View Latest Blog Entries
Close
Categories
Testing & Assessment Certification Standard & Regulation Aging Wires & Systems Maintenance & Sustainment Protection & Prevention Management Conference & Report Research Miscellaneous Arcing
Popular Tags
Visual Inspection High Voltage AS50881 MIL-HDBK MIL-HDBK-525 FAR Electromagnetic Interference (EMI) AS4373 Maintenance FAR 25.1707 Wire System Circuit Protection
All Tags in Alphabetical Order
2021 25.1701 25.1703 abrasion AC 33.4-3 AC 43 Accelerated Aging accessibility ADMT Aging Systems AIR6808 AIR7502 Aircraft Power System aircraft safety Aircraft Service Life Extension Program (SLEP) altitude Aluminum arc damage Arc Damage Modeling Tool Arc Fault (AF) Arc Fault Circuit Breaker (AFCB) Arc Resistance Arc Track Resistance Arcing Arcing Damage AS22759 AS22759/87 AS23053 AS29606 AS4373 AS4373 Method 704 AS50881 AS5692 AS6019 AS6324 AS81824 AS83519 AS85049 AS85485 AS85485 Wire Standard ASTM B230 ASTM B355 ASTM B470 ASTM D150 ASTM D2671 ASTM D495 ASTM D8355 ASTM D876 ASTM F2639 ASTM F2696 ASTM F2799 ASTM F3230 ASTM F3309 ATSRAC Attenuation Automated Wire Testing System (AWTS) Automotive Avionics backshell batteries bend radius Bent Pin Analysis Best of Lectromec Best Practice bonding Cable Cable Bend cable testing Carbon Nanotube (CNT) Certification cfr 25.1717 Chafing Chemical Testing Circuit Breaker circuit design Circuit Protection cleaning clearance Coaxial cable cold bend collision comparative analysis Compliance Component Selection Condition Based Maintenance Conductor Conductor Testing conductors conduit Connector connector installation Connector rating connector selection connector testing connectors contacts Corona Corrosion Corrosion Preventing Compound (CPC) corrosion prevention Cracking creepage D-sub data analysis data cables degradat Degradation Delamination Derating design safety development diagnostic Dielectric breakdown dielectric constant Dimensional Life disinfectant Distributed Power System DO-160 dry arc dynamic cut through E-CFR electric aircraft Electrical Aircraft Electrical Component Electrical Power Electrical Testing Electrified Vehicles Electromagnetic Interference (EMI) Electromagnetic Vulnerability (EMV) Electrostatic Discharge EMC EMF EMI EN2235 EN3197 EN3475 EN6059 End of Service Life End of Year Energy Storage engines Environmental Environmental Cycling environmental stress ethernet eVTOL EWIS certification EWIS Component EWIS Design EWIS Failure EWIS sustainment EWIS Thermal Management EZAP FAA FAA AC 25.27 FAA AC 25.981-1C FAA Meeting failure conditions Failure Database Failure Modes and Effects Analysis (FMEA) FAQs FAR FAR 25.1703 FAR 25.1707 FAR 25.1709 Fault fault tree Filter Line Cable Fixturing Flammability fleet reliability Flex Testing fluid exposure Fluid Immersion Forced Hydrolysis fuel system fuel tank ignition Functional Hazard Assessment functional testing Fundamental Articles Fuse Future Tech galvanic corrosion Glycol Gold Gold plating Green Taxiing Grounding hand sanitizer handbook Harness Design harness protection hazard Hazard Analysis health monitoring heat shrink heat shrink tubing high current high Frequency high speed data cable High Voltage High Voltage Degradation HIRF History Hot Stamping Humidity Variation HV connector HV system ICAs IEC 60851 IEC60172 IEEE immersion insertion loss Inspection installation installation safety Instructions for Continued Airworthiness insulating material insulating tape Insulation insulation breakdown insulation resistance insulation testing interchangeability IPC-D-620 ISO 17025 Certified Lab ISO 9000 J1673 Kapton Laser Marking life limit life limited parts Life prediction life projection Lightning lightning protection liquid nitrogen lithium battery lunar Magnet wire maintainability Maintenance Maintenance costs Mandrel mean free path measurement mechanical stress Mechanical Testing MECSIP MIL-C-38999 MIL-C-85485 MIL-DTL-17 MIL-DTL-23053E MIL-DTL-3885G MIL-DTL-38999 MIL-E-25499 MIL-F-5372 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-1353 MIL-STD-1560 MIL-STD-1798 MIL-STD-464 MIL-T-7928 MIL-T-7928/5 MIL-T-81490 MIL-W-22759/87 MIL-W-5088 MIL–STD–5088 Military 5088 modeling moon MS3320 NASA NEMA27500 Nickel nickel plating No Fault Found OEM off gassing Outgassing Over current Overheating of Wire Harness Parallel Arcing part selection Partial Discharge partial discharge at altitude Performance physical hazard assessment Physical Testing polyamide polyimdie Polyimide-PTFE Power over Ethernet power system Power systems predictive maintenance Presentation Preventative Maintenance Program Probability of Failure Product Quality PTFE pull through Radiation Red Plague Corrosion Reduction of Hazardous Substances (RoHS) regulations relays Reliability Research Resistance Revision C Rewiring Project Risk Assessment S&T Meeting SAE SAE Committee Sanitizing Fluids Secondary Harness Protection separation separation distance Separation Requirements Series Arcing Service Life Extension Severe Wind and Moisture-Prone (SWAMP) Severity of Failure shelf life Shield Shielding Shrinkage signal signal cable Silver silver plated wire silver-plating skin depth skin effect Small aircraft smoke Solid State Circuit Breaker Space Certified Wires Splice standards Storage stored energy superconductor supportability Sustainment System Voltage Temperature Rating Temperature Variation Test methods Test Pricing Testing testing standard Thermal Circuit Breaker Thermal Endurance Thermal Index Thermal Runaway Thermal Shock Thermal Testing tin Tin plated conductors tin plating tin solder tin whiskering tin whiskers top 5 Transient Troubleshooting TWA800 UAVs UL94 USAF validation verification video Visual Inspection voltage voltage differential Voltage Tolerance volume resistivity vw-1 wet arc white paper whitelisting Winding wire Wire Ampacity Wire Bend Wire Certification Wire Comparison wire damage wire failure wire performance wire properties Wire System wire testing Wire Verification wiring components work unit code

