system will be designed.
A12.5. Air Force Tiedowns:
A12.5.1. Type. For Air Force, tiedowns will be a 3 meter [10 foot] rod with a closed eye. The 3 meter [10
foot] rod will have a diameter of not less than 19 millimeters [0.75 inches], and the top will be bent with a
closed eye (often referred to as a shepherd's crook bend), having an inside diameter of not less than 40
millimeters [1.5 inches] as shown in Figure A12.12. The rod will be copper, copper-clad steel, galvanized
steel, or copper-zinc-silicone alloy. The Air Force tiedown is a mooring point and may be used as a static
ground, but not an electrical ground.
Figure A12.10. Mooring and Ground Point Layout for Rotary-Wing Parking Spaces.