View Latest Blog Entries
Close
Categories
Testing & Assessment Certification Aging Wires & Systems Standard & Regulation Management Maintenance & Sustainment Conference & Report Research Protection & Prevention Arcing Miscellaneous
Popular Tags
Visual Inspection AS50881 MIL-HDBK MIL-HDBK-525 High Voltage FAR Electromagnetic Interference (EMI) FAR 25.1707 AS4373 Maintenance Wire System Arcing Damage
All Tags in Alphabetical Order
2021 25.1701 25.1703 abrasion AC 33.4-3 Accelerated Aging ADMT Aging Systems AIR6808 AIR7502 Aircraft Power System aircraft safety Aircraft Service Life Extension Program (SLEP) altitude arc damage Arc Damage Modeling Tool Arc Fault (AF) Arc Fault Circuit Breaker (AFCB) Arc Track Resistance Arcing Arcing Damage AS22759 AS22759/87 AS23053 AS4373 AS4373 Method 704 AS50881 AS5692 AS6019 AS83519 AS85049 AS85485 AS85485 Wire Standard ASTM D150 ASTM D8355 ASTM F2696 ASTM F2799 ASTM F3230 ASTM F3309 ATSRAC Attenuation Automated Wire Testing System (AWTS) Automotive backshell batteries Bent Pin Analysis Best of Lectromec Best Practice bonding Cable Cable Bend cable testing Carbon Nanotube (CNT) Certification Chafing Chemical Testing Circuit Breaker circuit design Circuit Protection Coaxial cable cold bend collision comparative analysis Compliance Component Selection Condition Based Maintenance Conductor conductors conduit Connector connector selection connectors contacts Corona Corrosion Corrosion Preventing Compound (CPC) Cracking 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 Electrical Aircraft Electrical Component Electrical Power Electrical Testing Electromagnetic Interference (EMI) Electromagnetic Vulnerability (EMV) EMC EMF 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 tree Fixturing Flammability fleet reliability Flex Testing fluid exposure Forced Hydrolysis fuel system fuel tank ignition Functional Hazard Assessment functional testing Fundamental Articles Future Tech galvanic corrosion Glycol Gold Gold plating Green Taxiing Grounding hand sanitizer handbook Harness Design Hazard Analysis health monitoring heat shrink heat shrink tubing high current high Frequency high speed data cable High Voltage HIRF History Hot Stamping Humidity Variation HV system ICAs IEC60172 IEEE 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 liquid nitrogen lunar 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-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-1353 MIL-STD-1560 MIL-STD-1798 MIL-STD-464 MIL-T-7928 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 polyimdie Polyimide-PTFE Power over Ethernet power system Power systems predictive maintenance Presentation 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 Requirements Series Arcing Service Life Extension Severe Wind and Moisture-Prone (SWAMP) Severity of Failure shelf life Shield Shielding 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 supportability Sustainment System Voltage Temperature Rating Temperature Variation Test methods Test Pricing Testing 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 vw-1 wet arc white paper whitelisting 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
Key Takeaways
  • The AS2279/80 -/92 use restriction on US Navy aircraft may soon be removed.
  • NASA has a great online resource for those interested in learning about the best practices for using high voltage in aerospace applications.
  • The SAE is still seeking presenters for the October 2022 AEISS meeting.

After two unsuccessful attempts to meet in Charleston, SC (the first canceled by a hurricane, the second by COVID-19), the SAE AE-8A/D committee finally met to update several of the standards whose progress has been slowed over the last two years.

Changes to PTFE/PI Wire

For several iterations of the AS50881, the AS22759/80 – /92 wire constructions, which are a combination of PTFE and polyimide, have been restricted for use on naval aviation platforms. The rationale behind this was based on the performance uncertainty of polyimide in high humidity environments such as those in which NAVAIR typically operates. However, since the improvements with the polyimide tape performance, there is now a requirement in the /80-/92 wire specifications that it must endure 5,000 hours of forced hydrolysis. As the forced hydrolysis performance requirement for AS22759/80 – /92 constructions is the same as the new AS22759/180-/192 constructions which do not have a use restriction (the /180-/192 wire constructions are also PTFE and polyimide insulation albeit with a seamless edge), there is no technical reason why the limitation of these wire constructions should be upheld. As such, the SAE 8A committee recently voted to remove the restriction for Navy aviation applications.

