scope:

Purpose. The purpose of this handbook is to provide aircraft maintenance personnel with the information required for electrical safety grounding of each type of operational aircraft in the U.S. Navy inventory.* In addition this handbook provides background information pertaining to the operational concerns for aircraft grounding, static electricity theory and how it affects aircraft, and techniques used for measurement of grounding points. five sections as follows:

SECTION 1 - SCOPE

SECTION 2 - AIRCRAFT GROUNDING AND BONDING METHODS

SECTION 3 - OPERATIONAL GROUNDING CONCERNS

SECTION 4 - THEORETICAL BASIS FOR AIRCRAFT GROUNDING

SECTION 5 - TESTING AND IDENTIFICATION OF GROUND POINTS

This handbook is intended for use by all U.S. Naval aircraft operational and maintenance personnel including maintenance officers and public works officials for the purpose of ensuring that each aircraft is properly grounded and that the grounding system is adequate for this purpose. primarily for use by line maintenance personnel. This section provides step-by-step intended for those desiring to obtain additional theoretical and background information. Section 5 is essential for public works department personnel. Each section is designed to stand alone.

The information contained in Section 2 is intended to be used by line maintenance personnel. grounding each of the aircraft in the Navy inventory during each of the following evolutions : parked, fueling/defueling, maintenance and stores loading/unloading Each evolution is shown in a separate illustration depicting the particular aircraft with proper grounding/bonding cables connected. The illustrations show primary grounding points and also provide alternate grounding points should the primary grounding point be inaccessible. Also provided on the illustrations are pertinent cautions and warnings to be observed during the grounding procedure. Accompanying each illustration is a step-by-step procedure for grounding/bonding the particular aircraft.

Section 3 provides background and general information necessary to understand the rationale behind the requirements for grounding and bonding. section also discusses the grounding problems and hazards encountered in the everyday ground handling of aircraft during flight operations. Energy sources and grounding effects are identified. The aircraft scenarios or servicing situations (evolutions) are introduced and the aircraft safety problems associated with each are described. In addition, a brief discussion of static electricity and how it affects aircraft operation is provided.

Section 4 details basic electrostatic theory and its application to aircraft grounding. Sources of static electricity associated with aircraft operation are a180 described. These include triboelectric effects, fuel flow, induced charge, and friction. Hazards from ground power faults, rf energy, and lightning are presented. Also included in this section are descriptions of aircraft electrical parameters and a discussion of hazardous threshold and the possible dangers they present to personnel and aircraft safety, The section also illustrates that proper grounding will reduce these hazards.

Section 5 is intended for use by the public works department personnel and provides a description of the methods and techniques used to measure the resistance of the grounding system. Also included in Section V i s a suggested schedule for accomplishing the measurement of ground points, identifying ground points, the use of mooring eyes as static ground points, and a discussion of the test equipment used to measure ground point resistance.

^*UmS. Navy aircraft use power equipment not equipped with ground fault interrupters (GFI 1).