ASTM F2696-14

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2696 − 08 F2696 − 14
Standard Practice for
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Inspection of AirplaneAircraft Electrical Wiring Systems
This standard is issued under the fixed designation F2696; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers basic inspection procedures for electrical wiring interconnect systems for normal and utility category
aircraft electrical wiring systems.
1.2 This practice is not intended to replace any instructions for continued airworthiness published by the aircraft or accessory
manufacturer or type design holder.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 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.
2. Referenced Documents
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2.1 Military Standard:
MIL-C-85049 Connector Accessories, Electrical, General Specification for
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2.2 FAA Guidance Material:
FAA Advisory Circular 33.4-3 Instructions for Continued Airworthiness; Aircraft Engine High Intensity Radiated Fields (HIRF)
and Lightning Protection Features
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2.3 SAE Documents:
SAE ARP1870 Aerospace Systems Electrical Bonding and Grounding for Electromagnetic Compatibility and Safety
SAE Aerospace ARP5583 Guide to Certification of Aircraft in a High Intensity Radiated Field (Hirf) Environment
3. Terminology
3.1 Acronyms:
3.1.1 EWIS—electrical wiring interconnection system
3.1.2 HIRF—high-intensity radiated fields
3.1.3 ICA—instructions for continued airworthiness
3.1.4 LRU—line-replaceable unit
3.1.5 MS—military standard
3.1.6 MTBF—mean time between failures
3.1.7 PTFE—polytetrafluoroethylene
3.1.8 RF—radio frequency
3.1.9 STC—supplemental type certificate (Federal Aviation Administration)
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This practice is under the jurisdiction of ASTM Committee F39 on Normal and Utility Category Airplane Electrical Wiring Aircraft Systems and is the direct
responsibility of Subcommittee F39.02 on Inspection, Maintenance, and Repair.
Current edition approved Jan. 15, 2008May 1, 2014. Published February 2008June 2014. Originally approved in 2008. Last previous edition approved in 2008 as
F2696 – 08. DOI: 10.1520/F2696-08.10.1520/F2696-14.
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Available from the U.S. Government Printing Office, Superintendent of Documents, Stop: SSOP, Washington, DC 20402-0001.
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Available from Federal Aviation Administration (FAA), 800 Independence Ave., SW, Washington, DC 20591, http://www.faa.gov.
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Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http://www.sae.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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F2696 − 14
4. Significance and Use
4.1 The term “electrical system” as used in this practice means those parts of the aircraft that generate, distribute, and use
electrical energy, including their support and attachments.
4.2 The satisfactory performance of an aircraft is dependent upon the continued reliability of the electrical system.
4.3 Damaged wiring or equipment in an aircraft, regardless of how minor it may appear to be, cannot be tolerated. It is,
therefore, important that maintenance be accomplished using the best techniques and practices to minimize the possibility of
failure.
4.4 When inspecting and evaluating EWIS, improper wiring, routing, or repairs shall be corrected regardless of the origin of
the error.
4.5 This practice is not intended to supersede or replace any government specification or specific manufacturer’s instruction
regarding electrical system inspection and repair
5. Causes of Wire Degradation
5.1 The following are considered the principal causes of wiring degradation and should be used to help focus maintenance
programs:
5.1.1 Vibration—High-vibration areas tend to accelerate degradation over time resulting in “chattering” contacts and
intermittent symptoms. High vibration of tie-wraps or string ties can cause damage to insulation. In addition, high
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