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The Potential 270VDC EWIS Component Failure Impact

June 27, 2019 Michael Traskos

The More Electric Aircraft (MEA) design concept has placed, and will continue to place, a greater importance on aircraft electrical power and the supporting Electrical Wiring Interconnection System (EWIS) to accomplish flight critical tasks. To take the greatest advantage of weight savings from using electrically powered components, higher voltages have been brought into the aircraft power architecture.

The goal of Lectromec’s research was to generate data of the potential impact of EWIS component failure. Even with high voltage systems having been fielded for a couple decades, much of the published research provides information on the failure of 115VAC and 28VDC power systems. This research performed by Lectromec sought to fill in that gap.

Common Questions About Kapton® Wire

June 12, 2019 Michael Traskos

Love it or hate it, the fact is that Kapton® insulated wires will be on aircraft for at least another couple of decades, and because of this, we should learn to live with the insulation type. Part of living with it is understanding it. If you have questions that you would like to see answered, please send them to Lectromec or add them to the comments section below. We plan to add to this article as the questions arise. Read more

Where EWIS Stops

April 8, 2019 Michael Traskos

Having well-defined and recognized system boundaries is the best means to ensure an analysis of that system is robust and does not leave any analysis gaps. Without an established limit and assigned responsibilities, arguments will ensue as to who is the responsible party and time/effort will be wasted with duplicated analysis.

Because an aircraft’s wiring touches nearly all of the systems, it can be confusing to understand where the system starts and stops, and this has led to confusion as to the responsible party for the wiring system design and/or maintenance. Some organizations have seen the responsibility fall on the electrical power systems teams, others, avionics. Regardless of who takes up the responsibility, a clear definition of the wiring system’s physical and logical boundaries must be agreed upon. Thankfully, there are several industry documents that can be relied upon.

High Voltage Impact the Aircraft Wiring System

March 18, 2019 Michael Traskos

For aerospace applications, high-voltage power is a rapidly growing interest and being addressed across several industry technical committees. The basic idea is that the power generation is increasing the supplied voltage and creating a need for the electrical wiring interconnects systems (EWIS) to have components designed to sustain these higher voltages for the entire length of the aircraft life. Just as it should not be expected for a connector to operate in a 300°C environment if it is only rated to 150°C, a connector should not be expected to perform perfectly with voltages exceeding its voltage rating. Read more

SwissAir 111 Incident

February 16, 2019 Devon Gonteski

The year of 2018 was yet again another substantial year in commercial air travel. The first quarter of 2018 saw commercial flights carry over 202 million passengers in the US, approximately 8 million more than in the first quarter of 2017. Air travel remains increasingly popular, accessible to the public, and statistically the safest way to travel. This level of safety has been earned through decades of groundbreaking innovation, sometimes undeniably spurred by the desire to avoid repeating past tragedy.

An impactful and memorable incident that caused the industry to reevaluate its processes and procedures was the crash of Swissair Flight 111. Occurring almost two years after the Trans World Airlines Flight 800 (TWA800), the Swissair Flight 111 and TWA800 shared a common issue: wiring system failure.

DelTest

The Lectromec DelTest™ is a patented technology that has been used by commercial and military organizations to support their maintenance efforts and maximize the service life of their investments. The DelTest™ identifies breaches in wires that often go undiagnosed until an event happens. These events, common to active aircraft, can lead to spurious signals, noise, […] Read more

Mechanical Performance of Cables at Low Temperatures

October 5, 2018 Michael Traskos

The environmental extremes under which wiring exists in aircraft can rapidly degrade materials that are not prepared or designed for those conditions. Without a doubt, high-temperature ranges that are typically considered for aircraft wiring eliminate most wire insulation types that are suitable for ground-based home applications. Lectromec has covered several types of high-temperature tests in past articles. But at low temperatures, what tests exist to help identify which wires are ideally or adequately suited for aerospace applications? One of the tests that investigates the performance of wires in cold conditions is known as the cold bend test. Read more

Should Polyimide Insulated Wire be Trusted?

September 25, 2018 Michael Traskos

The history of polyimide insulated wire is one that has numerous opinions and a lot of misconceptions. After several incidents involving polyimide wire on aircraft in both military and commercial, many within the aerospace industry refused to put any polyimide insulated wire/cable onto the aircraft they design/maintain. As is often the case with components involved in incidents, a lot of facts and myths get jumbled together. Read more

25.981 is Not a Barrier – Part 2

September 18, 2018 Michael Traskos

FAA regulation 25.981 covers the requirements of fuel tank ignition prevention. While there are numerous elements that must be considered as part of the 25.981 regulation, this is a Lectromec series of articles, and here we focus on the electrical hazards that must be identified and mitigated as part of certification. Read more

25.981 is Not a Barrier

September 8, 2018 Michael Traskos

One area of aircraft certification where electrical energy and risk have always been considered is the fuel system. While it is obvious that limiting the exposure of fuel to electrical energy is advantageous, how this gets addressed from a safety and certification perspective is far from obvious. Read more