EWIS, in depth.
393 technical articles on wire system testing, certification, standards, and sustainment — published continuously since 2014. Get new articles by email →
2026
Velocity of Propagation: What Conductor Metal Really Changes in Cable Design
For low-latency cable design, the best path is not simply “use a better metal”; it is to engineer the electromagnetic field path by selecting the right dielectric and geometry, then choose the conductor system that preserves that performance in service. In this article, we review the concept of velocity of propagation, where it impacts system design, and the practical design factors for cable constructions.
2026-07-07 Testing & AssessmentFirst-Article Testing of Wire Harnesses
First-article testing of wire harnesses is a layered system-level verification plan often unique to the harness under test. Wiring harness first-article plans usually adapt existing wire, cable, and…
2026-05-12 Standard & RegulationMIL-DTL-32630 vs ASTM B33 and AS29606
Metal conductors have been the primary (and pretty much only) means of transferring electrical energy for centuries. With recent technological developments, it is possible to use alternative…
2026-04-29 Standard & RegulationHIRF and EWIS in the Age of High-Voltage Aircraft
High-Intensity Radiated Fields (HIRF) have often been viewed and treated mainly as an avionics certification problem. For modern aircraft, especially those moving toward higher-voltage power…
2026-04-02 CertificationFAA EWIS ICA Update
AC 120-102B replaces AC 120-102A and modernizes the FAA’s operator guidance for EWIS ICA incorporation by tightening the legal framing of AC usage, updating oversight terminology and contact…
2026-03-17 Standard & RegulationComparison of MIL-DTL-38999 and MIL-DTL-22992
In aviation Electrical Wiring Interconnection Systems (EWIS), the MIL-DTL-38999 is nearly synonymous with connector testing. Connectors qualified to the 38999 are considered suitable for rather…
2026-01-28 ResearchAdditive Manufacturing of EWIS Components
Additive manufacturing (AM), commonly known as 3D printing, is emerging as a promising method to produce certain EWIS components. This technology offers design freedom to create complex, lightweight…
2026-01-052025
WAIC in Aircraft: Which Systems Will Stay Wired?
Miles of copper wire connect sensors, controls, and systems which add thousands of pounds to an aircraft, thus there has been a continuous drive for the use of lighter aluminum conductors, and maybe…
2025-12-11 Standard & RegulationAn Exploration of AS39029: Part 1
The intermateability of electrical contacts is critical for electrical system reliability and performance. This article discusses one of many critical factors, the contact retention mechanism, which…
2025-11-11 Standard & RegulationPotting Compounds
Potting compounds covered in MIL-M-24041 are reliable compounds that have been part of aerospace wiring systems for decades. This article reviews a specific implementation of potting compounds and…
2025-10-13 Standard & RegulationWiring Diagram Guidance for Aerospace Systems - MIL-HDBK-863
Aircraft wiring schematics require clear standardized diagrams for design, fabrication, installation, maintenance, and safety assessments. This article explores the scope of MIL-HDBK-863, details it…
2025-09-02 Testing & AssessmentCable Impedance in EWIS Applications
Impedance matching is crucial to minimize reflection and signal loss in many high frequency EWIS applications. In this article, we discuss the factors impacting cable impedance, its impact on…
2025-07-30 Standard & RegulationSAE J1127 and J1128: Battery Cable and Primary Wire Specifications
The SAE J1127 and J1128 standards define two classes of automotive vehicle wiring. SAE J1127 covers heavy gauge *battery cables* (e.g. starter and chassis ground leads) and SAE J1128 covers lighter…
2025-07-07 Standard & RegulationQuadrax Cable
In the case of high reliability, high-bandwidth data transmission, quadrax cables may emerge as a viable option for some designs. A typical quadrax cable has two layers of shielding each with at…
2025-06-05 Standard & RegulationISO 6722
The aerospace industry should consider automotive standards like the ISO 6722 as a basis for high-voltage wire qualification. Automotive and aerospace standards development around electrical wiring…
2025-05-05 Maintenance & SustainmentBenefits of Supplying a Completed Connector Harness for Aircraft Installation
The decision of whether to fully complete cable harness assembly before or during installation on aircraft is non-trivial and requires multiple engineering perspectives. The decision may depend on…
2025-04-10 Testing & AssessmentDeciphering Partial Discharge Test Results
Partial discharge testing serves as a valuable tool for assessing the health and reliability of wire and cable systems. Understanding the implications of PD test results, including PDIV, PDEV, and…
2025-02-20 Testing & AssessmentThe Complexity of Fire Ratings
Understanding the differences in fire and flammability tests for aircraft components is critical to ensuring safety and compliance with FAA regulations. In this article, we discuss the varying fire…
2025-01-29 Testing & AssessmentConnector Failure Modes - Mating/Demating
EWIS maintenance sometimes includes the demating and remating of electrical connectors for testing, cleaning, removal to access other equipment, etc. The repeated action of mating/demating can cause…
2025-01-062024
A Spark of Holiday Cheer - Holiday Season 2024
Every year, Lectromec creates a video to celebrate the holiday season. This year, we decided to utilize some of the lab's high voltage test equipment. This year's holiday video titled, "A Spark of…
2024-12-19 Testing & AssessmentUnderstanding Outcomes of Scrape Abrasion Testing
Scrape abrasion is a useful test for aviation wiring, although liable to inherent variability in test data. Thus, the results should be considered as a general assessment rather than a specific time…
2024-11-21 Standard & RegulationAluminum Conductors
While there are benefits to replacing copper wires with aluminum, parts selection must align with the specific installation requirements. Here, we discuss the fundamentals of aluminum conductors…
2024-09-05 Testing & AssessmentTesting and Qualification of Fuses
Aircraft electrical fuse testing includes electrical, mechanical, chemical, and thermal conditions that are representative of the aircraft in question. This article discusses the basics of electrical…
2024-08-20 Testing & AssessmentHigh Voltage, Low Current Material Arc Resistance Testing
Long-term exposure to high-voltage can cause an insulating material to break down and, over time, even form conductive paths along its surface. The ASTM D495 test method is a preliminary assessment…
2024-07-26 Protection & PreventionUnderstanding Filter line Cables: Purpose, Construction, and Key Concepts
The primary purpose of filter line cables is to minimize EMI and RFI, which are prevalent in environments with high levels of electromagnetic noise. In this article we discuss the unique construction…
2024-07-15 Protection & PreventionTo Shield or Not to Shield – A Question on High Voltage DC Cables
Shielding on aerospace cables offers several benefits but can introduce some drawbacks that must be considered. In this article, we explore the pros and cons of using shielded cables on aircraft.
2024-06-21 Standard & RegulationAS50881 and Connectors
Amidst the vast amount of aerospace standards, AS50881 stands out as a comprehensive guide to requirements to ensure wire termination safety specifically in connector installation and design. In this…
2024-06-03 Maintenance & SustainmentInspectability of EWIS
Though EWIS should be protected from hazards such as tampering, FOD, and fluid exposure, the system does need to be periodically inspected and maintained throughout its service life. In this article…
2024-04-01 Testing & AssessmentInsertion Loss and Attenuation
Insertion loss and attenuation are similar concepts, but one is assigned to a single component (insertion loss) whereas the other is assigned to generalized performance (attenuation). In this…
2024-03-14 Standard & RegulationThe Use of Splices
Though useful in repairs and modification, overuse of splices can lead to serious electrical and mechanical problems in an electrical system. This article discusses the applications and restrictions…
2024-02-20 Protection & PreventionProtected Harness Design
Wiring harness protection materials address needs such as fire protection, physical damage protection, chemical protection, and wire management but may also present challenges such as overheating or…
2024-01-30 Testing & AssessmentForced Hydrolysis
The goal of forced hydrolysis testing is to represent decades of wet/humid environmental exposure on polyamide-insulated aircraft wiring. This article discusses forced hydrolysis testing in detail…
2024-01-102023
Physical Impact on Coax Cable Performance - Holiday Season 2023
Every year, Lectromec creates a video to celebrate the holiday season. This year, we decided to piggyback on an article from last month and continue testing coax cable. This year's holiday video…
2023-12-22 ResearchSuperconductors and Wire Qualification
Discovery of a room temperature superconductor would have a tremendous impact on the aerospace industry and could result in lighter aircraft. In this article, we consider this impact and discuss…
2023-12-05 ResearchMinimum Coaxial Cable Bend Radius
The impact of a coaxial cable's bend radius is not well defined from an initial evaluation standpoint. Standard restriction on the minimum bend radius for coaxial cables has remained unchanged for…
2023-11-15 Standard & RegulationA Guide to Aircraft Lightning Standards
Lightning protection requirements are not as straightforward as looking up a numerical value for insulation resistance or verifying the interchangeability of connector pins, and it is not exclusively…
2023-10-27 Testing & AssessmentCreepage and Clearance
High voltage systems on aircraft will be more commonplace as the eVTOL market “takes-off.” One safety aspect that often comes up is the separation of the high voltage; often, this comes down to…
2023-10-13 Testing & AssessmentHeat Shrink Volume Resistivity
Heat shrink tubing is used throughout an aircraft’s Electrical Wiring Interconnection System (EWIS) and must withstand the stresses set upon it in the standard testing. Volume resistivity is just one…
2023-10-03 Testing & AssessmentVoltage, Current, and Thermally Rating Connectors
While electrical component qualification is nothing new to the aerospace industry, the emerging trend toward full aircraft electrification requires every component to be electrically connected; for…
2023-09-13 Standard & RegulationCopper Hookup Wire
Aerospace standards like the ASTM B470 or the ASTM B355 provide specific performance characteristics of electrical wire conductors. This article discusses some of the test methods covered in these…
2023-08-15 Protection & PreventionA Brief Explanation of Thermal Runaway
In this article, Lectromec provides a basic summary of thermal runaway and the specific challenges it poses in aircraft, specifically regarding the shift toward more electric vehicles and the…
2023-07-25 Standard & RegulationCFR 25.1717 - Circuit Protection and EWIS
Circuit protective devices are circuit components whose purpose is to disconnect power to the circuit in the event of a fault condition. The fault conditions vary based on the circuit type, attached…
2023-06-30 CertificationAre New EWIS Regulations Needed for High Voltage EWIS?
