Robert Seddon May 23, 2020 07:13 PM Whatever happened to Moller? He was one of the first, but dropped out of sight. Thud May 23, 2020 08:56 PM Damn Loz! Lotta work on this piece. Nice article. byrneheart May 23, 2020 09:09 PM The 'death zone' has a very simple answer. Build the take off and landing platforms at or above that height. Towerman May 24, 2020 12:50 AM Wow what a great breakdown thanks Loz !There is so much to comment on however i will highlight a few things i feel is important:""Remote operators will take over and save the day as if they're flying a Mavic drone, and every pilot gone will be an extra passenger seat in the sky.""Exactly, people need to get used to and understand this, there is no thing and never will be such a thing as Autonomy without human intelligence as REALTIME backup. This is the Backbone of any autonomous system (So the point is this fact makes it safe to integrate autonomy)""""The first is the same problem that's holding back high-performance electric motorcycles: current lithium battery technology simply doesn't allow you to carry enough energy yet. Until energy density is at least doubled, most of these designs don't offer range endurance long enough to make them commercially viable. These big battery packs will need charging, too, which would ground the aircraft for a significant time.""""Granted this is true, however one must stress the advancements that is being made in the field, Elon musk is planning on expanding his batetry empire, Dyson has got enourmous amounts of research into batteries that will also be taken further, look at lamborhini who is bound to advance supercapacitor research that they are currently using as a battery replacement in their vehicles, these are a few major players in conjunction with fuel cells by toyota nad hundai as Loz mentioned above. So i believe the ability for long range Evtol's will be resolved within at least the next 5 years . But in the meantime we could finalize the product and do short distance flights, and simply incorporate the longer range power systems as they come along, so absolutely no need to wait ! Towerman May 24, 2020 01:02 AM """""But here's the issue; ballistic parachutes can only save you above a certain altitude, maybe 120 feet or so. Below that, they don't have time to open up, which means that every time you take off or land in one of these machines, you're exposed to a window of time in which total system failure would drop you like a stone."""""Now there is a lot to discuss here in detail, but the TLDR version:1st let me make this clear: The notion that helicopter autorotation is safer than an electric motor as backup is FALSE.Autorotation is FAR FROM a failsafe guarantee, Many helicopters that goes into autorotation does not make it down safely.People NEED to get used to this. Having an extra electric motor on standby that is practically NEVER being used will be Heaps safer compared to autorotation. There is no "Complete power failure" like on a helicopter or aircraft with multirotors. Many multiple means of seperate power source distribution is incorporated into the very GENES of a multicopter, this single fact alone makes it safer than Autorotation ! Once the failsafe motor kicks in, the outcome is NOT questionable as the system would stabilize the aircraft so the pilot or autonomous flight can resume flight as normal, and do a perfect landing ! Towerman May 24, 2020 01:13 AM """""""We've been calling the area between 30 and 120 feet off the ground the "death zone," and I'm sure eVTOL manufacturers wish we'd stop talking about it. We have heard, off the record, about some pretty wild solutions to this problem, but as of yet nobody has come forward to say they've solved it."""""""The problem has already been solved as per my comment above (add an extra motor for each arm in STANDBY mode, not in running mode, we HAVE a multiple redundant power supply system. It's not like ICE aircraft or a helicopter which lose its power once the engines die where a boeing or airbus needs to use a RAT just to provide basic functionality of avionics, we need to erase this TOTAL TUNNEL VISION mindset that multirotor power systems works the same, IT DOES NOT ! It is far much more REDUNDANT It is much simpler and much SAFER ! So there will never be a Complete blackout whatsoever ! The problem is the FAA/CAA is behind the times, immediately pinning the power systems of Multicopters to the power systems of passenger aircraft which is totally incorrect because the 2 systems exist in a completely opposite manner from each other. Airplanes rely on its ICE to provide power, Multicopters could have as many as 10 to 20 separate power distribution points and sources ! andrew munday May 24, 2020 01:31 AM A good summary Loz, the one that jumps out at me as missing is https://www.vertical-aerospace.com they have already flown two prototypes and are based in Bristol, UK, where Concorde was built. Towerman May 24, 2020 01:33 AM I lost count of the many helicopters that did crash with engine failure, auto-rotation is a hit or miss. No matter how much you try to defend it, its just fact. YET they are certified, multicopters with its multitude of redundant power sources and failsafe distribution kicks autoration's reputation into oblivion !Now some comments on the ships:It's no secret that i really like the SKAI craft and the innovation wrt the Fuel Cells they are working on !It's the ultimate in simplicity (yet sophsticated) and the ultimate in aesthetics when it comes to brute and realiable multicopter design. To put it simply, they have taken it to the extreme, building the ultimate bold and sleekest looking machine its the best looking multicopter that you can build and one of those designes that tells you just by looking at that it will fly as good as it looks ! Well done SKAI PLEASE keep us updated.As for the rest, i like most all designs, Joby stands out for sure, i want to see this machine get to full production ! Lilium very different but when i've seen that last practical flight, it made me want to see more ! I was skeptical at first but am more of a believer now.Airbus, the actual product looks more "rough" and unfinished than the showcase concepts that was presented. I hope they keep perfecting it until it flies and looks as sleek as the showcase concepts.Bell's looks interesting, but we need a practical demonstrator and as Loz mentioned only 4 rotors...Ehang and of course Volo also needs to push forward.4 smaller time inventors i want to mention, not criticizing Loz for not mentioning them as he certainly listed the major playershowever i feel i want to mention them simply via observing their superbly stable flights on youtube as they are extremely capable one man machines:Which is Tomasz Patan super stable flying machine, and he is not afraid to fly it !And also Flying Kyxz ! Well done to this team in the eastern region.HeroFlyer, a super one man crotch rocket ! And the pilot does not hold back !Finally the manned Racing Drone by FliteTest !Again thanks for this review Loz it was a nice write up, we needed it ! martinwinlow May 24, 2020 01:43 AM What is it with all the ' 'ol 's in your article? It doesn't convey much in the way of gravitas to it.Sadly, you are stuck in the same lame mindset as everyone who thinks all vehicles must be able to go for hundreds of miles without stopping when, in reality, the *vast* majority of journeys for passenger vehicles are very short. Ergo, most of the machines in your otherwise interesting article would be commercially viable today (ignoring the current issues around certification.) Anyway, if ever there was a valid, workable case for battery swapping, this is it.And you *really* come unstuck with the usual giggly reference to using hydrogen for passenger vehicles. It isn't going to happen... ever. Battery technology advances will make it unnecessary for all but extremely niche markets (most of which will not be used on this planet). And certification of these things is going to be difficult enough without trying to convince the authorities that whizzing about with a load of highly volatile H2 on board is going to be, in any way, 'safe'! And then there's the thorny issue of making a fuel cell small, light and cheap enough to do the job that countless organisations have tried for 50 years to achieve and still haven't managed to do it. AND THEN, you have the problem that most H2 is currently made from natural gas which, as I'm sure you know (but appear to have temporarily forgotten) is a fossil fuel... Which kind off clashes with the 'running on zero-local-emission electric power' utopia from your introduction! And before you start wittering on about hydrolysing water, just have a look at how inefficient that would be compared to just putting the electricity into a motor via a battery.So, close, but no cigar! dan May 24, 2020 02:24 AM Cool eVTOL collection! But unless they solve the battery weight and safety problems, it will remain a dream. In 2020, best performing batteries are still ca. 40 times less powerful than fuel (at the same weight). So, all these eVTOL are nice toys for engineers and a nightmare for investors and air safety, at least for this decade. Currently, there are not even theoretical concepts, how to increase battery performance 400 % and keep it safe (!), but we need 4’000 %... Better to use/manufacture lighter and more efficient aircrafts!