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Results for: wire system certification

Understanding Life Prediction Technology

February 13, 2020 Michael Traskos

To understand the basis for wire life prediction, there are parts of the process that must be understood from a fundamental perspective and how these fundamentals are applied to the long-term reliability and life prediction of the components. This article will cover some of these basics, the research that has gone into this field, and how it is used as part of EWIS sustainment and service life extension projects. Read more

Review of EWIS for Sustainment

January 30, 2020 Michael Traskos

We measure everything that matters. In the last decade, the efforts of organizations to measure EWIS has been progressively increasing. Perhaps this is because wiring is now considered a system, or because regulations and requirements have emerged, or it may be due to a better understanding of the EWIS maintenance costs. Whatever the reason for better EWIS maintenance issue quantification, it has been a positive because there is data available to substantiate aircraft maintenance actions. The old saying is, “You can’t beat something with nothing”, and for too many years, EWIS maintainers were trying to take on EWIS maintenance without supporting data. 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

Non-Standard Standard Part Performance

November 11, 2019 Michael Traskos

Standardized products made by different manufacturers through different processes will undoubtedly yield variable product performance. The expectation is that each ‘qualified’ product should perform comparatively well, but anecdotal evidence suggests that this is not the case. This paper reviews recent work performed by Lectromec investigating the qualified wire/cable performance variability in both qualification tests as […] Read more

Determining Voltage Drop

October 11, 2019 Michael Traskos

If voltage is applied to a circuit and the attached equipment does not turn on, then there is an issue with either the circuit or the applied voltage (assuming the device is fully functioning). Sometimes glossed over in circuit design, the length and gauge of a wire can impact the voltage to the load; this is known as “voltage drop”. Just as the current carrying capacity of a wire/wire harness is impacted by the system and environment, so too is the voltage drop.

In this article, we go over the idea of voltage drop, guidance on its application in design, and an example of quantifying the voltage drop on a wire/cable.

Checking a Coaxial Cable for Damage with a Multimeter – Part II

September 11, 2019 Michael Traskos

In the last article, Lectromec introduced a damaged coaxial cable and tried three techniques to distinguish it from an undamaged cable. The standard multimeter tests (capacitance, inductance, and resistance measurements) found no appreciable difference.

The idea of this evaluation was to demonstrate that the classic multimeter, while a great tool, is not suitable for detecting damage to coaxial cables.

But we cannot run an article and leave it without a solution. In this article, we continue the testing of a damaged coax cable to see what technology, if any, can identify and perhaps locate the damaged section of cable.

Checking a Coaxial Cable for Damage with a Multimeter

August 23, 2019 Michael Traskos

The electronic multimeter is a great tool; invented in the 1920s, the multimeter has been used by millions of technicians and engineers seeking to measure circuits and troubleshoot electrical issues. So common are these tools now that it is almost impossible to consider a toolbox complete without one.

While these are great tools and can be employed in a million situations, they are not the magic tool that can diagnose every circuit. If only one thing is remembered from this article: multimeters are not the tool to use for coaxial cables

EWIS Physical Hazard Assessment

August 14, 2019 Michael Traskos

Aircraft system safety assessments are not a new concept. These safety assessments have a defined process for evaluating an aircraft which involve identifying its failure modes, top-level events, and eventual means to achieve an unsafe condition. Documents such as the SAE ARP4761 provide guidelines and methods for conducting the safety assessment process on civil airborne systems and equipment.

To follow the typical development cycle, the aircraft failure hazard assessment (FHA) is followed by the system failure hazard assessment and performed in parallel with the preliminary system safety assessments (PSSAs). This then evolves into the system safety assessments (SSA) and common cause analyses (CCAs). For those with a systems reliability background, this should all be second nature. For the rest of the community, these are often terms that we come across because of our work in this field.

Consequences of EWIS Implementation

July 24, 2019 Michael Traskos

In June 2019, Lectromec was asked to present at the USAF Mechanical Equipment and Subsystems Integrity Program (MESCIP) conference. With the electrical wiring interconnect system (EWIS) working its way into fleet sustainment activities, fleets now must take and apply the EWIS lessons learned.

Since the commercial segment has been subject to the 25.17XX EWIS regulations for more than a decade, the presentation examined the intended and unintended consequences of these regulations. For those seeking to integrate EWIS concepts into their fleet maintenance practices, this presentation gives an overview of the factors to be considered for your fleet.