Headquartered in Logan, Utah, Electric Power Systems (EPS) has emerged as one of the companies to watch in the eVTOL battery space. A principal supplier for the hybrid-electric Bell Nexus, EPS has also supplied battery systems for NASA’s X-57 Maxwell, Bye Aerospace’s eFlyer, and Embraer’s electric Ipanema demonstrator, among other projects yet to be revealed. During our visit to Logan to learn more about the company, we sat down with CEO Nathan Millecam for a deep dive on some of the most pressing issues related to battery development and certification. (This interview has been edited and condensed.)
eVTOL.com: In terms of making [eVTOL batteries] safe and viable, weight is obviously a big issue. How are you approaching that?
Nathan Millecam: Our strategy is basically to exceed the certification requirements as they’re written today. If you look at the way that containment works in safety, you’re required to contain a thermal event, with all your safety features defeated, within a module level. So what we do is we look at more cell level containment, and not only have it be thermally contained, but also electrically isolated as well. If we lose one cell, we don’t necessarily lose the whole module. You’re still able to discharge, which we see as crucial for all-electric vehicles that require high-integrity propulsion. So a lot of our IP is: How do you do that really, really light?
We worked very closely with NASA on the X-57. NASA had a great philosophy around how to do that, that was being deployed in space. We were able to work with NASA on the X-57 and really innovate on that philosophy to create something that was significantly lighter than anything that they had ever fielded, but more importantly, it could hit cost targets that companies like Uber wanted for the eVTOL space.
eVTOL.com: You earlier referenced the automotive space and building off of the automotive world. [How are you] leveraging lessons from that world, and what’s different about aerospace?
Millecam: Where we like to learn from automotive is how to do things at scale and how to implement automation technologies. Automotive is highly automated. They also have a very good quality approach with a lot of statistical sampling to continually refine and improve the product, enabling a very low PPM [parts per million defective rate] with a very high on-time delivery rate. We believe this performance is critical for eVTOL to be successful in the future.
Where things start to diverge is: How do you document, how do you validate, and how do you claim airworthiness of a unit before you ship it out? We have a proprietary process that we think exceeds continued airworthiness requirements today that can be highly automated and digitized, giving us full traceability on the unit.
eVTOL.com: What’s the landscape of certification now? Are the standards sufficient and well-defined for the space, or is that an ongoing process?
Millecam: It’s ongoing process. It’s a very interesting question because in some regards, thanks to programs such as the [Boeing] 787 or business jet programs, there are a lot of precedents that have been set around safety. The nice thing is we don’t necessarily have to reinvent the wheel, or re-create things such as how we do software certification. Where there’s potential opportunities for improvement and defining the standards would be around things like: How do we handle high voltage, particularly at high altitude? What kind of handling requirements should we have, particularly when we’re talking about charging and charging infrastructure? Those have still yet to be matured.
eVTOL.com: In terms of further refinement of the standards, how are those conversations happening?
Millecam: There’s a significant amount of dialogue on standards and what the new standards should be, with a number of committees trying to clarify. I think the key question is: Does the standard really work and does it actually meet the safety that’s going to be required for this marketplace? I think that’s a wait and see. There’s also a big question of what will the cert authorities really accept in terms of new standards. I think what’s encouraging is cert authorities are actively engaged in the dialogue looking at other industries’ approaches, and incorporating other government agencies such as NASA.
eVTOL.com: In terms of certification testing, how well defined is [what] you’re going to have to demonstrate?
Millecam: Some things around environmental testing, that’s very well-defined. There are some unique elements when you start talking about high voltage and how that interacts with its environment, whether we’re talking about altitude or whether we have an event where an airplane goes down in a water landing — some of those things still need to be discussed and defined.
I think where batteries will be unique is in the safety testing, and will the containment methodology that’s been defined in DO-311 really be adequate? It’s kind of a catch-all method to try and prove that your system is safe. The technology around cells is advancing so fast that there may be much more effective ways to demonstrate if you’ve truly got a safe system or not, beyond what is documented in DO-311 today.
We’re actively involved with the [Federal Aviation Administration] in those discussions, and with NASA and some other authorities on what we think certification should look like. Our plan would be to help the conversation and set a benchmark that we think is very high to ensure that that the flying public will trust these systems; that they’ll want to fly in these systems; that the industry is being very, very responsible in how they’re bringing products to market.
eVTOL.com: In terms of public perception, what do you think are some of the big lessons in terms of managing public fears and educating the public?
Millecam: I think there are things we can do that just make sense economically as well as for the public. There are a lot of applications that lead up to manned flight — logistics missions, for example. We can start to adopt technologies that we think will work for manned flight in those applications very early, get the service data set and learn from those applications, and then apply them to manned flight missions such as the Uber eVTOL mission.
eVTOL.com: What is your opinion of the timeline of the industry moving towards this? Uber is saying 2023 [for its first commercial eVTOL operations]. From your side of the house is that, how realistic is that?
Millecam: I think credible demonstrations of the technology are possible in 2023. It’s aggressive. I like aggressive, and I like hard targets. Realistically, if it’s 2024, 2025, I don’t think the market’s going away. It will happen as soon as we can prove that it works.
What’s very encouraging is how the industry has mobilized. It has really transitioned from, “Can we do this, or how would we do this?” to, “Well, let’s define what the right requirements are, let’s design the right product, and then let’s make sure we have the product development, the manufacturing, and the support infrastructure to really make it happen.” We’re very optimistic and we generally think it’ll happen much sooner than people think. I don’t think anybody knows exactly the time frame.
eVTOL.com: One of the big claims of naysayers is that the battery technology is not there yet. Obviously you’re on the leading edge of that. How do you respond to that argument?
Millecam: My response is that the final barriers for us to cross on the battery for manned eVTOL missions in an urban environment at scale are mostly from a business and economic standpoint. This may require emerging cell technologies for some aircraft configurations. For other applications, such as an all-electric fixed-wing trainer, this is not the case. I think if you are in an aerospace company, and you are an executive in the C-suite, and you truly believe that the technology is not there, then you’ve probably missed the market already, and you will not be a credible player in this marketplace.