High voltage power has been a hot topic in the aerospace industry for several years now. As programs have been getting closer to a marketable product, regulators are seeking to determine the…
2023-06-20 Testing & AssessmentHV Connector Failures and Part Selection
With the current shift toward hybrid and electric aircraft, deeper understanding of high voltage connectors and their potential failure modes is required. In this article, we discuss failure modes…
2023-06-02 Maintenance & SustainmentCorrosion Prevention and AC 43-206 Part 3
In this article, we continue the discussion of AC 43-206 by addressing the equipment and tools utilized in corrosion prevention and maintenance as well as identifying potential hazards to personnel…
2023-04-27 Conference & ReportS&T 2022 Meeting Report
As in any scientific industry, aerospace across the globe benefits from the sharing of information and research. The annual S&T Electrical Systems and Wiring Inter-Agency Meeting is held each…
2023-04-06 Maintenance & SustainmentCorrosion Prevention and AC 43-206 Part 2
In this article, we look at procedures identified in AC 43-206 for the cleaning of avionics equipment to remove and prevent corrosive deposits. After initial inspection and identification of…
2023-03-10 Testing & AssessmentFluid Immersion Testing of EWIS Components
From fuel to hydraulic oil to sodas, aircraft wires and cables are exposed to a wide range of fluids and, generally, the insulations must not show degradation that would impact their airworthiness…
2023-01-31 Maintenance & SustainmentCorrosion Prevention and AC 43-206
This article will discuss inspection methods for evidence of corrosion on aircraft and aircraft systems; a future article will address some of the maintenance and cleaning guidance offered by AC…
2023-01-192022
Top 5 Articles of 2022
With the ramp-up of production across the entire supply chain, new vehicle concepts coming closer to being fielded, and continued research supporting the next generation of aircraft, 2022 was a big…
2022-12-30 MiscellaneousThe Special Little Wire - Holiday Season 2022
“The Special Little Wire” is a story about a cheerful 24AWG wire journey to achieve his dream of being installed on an aircraft. But will he be able to become part of an aircraft Electrical Wiring…
2022-12-14 Testing & AssessmentFlex Endurance Test Basics
While most wire installed in an aircraft is placed in static conditions, there are still several harnesses that must support regular flexing. Applications such as landing gears, wiring attached to…
2022-11-06 Testing & AssessmentIEC 60851-5 Winding Wires – Electrical Property Test Methods
Winding wires, or magnet wires, are the wires used to construct coils in electronic components (transformers, relays, etc.) that generate the component’s magnetic field. These wires are primarily…
2022-10-18 Testing & AssessmentHeat Shrink Tubing Tests
Heat shrink tubing is a very commonly used component in Electrical Wiring Integration Systems (EWIS). Just as with any other component of an aircraft wiring system, heat shrink tubing must withstand…
2022-09-30 ResearchGlycol and Silver-Plated Conductors
In this article, we discuss silver's susceptibility to corrosion when exposed to glycol, its impact on aircraft, and ways to mitigate potential degradation.
2022-09-14 Testing & AssessmentHeat Shrink Tubing Flammability Tests
As is the case with many components in electrical wiring, one of the most important properties of heat shrink tubing is its resistance to fire. Take a look at several methods used to determine and…
2022-08-31 Testing & AssessmentWhich Red Plague Testing is Right for My Application?
In short, red plague is corrosive galvanic corrosion that occurs between the silver plating and copper core of silver-plated copper wire. This has been a known issue since at least the 1950s and has…
2022-08-18 Conference & ReportSAE April 2022 Update
After two unsuccessful attempts to meet in person, the SAE AE-8A/D committee met to update standards whose progress has been slowed over the last two years.
2022-07-25 Standard & RegulationAIR7502 and Future Implications for Aviation
The AIR7502 defines voltage levels for HV aircraft and components. The extent to which AIR7502 is incorporated into the aerospace industry remains unsure, but the implications of the document are…
2022-07-08 Testing & AssessmentHigh Voltage Arc Tracking Requirements (Part 2)
In part 2 of this article series, we continue to discuss how arc track resistance testing as we know it must be re-evaluated as more HV systems with unique testing requirements lead the aviation…
2022-06-18 Testing & AssessmentHigh Voltage Arc Tracking Requirements (Part 1)
Arc track resistance testing has been a staple of the aerospace industry for nearly 40 years. This originated from the issues raised in the 1980s with polyimide insulated wire. Since that time, test…
2022-06-06 CertificationEWIS High Voltage Certification
With the gradual industry implementation of high voltage EWIS systems in aviation, the demand for HV-specific safety standards is rapidly growing. High voltage OEMs currently use available industry…
2022-04-14 CertificationLife-Limiting High Voltage Parts
Life-Limited EWIS parts can be useful where high voltage conditions make component degradation rates uncertain. Though accelerated aging can offer insight to the component's condition, further…
2022-03-15 Maintenance & SustainmentICA Guidance for HIRF and Lightning Protection
The advisory circular 33.4-3, issued by the FAA offers guidance for developing adequate ICA for an aircraft’s HIRF and lighting protection functions.
2022-02-21 Testing & AssessmentThe Longevity of High Voltage Components
What does a wire need to do in the high voltage system, and how does it need to perform? This article reviews some of the fundamental concepts involved and what needs to be done to show a wire is…
2022-02-07 Conference & ReportS&T 2021 Meeting Report
A discussion covering the topics of interest presented at the FAA's annual S&T meeting in 2021.
2022-01-20 Conference & ReportTop 5 Articles of 2021
It was a busy year for Lectromec’s publishing team; in 2021 we published 22 articles, one brand new whitepaper, and several of our articles were picked up for redistribution. We took some time at the…
2022-01-042021
An Over-Current of Christmas Joy
Nearing the end of 2021 we wanted to share one last wire experiment. Please enjoy Lectromec's Over-Current of Christmas Joy. Happy Holidays! - the Lectromec team
2021-12-21 Maintenance & SustainmentAS23053 Dimensional Life of Heat Shrink Tubing
We are told that low humidity and cool temperatures are the best way to extend component life, but even in such conditions not all components can sit on a warehouse shelf indefinitely awaiting the…
2021-12-15 ResearchLow Temperature Bend Testing for Lunar Applications
NASA sought to evaluate wire and cable flexibility for lunar applications; specifically looking to evaluate the ease of reeling/unreeling wire and cable in lunar environments. Bend testing was…
2021-11-30 CertificationRisk Assessment and Small Aircraft Certification
The basic idea behind the F3230 is to limit the total number of assessments to those that are of particular concern for aircraft safety. This aligns with the change of part 23 aircraft the FAA has…
2021-11-17 CertificationVerification and Validation
Amidst the manufacturing process, a structured system of quality assurance is of utmost importance; implementation of a standardized evaluation system is key to ensuring that whatever is being made…
2021-11-01 Standard & RegulationA New Revision of MIL-HDBK-522
A new version (Revision C) of MIL-HDBK-522 was released on May 11, 2021. This article examines many of the changes made between Revision B and Revision C.
2021-10-20 Standard & RegulationAerospace High Voltage Systems: Addressing the Gaps in Current Standards
The aerospace segment has been dealing with questions of high voltage systems for the last decade. Many of these questions revolve around the generation, storage, and use of this power, but what has…
2021-10-06 Protection & PreventionSkin Effect
An area of power transmission that we have not talked about in any Lectromec article thus far is the impact of skin effect. While this is an area that is well documented and understood for…
2021-09-15 Maintenance & SustainmentIn Consideration of Backshells
The backshell of a connector is an item that perhaps does not get the attention that it should. Often the discussion of EWIS focuses on the wiring, the connectors, or managing the risk of EWIS…
2021-09-01 Testing & AssessmentPull Through Testing- An Addition to NEMA 27500
An area that has been poorly defined until recently has been the potential damage to wire/cable insulation due to wiring installation on aircraft. The latest revision of NEMA 27500 has looked to…
2021-08-18 Protection & PreventionPartial Discharge at Altitude
PD is not a simple phenomenon to model as there are many environmental factors that have influence. Factors such as heat, humidity, pressure, are some that can change the voltages required to…
2021-07-27 Standard & RegulationDetailed Discussion of MIL-STD-1353 (Part 2): Nickel and Gold Plating
Plating materials used on electrical connectors are imperative to the connector maintainability and dependability throughout its service life. In the last article on MIL-STD-1353, we discussed Tin as…
2021-07-12 Standard & RegulationAn Introduction to AS50881
For the last 17 years, Lectromec publications have discussed items related to the aerospace wiring installation standard AS50881. The standard is often referenced in many of our articles, but…
2021-06-30 Protection & PreventionAddressing the Big Questions of Partial Discharge
In this high-voltage present, wires and cables must address new challenges, perhaps the most notable is partial discharge (also referred to as corona). This article discusses the fundamentals of…
2021-06-11 Maintenance & SustainmentIntegrating EWIS into Fleet Sustainment and MECSIP
While the Electrical Wiring Interconnection System (EWIS) evaluations and sustainment requirements have been part of the Mechanical Equipment and Subsystems Integrity Program (MECSIP) since 2013, it…
2021-05-06 Standard & RegulationDetailed Discussion of MIL-STD-1353 (Part 1): Tin Plating
The mating of the electrical wiring interconnect system (EWIS) is a non-trivial task. Between the functional requirements (the correct number of pins, sizing of contacts, etc.), there are also the…
2021-04-21 Standard & RegulationA Summary of MIL-STD-1353, A Guide to Connector Selection
Due to the diversity of connector applications, each connector is liable to be subject to entirely different electrical stress, mechanical stress, environmental conditions, etc. Knowing the severity…
2021-03-26 CertificationElectric Aircraft Design Considerations
Electrical energy storage has reached a point where it is possible for the manned vehicle propulsion to use non-petroleum based energy. To achieve this goal, it has required a lot of research…
2021-03-18 Standard & RegulationASTM F3309- A Simplified Safety Analysis for Small Aircraft
Aircraft safety requirements vary depending on the size of the aircraft. Typically, larger aircraft have stricter requirements as a catastrophic failure in large aircraft has the potential for a much…
2021-03-10 Standard & RegulationEN2235 Review and Comparison to NEMA 27500
Cables are complicated engineered products. They range from the simple twisted pair (simple but requiring precise twists per foot) to the complicated signal and data cables used in many applications…
2021-02-04 Maintenance & SustainmentEWIS and Aircraft Maintainability
The maintainability of the electrical wiring interconnection system (EWIS) is integral to the longevity of an aircraft. EWIS maintainability affects not only the EWIS itself, but any nearby system…
2021-01-19 Conference & ReportTop 5 Articles from 2020
In 2020, Lectromec’s website repository of articles on EWIS and EWIS related topics exceeded 300. The best part is that there is so much more to cover, and we will continue to do so in 2021. But…
2021-01-052020
EWIS Yule Log
With 2020 drawing to a close, we wanted to finish our busiest year in our lab with one more experiment. We hope that you all enjoy Lectromec’s version of the traditional yule log.
2020-12-21 ResearchImpacts of Sanitizing Fluids on Wiring
With operators increasing the amount of disinfectant used on their aircraft, the FAA released a Special Airworthiness Information Bulletin (SAIB)
2020-12-08 Testing & AssessmentNew Means to Assess Corrosion Susceptibility
Low outgassing materials are critical for space applications. As one might imagine, a small, enclosed space with outgassing materials is not an ideal environment. To that end, space system developers…
2020-11-02 ResearchWPAFB Wire Study
the USAF undertook a large effort: capture the performance of wiring components in the market and not just the samples that were sent in for qualification.
2020-10-14 Standard & RegulationIEEE 1584-Arc Standard
The core of the IEEE 1584 document is the set of formulas for calculating the necessary safe separation distance for personnel.
2020-09-16 Testing & AssessmentConductor Resistance ASTM B193
The measurement of resistance seems to be a trivial task. Hook up a standard handheld multimeter with two probes and attach the probes to either side of the device or component that you want to…
2020-08-13 CertificationAS4372 – Building a Wire/Cable Specification
While it is possible to start from scratch and develop an independent set of tests and performance requirements, there are existing standards that can be used to expedite the process.
