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All-electric Cessna Grand Caravan makes maiden flight
- flyGuyOnTheSly 6y agoAmazing that the only thing you hear is the wind rustling by. Silent planes would be welcomed by many people living in densely populated cities with high air traffic. They're almost giving away apartments near Pearson Airport in Toronto, for example. The price per square foot in that area is ~10x lower than the rest of the city and for good reason. (You are constantly bombarded by the sound of jet engines passing by).
- dmitrygr 6y agoI love the sound of airplanes and all things airplane related. I think you may have just given me a great tip as to where to buy real estate. Thanks!
- deleted 6y ago[deleted]
- perl4ever 6y agoFor all that you read about people complaining about airplane noise, I grew up only a mile or two from an airport and never thought about it nor do I remember anyone else complaining. But one of my recurring dreams/nightmares for most of my life is of watching a plane overhead and realizing at first something is wrong and then that it's going to crash in the back yard.
- jeffbee 6y agoConsidering the rate at which the general aviation fleet turns over (~none in ~forever), and that the typical Cessna is flying around with a World War 2 engine or its closely related descendant, I predict that it will be roughly infinity years before people who live at the ends of airports stop cursing the noises. Of course, if they just outlaw 100LL avgas and pass some noise regulations the problem will solve itself.
- perl4ever 6y agoI was never clear on why leaded avgas wasn't banned long ago. I know I've run across information on the internet about aircraft engines that can run on unleaded.
- NikolaeVarius 6y agoThey're working on it. Can't ban it since many airplanes still require it.
- amluto 6y agoI’m not entirely sure I buy this argument. Ban it effective on a fixed date in a few years and introduce a favorable regulatory regime to help with replacements. If some planes won’t be able to fly, so be it. Alternatively, introduce a Pigouvian tax: charge an obscene and increasing amount to burn leaded fuel. This is kind of like the regulations that permit grossly polluting old collectible cars to operate. Sure, they have history, but that’s not a sufficient excuse to allow them to operate unmodified near other people.
- dpe82 6y agoMost piston engine aircraft in the country require, by regulation, 100LL. Oil companies and the FAA have been working for years to develop a replacement and came very close a couple years ago, but since the FAA strongly favors safety and reliability over almost any other consideration it takes a very long time to collect enough data to have confidence a potential replacement is truly equivalent. We have ~80 years of safety data for 100LL. Generally speaking, airports are reluctant to spend money on a second set of tanks, pumps, etc. required during a transition period; though some have - particularly in the midwest where there are a lot of less regulated homebuilt aircraft that can burn alternative fuels. A lot of pilots would love to burn something else. 100LL is relatively nasty and builds up in engines, shortening their life. It's even actively discouraged to burn 100LL in some more modern small aircraft engines like the Rotax 912 and pilots like myself who run that engine look for non-leaded fuel whenever practical because it's healthier for the engine. But well maintained aircraft last just about forever and the legacy fleet is absolutely enormous.
- sokoloff 6y agoProps still make significant noise, especially at takeoff RPM. A friend of mine owned a house under the approach path to a medium-volume reliever airport (KBED). All of the piston airplanes that flew overhead were perfectly pleasant (at least to me), but the jets were notably more annoying. Carrying more power/noise, more speed, and more disturbance to stay flying while dirtied up, the difference was night and day. I suspect the PT-6 powered C208 would already fall on the “not so annoying” side of that spectrum (closer to the piston props than the turbojets’ noise profile), so changing fuel might not provide that much relief to those who bought houses near airports.
- inamberclad 6y agoI have a theory that we'll be able to reduce the RPM and increase the torque of these engines, versus conventional gas turbines and piston engines, thereby reducing the tip speed of the blades
- sokoloff 6y agoMaybe. The PT6A already has a gearbox, so the engineers are presumably able to choose a reduction ratio and prop RPM quite independently of the gas and power generator rotational speeds. (There are still torque limits in the gearbox output, though it seems the same constraints would face an electric motor.)
