voyagerB Posted October 7, 2017 Author Posted October 7, 2017 I think a lot of pro electric aircraft people just don't understand chemistry. If batteries were better than pistons/turbines we'd have seen combustion engines scrapped a long time ago. Don't believe any of the hype about batteries becoming more efficient, they increase in energy density about 1%/yr. So at that rate we could see batteries become competitive with fossil fuels around 2090, unless someone invents a more efficient battery. I tend to agree with you. The most astonishing example of winning over investors with a flawed idea (according to experts) is Lilium that received a $90 million infuse recently. See my earlier posting. Quote
voyagerB Posted December 30, 2017 Author Posted December 30, 2017 Curious what the solid state battery technology might bring in 3-4 years...https://cleantechnica.com/2017/10/31/toyota-exec-solid-state-battery-tech-game-changer-evs-arent-backing-away-hydrogen-fuel-cell-vehicles/ Quote
chris pochari Posted December 31, 2017 Posted December 31, 2017 I'm paying close attention to the development of solid state, quite amazing that the inventor is 94 years old! Quote
Boatpix Posted January 11, 2018 Posted January 11, 2018 Will eVTOL take over the commercial small-helicopter market? I think there is room for both just like for dinner you might have chicken, fish or meat. Or tofu, lol. There is a seat for every stool and eVTOL or Tesla aren't going to take over the market just good conversation. I watched the Surefly get light on it's skids in a test flight the other day in Nevada. I've sat in the Swiss/German drone that flew last year. These won't take over the duty your helicopter was designed for but if the Marines have a drone Huey and just need to ship a small part over the ridge why not send this drone type thing to battle? 1 Quote
voyagerB Posted January 14, 2018 Author Posted January 14, 2018 Will eVTOL take over the commercial small-helicopter market? I think there is room for both just like for dinner you might have chicken, fish or meat. Or tofu, lol. There is a seat for every stool and eVTOL or Tesla aren't going to take over the market just good conversation. I watched the Surefly get light on it's skids in a test flight the other day in Nevada. I've sat in the Swiss/German drone that flew last year. These won't take over the duty your helicopter was designed for but if the Marines have a drone Huey and just need to ship a small part over the ridge why not send this drone type thing to battle? Everything with eVTOLs stands or falls with the battery technology. If it's substantially better than today in let's say 3-4 years, I see eVTOLs take off so to speak big time. For now, range shortage can be compensated for by using hybrid drive, so, have a potent ICE onboard that can either provide necessary boost during takeoff, extend range and/or help to recharge the batteries. There might even be a way to combine a lightweight electric car and an eVTOL. 1 Quote
mechanic Posted January 17, 2018 Posted January 17, 2018 https://www.youtube.com/watch?v=_tFG-uk3WcE 7 versions being tested. I like number 7. https://www.youtube.com/watch?v=ZI5rH8bS5cE https://www.youtube.com/watch?v=SyRpZILjT2w 2 Quote
chris pochari Posted February 15, 2018 Posted February 15, 2018 another issue is engine failure, helicopters can autorotate, quadcopters cannot autorotate, if one engine fails, it will fall out of the sky. They would need to be equipped with a parachutes Cirrus style, otherwise it would be too risky. Even considering that electric engines are far more reliable, something can always go wrong. Quote
voyagerB Posted March 15, 2018 Author Posted March 15, 2018 another issue is engine failure, helicopters can autorotate, quadcopters cannot autorotate, if one engine fails, it will fall out of the sky. They would need to be equipped with a parachutes Cirrus style, otherwise it would be too risky. Even considering that electric engines are far more reliable, something can always go wrong. It's why some seek a combination of rotorcraft and small aircraft. Throw the car into the equation, and you get something like this: 1 Quote
chris pochari Posted March 15, 2018 Posted March 15, 2018 It's why some seek a combination of rotorcraft and small aircraft. Throw the car into the equation, and you get something like this: The helicopter industry is divided on the future of EVTOL 2018-industry-split-on-air-taxi-power my stance is similar to the opinion that Sikorsky has, autonomous but conventional rotorcraft are the most promising. Since 80% of helicopter accidents are caused by operation, the accident rate could possibly be reduced by at least 80%. EVTOL will probably find a niche, like short distance building-building shuttle. Conventional rotorcraft aren't going away anytime soon, but pilots, like truck drivers and real estate agents, are going way eventually. due