2020-07-27 Maintenance & SustainmentSelection of Zones for Degradation Testing
Maintenance zones within an aircraft are not homogeneous. They vary from the extreme Aircraft areas within the aircraft (engines) to more benign areas (inside pressure and temperature-controlled…
2020-06-26 Testing & AssessmentSolder Sleeves and Splicing in Shields
Shielded cables are necessary. They provide necessary EMI protection to ensure signal fidelity, and in some cables, such as coaxial cables, the shield is integral for signal transmission. Trying to…
2020-05-15 Testing & AssessmentDielectric Constant
There are some properties that are taken for granted with wires and cables until they are needed for precision applications. A conductor’s conductivity is assumed until the impact of a voltage drop…
2020-04-22 Testing & AssessmentLight Weight and Normal Weight Wire Constructions
Saving weight is a large part of any aircraft design. Naturally, the electrical system is not exempt from the goal of shaving off a couple of pounds. This often comes in the form of looking for…
2020-04-10 Testing & AssessmentThe Impact of a Short Circuit on Conductor Performance
Over-current and shorting are an ever-present risk to power wires and cables. The hope is that circuit protection can quickly respond to over-current conditions fast enough to prevent any damage to…
2020-03-17 Testing & AssessmentNotch Testing and the Impact of 1000 Cuts
How much damage can a single wire take? Does the failure of a wire’s insulation require one large trauma (think of dropping a hammer on it), or is it possible for the insulation to fail due to 1,000…
2020-03-04 MiscellaneousInfographic - The Journey of An Aerospace Wire
From beginning of its life, aircraft wire and cable undergo thousands of hours of testing to ensure their reliable performance. To grasp how this process evolves, Lectromec has put together this…
2020-02-21 Aging Wires & SystemsUnderstanding Life Prediction Technology
To understand the basis for wire life prediction, there are parts of the process that must be understood from a fundamental perspective and how these fundamentals are applied to the long-term…
2020-02-13 Maintenance & SustainmentReview of EWIS for Sustainment
We measure everything that matters. In the last decade, the efforts of organizations to measure EWIS has been progressively increasing. Perhaps this is because wiring is now considered a system, or…
2020-01-30 Conference & ReportTop 5 Articles from 2019
The team here at Lectromec would like to start this article thanking all of our clients for trusting us with your EWIS component and system testing/certification needs and we look forward to…
2020-01-052019
S&T 2019 - Meeting Report
To get the most from the industry, it is necessary to learn and share with the community as much as possible. Some would call it reciprocity, others, seeking to work to a common goal. Whatever you…
2019-12-20 Protection & PreventionImpact of Secondary Wire Harness Protection on Heating
If you are standing outside on a cold winter day, would you be warmer in a T-shirt or in a jacket? The answer is obvious, but somehow that ‘obvious answer’ is obscured when thinking of aircraft wire…
2019-12-10 Protection & PreventionGetting the Right Bonds
Things were so much easier with aluminum aircraft structures. The structure acted as an EMI shield, electrical grounding could be done right to the structure without additional effort, and the…
2019-11-22 Testing & AssessmentNon-Standard Standard Part Performance
Standardized products made by different manufacturers through different processes will undoubtedly yield variable product performance. The expectation is that each ‘qualified’ product should perform…
2019-11-11 Conference & ReportSAE Wire and Cable Committee Meeting Update - Fall 2019
The SAE wire and cable committee held their fall 2019 meeting in San Diego this year. As with every committee meeting, a lot of technical areas were discussed, progress was made, and some new…
2019-11-03 Testing & AssessmentDetermining Voltage Drop
If voltage is applied to a circuit and the attached equipment does not turn on, then there is an issue with either the circuit or the applied voltage (assuming the device is fully functioning)…
2019-10-11 Maintenance & SustainmentWire Diagnostic Equipment
Finding wire faults/damage is not an easy task; now consider that problem across an entire aircraft. In-situ testing of wires/cables has always been viewed as something of a challenge to the…
2019-09-17 Maintenance & SustainmentChecking a Coaxial Cable for Damage with a Multimeter - Part II
In the last article, Lectromec introduced a damaged coaxial cable and tried three techniques to distinguish it from an undamaged cable. The standard multimeter tests (capacitance, inductance, and…
2019-09-11 Maintenance & SustainmentChecking a Coaxial Cable for Damage with a Multimeter
The electronic multimeter is a great tool; invented in the 1920s, the multimeter has been used by millions of technicians and engineers seeking to measure circuits and troubleshoot electrical issues…
2019-08-23 CertificationEWIS Physical Hazard Assessment
Aircraft system safety assessments are not a new concept. These safety assessments have a defined process for evaluating an aircraft which involve identifying its failure modes, top-level events, and…
2019-08-14 CertificationWires and Fuel Compatibility
Whether by design or by accident, some wires in an aircraft will be exposed to jet fuel. Because of this, it is necessary to be prepared and select wires/cable types that will not suffer adverse…
2019-08-07 Aging Wires & SystemsConsequences of EWIS Implementation
In June 2019, Lectromec was asked to present at the USAF Mechanical Equipment and Subsystems Integrity Program (MESCIP) conference. With the electrical wiring interconnect system (EWIS) working its…
2019-07-24 ArcingThe Potential 270VDC EWIS Component Failure Impact
The More Electric Aircraft (MEA) design concept has placed, and will continue to place, a greater importance on aircraft electrical power and the supporting Electrical Wiring Interconnection System…
2019-06-27 Aging Wires & SystemsNew Guidance for Wiring System Inspection
Back in November 2018, the US Navy released the second revision to the military handbook on “Guidelines for inspection of aircraft electrical wiring interconnect systems” (MIL-HDBK-522). This…
2019-06-21 Aging Wires & SystemsCommon Questions About Kapton® Wire
Love it or hate it, the fact is that Kapton® insulated wires will be on aircraft for at least another couple of decades, and because of this, we should learn to live with the insulation type. Part of…
2019-06-12 CertificationPrinciples of EWIS System Safety (25.1709)
Of the regulations encapsulating the 25.17XX EWIS group, none is more complicated than 25.1709. This regulation, consisting of only 31 words, can be the result of thousands of hours of labor…
2019-06-04 Testing & AssessmentImpact of Wires Used as Ladders
Ideally, an aircraft’s EWIS aging is considered and monitored over time, but something as simple as gripping and pulling a wire or cable can change its electrical performance, specifically…
2019-05-22 Conference & ReportLatest Developments in Wire and Cable (Spring 2019)
Wire and cable standards are never proactive, but reactive to industry needs, and as the aviation world moves to high power systems, wire and cable must catch up to ensure the products are available…
2019-05-14 Testing & AssessmentThermal Life of Wires and Cables
While there is a wide range of products from which to choose, across many of these specifications there is a common element: maximum temperature rating. Here, we walk through a couple of the methods…
2019-04-22 Standard & RegulationWhere EWIS Stops
Having well-defined and recognized system boundaries is the best means to ensure an analysis of that system is robust and does not leave any analysis gaps. Without an established limit and assigned…
2019-04-08 MiscellaneousHigh Voltage Impact the Aircraft Wiring System
For aerospace applications, high-voltage power is a rapidly growing interest and being addressed across several industry technical committees. The basic idea is that the power generation is…
2019-03-18 Maintenance & SustainmentHow Much Does the Aircraft Environment Impact Wire Life?
When looking to select any aircraft component, typically the first means of down selecting from the wide variety of components that exists is based on the component’s performance characteristics i.e…
2019-03-01 Aging Wires & SystemsSwissAir 111 Incident
The year of 2018 was yet again another substantial year in commercial air travel. The first quarter of 2018 saw commercial flights carry over 202 million passengers in the US, approximately 8 million…
2019-02-16 Maintenance & SustainmentIs my aircraft wiring serviceable?
A concept employed in the civil engineering field is that of serviceability. At its core, a structure should only remain in-service as long as it is serviceable. A serviceability limit should be…
2019-01-29 Testing & AssessmentInternational Test Standards for Aircraft Wire Tests
Frequently, Lectromec’s articles have focused on wire and cable testing from US-focused standards such as the SAE and US military (MIL) documents. While these are standards frequently cited, there…
2019-01-15 Conference & ReportTop 5 Articles from 2018
At the end of every year, Lectromec rummages through that year’s publications and articles to find the most popular ones. In 2018, this required going through 32 articles (7 were picked up by…
2019-01-082018
Do I Need to Replace My 15/20/30/40 years Old Aircraft Wiring?
As aircraft age, it is natural to contemplate the aircraft condition as to how much longer the equipment can be maintained. Typically, after the engines, structures, environmental control system…
2018-12-27 Testing & AssessmentUse of MIL-T-81490 cable in place of a MIL-DTL-17 cable
A common ‘go-to’ cable for RF applications is the MIL-DTL-17 cable. Many of the MIL-DTL-17 cables are rated to 1 GHz, some to 12.4 GHz (like M17/128), and only a couple at 20GHz (e.g. M17/130 and…
2018-12-20 Maintenance & SustainmentEWIS Instructions for Continued Airworthiness
Here we look at the last 95% of an aircraft life: operation and maintenance. In this, we review the regulatory requirements around EWIS instructions for continued airworthiness (ICA) and some of the…
2018-11-27 CertificationHave we Reached the End of Aging Aircraft Wiring Systems? - Part II
At the start of the last article, the question was posed, “Is it possible that aircraft wiring reached a point where aging/degradation is a thing of the past?” In that article, four elements were…
2018-11-05 Aging Wires & SystemsHave we Reached the End of Aging Aircraft Wiring Systems?
The way some in the aerospace industry maintain their aircraft wiring system can only lead an external observer to reason that aircraft wiring is impervious to damage with a life-span greater than…
2018-10-17 Testing & AssessmentMechanical Performance of Cables at Low Temperatures
The environmental extremes under which wiring exists in aircraft can rapidly degrade materials that are not prepared or designed for those conditions. Without a doubt, high-temperature ranges that…
2018-10-05 Testing & AssessmentShould Polyimide Insulated Wire be Trusted?
The history of polyimide insulated wire is one that has numerous opinions and a lot of misconceptions. After several incidents involving polyimide wire on aircraft in both military and commercial…
2018-09-25 Certification25.981 is Not a Barrier - Part 2
FAA regulation 25.981 covers the requirements of fuel tank ignition prevention. While there are numerous elements that must be considered as part of the 25.981 regulation, this is a Lectromec series…
2018-09-18 Certification25.981 is Not a Barrier
One area of aircraft certification where electrical energy and risk have always been considered is the fuel system. While it is obvious that limiting the exposure of fuel to electrical energy is…
2018-09-08 Testing & AssessmentHigh Current Testing
Several things can go wrong when a wire or cable is subjected to an electrical current exceeding its design limitation and none of them are good. These include, but are not limited to, melting of the…
2018-08-14 Testing & AssessmentDO-160, EWIS, and EMI
Designing a circuit diagram for a system comprised of Line Replaceable Units (LRUs) is usually a straightforward process: identify the inputs and outputs of the system and connect them with wires and…
2018-08-06 Maintenance & SustainmentSelecting Aircraft for Inspection and Work Unit Codes
What documents and standards are there for justifying the evaluation of an aircraft's EWIS? There are actually several.
2018-07-24 CertificationTesting the Performance of AFCBs
Arc Fault Circuit Protection has been a technology that dates back to the 1990s. Despite this not being a new technology, the breath of its implementation is still limited. The device owes its…
2018-07-16 Testing & AssessmentGalvanic Corrosion and Red Plague
Some have brushed the issue aside saying that they have never seen it, thus it is not a problem. To put the issue of red plague into perspective, a worst-case estimate suggests as much as 3% of…
2018-07-07 Maintenance & SustainmentCondition Based Maintenance and Risk Quantification
Aircraft maintenance is usually broken down one of two ways: by physical zones or by systems. The mechanical equipment and subsystems integrity program, also known as MECSIP, is the US Air Force’s…
2018-06-29 Testing & AssessmentUnwanted Energy Storage in Cables - Dielectric Constant
A good wire insulation is more than just preventing electrical energy from leaving the conductor; there are dozens of properties that are important to its performance and usability. One of these that…
2018-06-22 CertificationMaximum Harness Ampacity
The fundamental concept here is harness ampacity: the maximum amount of current transferred down a wire harness without exceeding the temperature rating for any component.
