Taylor Alberstadt, Honeywell Aerospace’s senior director, business development electric & hybrid electric propulsion, reveals how the company is really driving the future of urban air mobility and unmanned aerial systems.

Honeywell is a major player in the urban air mobility (UAM) market, offering a full line of avionics, electric and hybrid-electric propulsion systems, and operational systems — all tailored for unmanned aircraft and UAM vehicles. The company also offers aerospace integration and certification expertise for enabling their commercialisation. So, just how up to speed is Honeywell with the latest UAM philosophies and partnership programmes?

“In our technology roadmaps and customer engagements, all electric aircraft and more electric aircraft have been prominent themes,” begins Taylor Alberstadt, senior director, business development electric & hybrid electric propulsion, Honeywell Aerospace. “Looking at the maturity of available offerings today, there will likely be different architectures necessary based on various OEM mission profiles and technical requirements. We feel very well positioned to be an overall vehicle integrator, including both avionics and propulsion, and with our newly created UAS/UAM Business Unit, have emphasised opportunities in that space.

“Honeywell’s unique capabilities – along with strong partnerships with aircraft manufacturers, airlines, and component providers – permit us to look holistically at these exciting new markets and applications, and with our partners, help drive the industry forward towards a much greener aviation future. Two examples of these are the awards Honeywell has received from the Department of Energy as part of the ARPA-E ASCEND and REEACH programmes.”

Is an initiative like more electric aircraft (MEA), which places less reliance on traditional pneumatic and hydraulic systems the way to truly realise future weight savings in tomorrow’s civil aircraft?

“Honestly, the jury may still be out. Weight savings can certainly be the case at a product or system-level, but for example, the majority of weight savings in the case of the 787 came from the composite fuselage. MEA will be a piece of the larger OEM weight puzzle. We also expect to see MEA benefit from reduced maintenance intervals, driving lower operating costs, and less complex system architectures.”

Harnessing the power

What are the technology barriers to harnessing electricity as a common energy carrier in terms of establishing more versatile and intelligent power architecture, and more efficient and higher density conversion technology?

“A main barrier is identification of a way to safely increase the voltage levels from 600-800VDC to 3-4kVDC. A higher voltage range will allow increased density of electric power generation, conversion, and distribution as well as the increased efficiency at higher voltages. At the same time, higher voltages will allow distributing megawatt-class power levels while minimising the burden of heavy wiring and distribution units.”

What are you doing to enable even more sophisticated materials and electronics that can work in harsh environments and exhibit the high reliability demanded by the aerospace industry?

“Honeywell has extensive R&D efforts, many driven by defence and space applications, that are aimed at robust operation in extreme environmental conditions. It is our experience that the knowledge and expertise gained during these long-term initiatives can often be applied to commercial aviation and aerospace environments – and we fully intend to continue to bring the results of these efforts to commercial products.”

For typically harsh areas of the aircraft, what advances have you made in terms of producing robust components and materials that can withstand higher altitudes and elevated temperatures?

“The harsh environments will be addressed by using highly-effective and innovative thermal management systems with high-speed air flow via innovative heat sink that minimises the thermal resistance. These will be combined with silicon carbide devices, advanced coatings, high performance insulation and robust designs accounting for high altitude and temperature effects.”

Together in electric dreams

Would you agree that the fundamental aspect of the MEA efficiency proposition is in making equipment multipurpose, so that the aircraft no longer carries electrically-powered engine starter mechanisms which, once they’ve done their job, are just dead-weight and carried for the entire flight?

“Certainly, by reducing the number of on-board components, a weight-savings can be realised. The ability to eliminate the bleed system from the engine is a big opportunity to reduce weight and improve engine efficiency. Another example of eliminating the dead weight is using the generators driven by engines as starters for the engines and the start controllers to drive the motors in electric cabin air compressors.”

When in the future do you foresee the tipping point for full short-haul electric aircraft adoption?

“It will certainly be an evolution, with technology development currently in process. Some UAM and smaller fixed-wing projects envision flying passengers this decade, while scaling up into larger aircraft will likely occur through the 2030s.”

In general, what kinds of power performance demands are placed on Honeywell by today's airframers?

“While we are aware and have seen various OEM battery requirements, and they are critical to overall system performance and architecture, Honeywell is not today a battery provider, although we do have battery partners that we work with. However, the industry is pushing for greater energy density (kw-hr/kg), increased cycle life, charging speed at high discharge rate, and increased safety, such as the avoidance of thermal runaway and other known risks with lithium batteries.

“Nevertheless, the industry will not get where we need to go, at least in the near to mid-term, with battery power alone. From Sustainable Aviation Fuel (SAF) to hydrogen combustion and fuel cells to battery and hybrid power systems, our partners need diverse approaches to meet their business models of the future.”

Getting the weight down

Aircraft battery technology seems to be a sticking point in terms of weight reduction. So much is being done to reduce the weight of materials and components, but batteries are still heavy. Is battery technology lagging behind industry demands and are the interconnect guys, for example, getting impatient waiting for the battery design engineers to catch up?

“We in the aerospace industry are always eager to cut weight. Weight is drag and weight is cost. The priority of the moment is indeed to increase battery energy and power density. However, UAM and short-range regional applications are less sensitive to battery weights and provide great leading applications for electrification.

“Electrification by the way is also more than just pure battery plays - we have rather a range of energy storage architectures enabled by batteries. Finally, we are also fortunate that aerospace is not the only industry trying to cut battery weight - sure, we may have uniquely challenging discharge and safety requirements - but we are not alone in this electrification journey.”

What really differentiates and sets Honeywell apart from the competition?

“Honeywell has the breadth and depth of portfolio and expertise to be a system integrator, which can be especially helpful for many start-ups by reducing their programme and schedule risks. We have created a business unit dedicated to UAS/UAM. We have product roadmaps established around the development of building blocks of technology that can be applied across segments and evolve with the market needs, and beyond being a supplier of products, have a history of systems integration and certification expertise for aerospace applications.”

Finally, where do you see the biggest business challenge coming from this year?

“Worldwide there is a focus on returning to a new ‘normal’ in a post-Covid world,” Alberstadt concludes. “From venture capital funding for start-ups to OEM deliveries to air transport flight hours, certainly the impact of the virus has been felt across the entire industry. The timing around bringing back travellers and restoring passenger confidence to fly again during these Covid and post-Covid times is crucial. This year is also important for us from a technology development point of view with new products coming to market and maturation of key development programmes.”

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