- dpe82 6y agoIn most planes, pilots are already able to chose their propeller RPM somewhat independently of torque by varying the pitch of the propeller. However, pilots typically optimize for rate of climb and not noise in order to get out of the low altitude / low airspeed danger zone as quickly as possible.
- sokoloff 6y agoYes. What GP is talking about though is changing the range of speeds available for pilot selection by changing the prop length, airfoil, maybe number of blades, and other design parameters. IOW, the design elements, not so much the operational element. Similar to how the C421 cruises at 1800-1900 prop RPM to give a(n eerily) quieter cabin.
- AdrianB1 6y agoNot true; the only aircraft that does what you describe is a glider. Any propeller will generate a lot of noise, the tips of the blades get close to the sound barrier. Disclaimer: pilot here, I did fly gliders and I fly propeller planes regularly.
- m4rtink 6y agoWell, even in a glider all the air moving by does quite some hissing, so its not completely silent (judging from the two flights I took as a passenger in a Blanik and Super Blanik respectively). Still much quieter than a small prop aircraft & you can talk with the pilot just fine. On the other hand from the ground - yeah, a glider is pretty much silent. You might sometimes hear some rather earie whistling from some types when they are directly above, but thats it.
- AdrianB1 6y agoHe said the wind is the only thing you hear. Yes, in a glider you hear the air moving, but adding a propeller adds a huge amount of noise over that base sound.
- WalterBright 6y agoThat price differential can make a lot of soundproofing worthwhile.
- sokoloff 6y agoI’m skeptical about the $6 of electricity for the 30-minute flight, or at least want to see the assumptions there. Even at super cheap $0.06/kWh rates, and 100% plug-to-motor efficiency, that’s only 100kWh. For a rated power of 560kW, that suggests an average power setting of around 35%.
- latchkey 6y ago$0.06 isn't super cheap for commercial electric rates, even in the US... for that, you're looking around $0.01-$0.03.
- goodcanadian 6y ago. . . average power setting of around 35% That actually sounds about right. You only need full power for take-off. EDIT: Thanks for the corrections.
- dmitrygr 6y agonot even close. Piston planes cruise at about 75% rated power (engine manufacturers do not suggest running engines beyond that for extended periods of time). Jets closer to 90
- sokoloff 6y agoJets typically can’t make 90% power in cruise and are often flying at 50% or lower fuel flows than takeoff. (You might be setting almost 100% N1 speed as your power setting, but that’s not the same as setting 100% actual power in a jet in high-altitude cruise.) Fuel flow is a good proxy for power. From the Citation II flight manual: max cruise thrust settings (104% N1 over 25K feet) have a peak fuel flow of 1716 lb/hr at 15K feet vs 1083 lb/hr at 35K vs 721 lb/hr at 43K ft. Sea-level takeoff fuel flows are not given in the manual, but are around 2000 lb/hr, so typical low 30s cruise flight is 55-65% power.
- SomeHacker44 6y agoAs a pilot, I fly full power at takeoff, of course. In my usual piston plane, I fly at 75% power until it cannot maintain that power (due to normal aspiration and no boost from, eg, a turbocharger), and then "flat out" beyond that. I do not think I have ever flown at 35% power except in the short time between final and touchdown.
- war1025 6y agoFirst thought seeing this was of the Dodge Grand Caravan minivan we had growing up. It's interesting how often names get reused.
- yellowapple 6y agoFunny enough, there are all-electric versions of those, too: http://www.evalbum.com/2403 http://www.evalbum.com/2403
- Havoc 6y agoAs a workload it sorta makes senses. You want raw output for take-off and then steady efficient power for cruise. Both of which electric motors can do. ...just a question of battery weight, which is dropping
- deleted 6y ago[deleted]
- AdrianB1 6y agoPiston engines can also do. You want max output for take-off, but to maintain the cruise speed you need around 75% of the engine output and you fly at "steady efficient power" (75%) for cruise; there is no difference here. It's not like cars where you brake and accelerate many times.