2018-06-15 Maintenance & SustainmentFAQs of EWIS Service Life Extension Programs
Lectromec has accumulated a set of frequently asked questions related to wire system sustainment. Here, we cover several high level questions about the assessment and its value and the subsequent…
2018-06-05 MiscellaneousAging Aircraft Wire
Aging aircraft wiring is a problem affecting the entire aviation industry. Lectromec’s evaluation of the 2016 service difficulty reports found that aircraft over 25 years old were more than two times…
2018-05-22 Testing & AssessmentInsulation Resistance: Measuring Leaky Wires
Wire insulation integrity is a fundamental part of wire performance. Without it, the safety and reliability of a wire is significantly reduced. Over the years, the industry has developed dozens of…
2018-05-10 MiscellaneousGetting the Right Data
How important is it to have the right data on your wire and cable products? For those seeking qualification to a product standard, having test data that matches the requirements is important. Without…
2018-05-02 Conference & ReportLatest Developments in Wire and Cable - SAE 8A 8D Spring 2018
It is not often that you find more than two people in a room with a passion for aerospace wiring systems. One of the exceptions is the bi-yearly gathering of wiring system component and EWIS experts…
2018-04-18 Maintenance & SustainmentWhen to Pull the Component - End of EWIS Component Service Life
What is the end of life for a wire, cable, connector, or any Electrical Wiring Interconnect System (EWIS) component? Three ways to assess.
2018-03-30 Testing & AssessmentShield Grounding and EMI Protection - Part 2
EMI, the concept of electromagnetic interference, is a relatively simple one to convey: radiated energy from other sources induces a voltage in another circuit. But like many things, the simplicity…
2018-03-20 Protection & PreventionShield Grounding and EMI Protection
The push for more electric aircraft is driven by weight savings and the availability of reliable electrical components. This is made possible with greater power generating capacity, however, this…
2018-03-05 Aging Wires & SystemsCorrecting Bad Wire System Guidance
Consider a common aircraft wire: how many requirements and standards must be considered during its design and fabrication? A simple back-of-the-envelope calculation suggests at least 30 various…
2018-02-20 CertificationCircuit Protection Selection Guidance
Circuit protection devices have existed since 1864; one would think that selection of circuit protection would be a straight forward task. However, it is not. NASA developed a seven-step process for…
2018-02-13 CertificationWhat is an EWIS Qualified Wire?
This is a question that Lectromec regularly receives. The reason for this question is that a parts-supplier or system-integrator is looking to find wires in compliance with EWIS requirements. Since…
2018-02-02 CertificationConnector Failure Rates - Part #2
In Lectromec’s previous article , we introduced a basis for estimating connector failure rates. The framework utilized the failure information available from military handbook MIL-HDBK-217. In this…
2018-01-26 CertificationConnector Failure Rates - Part #1
Coming up with failure rates of electrical components is always a difficult task. Historically, when failure modes and effects analyses were created for aircraft systems, the level of detail of EWIS…
2018-01-17 MiscellaneousWhat Are You Missing from Your Risk Assessment?
Creating maintenance action plans for vehicle sustainment is a heavily detailed process involving the collaboration between multiple groups. If any group has a less detailed (or flawed) analysis, the…
2018-01-082017
Top 5 Articles of 2017
At the end of each year, we look back at the most popular Lectromec articles. This year, Lectromec generated a wide range of content ranging from cable testing to corrosion protection. This range of…
2017-12-26 Testing & AssessmentHappy Holidays from Lectromec
Lectromec’s lab did one last set of tests before the 2017 holidays. We bring you a polyimide Christmas tree powered by 270VDC.
2017-12-22 Standard & RegulationAS50881 and EN3197 Harmonization
When considering aircraft wiring systems, a consistent basis for design, certification, and maintenance are pivotal for success.
2017-12-14 CertificationDesigning for Relays
Power transfer through aircraft or any electrical system requires components that have the capability to turn on and off. These components degrade.
2017-11-30 Aging Wires & SystemsFrequency of Wire System Incidents
In July 2017, Lectromec published a white paper on electrical wiring system failures on commercial aircraft. This is a brief video of the finding and what can be done to improve EWIS reliability in…
2017-11-14 Aging Wires & SystemsGetting the Most Value from Wire System Degradation Assessments
Task four of military handbook MIL-HDBK-525 (also incorporated into the mechanical subsystems integrity program standard MIL-STD-1798) outlines a set of considerations and procedures for the…
2017-11-06 Testing & AssessmentStreamline Production with Whitelisting Cable Suppliers
Since each wire/cable manufacturer has its own specialization and processes, significant performance variations can be found despite using the exact same product specification. Tests performed by…
2017-10-25 Maintenance & SustainmentGetting the Most from Visual Inspections
Good data is anything that can be turned into actionable information; this is a critical element in nearly every project. For those that regularly perform EWIS inspections, unless the data is…
2017-10-12 Testing & AssessmentEvaluating Secondary Wire Harness Protection Performance
There are several reasons to deploy secondary harness protection (SHP): chafe protection, maintenance protection, fire protection, harness cable management and, in some cases, arc protection. The…
2017-10-04 Standard & RegulationFall 2017 SAE Wire and Cable Meeting Update
Every six months, the SAE wire system installation and wire/cable subcommittees come together to advance the state of the industry. This year, the Fall meeting was held in sunny Temecula, California…
2017-09-27 Testing & AssessmentPower over Ethernet and Potential Application Problems
The primary purpose of power over ethernet (PoE) is to use a single ethernet cable to provide a datalink and low-level power to devices. Since PoE became standardized in 2003, it has been implemented…
2017-09-15 CertificationSelecting the Right Wires and Cables
In reviewing Lectromec’s articles, one can find over 250 articles covering different segments of aerospace wiring systems and lifecycle. For some, this may be an overload of information. But, if…
2017-08-30 CertificationDoes a Connector's Plating Type Impact Performance?
Design and installation of an aircraft’s electrical system has been made significantly easier with the adoption of modular harness design. This design pattern allows for discrete wiring sections to…
2017-08-23 Testing & AssessmentWhy use Lectromec for your Testing?
Not all testing is created equal. We have all seen the results of poorly performed tests – not only do they result in a waste of money, but also a waste of time – and when testing is delaying a…
2017-08-01 Protection & PreventionFuel System Protection Part II
Lectromec has written multiple articles on fuel system safety as it relates to SFAR88 , AC 25.981 , and AC 25.1701 . In this article, we continue the discussion by reviewing some of the…
2017-07-19 Aging Wires & Systems2016 EWIS Failure Analysis of Commercial Airlines White Paper
Once every couple years, Lectromec reviews the FAA's service difficulty reporting (SDR) system to determine the number of EWIS failures in the American commercial airline fleet. We have reviewed the…
2017-07-10 ManagementBuilding Wire Harnesses Right
Some of the most important elements to the electrical and electronic functions of aerospace vehicles are the cable and wiring harnesses. Accurate transmission of control and data signals is heavily…
2017-06-28 CertificationMaximizing Electrical Component Performance
Most components for electrical systems will have an accompanying product specification or product information sheet. These information sheets contain a lot of information that include mechanical…
2017-06-09 Maintenance & SustainmentUpdating Periodic Maintenance Procedures
An area of aircraft maintenance and wire system sustainment which has been around for the last decade is the enhanced zonal analysis procedures, or EZAP for short. EZAP is a set of procedures…
2017-06-01 Testing & AssessmentHow to Derate a Wire Harness
One of the question that we frequently receive at Lectromec is regarding the derating of wire harnesses. For those unfamiliar with the topic, we have covered this extensively in past articles. The…
2017-05-19 Standard & RegulationDevelopments in High-Voltage
The first meeting of the 8A and 8D committees for 2017 was held in Kissimmee Florida in April 2017. There were several topics discussed and voted upon that will have an impact on future wire…
2017-05-10 Aging Wires & SystemsSigns of an Aging Wiring System
All components wear out over time, but the rate at which they degrade will vary depending on the quality of the product, how is it handled, and the environmental conditions in which the component is…
2017-05-01 CertificationCan the EWIS be Safe After a Modification?
The days of ‘fit and forget’ EWIS are at least a decade behind, the aircraft industry’s understanding of the implications of wiring as a system continues to evolve. New aircraft have gone through…
2017-04-11 Testing & AssessmentLectromec’s Testing Process
Testing can be complex. From test identification, locking down on test parameters, sample preparation, accurate test performance, proper data analysis, and delivery of a final report, an error…
2017-04-03 Testing & AssessmentBasics of Connectors
Aerospace connector standards cover thousands of configurations. Learn how to select the correct one for your application.
2017-03-21 CertificationSpace Certified Wires and Cables
In the last three months, Lectromec has been asked numerous times about “Space Certified Wires” (SCW). The basic premise of these questions has been whether there is a defined set of criteria that…
2017-03-09 MiscellaneousNext 15 Years of EWIS Design
The field of aircraft Electrical Wiring Interconnection Systems (EWIS) has changed significantly in the last two decades. These changes have impacted the design, installation, maintenance, and…
2017-02-24 CertificationEWIS Considerations for UAVs
Many of the Unmanned Aerial Vehicles (UAVs) built have been for military applications. As this technology has matured so has the reliability. The improvements in reliability have made it a viable…
2017-02-13 Testing & AssessmentImpact of Corona on Electrical Systems
Corona is an area of electrical systems that many have some knowledge, but often only to the point of knowing that there is a voltage that should not be exceeded. It is common knowledge that factors…
2017-02-03 Testing & AssessmentHow many Cables Should be Shielded?
A common question when it comes to designing an aircraft EWIS is which of the cables should be shielded? There are several standards, such as MIL-STD-461, “Requirements for the Control of…
2017-01-27 Testing & AssessmentAS4373 - Testing Aerospace Cables - Part 2
When is a wire good enough to be placed onto an aircraft? What environmental tests should be considered to clear it for flight? Are there ways to determine how easy it will be to handle for…
2017-01-21 Testing & AssessmentAS4373 - Testing Aerospace Cables - Part 1
When testing aerospace wire, there are several test standards that might be considered; however, the one that is most commonly referenced is the SAE AS4373 “Test Methods for Insulated Electric Wire”…
2017-01-102016
Lectromec’s Top 5 Articles of 2016
At the end of each year, we look back at the most popular Lectromec articles. This year, Lectromec generated a wide range of content ranging from component testing to protecting fuel tanks. This…
2016-12-30 Protection & PreventionNuisance Trips
Circuit protection devices are primarily responsible for protection of electrical circuits from low impedance faults. These device types may be thermal, arc fault circuit breaker (AFCB), or…
2016-12-16 CertificationEuropean Arc Track Resistance Testing
The arc track resistance test is a basic performance test for most aircraft power carrying wires. As with any component assessment tests, there are many ways to evaluate a wire insulation’s…
2016-12-02 CertificationAvoiding Fuel Tank Ignition
The number of aircraft accidents involving fuel tank ignition has thankfully been very low. However, the growing use of electrical power in aircraft has increased the number of wires and the…
2016-11-21 CertificationEWIS Design Changes – How to Achieve a Safe Separation Distance
Those familiar with aircraft wire system design know the limited available space in which wiring is usually routed. Often in tight quarters with other wire harnesses, redundant systems, and hydraulic…
2016-11-06 Testing & AssessmentAmpacity Improvements
When electrical current flows down a conductor, it gets warm due to resistive heating. The more current that flows, the warmer the conductor gets. Depending on the wire gauge, conductor conductivity…
2016-10-24 CertificationMeeting Requirements for EWIS Certification
There are more than 17 parts to the FAA’s Electrical Wiring Interconnection System (EWIS) regulations enumerated in the 25.1700 series. To show compliance with each of these regulations require a…
2016-10-14 Testing & AssessmentUnderstanding Coaxial Cables
The development and use of coaxial cables have come a long way since its invention in 1880. Improvements in design and reliability have made it a frequent feature for aircraft data transmission…
2016-10-04 Standard & RegulationTesting for AS50881
For several decades now, the AS50881 has been a fundamental knowledge base used for the installation of aircraft wiring systems. The requirements laid out in this standard cover the electrical wiring…
2016-09-23 Testing & AssessmentWhat are the Potential Issues with Tin Plated Conductors?
