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

Testing and Qualification of Fuses

August 20, 2024 Michael Traskos

Aircraft electrical fuse testing includes electrical, mechanical, chemical, and thermal conditions that are representative of the aircraft in question. This article discusses the basics of electrical fuses and how they are qualified for aerospace use. 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

Insertion Loss and Attenuation

March 14, 2024 Michael Traskos

Insertion loss and attenuation are similar concepts, but one is assigned to a single component (insertion loss) whereas the other is assigned to generalized performance (attenuation). In this article, we will discuss the similarities and differences of these concepts and how proper testing of each can ensure reliability in signal transmission. Read more

Forced Hydrolysis

January 10, 2024 Michael Traskos

The goal of forced hydrolysis testing is to represent decades of wet/humid environmental exposure on polyamide-insulated aircraft wiring. This article discusses forced hydrolysis testing in detail, including history, applicability, and performance of the test. Read more

Creepage and Clearance

October 13, 2023 Chris Wollbrink

High voltage systems on aircraft will be more commonplace as the eVTOL market “takes-off.” One safety aspect that often comes up is the separation of the high voltage; often, this comes down to creepage and clearance distance of these systems. Read more

Heat Shrink Volume Resistivity

October 3, 2023 David Lloyd

Heat shrink tubing is used throughout an aircraft’s Electrical Wiring Interconnection System (EWIS) and must withstand the stresses set upon it in the standard testing. Volume resistivity is just one of many properties that are evaluated while qualifying heat shrink tubing. Read more

Voltage, Current, and Thermally Rating Connectors

September 13, 2023 Michael Traskos

While electrical component qualification is nothing new to the aerospace industry, the emerging trend toward full aircraft electrification requires every component to be electrically connected; for most equipment, this means incorporation of electrical connectors. Weight, cost, reliability, and performance are the four most common elements initially considered in connector selection, but the finer details of electrical connectors use must also be considered. Here, we discuss how one might go about qualifying an electrical connector, specifically, to address its voltage, current, and thermal limitations. Read more

HV Connector Failures and Part Selection

June 2, 2023 Michael Traskos

With the current shift toward hybrid and electric aircraft, deeper understanding of high voltage connectors and their potential failure modes is required. In this article, we discuss failure modes and selection criteria for high voltage connectors on aircraft. 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.

Testing & Assessment