W. L. Gore recently announced a new wiring product that meets the need of higher voltages for the next advancements in aircraft electrification. GORE High Performance Aerospace Wires, GWN3000 Series, provide a combination of mechanical strength and electrical reliability without increasing wire bundle size or weight, the company says. We spoke with Jim Carothers, Gore product specialist, to ask what differentiates this new offering from what is on the market now.
Tell us about how you became a subject matter expert in wiring.
I actually started working in aerospace actually on the space side. I supported antennas and RF components and power systems and vehicle integration for space systems during my time at Lockheed Martin. You’re working a lot with wiring cables while integrating spacecraft. And, when the opportunity with Gore came, there was a nice fit between what my experience had passion for getting vehicles integrated and Gore being an integration company. I’m on the component level. It was just a natural fit.
And is your background in engineering?
My undergrad was mechanical engineering and then I got my master’s in systems engineering. The Lockheed electrical guys would always make fun of me as the only mechanical engineer who understood return loss (a measure in relative terms of the power of the signal reflected by a discontinuity in a transmission line). I’ve always kind of been this bridge between different disciplines. I think if you’re going work in wire and cable, you need to be comfortable going across disciplines because you’re always dealing with these electrical parameters, but they have to live in the physical world.
Why is Gore interested in high performance aerospace wires and why have you all worked so hard to differentiate the GWN3000 Series from other products that are on the market?
The big reference point, for me, is with F 35 switching over to 270 volts. That’s, that’s a clear sign that electrical energy is a key component of the functionality of future aircraft systems. And anytime a component like that becomes critical, the performance becomes more appreciated at the system level. We have a long running heritage on the space and semiconductor businesses, particularly for data transmission. But when these systems rely on voltage just to complete their basic functions, as they become electrified and replace hydraulics for the electrical systems, that’s where our expertise in the system need really converges. That’s when the development started. We were seeing these needs, these systems and the trend is not going away. We also understand dielectric (insulating material) as well. And if you want to move electricity through aircraft reliably, you need to have good dielectric.
Is this product for use in military or civilian aircraft or both?
I think it’s more about what the systems are being asked to do as opposed to the segment. For example, look at urban air mobility. They’re going to be incredibly electrified vehicles. They’re going to have very similar needs. On the defense side, there’re obviously aircraft that are going into very challenging environments, but they need this performance as well. The high-performance aerospace wire offering really plays in both segments.
Explain how the product that allows for extra strength and reliability without bulking up and adding weight.
It really gets into Gore’s sweet spot. It’s being able to manipulate and an engineer for polymers that have really specific attributes. Fluoropolymers are our real expertise. Our initial expertise was in PTFE, which is commonly known as Teflon. What we can do is engineer the structure of that to get really specific mechanical, electrical, or chemical properties. And given that we engineer and manufacture that material, we can really tailor it to the needs of any system that we’re targeting. This is an offering that even though it’s new to the market in this form, we’ve been working with these materials for 60 years. We get to go into our portfolio and select what’s best for this need on the market.
It’s possible to customize this wiring, is that true?
If you look at our portfolio, that’s effectively what we’re doing. We’re using a different dielectric that is really great at surviving the mechanical environment of an aircraft and conveying voltage without breaking down.
Talk a little bit more about the challenges of the higher voltages that you’re seeing today in terms of this wiring. So how is this solving the problem of the more electric aircraft, the higher voltages, et cetera.
I always think of aircraft in terms of like an FMEA [Failure Modes Effects Analysis] perspective. We’re all trying to avoid arc events or system failures. As aircraft become more electrified, the severity of that type of failure only increases, because you’re talking about a plane going down from a harness instead of just losing a display or some type of functionality. So I think it’s only more imperative that these systems are evaluated and the performance of these systems is increased.
You mention the risks that can occur. There are some things like chafing, abrasion and environmental concerns. Can you talk about how your product protects wiring from those things being an issue?