Tin plated copper is a common choice for wire conductor within the aerospace industry. The advantages of using tin as the plating for copper conductors is the low cost, increases to solderability…
2016-09-11 MiscellaneousStandard Practice for Maintenance of Aircraft Electrical Wiring Systems
ASTM F2799 is a recommended set of practices for EWIS sustainment. Understand how this standard can support procedures for EWIS maintenance/inspection.
2016-09-02 Aging Wires & SystemsEWIS SLEP Reassessment
How often should an aircraft wire system be evaluated? There are six areas that must be considered before your next EWIS assessment.
2016-08-09 Testing & AssessmentUse of Cables on Aircraft - Part 3 - Testing
To continue the series of articles on NEMA27500 cables discussing their use on aircraft ( part 1 and 2 ), this article focuses on the several tests that are necessary for cable verification and…
2016-08-03 Testing & AssessmentUse of Cables on Aircraft - Part 2
In this article, we will continue the discussion by exploring the NEMA27500 cable. Four sections were covered in the Part 1 (Specification, identification and shield coverage, conductor size, and…
2016-07-14 Testing & AssessmentUse of Cables on Aircraft - Part 1
Electrical wire cables are an integral part of an aircraft’s Electrical Wire Interconnection System (EWIS). It would be difficult to imagine the design of an aircraft electrical system without the…
2016-07-06 CertificationElectrical Fault and Fire Prevention and Protection
The prevention of electrical fires is a common goal for most aircraft systems. Advisory Circular (AC) 25-16, “Electrical fault and Fire Prevention and Protection”, released in 1991, can be considered…
2016-06-03 CertificationHigh-speed footage of wire failure near fuel line
As with most fields, the more we learn about a particular topic, the better our understanding of its complexity and the finer details involved. One area Lectromec has done extensive research in is…
2016-05-13 Testing & AssessmentEWIS component test listing now available
Find information and pricing for aerospace electrical component tests for qualification, verification, and performance assessment.
2016-05-05 Conference & ReportLatest news on aircraft wire from the SAE’s Spring 2016 Wire and Cable Committee Meeting
he Spring 2016 SAE AE-8A and 8D wire cable standard and wiring installation guidance committee meetings were held last week in Denver, Colorado. The continuing process of wire improvement, both in…
2016-05-05 Maintenance & SustainmentA case study addressing EWIS sustainment needs
This white paper is a case study on recent work performed by Lectromec for the U.S. military to achieve Electrical Wire Interconnection Systems (EWIS) sustainment of an aircraft fleet.
2016-04-10 Conference & ReportJoint Services Wiring Action Group (JSWAG) Spring 2016 updates
The Spring 2016 Joint Services Wiring Action Group (JSWAG) meeting was held in San Diego last week. Lectromec had the fortune to be able to attend this great meeting that included participants from…
2016-03-25 Protection & PreventionWhat do advanced arc fault circuit protection devices protect?
The use of circuit protection devices is a fundamental part of circuit design; it is difficult to think of systems without them. For the aircraft industry, thermal circuit protection devices have…
2016-03-16 Standard & Regulation11 improvements to MIL-HDBK-522 for aircraft wire systems
One of the best handbooks on EWIS routine inspection for aircraft wire systems is the military handbook MIL-HDBK-522 , Guidelines for Inspection of Aircraft Electrical Wiring Interconnect Systems …
2016-03-02 Testing & AssessmentHow to automate aerospace bent pin wire analysis with Nat Ozarin
Today's guest is Nat Ozarin, Senior Software and Reliability Engineer with The Omnicon Group Inc. He has decades of experience troubleshooting a wide range of issues with a particular emphasis on…
2016-02-11 ResearchHigh temperatures and testing electrical aircraft components
An aircraft must perform under a wide range of temperature conditions. As a result, designers must pay attention to testing electrical aircraft components to see if they can endure constant changes…
2016-02-10 Protection & Prevention4 aspects of wiring selection for special aircraft applications
Not all wires are created equal. Through the years, Lectromec has learned the best practices for wire selection that would ensure the Electrical Wire Interconnect Systems' (EWIS) longevity.
2016-02-04 Testing & AssessmentAircraft wire systems: Bent pin analysis
Previous Lectromec articles have focused on certain parts of system design such as the physical separation between systems. In particular, the articles have focused on the wiring. In this article, we…
2016-01-29 Maintenance & SustainmentEWIS system design: Aircraft wire maintainability
The SAE Wire Installation Guidance document, AS50881, provides guidance on considerations for designing an aircraft wiring system. In this article, we examine sections of the AS50881 and discuss how…
2016-01-19 Testing & AssessmentWhat are the top 10 articles for aircraft wiring systems professionals for 2015?
Through its research, articles, videos, and continuous involvement in the aerospace community, Lectromec has been contributing to the knowledge base for aircraft wiring systems for three decades. To…
2016-01-13 Testing & AssessmentThe benefits of aircraft electrical system analyzers with Chris Teal
Welcome to the Lectromec podcast with John Gilroy. The podcast that helps you improve your understanding of aircraft electrical systems. Every month we interview experts in the public and private…
2016-01-052015
What is the cost of arc track resistance testing?
Arc track resistance testing is an important topic that is of interest to many in the aerospace industry. In this article we discuss the test itself, common test types, the process, and the price of…
2015-12-30 CertificationWhy use an ISO 17025 certified lab for testing aircraft electrical systems?
Lectromec has an ISO 17025:2005 certified lab . What value does that bring to you? What impact will it have for testing aircraft electrical systems?
2015-12-24 Conference & ReportMore Electric Aircraft (MEA) Conference, December 2015
The second conference on More Electric Aircraft (MEA) Wire and Cable was held in Hamburg, on December 1-3, 2015. This conference brought together various groups that are focused on the future of…
2015-12-17 Testing & AssessmentHow you can protect aircraft electrical systems from EMI
Today's interview is with Dan Schettler, Product Specialist at Micro-Coax. He talks about how to protect aircraft electrical systems from electronic magnetic interference (EMI).
2015-12-07 ManagementHow to identify an aircraft wire or cable
If you are trying to identify an aircraft wire or cable, you may want to take advantage of the lessons Lectromec has learned in the past three decades. Because we are in the business of evaluating…
2015-11-30 Protection & PreventionHow to prevent overheating of wire harnesses in space
In the aircraft industry, a lot of effort goes into thermal management of the electrical wire interconnection system (EWIS). If not effectively managed, systems fail to operate and may lead to…
2015-11-23 Testing & AssessmentWhat is an aircraft wire Service Life Extension Program (SLEP)?
Over the years, the Lectromec website has received hundreds of thousands of visits. Often the topic of interest deals with Aircraft Wire Service Life Extension Programs. Because of this popularity…
2015-11-10 Testing & AssessmentCompleted aircraft wire harness testing
When it comes to examining aircraft wire systems, a lot of time is spent examining the performance of individual components like wires, cables, connectors, and pins. However, when we install complete…
2015-10-30 Testing & AssessmentWhat role does a humidity chamber play in an aircraft wire evaluation?
In our first installment of “Two Minute Tuesday” we have a two-minute video description of a humidity chamber and the role it plays in aircraft wire evaluation. We also take a look at testing one…
2015-10-20 ManagementWhat does an aircraft wire testing lab look like?
It is quite possible many aerospace professionals have never seen the inside of an aircraft wire testing lab. If you haven’t had a chance to see our lab, here we present a quick tour.
2015-10-13 Conference & ReportLatest news on aircraft wire from the SAE’s Fall 2015 wire and cable committee meeting
The world of aircraft wire is rapidly changing. Lectromec attended this event and is providing a summary of the most current issues discussed during this fall's SAE Wire and Cable Committee Meeting.
2015-10-01 Testing & AssessmentWhat are the common tests for aircraft wire?
The hundreds of wire tests that exist for aircraft wire and cable can be categorized into five groups: environmental, electrical, mechanical, chemical, and thermal. In this series, we will look at…
2015-09-19 ManagementUnderstanding unexpected arc track resistance test results
Lectromec has been testing wire for the past thirty years. We have seen nearly every conceivable variation of aerospace wire testing. Some tests are straight forward and require little or no…
2015-09-12 ManagementWhat is the impact of increased electrical loads on aircraft wire systems?
With More Electric Aircraft (MEA) being the big push in the industry, it is important to take a moment and think about the wiring system that is going to be supporting these new designs. The…
2015-09-04 ManagementAircraft secondary harness protection with Gregg Turcich
Today Gregg Turcich sat down with Lectromec to discuss the topic of aircraft secondary harness protection, or what some call aerospace protective sleeves. Gregg is certainly qualified to talk about…
2015-08-21 Testing & AssessmentWhere can I get aircraft wire and cable tested?
This is a common question for aerospace engineers who are working with the Electrical Wiring Interconnect System (EWIS) as well as aerospace Maintenance Repair and Operations (MRO) professionals.
2015-08-20 Testing & AssessmentWhat does aircraft wire testing cost for AS22759/87?
Aerospace wiring systems are often underappreciated by other aircraft system engineers for their complexity. Aerospace wires and cables, like all aerospace components, undergo a rigorous set of…
2015-08-12 ManagementEffects of high voltage on aircraft wire connectors
One of the challenges that exist in modern aircraft design is performing more with less. That means using less space, less power, and less weight. For the most part, the technologies integrated into…
2015-08-09 ManagementAircraft solid state power distribution with Fred Potter
Today’s interview is with Fred Potter, Chief Engineer at Astronics AES. He has worked in complex engineering projects since he got his bachelors of science in electrical engineering from Rutgers…
2015-08-03 Testing & AssessmentTaking a look at aircraft wire testing and evaluation
For the past thirty years, Lectromec has been a leader in the area of aerospace wire testing and evaluation. In order to provide aerospace professionals with information to increase their knowledge…
2015-07-15 Conference & ReportAircraft wiring, nanotubes, and much more with George Slenski
Today's interview is with George Slenski, a senior electrical and electronic materials consultant. The term “subject matter expert” is thrown about casually these days. However, every now and then…
2015-06-26 Testing & AssessmentMIL-HDBK-683: Techniques for effectively analyzing data
Failure analysis and system reliability are a fundamental part of the aerospace industry. With the extremely rare exception, modern aircraft are assessed and evaluated at the component, system, and…
2015-06-23 Testing & AssessmentEWIS regulatory compliance: 25.1703, Part II
Aerospace wiring requirements like the FAA regulation §25.1703 can be difficult to comprehend in one sitting. Lectromec has taken this complex document on EWIS regulatory compliance and divided it…
2015-06-16 Standard & RegulationEWIS regulatory compliance: 25.1703, Part I
Proper aircraft wire installation begins with selecting the right components. There will never be a perfect component, because there will always be tradeoffs between performance, cost, weight, and…
2015-06-05 CertificationAn aircraft EWIS perspective with Petar Glamoclija
Today’s interview is with Petar Glamoclija, Senior Consultant at Mitsubishi Aircraft Corporation. Petar shares an aircraft EWIS perspective and his vast experience in aerospace wiring that includes…
2015-05-29 Conference & Report5 takeaways on aircraft wiring from a recent SAE committee meeting
The three-day SAE 8A (Wire Installation) & SAE 8D (Wire and Cable) committee meeting was held in Melbourne, Florida on the famous Space Coast. The focus of the meeting was aircraft wiring.