to peak oil demand and EVs the future the price of oil could be a lot lower than it currently is, although not good for offshore it could make helicopters more attractive for commuting, charter and other non utility uses. But at their current accident rate helicopters remain unappealing. Advances in new materials could result in longer component and engine lifetimes, for example the TBO of the Arriel series has almost doubled in 40 years. And finally Autonomous technology will also reduce the accident rate. All these trends combined could make conventional rotorcraft very attractive in the future, contrary to the current gloom and doom about the future of the helicopter industry. If the cost of operation for most helicopters could be reduce in half and the accident rate could be lowered by 80%, the industry would boom. 1 Quote
overtorque Posted March 15, 2018 Posted March 15, 2018 Man if there was only some way to store a lot of energy in a dense and portable way, preferably a liquid form. Now that's future talk! In my opinion energy storage is a problem we have solved a long time ago. I think it would be much more beneficial to everyone to figure out how convert heat energy into mechanical motion very efficiently. An enormous amount of heat is lost from a running engine, it's a damn shame! 1 Quote
voyagerB Posted March 16, 2018 Author Posted March 16, 2018 https://www.cnbc.com/2018/03/13/kitty-hawk-cora-larry-page-backed-firm-unveils-autonomous-flying-taxi.html 1 Quote
TomPPL Posted March 16, 2018 Posted March 16, 2018 https://www.cnbc.com/2018/03/13/kitty-hawk-cora-larry-page-backed-firm-unveils-autonomous-flying-taxi.html I reckon this one is about the most sensible so far.... It'd still need ballistic chutes though which would add to the weight. Quote
LJS1993 Posted March 16, 2018 Posted March 16, 2018 You know guys not to get too off topic but how about un-manned commercial flights? Personally at this time there is no way I would take a 747 without an actual breathing pilot at the helm but some say it's coming in the near future. What are your thoughts on that? Yes aircraft of that size and complexity are highly automated to a certain point but they still have to be managed, taken off, and landed. 1 Quote
Eric Hunt Posted March 17, 2018 Posted March 17, 2018 What are your thoughts on that? I don't think about that, just a waste of neurons. Ain't gonna happen in our lifetimes, despite the number of pretty computer graphics around the place. Quote
Eric Hunt Posted March 19, 2018 Posted March 19, 2018 Interesting that today, Uber cancelled their driverless car project after one of their cars killed a lady. I reckon this will help to kill pilot-less passenger ops too. Quote
voyagerB Posted March 21, 2018 Author Posted March 21, 2018 Interesting that today, Uber cancelled their driverless car project after one of their cars killed a lady. I reckon this will help to kill pilot-less passenger ops too.No, it won't.Besides the 'fact' that most experts think it will be easier to implement '3D auto-piloting' than '2D AP'. 2 Quote
voyagerB Posted March 21, 2018 Author Posted March 21, 2018 The helicopter industry is divided on the future of EVTOL 2018-industry-split-on-air-taxi-power my stance is similar to the opinion that Sikorsky has, autonomous but conventional rotorcraft are the most promising. Since 80% of helicopter accidents are caused by operation, the accident rate could possibly be reduced by at least 80%. EVTOL will probably find a niche, like short distance building-building shuttle. I've been to that particular conference, what a coincidence. Here is an overview of all known eVTOL projects, the U.S. proudly leading. 2 Quote
voyagerB Posted May 9, 2018 Author Posted May 9, 2018 Latest version of what UBER and NASA are working on: Quote
nycflyer17 Posted May 9, 2018 Posted May 9, 2018 Hi voyagerB, thanks for posting about this, I was actually about to make a very similar post as my first post on this forum (I've been a lurker for years). As a 20-something year old very close to my PPL, and highly considering a career change, this is something I'm very concerned about. As expected, there are a lot of people instantly being dismissive. But I think it's foolish to instantly dismiss eVTOLs having a significant impact on the market. Uber is working with the right people regulation wise as well - they had the acting administrator of the FAA at their Uber Elevate summit yesterday! And he sounded quite supportive. As well as partnerships with Bell, Army research lab, and other manufacturers. Clearly, these guys know more about the feasibility of making this happen than we do. I'm fairly confident that in the next 5-10 years, we will see their vision start to take off. The question for someone young looking to enter this career like me though is - how soon until eVTOL and autonomous aircraft starts having a big impact on the employee-ability of helicopter pilots? What happens if there's suddenly a huge oil crisis? I'm nervous about these things. I think it may happen sooner than most people think. The pace of technology is moving MUCH faster than it was twenty plus years ago. 2 Quote