- lallysingh 6y agoI'm not sure people will be as ready to go back into 200+ passenger aircraft as before. Small party flights could become more popular as the range goes up.
- ahelwer 6y agoThere's a very long way to go before safety is comparable. Last time I looked into it, you have better odds skydiving from a small plane than landing in it.
- AdrianB1 6y agoNot at all, skydiving from a plane without a parachute is almost always deadly (very few exceptions) while landing with an engine failure is something every student practice in the flight school (at least in my country). The smaller the plane, the easier to land it with an engine failure, the smaller the plan the fewer pieces that can break. yes, the average General Aviation pilot is quite bad, that explains the huge accident rate compared to airliners, but the reliability of the planes is not bad at all.
- m4rtink 6y agoThat's why I like gliders - one less component to fail (the engine) and every landing is an engine out landing, with the plane built and pilot trained to do that. :)
- AdrianB1 6y agoAll pilots are trained to land with the engine out. Some are better and most are not, that's not the plane's fault. Yes, glider pilots are the best at this :)
- alfalfasprout 6y agoMost small aircraft accidents are completely preventable loss of control (either by taking off with too much weight, stalling during takeoff, or stalling during landing) or flying into IMC (instrument metereological conditions including clouds, fog, etc.) and becoming disoriented and losing control. Simple engine failure is something that every private pilot trains for. Improvements in training can significantly help with both. Instrument training in particular drastically reduces the risks of inadvertent IMC. Some technology also assists with the latter (eg; synthetic vision on foreflight on aircraft with garmin G1000 cockpits gives you references for how the plane is positioned and any terrain around you you could hit).
- danielfoster 6y agoThis is amazing for rural communities and student pilots. And if it became safely possible to run the plane with just one pilot onboard for commercial service, this lower cost plane would have even more potential. Up to 40 minutes for charging could be an issue for airlines who want to turn planes around quickly, though I doubt Cessna operators are striving for Ryanair economics yet.
- Gibbon1 6y agoI think if you were able to get the range up to 250-300 miles that would be a very big deal for far flung communities. All of those are underserved by air transport. Offhand thought is you probably could justify small pilotless freight aircraft.
- AdrianB1 6y agoThe number of pilots has no correlation with the electric propulsion. For student pilots it is not amazing, in the flight school you need to do a raid (this is how it is called on this side of the ocean) flying between 3 cities and 500 miles minimum; you cannot do it with the electric plane and as a student you are not good enough to fly a different plane model (with ICE power plant) just for the raid, so you cannot complete the school.
- inamberclad 6y agoYou'll still be able to do most of your pattern work and general handling training in vastly cheaper electric aircraft.
- AdrianB1 6y agoThen what do you do, transition on a different plane during school? At that point you will need a full 45 hours or more on the second plane, negating the cheaper first plane.
- inamberclad 6y ago
- chrisseaton 6y agoWow that's a strange choice for a name. Can't think of anything I'd less like to fly in than a caravan. Makes me think of boring trips and cheap flimsy tacky boxes liable to be blown away by the wind.
- anamexis 6y agoIf it's any consolation, the Cessna Caravan predates the Dodge Caravan by 3 years.
- chrisseaton 6y agoI don't know what a Dodge Caravan is specifically. This is what 'caravan' makes me think of though - https://www.practicalcaravan.com/wp-content/uploads/2018/02/6725064-scaled.jpg https://www.practicalcaravan.com/wp-content/uploads/2018/02/... - not what you'd want to fly in!
- mr_spothawk 6y agothis is what i was thinking https://duckduckgo.com/?q=caravan+waggon&t=brave&iar=images&iax=images&ia=images https://duckduckgo.com/?q=caravan+waggon&t=brave&iar=images&...
- the8472 6y agoWhy is everyone thinking of cars? There is a far more picturesque and older meaning of the word. http://remarkablejourneys.com/wp-content/uploads/2015/09/Day-5_Sahara-Desert-Morocco-Camel-Caravan-1.jpg http://remarkablejourneys.com/wp-content/uploads/2015/09/Day...