2015-05-24 Standard & RegulationA new standard for EWIS design: IPC-D-620
As EWIS (Electrical Wiring Interconnection System) engineering is becoming a more mature field, additional standards and requirements are being developed. The latest of these EWIS design standards is…
2015-05-19 Maintenance & SustainmentTrends in aircraft wiring and risk assessment with John Ashour
The purpose of the Lectromec Podcast is to keep you informed of trends in the rapidly changing aerospace industry. Once a month we interview leaders and seek their insight on topics related to…
2015-04-28 Aging Wires & SystemsWire & Cable meets Lectromec: A summary of the interview
Last week Michael Traskos, President of Lectromec and noted EWIS expert, sat down with Mary Gannon, Senior Writer from Wire & Cable Tips, for a podcast interview. This article summarizes the…
2015-04-24 ManagementIntroduction to aircraft electrical power distribution systems
The trend in modern aircraft design is away from mechanical systems (hydraulics, pneumatics, etc.) and toward electrical components, or Aircraft Electrical Power Distribution Systems. There are…
2015-04-17 Testing & AssessmentWhat do the results of arc track resistance testing mean?
Wire manufacturers must ensure that their products can withstand a wide variety of tests. One important test for aerospace professionals is called the “arc track resistance” test. This test is…
2015-04-09 Maintenance & SustainmentAircraft EWIS failure trends
The process for identifying an EWIS problem on an aircraft often follows these steps:
2015-04-01 ManagementAircraft wire inspection? Time tested guidelines
Performing routine aircraft wire systems visual inspections is a critical aspect of maintaining aircraft airworthiness and extending the component lifecycle. A visual inspection is the first step in…
2015-03-18 ManagementOverlooked but critical: Impact of storage on aircraft EWIS components
Aircraft maintenance engineers do not pay much attention to the impact of storage on electrical components. This article discusses several aspects of storage in the general category of the electrical…
2015-03-09 Testing & AssessmentPerspectives on arc fault protection
Lectromec has published several articles and a white paper on our web site that discuss the hazards of electrical arcing and how they can be mitigated. In order to broaden the discussion, this…
2015-02-27 Conference & ReportInsights from Europe: The More Electric Aircraft (MEA) Conference
Recognizing the tremendous interest in making a transition to electrical components, Lectromec attended the More Electrical Aircraft conference held in Toulouse, France, on February 3rd – 5th. This…
2015-02-18 Protection & PreventionPrinciples of aircraft wiring system safety
System safety supports risk management with the ultimate goal of optimizing safety on aircraft systems. Risk management is a vital aspect of system development that takes effect during the design…
2015-02-11 Testing & AssessmentElectrical tests for aircraft wires and cables
Equipment installed onto aircraft goes through a range of tests designed to verify that the component meets the operational needs and environmental factors. For wires and cables, these tests include…
2015-01-26 Aging Wires & SystemsCommercial airliner EWIS life extension
This article is the first in a series aimed to inform how to safely extend the life of commercial aircraft from the electrical wire interconnection system (EWIS) perspective, or what some would call…
2015-01-19 Conference & Report5 lessons learned from NASA on electrical wiring interconnection systems (EWIS)
This is the second article on Lessons Learned from NASA. The documentation is based on NASA's years of EWIS design and fabrication experience. Several of these EWIS-related recommendations are…
2015-01-092014
What's next for aircraft EWIS: Carbon nanotubes
This article describes findings from a Rice University study showing the potential for creating new products based on carbon nanotube (CNT) technology. According to the research, CNT fibers have…
2014-12-17 Aging Wires & SystemsEWIS SLEP: 5 days in the desert
As part of a project with the US Navy, Lectromec staff was in Tucson for one week supporting a service life extension program (SLEP). We all know that aircraft are designed for a given number of…
2014-12-05 Conference & ReportPartial analysis of 2014 aircraft EWIS failure rates
Periodically, Lectromec reviews the state of the industry and EWIS failure rates. In this article, Lectromec reviews the January – November data in the FAA's service difficulty report (SDR) database…
2014-11-24 Standard & RegulationMIL-HDBK-454 handbook guidelines for EWIS components
This article covers eight out of the 78 military guidelines from the General Guidelines for Electronic Equipment handbook (MIL-HDBK-454) applicable to wire system component testing, EWIS component…
2014-11-14 CertificationDealing with EMI and EMV on radio frequency (RF) cables for aerospace applications
The aerospace industry has been dealing with Electromagnetic Interference (EMI) and Electromagnetic Vulnerability (EMV) since the early 1900s. EMI can cause interruptions ranging from poor signal…
2014-11-05 Conference & ReportLatest update from the October 2014 SAE Wire Committee Meeting
The meeting for the SAE Fall 2014 8A and 8D groups covered a lot of ground and developments in the aerospace wire and cable world. The SAE Wire Committee Meeting, held in Tempe, Arizona, consisted of…
2014-10-22 ResearchAircraft wire abrasion resistance
The proper installation of wiring will dramatically reduce unnecessary stresses and result in an uneventful service life. In the real world, wires rub against various airplane components and can…
2014-10-15 CertificationAircraft EWIS regulations in China
There have been significant developments in the Chinese aerospace industry over the last couple of years. The largest of these developments is the design commencement of the Comac C919 narrow-body…
2014-10-02 CertificationAssessment of mechanical stress on aircraft wire insulation
Mechanical damage is one of the most common causes of aircraft wire insulation failure. This mechanical damage can come from a hundred different sources (maintenance actions, chaffing, pinching…
2014-09-19 ArcingThe impact of series arcing
While electrical arcing on aircraft is often associated with a dramatic failure event, a much more common occurrence on aircraft is series arcing. Series arcing can contribute to overheating and…
2014-09-15 Aging Wires & SystemsAircraft EWIS failure investigation
When systems fail, it is often necessary to identify the fault source in order to know where to assign the blame (legal), determine if a maintenance action is necessary (customer support), or improve…
2014-09-05 CertificationCorrosion prevention compounds (CPCs) and aircraft EWIS
Corrosion prevention compounds (CPCs) are compounds that are placed on many aircraft components. Applied to a variety of mechanisms, these compounds have been found to increase structural life by…
2014-08-29 Aging Wires & SystemsEWIS failure and the MQ-1B Predator incident
On May 2013, a US Air Force MQ-1B General Atomics Predator aircraft crashed north of Creech Air Force Base in Nevada. The estimated loss was over $4.5 million. This is a good example of EWIS failure…
2014-08-22 ResearchAircraft wire degradation and looking in the arc
Those who have witnessed electrical arcing and aircraft wire degradation first hand know the feeling of the intense heat radiating from the arc location, the screeching sound (AC arcs), and the…
2014-08-15 Protection & Prevention7 tenets of aircraft wire systems installation
There are a number of considerations when designing the installation of EWIS on aircraft wire systems. They include part selection, system integration, routing, safety and separation , regulation…
2014-08-08 Conference & ReportTakeaways from the 2014 UL Wire and Cable International Conference
Interest in wires and cables is not limited to the United States. Every year Underwriter’s Laboratories (UL) conducts a trade show in the People’s Republic of China in a city called Humen, which is…
2014-07-29 CertificationDO-254 process for aircraft component certification
RTCA/DO-254, Design Assurance Guidance for Airborne Electronic Hardware is a commonly used document that provides instructions and process for airborne electronic hardware development and aircraft…
2014-07-18 Protection & PreventionLessons learned from NASA: Wire identification, harness clamping, and more
Learning from the mistakes of the past is critical for ensuring reliability of systems created today. These lessons may be contained in industry standards documents with little or no explanation as…
2014-07-10 Protection & PreventionHeat shrink tubing application and aircraft EWIS components
Heat shrink tubing can be found in nearly every location on aircraft and can interact with aircraft EWIS components. These materials protect wire repairs, provide additional abrasion protection, and…
2014-06-30 Aging Wires & SystemsLife prediction of aircraft EWIS components
Aircraft vehicle reliability rests on well-designed components maintaining full functionality through the entire life cycle, or at the very least, maintaining full functionality until a predictable…
2014-05-29 CertificationConsiderations for Electrical Bonding
Electrical bonding is the practice of connecting equipment cases or structure to ground to prevent electric shock. This provides a return path for any stray voltage that the case may be exposed to…
2014-05-15 Aging Wires & SystemsEWIS: A 13-minute summary of MIL-HDBK-525
This Lectromec presentation provides a brief summary of MIL-HDBK-525, “Electrical Wiring Interconnect System (EWIS) Integrity Program.” It provides a starting point for those involved in Mechanical…
2014-04-30 ManagementAircraft circuit protection: A review of 5 technologies
Two weeks ago we posted a blog on the selection process for circuit protection/wire pairs . Today, we produce a grid to help you understand common aircraft circuit protection types that can be found…
2014-04-29 Research270VDC arcing in aircraft wiring
In a recent presentation to the SAE at the biannual meeting, Lectromec presented a summary of the work that was performed by several companies and the Federal Aviation Administration (FAA) last…
2014-04-15 Management7-step process for aircraft wire size and circuit protection selection
Sometimes the design guidance that is a couple of decades old is still valid. The following flowchart is from the NASA Technical Memorandum 102179 – 1991 .
2014-04-14 Conference & ReportWhat you missed from the SAE meeting regarding aircraft wire testing
If you had other business commitments and couldn't make the recent SAE 8A/D meeting this week that included topics related to aircraft wire testing, we have put together a quick summary from the…
2014-04-10 Aging Wires & SystemsThe "Big 3" aircraft wire system degradation assessment options
If you have concerns about aircraft wire system degradation and need to assess the condition of an aircraft’s wire system, there are several options. For those looking for opens and shorts type…
2014-04-09 Conference & ReportAerospace electrical systems news
The AEROSPACE Electrical Systems Expo took place on April 1 – 3, 2014 in Long Beach California and drew the usual suspects. There was a good representation from all parts of the aerospace electrical…
2014-04-04 Certification7 considerations for aircraft wire separation
The development of a safe, reliable, and easy to maintain Electrical Wire Interconnection System (EWIS) is a challenging task. The considerations range from selecting each EWIS component, to matching…
2014-03-30 Research2 EWIS insights from a presentation at the AIAA conference
The 51 st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference was held on January 2010 and included presentations of a wide range of technical papers. From the…
2014-03-23 ResearchAircraft EWIS high voltage testing considerations
There are two factors that need to be considered when using aerospace wires/cables for higher voltage systems: (1) Determining the long-term insulation life impacts of high voltage utilization, and…
2014-03-21 CertificationEWIS regulatory compliance with 25.1707, Part VII
This is the final article on the series devoted to the FAA regulation 25.1707 on EWIS separation. The previous six articles in this series are listed below:
2014-02-28 CertificationEWIS regulatory compliance with 25.1707, Part VI
This is the sixth article in the series focused on FAA 25.1707 that discusses electrical wire interconnection system (EWIS). The previous articles in this series are listed below:
2014-02-25 CertificationEWIS regulatory compliance with 25.1707, Part V
Each of the last four articles has focused on a subpart of the FAA 25.1707 regulation.
