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 D2671 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-23053E 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 Shrinkage 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 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 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

As with any discipline, a field is best able to grow and evolve when new ideas and products are shared among the community. To support this, the FAA hosts an annual meeting for researchers and industry professionals to come together and discuss research, lessons learned, and active projects. This meeting, the S&T Electrical Systems and Wiring Inter-Agency Meeting, was held virtually in December 2021. The following sections briefly discuss some of the topics of interest at this year’s meeting.

eVTOL

The direction of innovation within the industry is presently led by electric aircraft with a particular interest in electric Vertical TakeOff and Landing (eVTOL) and Urban Air Mobility (UAM). A quick web search will verify that there are dozens of eVTOL vehicles in development or concept worldwide. A common goal is to provide an alternative to ground vehicle travel (cars, buses, etc.) for densely populated areas such as large cities. With fully electric aircraft, developers seek to create a cleaner, safer alternative for relatively short-range aircraft by reducing/eliminating fuel emissions and avoiding the dangers of dense traffic.

The challenges that the eVTOL community faces align with the challenges that small aircraft manufacturers often face (namely spacing), but also how to manage the requirements for the energy storage system (e.g. batteries) and mitigation of the risks of high-voltage. Lectromec has written several articles on the risks of high voltage and how to mitigate them as they relate to the EWIS [link], and we will have several more in the first half of 2022.

Certification

One of the common issues aircraft designers are actively experiencing is the lack of certification guidance for fully electric aircraft. Current aerospace standards are a good starting place for designers to look for guidance, but the industry needs to develop official certification standards to address the unique needs of electric aircraft. Electric aircraft performance requirements, safety concerns, and battery capacity are all examples of new topics to define that are not specified in existing standards, not to mention that high-voltage systems are not clearly defined or regulated in aerospace.

This effort will require input from both industry and standard committees to determine the scope of and acceptable limits for electric aircraft. Industry experts may be able to offer valuable perspectives regarding the new technologies being developed that may drive the development of certification criteria.

Industry guidance, such as can be found in ASTM F3230, leave much of the work of defining the certification path and assessing the risks on the designer. While the FAA does not dictate design, additional guidance to help OEMs bridge the gap from new vehicle design to certified vehicle would be advantageous to the industry.

Thermal Runaway

Thermal Runaway was a common topic of discussion at this year’s meeting. Thermal runaway is a phenomenon that occurs when a battery is unable to dissipate heat as rapidly as it produces heat. Such phenomena can quickly cause permanent damage which is of particular concern in fully electric aircraft where battery reliability is crucial for safety as well as long-term product viability.

Thermal Runaway FAA NASA 2021
Example photograph of thermal runaway testing on battery cells performed by NASA. Other trials tested different orientation(s) of cells.

The research shown at the meeting shows different paths and approaches that were taken to assess thermal runaway and means to mitigate the risk. To support this, Standards will need to be developed to govern the heat production and dissipation surrounding energy storage systems. Presenters addressed a need for a system-level thermal runaway test method for electric aircraft with considerations on determining worst-case scenarios. Thorough testing of design concepts will be crucial in the development of these standard criteria and test methods.

Developments in Industry

Lectromec was also fortunate to present to the S&T committee. Our presentation focused on the developments within the SAE community as it relates to the wiring systems committees (AE-8), the high-voltage committee (AE-10), and the high-voltage modeling committee (AE-11). Within each of these committees, there is a great deal of work involving the development of new standards, in particular how to address the needs of more electric vehicles and high-voltage systems. In the first quarter of 2022, Lectromec will post this presentation on our website; sign up for Lectromec’s newsletter to be notified when this is published.

Conclusion

Undoubtedly, the annual S&T meeting provides beneficial insight into the current needs and challenges facing the ever-advancing aerospace industry. The coming together of professionals throughout the industry is not only a valuable source of information but also promotes connection and communication among the community to further spread information and advancements. With so many exciting new challenges and developments on the horizon, we certainly hope to be back together at an in-person S&T meeting in 2022.

Laura Wishart

Laura Wishart

Engineer, Lectromec

Laura has been with Lectromec since 2019 and has been a key contributor on projects involving testing of EWIS/fuel system failure modes, the impact of poor installation practices on EWIS longevity, and wire/cable certification testing. Recent projects include work toward the definition and certification of high-voltage aircraft wiring systems. Laura’s knowledge and attention to detail have ensured consistent delivery of accurate test results from Lectromec’s lab.