r22butters Posted May 9, 2018 Posted May 9, 2018 Latest version of what UBER and NASA are working on: Uber and NASA, why am I not surprised? We've been ridesharing to space for years now. ,...damn the future sucks 1 Quote
Wally Posted May 9, 2018 Posted May 9, 2018 (edited) I'm puzzled as to why all these futuristic air frames have multiple 'props' instead of rotors? It can't be efficiency or that configuration would be flying now- lots of early vertical flight tried multiple props. Is it to ease transition to higher speed flight? The S97 scoots right along, Bell held the rotorcraft speed record for years with the 533 (an early, highly modified production UH1 with jet engines providing thrust), and the Fairey Rotodyne was pretty quick. Does the layout seem familiar, scalable because of drone popularity? Apples and oranges, I think. Drones fly pilotless or remotely controlled enabled by systems that allow stability and navigation with minimal training. Those systems would work with conventional rotors as well, yes? Even in a compound helicopter/rotodyne, I think. Efficiency will be at least as important in a battery powered aircraft, if not more so. Final thought- the popularity of these will require sophisticated air traffic control interfaces. Urban skies get pretty crowded now with conventional aircraft. That straight-line high speed flying taxi thing has a lot of hurdles. Edited May 9, 2018 by Wally 3 Quote
Eric Hunt Posted May 9, 2018 Posted May 9, 2018 Wow, that latest pic has some serious design things to sort out - how to slow and stop the rotors at 120-150 kt (when the wings can support the flight) and then make the mast retract into the pod, and then bring them out again and start up at the same speeds to enable the landing. And this is times four - a little fault with one pod coming back out for the landing, and the machine will have to land with speed, at a runway. But the people playing with the graphics to draw these things are getting paid, so there is some money in this game. 1 Quote
voyagerB Posted May 10, 2018 Author Posted May 10, 2018 I assume they opted for FPPs for the sheer simplicity, low maintenance and low costs of them. Notice that the model (probably) features co-rotating blades (rather than contra-rotating). NASA found out that stacked coaxial co-rotators have a better efficiency contrary to what had been assumed until recently. Less noise too (which is a form of waste). Quote
chris pochari Posted May 11, 2018 Posted May 11, 2018 Another challenge the EVTOL community faces is payload. Most scaled up quads Surfly, Ehang ect can only carry 1.3-1.4x their empty weight, compared to some turbine rotorcraft that can carry 2x empty weight. Quote
voyagerB Posted May 11, 2018 Author Posted May 11, 2018 I'm puzzled as to why all these futuristic air frames have multiple 'props' instead of rotors? It can't be efficiency or that configuration would be flying now- lots of early vertical flight tried multiple props. Is it to ease transition to higher speed flight? The S97 scoots right along, Bell held the rotorcraft speed record for years with the 533 (an early, highly modified production UH1 with jet engines providing thrust), and the Fairey Rotodyne was pretty quick. Does the layout seem familiar, scalable because of drone popularity? Apples and oranges, I think. Drones fly pilotless or remotely controlled enabled by systems that allow stability and navigation with minimal training. Those systems would work with conventional rotors as well, yes? Even in a compound helicopter/rotodyne, I think. Efficiency will be at least as important in a battery powered aircraft, if not more so. Final thought- the popularity of these will require sophisticated air traffic control interfaces. Urban skies get pretty crowded now with conventional aircraft. That straight-line high speed flying taxi thing has a lot of hurdles. Have answered your first question, I guess. Means that the FPPs rotate at a (reasonably constant) speed which is energy-efficient. One can imagine that the push prop will have variable blade settings. Low level ATC through V2V connectivity and GPS. Auto-piloting comes next. Vehicle autonomy is considered easier to implement in the 3D compared to the more complex '2D pane'. Energy efficiency is everything, particularly for battery power. The hope/expectations is for Next-Gen batteries with a much higher energy density. Notice the big pods. A high portion of the eVTOL's own weight will consist of batteries. More info:http://aviationweek.com/future-aerospace/uber-advances-evtol-design-common-reference-concepts 1 Quote
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