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Results for: arcing

Risk Assessment and Small Aircraft Certification

November 17, 2021 Michael Traskos

The basic idea behind the F3230 is to limit the total number of assessments to those that are of particular concern for aircraft safety. This aligns with the change of part 23 aircraft the FAA has implemented for a more performance-based certification approach versus the detailed and prescriptive approach that the FAA used prior to 2016. Read more

Detailed Discussion of MIL-STD-1353 (Part 2): Nickel and Gold Plating

July 12, 2021 Laura Wishart

Plating materials used on electrical connectors are imperative to the connector maintainability and dependability throughout its service life. In the last article on MIL-STD-1353, we discussed Tin as a plating metal, its restrictions in practical use, and the potential of whisker formation which can lead to destructive arcing or short circuit events. Here, we discuss the use of gold and nickel as plating metals and their effectiveness when used together.

Addressing the Big Questions of Partial Discharge

June 11, 2021 Michael Traskos

In this high-voltage present, wires and cables must address new challenges, perhaps the most notable is partial discharge (also referred to as corona). This article discusses the fundamentals of partial discharge, its impacts on wiring design, and test methods used to assess a component’s partial discharge performance. The PD may occur between (1) the conductor and insulation, (2) within void in the insulation, (3) between insulation layers, or (4) between the insulation surface and shield. Read more

Detailed Discussion of MIL-STD-1353 (Part 1): Tin Plating

April 21, 2021 Laura Wishart

The mating of the electrical wiring interconnect system (EWIS) is a non-trivial task. Between the functional requirements (the correct number of pins, sizing of contacts, etc.), there are also the performance requirements (operational environment, corrosion resistance, impedance matching, etc.). This is then further complicated by installation requirements (sizing), maintenance requirements (mating/demating cycles), and regulatory requirements (limitations of materials that can be used). Obviously, adding a connector to a wire harness is not a five-second activity. This article looks at the MIL-STD-1353 specific requirements for tin usage in aircraft connectors. Read more

ASTM F3309- A Simplified Safety Analysis for Small Aircraft

March 10, 2021 Laura Wishart

Aircraft safety requirements vary depending on the size of the aircraft. Typically, larger aircraft have stricter requirements as a catastrophic failure in large aircraft has the potential for a much larger loss of life than that of small aircraft which hold far fewer passengers. The ASTM F3309 provides a simplified qualitative approach to evaluate the safety of small aircraft. Read more

WPAFB Wire Study

October 14, 2020 Michael Traskos

Key Takeaways Publicly available recorded data compares many of the commonly used aerospace wire types. Corona extinction and inception voltages of cables decrease drastically with an increase of elevation. Many insulation types display a significant decrease in mechanical durability at increased temperatures. Modern wires of the AS22759 family are incapable of stopping 270 voltage DC […] Read more

IEEE 1584-Arc Standard

September 16, 2020 Michael Traskos

Key Takeaways IEEE 1584 provides a basis and a model for arc flash protection and necessary safe separation distance. The standard targeted the necessary calculations for power distribution. While there is some overlap with the aerospace industry wiring system requirements, the model’s range inhibits its use for aircraft. Research down an unfamiliar path often includes […] Read more

S&T 2019 – Meeting Report

December 20, 2019 Michael Traskos

To get the most from the industry, it is necessary to learn and share with the community as much as possible. Some would call it reciprocity, others, seeking to work to a common goal. Whatever you want to call it, the S&T Electrical Systems and Wiring Inter-Agency Meeting was held earlier this month in snowy Cleveland OH in December 2019. The following are a couple of the areas presented and discussed during the meeting. Read more

Getting the Right Bonds

November 22, 2019 Michael Traskos

Things were so much easier with aluminum aircraft structures. The structure acted as an EMI shield, electrical grounding could be done right to the structure without additional effort, and the electrical mating of the structure was straight forward. Now, with composite structures, aircraft design concepts such as electrical bonding, particularly in the case of handling lightning strikes, becomes more important.

When done right, the impact of a lightning strike should have a limited impact.

In this article, we review the concepts around primary aircraft bonding, its requirements, and the implementation as they relate to lightning strike.