View Latest Blog Entries
Close
Categories
Testing & Assessment Certification Aging Wires & Systems Management Standard & Regulation Conference & Report Maintenance & Sustainment Research Protection & Prevention Arcing Miscellaneous
Popular Tags
Visual Inspection MIL-HDBK MIL-HDBK-525 FAR AS50881 FAR 25.1707 Electromagnetic Interference (EMI) Wire System High Voltage FAR 25.1709 Degradation Arcing Damage
All Tags in Alphabetical Order
25.1701 25.1703 Accelerated Aging ADMT Aging Systems Aircraft Power System Aircraft Service Life Extension Program (SLEP) arc damage Arc Fault (AF) Arc Fault Circuit Breaker (AFCB) Arc Track Resistance Arcing Arcing Damage AS22759/87 AS4373 AS4373 Method 704 AS50881 AS5692 AS6019 AS85485 AS85485 Wire Standard ASTM F2799 ATSRAC Attenuation Automated Wire Testing System (AWTS) Bent Pin Analysis Best of Lectromec Best Practice Cable cable testing Carbon Nanotube (CNT) Certification Chafing Chemical Testing Circuit Breaker Circuit Protection Coaxial cable cold bend comparative analysis Compliance Component Selection Condition Based Maintenance Conductor conduit Connector connectors contacts Corona Corrosion Corrosion Preventing Compound (CPC) Cracking D-sub data analysis data cables degradat Degradation Delamination Derating dielectric constant Distributed Power System DO-160 Electrical Aircraft Electrical Component Electrical Testing Electromagnetic Interference (EMI) Electromagnetic Vulnerability (EMV) EMC EMF EN3197 EN3475 EN6059 End of Service Life End of Year Energy Storage engines Environmental Environmental Cycling ethernet EWIS Component EWIS Design EWIS Failure EWIS Thermal Management EZAP FAA AC 25.27 FAA AC 25.981-1C Failure Database Failure Modes and Effects Analysis (FMEA) FAQs FAR FAR 25.1703 FAR 25.1707 FAR 25.1709 fault tree Fixturing Flammability fleet reliability Flex Testing Forced Hydrolysis fuel system fuel tank ignition functional testing Fundamental Articles Future Tech Green Taxiing Grounding Harness Design Hazard Analysis health monitoring heat shrink tubing high current high Frequency high speed data cable High Voltage History Hot Stamping Humidity Variation ICAs IEC60172 Instructions for Continued Airworthiness Insulation insulation resistance IPC-D-620 ISO 17025 Certified Lab Kapton Laser Marking life limited parts life projection Maintenance Maintenance costs Mandrel Mechanical Testing MECSIP MIL-C-38999 MIL-C-85485 MIL-DTL-17 MIL-DTL-3885G MIL-DTL-38999 MIL-E-25499 MIL-HDBK MIL-HDBK-1646 MIL-HDBK-217 MIL-HDBK-454 MIL-HDBK-516 MIL-HDBK-522 MIL-HDBK-525 MIL-HDBK-683 MIL-STD-1560 MIL-STD-1798 MIL-STD-464 MIL-T-7928 MIL-T-81490 MIL-W-22759/87 MIL-W-5088 Military 5088 modeling MS3320 NASA NEMA27500 No Fault Found off gassing Outgassing Overheating of Wire Harness Parallel Arcing part selection Performance Physical Testing polyimdie Polyimide-PTFE Power over Ethernet Power systems predictive maintenance Probability of Failure Product Quality Radiation Red Plague Corrosion Reduction of Hazardous Substances (RoHS) relays Reliability Research Rewiring Project Risk Assessment SAE Secondary Harness Protection Separation Requirements Series Arcing Service Life Extension Severe Wind and Moisture-Prone (SWAMP) Severity of Failure Shield Shielding signal cable silver plated wire smoke Solid State Circuit Breaker Space Certified Wires stored energy supportability Sustainment Temperature Rating Temperature Variation Test methods Test Pricing Testing Thermal Circuit Breaker Thermal Endurance Thermal Index Thermal Shock Thermal Testing Tin plated conductors Troubleshooting TWA800 UAVs verification Visual Inspection white paper whitelisting Wire Ampacity Wire Certification Wire Comparison wire failure wire properties Wire System wire testing Wire Verification work unit code

Blog

New 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 handbook is a guide for the aircraft EWIS inspection and provides a lot of detailed examples of wiring evaluation from beginning to end of the EWIS. Read more

Common 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 living with it is understanding it. If you have questions that you would like to see answered, please send them to Lectromec or add them to the comments section below. We plan to add to this article as the questions arise. Read more

Principles 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, hundreds of pages of documentation, and requiring inputs from just about every system group working on the vehicle. If you step back from the regulation and ask, “What is necessary to show compliance?” it comes down to several factors. Here, we review some of the basic principles of 25.1709, where it impacts and interacts with other systems in the vehicle. Read more

Impact 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 conductivity and resistance. Read more

Latest 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 for long reliable service life. Twice a year the SAE wire/cable community comes together to slowly push the standards and industry guidance forward; this year, New Orleans was the setting.

During this three-day meeting, several topics were discussed impacting the next generation of aircraft designs. Here, we cover a couple of these developments.

Read more

Thermal 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 for assessing a wire/cable’s maximum temperature rating. At the end of this article, we delve into weaknesses of this assessment method and elements that should be considered when selecting a wire for your high temperature application. Read more

Where 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 responsibilities, arguments will ensue as to who is the responsible party and time/effort will be wasted with duplicated analysis.

Because an aircraft’s wiring touches nearly all of the systems, it can be confusing to understand where the system starts and stops, and this has led to confusion as to the responsible party for the wiring system design and/or maintenance. Some organizations have seen the responsibility fall on the electrical power systems teams, others, avionics. Regardless of who takes up the responsibility, a clear definition of the wiring system’s physical and logical boundaries must be agreed upon. Thankfully, there are several industry documents that can be relied upon.

Read more

High 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 increasing the supplied voltage and creating a need for the electrical wiring interconnects systems (EWIS) to have components designed to sustain these higher voltages for the entire length of the aircraft life. Just as it should not be expected for a connector to operate in a 300°C environment if it is only rated to 150°C, a connector should not be expected to perform perfectly with voltages exceeding its voltage rating. Read more

How 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. can it perform the function to support the system. Next, the question then evolves to selecting those components that are best suited for the environmental conditions. This last part is more than just selecting the parts that are rated for the environmental conditions but also those that will have a long service life in those conditions. Ideally, the part will be reliable the entire service life of the aircraft and not require any replacement or additional maintenance; however, that usually is not the case (see Lectromec’s article on the immortal wire/cable). Read more

SwissAir 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 more than in the first quarter of 2017. Air travel remains increasingly popular, accessible to the public, and statistically the safest way to travel. This level of safety has been earned through decades of groundbreaking innovation, sometimes undeniably spurred by the desire to avoid repeating past tragedy.

An impactful and memorable incident that caused the industry to reevaluate its processes and procedures was the crash of Swissair Flight 111. Occurring almost two years after the Trans World Airlines Flight 800 (TWA800), the Swissair Flight 111 and TWA800 shared a common issue: wiring system failure.

Read more