Vehicles are obviously a dynamic environment and when as a plane or a rotorcraft is in operation, the frame or chassis of the vehicle in a lot of cases where the harness or the wiring is connected down, are at odds with each other. Those dynamic forces can lead to wear on a harness. That’s the traditional kind of long-term effect that wiring can see and be exposed to as it breaks down. But there are other short-term factors that can occur. For example, when aircraft are being upgraded over time, the old harnesses are pulled through the vehicle and that’s where you get abrupt, sheer-type failures. That’s why we characterize our insulation against cut resistance. It’s important that the wiring survives the process of the upgrade. The other piece of this is chemical exposure. It’s really difficult to understand the long-term impacts of that on a harness, because you don’t see a harness every time you operate a vehicle. But it is a failure mechanism that could lead to latent defects on an aircraft because your if your harnesses are being compromised by chemical components, like hydrolysis or the solvents that are present in a vehicle, your performance over time is not what it is when you initially certified the vehicle.
Can you maybe put it more in layman’s terms why this wiring does not degrade after exposure to environmental concerns?
It’s a nice benefit of our PTFE material set. So PTFEs in general are relatively chemically inert. There’s a very short list of things that break that polymer down. PTFE is just chemically inert to water and to the long list of solvents that aircraft operate.
Talk about the limitations of the current installations that are in use and how the GWN3000 Series differs.
The aerospace industry is a very systems engineering-heavy industry. Systems engineers either have to prioritize electrical performance or they have to prioritize mechanical performance with most wiring insulation technologies. Aircraft designers are being tasked to choose because you typically can’t do both. Some are materials excellent mechanical performers, and some are excellent electrical/chemical performers.
It’s a tough time right now in the airline industry. Can this wiring help those airlines who may be keeping aircraft flying longer than anticipated? Can it help meet the future electrification needs of their aircraft that may occur when they’re ready to upgrade. What can you do for them with this wiring?
That’s a good question. Anywhere there’s a system critical functionality that’s being electrified on these aircraft is really where this product is meant to serve, especially as they switch away from 28v DC and up into the 270Volts.
Gore says this product can help you reduce total life cycle costs. That’s key right now for operators. How does wiring help?
In rotorcraft and even in fixed wing applications, there are instances where up to 70% of vehicles in a fleet can be showing signs of wire wear. That needs to be addressed through maintenance. This new installation technology that we’re bringing to market compared to typical installations, such as cross-linked ETFE — it’s orders of magnitude more wear resistant. That’s where customers get back that operational readiness and vehicle availability that results in lower maintenance calls.
What would you say are the biggest concerns when choosing wiring for an aircraft? If you’re looking at a new aircraft development, what would you say those concerns are and what should people be thinking about when they’re in the design phases of an aircraft?
I think it’s what’s the dynamic environment going to look like for the vehicle and how dependent is the vehicle going to be on electrified components? And if, if you’re going to be highly dependent and in a dynamic environment, that’s where you need to really consider ways to minimize the stress or exposure of the way that you’re interconnecting these components on the vehicle. I think that a lot of system designers don’t have the luxury of being able to invent every component in the system, right. Then they’re seeking to drive down risks as they develop these systems. And I think that’s an area where they’re well-suited to go with a conservative approach with designing the wiring and the inner connects to the vehicle.
How do the interconnects impact the wiring and why is that key?
Interconnects are like the vascular system of the aircraft. If an interconnect is compromised, it’s really the equivalent of having a clogged artery on the vehicle, especially as you become more electrified. And, it can compromise functionality immediately. Unfortunately, I think the interconnects tend to be one of the last considerations. If you go with a conservative approach or maximize your capability of the interconnect, you’re really driving risk out of the system. Then you can focus on the boxes and the panels that designers really like to focus on.
How do you see this product being used in UAM vehicles? Why is it important for that sector?
Most of the urban air mobility are centered on electric propulsion. They are talking about moving energy from an electric source motor. And that’s really our sweet spot: moving energy from these sources over to these systems. I’m really interested to see where that industry goes.
What is the most important thing to know about Gore GWN3000 Series wiring?
This product really represents a step change in the combination of mechanical and electrical performance or interconnects on a vehicle.