FAR 25.1709

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

Can 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 EWIS evaluations to ensure that the EWIS complies to regulations – not an easy task. Obviously, as the OEM design choices remain […] Read more

EWIS 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 consideration to support civilian applications. Right now, the FAA has not certified a UAV, but undoubtedly this will occur. This video provides a cursory […] Read more

EWIS 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 lines, it can be very difficult and intimidating to identify safe separation distances in design and for retrofits. Adding to the complexity, a wire harness […] Read more

Aircraft 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 will switch our attention to a different, but no less important, area: the Electrical Wiring Interconnect Systems (EWIS) connector assessment. Specifically, we will examine […] Read more

Taking 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 of this complex topic, we began creating educational materials. Accordingly, Lectromec has published almost two-hundred articles, distributes a monthly newsletter, has a podcast, and […] Read more

EWIS 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 into some logical categories. In our last podcast titled An EWIS Perspective, we examined concepts in expected life and discussed how to select components designed for […] Read more

Aircraft 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 aircraft. It is a huge undertaking with the projected introduction into service in 2018. It has been necessary to standup an infrastructure capable to support […] Read more

7 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 the load and Electromagnetic Interference (EMI) requirements of the connected devices, to ensuring your design can maintain performance across multiple zone environments. EWIS design takes a […] Read more

Physical 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 requirements on system safety and certification of aircraft Electrical Wiring Interconnection Systems (EWIS). These new rules were effective as of December 2007. They are the culmination […] Read more