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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PARAGRAPH

5.12

CONTENTS

Shore-based grounding guidelines

PAGE

48

5.13

Shipboard grounding recommendations

51

5.13.1

Aircraft tie-down chains

52

5.14

Grounding cable details

52

5.14.1

Ground cable construction

53

5.14.2

Recommended cable parts

54

6.

NOTES

54

6.1

Intended use

54

6.2

Actual grounding problem

54

6.2.1

Details of grounding issue

55

6.3

Responsible technical activity

55

6.4

Changes from previous issue

55

6.5

Subject term (key word) listing

55

1.

Cloud-inducing charge on aircraft

10

2.

Possible return path for accumulated charge during remote discharge of

11

clouds

3.

Charge accumulation on clothing

13

4.

Lightning current pulse, time domain

23

5.

Lightning current pulse, frequency domain

23

6.

Simple electrical circuit utilizing Ohm's Law

32

7.

Illustration of Earth's resistance

32

8.

Illustration of Earth's shells

34

9.

Three-terminal test technique

34

10.

Three-terminal fall of potential method test setup

37

11.

Two-terminal method test setup

38

12.

Measured ground point identification

39

13.

Mooring eye details

40

14.

Combination tie-down/grounding receptacle

41

15.

Static ground receptacle

42

16.

Resistance measurement for alternate grounding points

44

17.

MIL-DTL-83413/7-1 clamp

45