4.1 Design—The design procedures defined in this practice are intended to provide acceptable guidance in the original design of electrical systems.

4.2 Alteration—The alteration procedures defined in this practice are intended to provide acceptable guidance for modification of general aviation aircraft. Design of any modification shall follow the practices and processes defined in the design sections of this practice.

4.3 Certification—Certification guidance provided in this practice is intended to provide generally accepted procedures and processes for certification of original and modified electrical systems and equipment. Requirements for certification shall be coordinated with the applicable National Aeronautics Association/Civil Aeronautics Administration (NAA/CAA) regulatory agency.

1.1 Definition—This practice defines acceptable practices and processes for the design, alteration, and certification of electric systems and installations in general aviation aircraft. This practice does not change or create any additional regulatory requirements nor does it authorize changes in or permit deviations from existing regulatory requirements.

1.2 Applicability—The guidance provided in this practice is directed to air carriers, air operators, design approval holders, Supplemental Type Certificate (STC) holders, maintenance providers, repair stations, and anyone performing field approval modifications or repairs.

1.3 Protections and Cautions—This practice provides guidance for developing actions and cautionary statements to be added to maintenance instructions for the protection of wire and wire configurations. Maintenance personnel will use these enhanced procedures to minimize contamination and accidental damage to electrical wiring interconnection system (EWIS) while working on aircraft.

1.4 “Protect and Clean As You Go” Philosophy—This philosophy is applied to aircraft wiring through inclusion in operators’ maintenance and training programs. This philosophy stresses the importance of protective measures when working on or around wire bundles and connectors. It stresses how important it is to protect EWIS during structural repairs, STC installations, or other alterations by making sure that metal shavings, debris, and contamination resulting from such work are removed.

1.5 This practice includes the following sections:

Title

Section

Wire Selection

5

 General

5.1

 Aircraft Wire Materials

5.2

 Table of Acceptable Wires

5.3

 Severe Wind and Moisture Problems (SWAMP)

5.4

 Grounding and Bonding

5.5

 Electrical Wire Chart

5.6

Wire and Cable Identification

6

 General

6.1

 Wire and Cable Identification

6.2

 Types of Markings

6.3

 Sleeve and Cable Marker Selection

6.4

 Placement of Identification Markings

6.5

Wiring Installation

7

 General

7.1

 Wire Harness Installation

7.2

 Power Feeders

7.3

 Service Loops

7.4

 Drip Loops

7.5

 Soldering

7.6

 Strain Relief

7.7

 Grounding and Bonding

7.8

 Splicing

7.9

 Fuel Tank Wiring

7.10

 Corrosion Preventative Compounds (CPC)
 (MIL-C-81309)

7.11

Electrical Load Considerations

8

 General

8.1

 Methods for Determining the Current-Carrying
 Capacity of Wires

8.2

 Acceptable Means of Monitoring and
 Controlling the Electrical Load

8.3

Electrical System Components

9

 General

9.1

 Alternators

9.2

 Generators

9.3

 Ground Power Units

9.4

 Auxiliary Power Units

9.5

 Batteries

9.6

 Circuit Protection Devices

9.7

 Conduit

9.8

 Connectors

9.9

 Inverters and Power Converters

9.10

 Junctions

9.11

 Junction Boxes

9.12

 Electronic Assemblies

9.13

 Relays

9.14

 Studs

9.15

 Switches

9.16

 Terminals and Terminal Blocks

9.17

 Waveguides

9.18

Electrical System Component Installation

10

 General

10.1

 Alternators

10.2

 Generators

10.3

 Auxiliary Power Units (APUs)

10.4

 Batteries

10.5

 Circuit Protection Devices

10.6

 Conduit

10.7

 Connectors

10.8

 Inverters and Power Converters

10.9

 Junctions

10.10

 Junction Boxes, Panels, Shields, and
 Microswitch Housings

10.11

 PC Board Assemblies

10.12

 Relays

10.13

 Studs

10.14

 Switches

10.15

 Terminals and Terminal Blocks

10.16

 Waveguides

10.17

EMI/RFI

11

 General

11.1

 Grounding and Bonding

11.2

 HIRF

11.3

 Lightning

11.4

Alterations

12

 General

12.1

 Wire Substitutions

12.2

 Commercial Off-the-Shelf (COTS) Components

12.3

 Electrical Load Considerations

12.4

 Batteries

12.5

 Circuit Breakers

12.6

 Junction Boxes

12.7

 Relays

12.8

 Switches

12.9

 Wire Marking

12.10

 Wire Bundle Routing

12.11

 Wire Bundle Combing

12.12

 Interference Tests

12.13

 System Safety Assessments

12.14

Certification Processes

13

 General

13.1

 Certification

13.2

 Alterations and Maintenance

13.3

1.6 Values—The values given in inch-pound units are to be regarded as the standard. The values in parentheses are for information only. See Appendix X2 for SI-based prefixes and powers of 10.

Note 1: Where SI units are required, refer to Annex 5 of ICAO.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.