2014-02-20 CertificationEWIS regulatory compliance with 25.1707, Part IV
This article focuses on the grounding and separation of power sources; it is a continuation of a series of articles discussing the Federal Aviation Administration (FAA)'s EWIS certification…
2014-02-14 CertificationEWIS regulatory compliance with 25.1707, Part III
This is the third article in this series that is looking at the individual components of Federal Aviation Administration (FAA)'s EWIS regulation 25.1707 and EWIS regulatory compliance. This is part…
2014-02-07 CertificationEWIS regulatory compliance with 25.1707, Part II
This is the second article in a series on EWIS Regulatory Compliance. The series is looking at the individual components of the Federal Aviation Administration (FAA) EWIS regulations 25.1707. The…
2014-01-28 CertificationEWIS regulatory compliance with 25.1707, Part I
We will start a series of articles on EWIS Regulatory Compliance. The next couple of articles will discuss some of the finer points of the Federal Aviation Administration (FAA) regulations 25.1707 -…
2014-01-202013
MIL-HDBK-525 EWIS overview: Task 6 — Action plan, Part II
This is a series on MIL-HDBK-525 EWIS overview. The eighth article in the series Electrical Wire Interconnection Systems (EWIS) Service Life Extension Programs (SLEPs), discusses the Enhanced Zonal…
2013-12-16 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 6 — Action plan, Part I
This is a series on MIL-HDBK-525 EWIS Overview. The seventh article in the series on Electrical Wire Interconnection Systems (EWIS) Service Life Extension Programs (SLEPs) develops an action plan and…
2013-12-02 ArcingF-22 crash and aircraft electrical arcing
In a report that was released August 2013 by the USAF, the results of a Lockheed Martin F-22 aircraft crash point to a chaffed power feeder cable as the likely cause of failure. On November 15, 2012…
2013-11-15 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 5 — Risk assessment
We are presenting an EWIS overview. This is the sixth article in the series on Electrical Wire Interconnection System (EWIS) Service Life Extension Programs (SLEPs). If you missed one, here are the…
2013-11-13 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 4 — Component assessment
This is a series that will give you a good EWIS overview. This article is the fifth in the series devoted to reviewing the guidance provided in MIL-HDBK-525 for Electrical Wire Interconnection System…
2013-10-26 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 3 — EWIS assessment
This is a series that will give you an EWIS overview. This article is the fourth in the series devoted to reviewing the guidance provided in MIL-HDBK-525 for Electrical Wire Interconnection System…
2013-10-11 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 2 — Task analysis for EWIS
In order to get a better understanding of wire degradation, this is a good view of task analysis for EWIS. This article discusses the second task “Data Analysis” in the series on EWIS Service Life…
2013-08-30 Aging Wires & SystemsMIL-HDBK-525 EWIS overview: Task 1 — EWIS documentation
This series on EWIS Service Life Extension Program (SLEP) risk assessment techniques discusses the implications and ideas contained in the EWIS handbook MIL-HDBK-525; an overview of the handbook…
2013-08-21 Aging Wires & SystemsMIL-HDBK-525 overview for service life extension
The newly published Electrical Wiring Interconnect System (EWIS) Integrity Program Handbook (MIL-HDBK-525) provides a comprehensive method for assessing an aircraft’s EWIS condition for service life…
2013-08-15 Protection & PreventionIn aircraft wire systems, how much slack should I give a wire?
Clearly wires shouldn’t be pulled so tight that they are under constant regular strain, but is there some guidance as to how much slack should be provided in aircraft wire systems? One source for…
2013-07-27 Protection & PreventionMinimum bend radius as applied to aircraft wire system degradation
Constant mechanical strain can and will reduce a wire’s longevity. Knowledge of minimum bend radius can reduce wire system degradation. These stresses can come from clamps that are too tight, over…
2013-07-26 ResearchHigh voltage systems on aircraft
Aerospace Information Report (AIR) 6127 currently being developed by the SAE AE-7 committee provides a framework for designing high voltage subsystems utilized for More Electric Aircraft (MEA). The…
2013-05-24 ManagementOdd wire gauges for aircraft wiring
Have you ever wondered why only even wire gauges are produced (e.g. 8, 16, 20, etc.) for aircraft wiring? For centuries, wire manufactures have produced even wire gauges because there has been little…
2013-04-25 ManagementBuilding an electrical wire testing program: Selecting tests, Part II
This article is a continuation in a series devoted to providing guidance to engineers on what should be considered when comparing different wire insulation types for a given application. It can be…
2013-03-18 ManagementBuilding an aircraft electrical wire testing program: Selecting tests, Part I
This article, which focuses on test selection, is a continuation of a discussion on wire selection that was started in the Determining the Right Wire for your Application article. The series could be…
2013-02-07 ManagementCorrect aircraft wire selection for your application
Wire selection for a particular application can be a time consuming process. Selection of the right wire for the particular application to maintain device reliability and prevent a potential…
2013-01-172012
The age of your aircraft and wire systems implications
A fleet age review of 16 American aircraft operators performed by Lectromec is shown below. This includes both regional and major airlines as well as shipping companies. The data is based on…
2012-11-15 ResearchFlammability for Aircraft Wiring
Among the multitude of new wire qualification tests is the wire flammability test for aircraft wiring. This article covers a test that is designed to assess a wire insulation’s ability to: 1) limit…
2012-11-05 Protection & PreventionHazards of hot stamping for aircraft wiring
Hot stamping is a technique that has been used to identify wires for decades. However, this technique has been banned by the US military aerospace platforms or significantly discouraged by the FAA…
2012-10-18 Aging Wires & SystemsAircraft wiring: Polyimide wire life projection
Polyimide wire (commonly referred by the trade name, Kapton®), is the mustard colored kind of aircraft wiring that can be found in older civilian and commercial aircraft made before the 1995…
2012-09-25 ManagementLectromec Harness Derating Tool (HDT) tutorial for EWIS
As mentioned on the WireFacts blog, the Lectromec Harness Derating Tool (HDT) is now up and running. The HDT is designed to follow the guidance provided in AS50881 on how much electrical current…
2012-09-22 ManagementUse of chafe protection for aircraft EWIS
When wire bundles are routed in high vibration zones or areas with repeated movement (e.g. landing gears), wire harnesses are regularly in contact with abrasive surfaces, which can cause damage to…
2012-05-02 Aging Wires & SystemsGiving your aircraft EWIS a good cleaning
During standard aircraft maintenance, it occasionally becomes necessary to clean the wiring, remove FOD (foreign object debris), and/or clean equipment near wiring (which is just about everywhere on…
2012-04-13 ManagementVisual inspection of electrical wiring for aircraft: A quick guide, Part III
This article is part of Lectromec's visual inspection series discussion and focuses on the issues that need to be considered when inspecting splices in harnesses.
2012-04-09 Aging Wires & SystemsWhy not perform certification test on aged aircraft wire?
Before a wire is first brought onto an aircraft, it must first go through a series of tests that validate the quality of the finished wire. Most of these tests are conducted on new wires that have…
2012-03-22 ManagementVisual inspection of electrical wiring for aircraft: A quick guide, Part II
This is intended as a quick guide for those performing visual inspection of electrical wiring for aerospace. There is more that needs to be considered than what is covered in this article, but…
2012-03-15 ManagementVisual inspection of electrical wiring for aircraft: A quick guide, Part I
This is the first of a three-part series of articles that go through a complete visual inspection to examine all the parts of an aircraft’s electrical wire interconnection system (EWIS).
2012-02-15 ResearchDoes the mixing of different aircraft wire types create problems?
Modifications or additions to an aircraft wire will typically require (at least in some locations) the addition of new wire constructions to existing bundles. The concern that some have had is that…
2012-02-14 Protection & PreventionAircraft wiring guideline: Review of incoming wire
To maintain good process management and quality of end products, it is important to review the quality of the incoming materials for aircraft wiring. Wiring should not be excluded from this process…
2012-02-08 CertificationGuidelines for aircraft wiring: Magnet wire
Magnet wire is a conductor (copper or aluminum) with a thin insulation used in motors or transformers that is used in aircraft wiring. The wire is wound around a core to generate a magnetic field…
2012-01-30 CertificationGuidelines for aircraft wiring: Which tests?
Aircraft wiring details are rarely found in common wire specifications. In fact, there is not a consistent set of specification tests for aerospace wiring. One wire type requires testing of the…
2012-01-132011
When should you consider adopting an aircraft wire life extension program? Part VII
Through this series of articles, we have gone over all of the components that are necessary to perform a full risk assessment to maximize wire life extension. In this article, we will examine what a…
2011-12-13 ArcingAircraft wire failure and incident investigation, Part II
A couple of weeks back, we wrote the Wire Failure and Incident Investigation article that reviewed some of the characteristics of wire failure and the means to detect them in a post aviation incident…
2011-11-23 ResearchAircraft wire degradation and new research on red plague
We have addressed the red plague concept behind the aircraft wire degradation process in the For wire systems, there is no perfect conductor, not even a silver plated one article. However, since this…
2011-11-20 CertificationA response to the TWA800 accident involving wire damage: SFAR-88
The SFAR88 requirements and related regulations ( 66 Fed. Reg. (May 7, 2001) ) was the immediate FAA response to the TWA800 accident investigation involving wire damage. The investigation, conducted…
2011-11-01 CertificationUnderstanding wire failure risk levels for aircraft EWIS
To determine the risk level for each EWIS component, one needs to look at the combination of failure probability and failure severity. This article will review the different levels for of failure…
2011-10-19 ArcingAircraft wire failure and incident investigation, Part I
The hazard of aircraft wire failure and electrical arcing will exist for as long as there is a need to deliver electrical power through wires. While electrical arcing is a common occurrence, the…
2011-10-13 ArcingAircraft EWIS failure and the process of electrical arcing
The hazard of aircraft EWIS failure and electrical arcing will exist for as long as there is a need to deliver electrical power through wires. While electrical arcing is a common occurrence, the…
2011-10-07 Aging Wires & SystemsWhen should you consider adopting an aircraft wire insulation assessment program? Part VI
SubTopic: Determining the Severity of Failure for wire life extension.
2011-09-22 Testing & AssessmentCommonalities between EWIS and structured risk assessments for life extension programs
One of the criticisms of the EWIS risk assessment field is that it is an inexact science. Another is that no real value is achieved from performing an EWIS risk assessment. This article reviews these…
2011-08-31 Aging Wires & SystemsWhat to look for with composite aircraft wire aging
This article continues the theme of identifying different kinds of wire aging, by describing the signs indicating when a composite wire is starting to age.