While this restriction has been removed, the /180-/192 wire constructions will likely continue to be the preferred choice for many new platforms (assuming the cost-benefit analysis warrants their use). For additional details on the seamless constructions, see Lectromec’s article on the topic.[link]

Updates Coming to the AS50881

Seamless Construction
The primary difference between the AS22759/80 – /92 family of wires versus the AS22759/180 – /192 family of wires is the latter is a seamless construction and authorized for use on US Navy aircraft. The restriction may be removed in the next revision of AS50881.

Another round of changes to the AS50881 was voted on and approved at April’s meeting. Many of these include minor changes and improvements to the documents that will clarify some of the design guidelines and requirements for aircraft wiring system designers.

Furthermore, the 8A group hopes to better coordinate with the fiber optic committee to improve the requirements and guidance for fiber optic installations. This is an area of the document that has not received particular attention or focused updates for quite some time; collaboration with the AS-3 group will greatly accelerate the improvement of the AS50881 document. For those interested in the release date for the next revision of AS50881, the hope is that a new one will be voted on this year.

Call for Papers

At the meeting, attendees were notified of the fall Aerospace Electrical Interconnect System Symposium (AEISS) that will be held in Houston at the next SAE AE-8 meeting. The AEISS has been a symposium occurring every two or three years for several decades and has been an effective means for technical interchange between the SAE committees and to highlight new developments, technology, and research in the field of aircraft electrical interconnect systems.

The SAE committees formally requested the submission of papers from those in the industry with relevant information for consideration at the upcoming AEISS. The formal call for papers can be downloaded from here. Those interested can email Michael Traskos (michael.traskos@lectromec.com) for any additional information or questions about the symposium. Those interested in presenting are encouraged to submit papers and attend the AEISS.

Resource for High Voltage

Among the presentations at the SAE meeting, NASA representatives discussed the upcoming requirements and research already performed to support the next decade of NASA projects. Among the interesting needs of NASA is the need to address the high voltage power necessary to support the lunar orbiter. This lunar orbiter will be a permanent station and a likely stop for vessels traveling to and from the proposed lunar surface base. These orbital and surface-based locations will highly likely require the use of high voltage power systems.

To support the engineering for these and other projects, the NASA Engineering & Safety Center (NESC) has created several hundred videos many of which are publicly accessible.

“The NESC Academy presents live and on-demand content from researchers, engineers, and field experts in 19 technical disciplines relevant to the design, development, test, and operation of NASA programs and projects. It hosts more than 800 videos containing interviews, tutorials, lectures, and lessons learned in an engaging format that features side-by-side video and slides, powerful search capabilities, downloadable course materials, and more”

A lecture and video on “High Voltage Engineering Techniques for Space Applications: Elemental Design” can be viewed here.

Improved PTFE Wires

Among the new wire specifications released by the AE-8D group is the AS22759/70 family of wires. This wire specification is an advanced PTFE insulation with high abrasion resistance properties typically uncommon for PTFE materials. This family of wires will be balloted within the upcoming months and may soon become an approved wire construction in the fluoropolymer insulated wires in AS22759.

Next Meeting

The next AE-8A/D meeting will be in October 2022 in Houston, Texas. Again, those interested in presenting to the AEISS are encouraged to submit abstracts before August 1, 2022.

Michael Traskos

Michael Traskos

President, Lectromec

Michael has been involved in wire degradation and failure assessments for more than a decade. He has worked on dozens of projects assessing the reliability and qualification of EWIS components. Michael is an FAA DER with a delegated authority covering EWIS certification and the chairman of the SAE AE-8A EWIS installation committee.