MIL-HDBK-274 Electrical Grounding For Aircraft SafetyThis handbook has been prepared to provide U.S. Navy and Marine Corps aircraft maintenance and operations personnel with the background and technical details of the different types of aircraft grounds and how they are applied. In addition, this handbook provides background information for aircraft grounding, static electricity theory and how it affects aircraft, and techniques used for measurement of grounding points. This handbook is intended for use by all U.S. Navy and Marine Corps aircraft maintenance and operations personnel for the purposes of ensuring that aircraft are properly and safely grounded. This handbook is for guidance only and cannot be cited as a requirement.

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MIL-HDBK-274A

5.5 Schedule for resistance testing of ground points. Static, power, ordnance and lightning grounds should be checked every 24 months. Guidelines on this topic can be found in NAVSEA OP 5, Chapter 5.

5.6 Identification of ground points. It is recommended that ground points be identified in the manner indicated on Figure 12.

5.7 Use of mooring eyes as static ground points. Mooring eyes (also referred to as padeyes) may be used as static ground points provided that they have been identified and measured properly. Surveys (for example, NAVAIR Report AIR-5181-1000, "Airframe Electrical Grounding Requirements Program Final Report") have indicated that samplings of the resistance values of mooring eyes showed them to be under 10,000 ohms and therefore acceptable as static ground points. Mooring eyes selected for use as static grounds should have their resistance measured.

5.7.1 Mooring eye installation details. Figure 13 shows typical mooring eye installation details. Additional information is available in NAVFAC Technical Specification TS-02614. At some facilities a stainless steel bead has been welded to the upper exposed area of the mooring eye. This prevents corrosion buildup on the mooring eye and reduces its likelihood of providing a poor ground.