2011-08-13 Aging Wires & SystemsWhat to look for with polyimide wire aging
Key to continued aircraft airworthiness is regular visual inspection of the wiring. However, depending on the particular wire insulation installed on the aircraft, the signs of degradation can vary…
2011-08-11 CertificationHere are some tips on conductor solderability with wire systems
An important property of a wire conductor is solderability (the ease of soldering the conductor) with wire systems. This property is greatly affected by the type of platting a wire has. Some…
2011-08-09 Aging Wires & SystemsWhen should you consider adopting an aircraft wire life extension program? Part V
The next step after determining the operating conditions within the aircraft is to review the aircraft from the fleet level. This is if you are considering an aircraft wire life extension program…
2011-08-05 ResearchResults of intrusive inspection on aircraft wire systems
In the Basic concepts of Wire Degradation article, we reviewed the degradation of wire insulation from a laboratory perspective. This article discusses some the findings of the Federal Aviation…
2011-07-23 ResearchBasic concepts in understanding aircraft wire degradation
Aircraft wire degradation often means a reduction in a wire insulation’s ability to withstand physical, electrical, or chemical strain. Such reductions can lead to insulation breaches, which can…
2011-07-19 Aging Wires & SystemsWhen should you consider adopting an aircraft wire life extension program? Part IV
For purposes of aircraft wire life extension, start with identifying what wires are on the aircraft (see Lectromec's When should you consider adopting a wire life extension program? Part III article…
2011-07-17 Aging Wires & SystemsWhen should you consider adopting an aircraft wire life extension program? Part III
This is the third article in a series addressing the concepts associated with wire life extension and an Electrical Wire Interconnection System (EWIS) analysis of aging aircraft. The When should you…
2011-07-04 ManagementImplications of circuit breakers and wire size for wire systems
Circuit breakers are designed to activate (open the circuit) when the electrical current is in excess of the device rating. This is done to protect both the electrical device and the wiring. As such…
2011-06-27 Aging Wires & SystemsWhen should you consider adopting an aircraft wire life extension program? Part II
This is the second in a series of articles addressing the concepts associated with an Electrical Wire Interconnection System (EWIS) analysis of aging aircraft. In other words, when to consider an…
2011-06-22 Aging Wires & SystemsWhen should you consider adopting an aircraft wire life extension program? Part I
Editor’s Note: This is the first part in a series of articles that addresses the needs of EWIS analysis and aging aircraft.
2011-06-06 Conference & ReportElectrical arcing of aircraft wire is hazardous even over separation
Recent research conducted by Lectromec confirmed the harmful effects of electrical arcing of aircraft wire events even in the presence of positive separation between the arcing source and the arcing…
2011-05-30 ResearchXL-ETFE aircraft wire degradation
XL-ETFE insulated wires can be found on many commercial and military aircraft built since the 1980s and need to be included in the study of XL-ETFE aircraft wire degradation. As such, some aircraft…
2011-05-30 CertificationEZAP, the FAA, and the electrical wiring interconnection system (EWIS)
The Enhanced Zonal Awareness procedure (EZAP) was introduced to the aviation industry that applies to Electrical Wire Interconnection System in 2005 was part of the FAA’s Notice of Proposed…
2011-05-17 ResearchAircraft wire insulation degradation and advancements with WIDAS 2.0
A fundamental principle of wire analysis technologies has been the fact that wire insulations degrade over time. To this end, Lectromec developed the first generation of the Wire Insulation…
2011-05-05 ManagementETFE vs XL-ETFE vs PTFE: What's best for wire circuit protection?
One reader of the blog asked Lectromec to compare products for wire circuit protection. A couple of the common wire insulations on the market are based on the PTFE and ETFE polymers. PTFE (DuPont…
2011-04-05 ResearchAn overview of the "Big 2" wiring insulations: PTFE and ETFE
Most aerospace wiring insulations on the market are based on the PTFE or ETFE polymers. These polymers have a high corrosion resistance and strength and excellent dielectric properties that make them…
2011-02-282009
FAA wire incidents report: February 2009
The following are examples of a FAA Wire Incidents Report.These are the wire incidents reported in the FAA’s February 2009 Advisory Circular 43-16A – Alert Number 367.
2009-09-01 Conference & ReportFAA wire incidents report: March 2009
The following are the wire incidents reported in the FAA’s March 2009 Circular 43-16A – Alert Number 368 .
2009-09-01 Conference & ReportFAA wire incidents report: January 2009
The following are the wire incidents reported in the FAA wire incidents report for January 2009 Advisory Circular 43-16A – Alert Number 366.
2009-04-03 Testing & AssessmentArc flash assessment on naval vessels
Arc flash is a problem for many industries; with increased demand for electrical power, arc flash is the likely consequence. To combat this growing hazard, most organizations have taken proactive…
2009-03-19 Conference & ReportThe future of aircraft wires and aircraft wire life projection
There no doubt has been tremendous growth in wireless technologies over the last decade. This constant change has produced an ever improving series of technology with longer ranges, high transfer…
2009-02-18 Conference & ReportFAA wire incidents report: October and November 2008
The following are the wire incidents reported in the FAA’s October 2008 Advisory Circular 43-16A – Alert Number 363 and November 2008 Advisory Circular 43-16A - Alert Number and 364 .
2009-01-012008
Aircraft wire selection, harness protection devices, and aircraft wire systems topic Q&A
From time to time, I get some basic questions about aircraft wire systems. To accommodate this, I have answered some of these questions and have posted the responses below.
2008-11-07 Conference & ReportFAA wire incidents report: September 2008
The following are the wire incidents reported in the FAA Wire Incidents Report September 2008 Advisory Circular 43-16A – Alert Number 362 .
2008-11-07 Conference & ReportFAA wire incidents report: July 2008
The following are the wire incidents reported in the FAA Wire Incidents Report July 2008 Advisory Circular 43-16A.
2008-08-07 ResearchArc damage modeling tool and damage at a distance
The amount of damage that can be caused by electrical arcing events continues to be an important question for both new and legacy aircraft. Many factors can affect the damage done by arcing events…
2008-07-04 Aging Wires & SystemsAircraft wire failure and wire component lifecycle
In the life cycle of components, including aircraft wiring and connectors that make up the interconnection harnesses, there are three phases of the component lifecycle that can be distinguished. They…
2008-06-20 ManagementUse of aircraft "shelf wire" and aircraft wire life projection
Suppose that your customer wants to know if the wiring in the cables, harnesses, or devices that your company produced is good. What if they have questions about aircraft wire life projection…
2008-05-26 Testing & AssessmentPhysical and functional EWIS issues included in Rule 25.1709
The recent set of FAA rules deal with physical and functional EWIS issues. The rules were released for the Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/FTS) places new…
2008-01-012007
Aircraft databases that impact aircraft engineers
There are a number of aircraft databases that exist on the web that can be used to survey aircraft incidents and service problems. One of these databases may have the answer to an important question…
2007-11-01 ResearchDamage at a distance on aircraft wire systems
What is the effective distance in wire systems that electrical arcing can cause? Both lab tests and in-service incidents have shown that arcing is hot enough to cause significant damage when in…
2007-08-01 ResearchEWIS evaluation of F-16
You may ask about EWIS evaluation of aircraft of a F-16. The results of recent testing indicated a rate of 5.4 breaches per 1000 feet of wire tested. Lectromec and InterConnect Wiring, at the 10 th…
2007-05-01 ResearchXL-ETFE and ETFE for aircraft wire compared
XL-ETFE and ETFE are not the same. ETFE (or commonly referred in the industry as Tefzel®) is a well known material used in the aircraft and space industry. In fact, ETFE is a widely used material in…
2007-03-01 ManagementWhen applied to aircraft wire systems technology, what is "delamination"?
Some failure mechanisms in aircraft wire systems technology are easy to find. Among the failure mechanisms faced by a wire, one is often overlooked: the failure of the layer to layer bond of wrapped…
2007-01-012006
Chemical formulas and structures for wire systems
Understanding wire systems includes the concept of chemical formulas and structures. In fact, it is the basis for a beginning understanding of all materials, and this includes wire systems. Most…
2006-12-18 ManagementAircraft wiring material considerations beyond insulators and conductors
The basic tool kit to understand aircraft wiring goes beyond some of the basics. Here are some topics of interest:
2006-12-12 ManagementHow to identify an aircraft wire to understand wire system degradation
If you try to identify an aircraft wire, particularly in service conditions, is not an easy task. However, we know it can assist with understanding details of wire system degradation. With the a…
2006-11-05 ArcingUnderstanding series and parallel arcing for aircraft engineers
Aircraft engineers should know that in recent years have shown increased talk of arcing and the possible damage to aircraft. There have been many examples of these events on aircraft. Recently…
2006-09-01 ResearchFor aircraft wire systems, there is no perfect conductor, not even a silver plated one
Aircraft engineers are always seeking perfect aircraft wire systems. Problems with silver plated copper wires were discovered during the 1960’s; in particular, a corrosive effect emerged that was…
2006-07-01 Aging Wires & SystemsThe scope of chafing on aircraft wire and its impact on wire reliability
Wire chafing can have an impact on wire reliability. The U.S. Navy found as part of a review for the allocation of labor and general wiring practices, roughly $94 million is spent annually in time…
2006-06-01 ManagementImproving aerospace wire reliability by understanding arcing vs protection schemes
Prior to the launch of the space shuttle Discovery in July of 2005, NASA engineers discovered a previously unidentified hazard. Perhaps they should have gotten a better understanding of aerospace…
2006-02-012005
Improving aircraft wire management systems: The entanglement of separation standards
Separation standards are starting to emerge to help improve wire management systems. A number of airworthiness directives have been recently issued dealing with the wire hazards that result from lack…
2005-11-01 ManagementUnderstanding aircraft wire differentiation to improve EWIS
The amount of aircraft wire on a civil aircraft has increased in recent decades such that today’s typical aircraft has hundreds of miles of wire connecting all of its subsystems. The increase in the…
2005-07-01 CertificationImportance of aircraft electrical wiring interconnection system (EWIS) analysis
A United Airlines B767-300 on a Jan. 9, 1998 flight, from Zurich to Washington DC, was forced to execute an emergency landing at London’s Heathrow airport because of a food chiller unit improperly…
2005-03-012004
Frozen circuit breakers and EWIS reliability
Frozen circuit breakers can have an impact on EWIS reliability. Like aircraft wiring insulation that ages over time, breakers can corrode. We use breakers as switches. This frequent use accelerates…
2004-10-01 Certification10 commandments of aircraft wire maintenance
When it comes to aircraft wire maintenance, consider the basic rule in medicine: “First, do no harm.” But where to find the best guidance to avoid inadvertent maintenance malpractice? Fortunately…
2004-08-01 CertificationEffects of SFAR-88 on aircraft wire maintenance
The acronym stands for Special Federal Aviation Regulation 88. It deals with fuel system safety , to include aircraft wire maintenance, aircraft wire and electrical components (pumps, fuel quantity…
2004-06-01 Aging Wires & SystemsThe importance of visual inspection for aircraft wire reliability
Thorough visual inspections of your aircraft’s wiring should be done on a regular basis to improve wire reliability. Even new aircraft can have wiring that was damaged during the manufacture and…
2004-04-01 Aging Wires & SystemsThe life of an aircraft wire and aircraft wire degradation
Aircraft age and new problems develop that impact the life of an aircraft wire. Fatigue, corrosion, and wire degradation are the three major causes of concern. Wiring degradation causes intermittent…
2004-02-01