- userbinator 6y agoBecause of this: https://en.wikipedia.org/wiki/Dodge_Caravan https://en.wikipedia.org/wiki/Dodge_Caravan They were immensely popular throughout the 90s and early 2000s.
- mceachen 6y agoFrom the article: "charging times correlate closely to flight times, says Ganzarski. That means the batteries would need about 30-40min of charging following a 30min flight. The weight of the batteries makes swapping spent cells for fresh cells unfeasible between flights, he says." Does utilization for these short-hop routes correlate to this sort of down time?
- eigenvector 6y agoIt becomes more and more feasible the shorter the flight is, since the 'turnaround' time on the ground starts to become longer than the actual flight time. That's why Harbour Air, which operates ~20 minute seaplane flights from Vancouver, will probably one of the first airlines to operate electric aircraft in commercial service. https://www.harbourair.com/about/corporate-responsibility/goingelectric/ https://www.harbourair.com/about/corporate-responsibility/go...
- ShakataGaNai 6y agoIt's probably longer than required for passenger flights. The Caravan is 9-13 passengers (depending), plus a little baggage. Wouldn't be hard to unload/load 10 people in less than 30 mn. However the question is how many small commuter airlines are operating a flight with repeated as-fast-as-possible turn around? Cargo configuration, certainly seems like you could charge it faster than a load/unload. The thing about fast turn around's is that planes only make money when flying. However a big part of flying is the expense of fuel. So if you can make your hour flight in $12 of electricity, that brings the cost way down. That offsets the cost of sitting on the ground for an extra X minutes. Also gotta take into account the electric versions reduced need and cost of maintenance. So there is reduced aircraft downtime for less maintenance, and it costs less each time. Overall, that probably greatly increases the time available to fly and therefor the profit potential for the plane.
- dzhiurgis 6y ago> Wouldn't be hard to unload/load 10 people in less than 30 mn. Ryanair is probably best at it, executing within time above but in a 737. You can hate Ryanair for some things, but I admire for how affordable they make flying.
- jedberg 6y agoDarnit. I saw Grand Caravan and thought it was an all-electric minivan. I've been waiting years for an electric minivan. The moment someone comes out with one, I'm turning in my current minivan, which I love, for an all electric van.
- Tade0 6y agoToyota, out of all companies, is planning on releasing an electric Proace: https://www.autoevolution.com/news/new-toyota-proace-ev-scheduled-for-2020-135894.html https://www.autoevolution.com/news/new-toyota-proace-ev-sche... Not exactly a minivan and probably won't reach the US, but it's a start.
- jedberg 6y agoAt least they’ll prove it makes sense! Maybe it will motivate Honda to do an electric Odyssey.
- thepangolino 6y agoThose kind of vehicles are fairly popular in Europe.
- legitster 6y agoSame. The Model X gets pretty close, but is way too gimmicky with it's touchscreen everything and cutesy doors. A modern minivan is already the most sophisticated vehicle on the road. I just want one in electric.
- jedberg 6y agoThe Model X sadly does not have nearly the versatility of my Honda Odyssey. And it costs an extra $100K. :)
- ashtonkem 6y agoThe model X is more expensive, but it’s not $100K more than a new Honda Odyssey. Heck, it’s not $100K more than your current Odssey! The X starts at $80k, while the Oddysey costs somewhere between $30k and $45k. It’s only the top of the line performance trim that costs $100K.
- arecurrence 6y agoOnly 6 months after the first commercial airplane electric flight. https://www.harbourair.com/harbour-air-and-magnix-announce-successful-flight-of-worlds-first-commercial-electric-airplane/ https://www.harbourair.com/harbour-air-and-magnix-announce-s...
- brent_noorda 6y agoEven as I bet against electric flight being commercially feasible except in extremely limited conditions, I'm excited by any news that I might possibly be worng.
