AS4373 – Testing Aerospace Cables – Part 2

January 21, 2017 Michael Traskos

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 maintainers? Over the last couple of decades, a single test standard has evolved to with test methods to address […] Read more

AS4373 – Testing Aerospace Cables – Part 1

January 10, 2017 Michael Traskos

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” which covers a wide range of mechanical, electrical, environmental, and workmanship tests. In this first article of a two part series, we describe the […] Read more

Understanding Outcomes of Scrape Abrasion Testing

November 21, 2024 Michael Traskos

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 to failure. Variability in the wire, cable, and wire harness construction will impact the test performance. In this Lectromec article, we examine how these factors impact scrape abrasion results and the value of such results when such variability is inevitable. Read more

High Voltage, Low Current Material Arc Resistance Testing

July 26, 2024 Megan Chambellan

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 of an insulating or dielectric materials’ resistance to carbon arc tracking. In this article, we discuss this test method as well as the impact and limitations of the provided results. Read more

Property Retention After Thermal Aging

The property retention test evaluates the mechanical properties of a specimen of finished insulated wire before and after 1000 hours of thermal aging. The test methods used to evaluate the mechanical properties of the specimen after heat aging are: Dynamic Cut-Through (AS4373 Method 703) Flex Life (AS4373 Method 704) Notch Propagation (AS4373 Method 706) Read more

Copper Hookup Wire

August 15, 2023 Michael Traskos

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 standards and how their implementation ensures acceptable quality in the development of aerospace wire. Read more

Fluid Immersion Testing of EWIS Components

January 31, 2023 Michael Traskos

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. Material compatibility is important for all parts of the aircraft and the wiring system is no exception. The means to assess material compatibility between fluids and wires/cables is done with fluid immersion testing.

Fluid immersion testing is straightforward but requires a lot of materials, a lot of prep work, and a lot of hands-on attention to detail. The fundamental idea of fluid immersion testing is for components to be submerged in the fluid and observed for any changes to the material or components. Some test details and the impacts of the test results are covered here.

Flex Endurance Test Basics

November 6, 2022 Chris Wollbrink

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 panels/doors, and flight control surfaces have regular flexing. What is the best approach to selecting and verifying wires/cables for these applications? It turns out that there are several options. Read more

IEC 60851-5 Winding Wires – Electrical Property Test Methods

October 18, 2022 Laura Wishart

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 composed of a copper or aluminum conductor with a very thin layer of insulation. The insulation layer is as thin as possible to keep the wire cross-section small making it possible to squeeze the highest number of windings in the motor. Whereas most electrical wires are cylindrical, winding wires often have a rectangular cross-section profile; this allows for maximum cross-section during winding, thus reducing potential losses. Read more

Glycol and Silver-Plated Conductors

September 14, 2022 Michael Traskos

In this article, we discuss silver’s susceptibility to corrosion when exposed to glycol, its impact on aircraft, and ways to mitigate potential degradation. Read more

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