Published on October 12th, 2019 | by Nicolas Zart0
Is Kitty Hawk Introducing Range Anxiety For eVTOL Aircraft With Its Heaviside?
October 12th, 2019 by Nicolas Zart
We finally heard about Kitty Hawk’s “secret project,” which sports the strange name of Heaviside. It introduces the notion of range for an electric vertical take-off & landing (eVTOL) aircraft. The demonstration of the aircraft flying is fantastic but I wonder if we’re about to witness another “range anxiety” war between eVTOL manufacturers? Let’s hope not. We’ve already gone through too much and are still reeling from a decade ago. I hope the fragile birth of our urban air mobility (UAM) world happens without focusing on what cannot be gauged just yet.
Kitty Hawk Heaviside and the eVTOL Range Aspect
Knowing the range for electric vehicles (EV) is a perfect expectation to have. Everyone should know how many miles their car delivers on a battery pack or gasoline tank. Savvy CleanTechnica readers might find it strange that EV range is disproportionately favored above efficiency. Most EVs have enough range to compete against $40,000 gasoline cars. I suspect most gasoline car owners don’t know the range of their cars or have a general idea but certainly don’t buy their cars because of range potential. When it comes to EVs, however, it becomes a point of contention. Are we going to see the same with eVTOL aircraft now?
Before we talk more about range, check out this video below to see how far Kitty Hawk took the HVSD. The aerial demonstration is stunning and shows some of the hidden potential that eVTOL and eCTOL aircraft have in store. This is flying very close to the envelop and it makes me want to jump in one.
Sebastian Thrun, the co-founder of X and the Alphabet moonshot factory, is the CEO of aviation startup Kitty Hawk Corp., amongst other things. Heaviside — abbreviated to HVSD — is what they’ve been working on for nearly two years. We’re happy to see the impressive results. The 8-rotor, 20-foot wingspan HVSD will have a range of 100 miles, according to TechCrunch. It’s not very clear if Kitty Hawk or TechCrunch is introducing the notion of range in the title of otherwise great news.
The reason why range is confusing at this stage is that there are no data on future eVTOL usage. We do know that eVTOL aircraft will mostly be used in urban areas. Gauging an eVTOL’s range will depend on many factors, including specific service, the topography of its terrain — altitude and climbing ration in VTOL modes, and mostly how it will operate. So far very little of this is known. It doesn’t exist just yet.
How will we calculate the range of an eVTOL that takes off from one building or vertiport at a given altitude and lands in another with another altitude? How long will it be in VTOL mode versus cruising? What about weather conditions, temperature, wind factor, and other localized atmospheric conditions? VTOL mode is notoriously energy-hungry but cruising much less.
Most current airliners use 90%+ of their energy at take-off. Cruising throttles back the turbofans to around a third of their capacity. Landing brings them back close to idle, depending on the many approach scenarios. Calculating the range of an airplane is similar to that of a car. It’s a big average. Rail locomotives did away with calculating how many hours a tank of diesel lasts, not the actual miles.
The problem with eVTOL urban air mobility (UAM) is that we don’t have much data yet. Usage and traffic don’t exist yet. There aren’t any eVTOL in services today. I hope to see the first one in December when eHang starts its inaugural service from Guangzhou, China this year. That’s history in the making a la Chinese Time — very fast pace of development and production.
Kitty Hawks’ fantastic work in the eVTOL industry is pushing the technology forward, no denying that. But I question introducing the notion of range for an aircraft that hasn’t been put into service yet. By the way, I’m game testing it in our congested southern California. Batteries are still shrinking energy density. We won’t know for another few years most UAM aircraft’s final configuration. Ampaire says it’s not ready to talk about batteries yet for good reasons. The fast pace of battery development means the original configuration will be a moot point in a few months. And lastly, there isn’t a traffic pattern to gauge an eVTOL range to date.
I’m excited hearing that the HVSD is 100× quieter than a helicopter and faster. It’s excellent news to know it can cover San Jose to San Francisco in 15 minutes, a 48 mile (77 km) areal trip. I assume we want to hear even more about noise at 88 decibels when landing. I’d love to hear the decibels when it takes off in VTOL mode. It’s good news to know the HVSD will be as loud as 40 decibels at about 600 ft in the air. Those are easier numbers to understand than an average 100-mile range for an aircraft that functions sometime in VTOL mode and cruises the rest of the time. What I’m really excited about is how no other eVTOL or eCTOL maker has shown how it can fly before Kitty Hawk. That’s some serious real flying the HVSD demonstrated in the video.
Is It Too Soon To Talk About eVTOLs Range?
So far, the super cool Flyer, an amphibious type of eVTOL, and the Cora from Kitty Hawk, never mentioned range. Volocopter “calculates” a range of 35 km (~22 miles), but that’s it unless I missed something. Given the unknowns, range is a strange topic to introduce this early in the game.
In the meantime, congratulations Kitty Hawk for a fantastic video showing a real-world flying demonstration. That is spectacular!
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