- lstodd 6y agoa range of 100 miles with 4-5 passengers where the kerosene-powered variant has about a thousand miles with ~7 passengers
- briandear 6y agoYou can carry 14 people in a typical Caravan EX.
- ggm 6y agoHow much further could an ePlane fly if it was possible to discard spent batteries? (Serious question)
- josephcsible 6y agoIn your hypothetical scenario, do you care whether the batteries are recoverable and reusable? If not, then you lose a lot of the benefit of electrification.
- crazygringo 6y agoImagine if there were large fields (or lakes) every few hundred miles designated as drop zones where huge battery packs would be parachuted down into and recovered every couple weeks, from cross-country commercial flights. I'm sure there are a million problems with it, but you never know.
- catalogia 6y agoThis is an interesting idea, but it would be most efficient if the battery drops were frequent. Maybe every few miles instead of every few hundred. Of course the more modular you make the battery, the more overhead you have in chutes, battery housings, etc.
- squarefoot 6y agoOr flying "recharge" stations where appropriately sized drones carrying a new set of batteries (not necessarily all of them) would dock with the aircraft, push the new batteries into a receptacle while taking the old ones on board, then separate from the plane and land to the closest ground station for recharging until next plane to service.
- ggm 6y agoI did think about going to the kind of electrochemical reactions which might provide power to a motor. I believe the flow batteries are low power density binary fluid systems so not very flight suitable. So then I went to ascent phase. Detachable battery with glide home. Keep smaller battery for controlled descent phase.
- purplezooey 6y ago...receives power from a 750V lithium-ion battery system weighing roughly one tonne... It's like a giant flying battery with a few seats.
- alfalfasprout 6y agoUnfortunately the real limitation here is still weight. You can get excellent torque and incredible reliability from electric motors vs. gas powered engines but the biggest difference is that as you fly longer the plane gets lighter with a gas powered plane. With an electric plane you're always at full weight and that limits your flexibility. Worse, batteries are still very, very heavy compared to the energy they store. I suspect that as battery technology improves we'll see a drastic shift toward electric planes being more appealing. For GA aircraft they'd be amazing. Excellent power, significantly higher reliability, much lower maintenance costs, and much lower cabin noise. But at the weights listed, I can't imagine a Cessna 182 going electric anytime soon.
- the-dude 6y agoDoesn't a full battery carry more electrons and is therefore heavier?
- jbotz 6y agoNo. Aside from the fact that the weight of the electrons, although not zero, is negligible, they also don't get "lost" in the process... they just get moved around, in the case of battery power literally from one end of the batery to the other. Combustible fuel in contrast, gets turned into gases (CO2 and H2O) which are blown out the exhaust and thus lost.
- arcticbull 6y agoYes. A small amount. A 100kWh Tesla battery has 3.6e+8 Joules of energy. E = mc^2 tells us that the mass of the stored energy is 4e-9 grams, so 4 nanograms.
- Dylan16807 6y agoNo. The number of electrons does not change. Instead, the different configuration causes a slight fluctuation in the mass of the atoms.
- umvi 6y agoIs it any quieter than gas engines? Last time I flew in a Cessna, the propeller was bone-jarringly loud.
- supernova87a 6y agoIf this really represents (in general) the weight and efficiency you're going to get, then electric planes of this size will have to remain a specialized niche for only certain kinds of rare flights. At 100 miles max range, the people would be better off driving, unless you're talking about mountainous or water-crossing flights where there is no alternative. (plus think about the added overhead of getting to/from airports, etc) You have to wonder why they chose a 208B -- when you would generally try for the smallest and lightest plane to start with. Answer: because they can't fit enough batteries in a smaller Cessna to get it to perform on a reasonable flight. The ideas elsewhere in the thread about having electric planes lower the cost of training flights, etc. won't work if you need a bus sized plane to hold the batteries. The plane has to be half empty, and even then can only eke out 100 miles. That's like a half hour of flight. A $2-3M plane can only handle a 1 hour ~50% duty cycle, max? That's not gonna...fly. I'm not intending to sound discouraging, and it's an interesting demonstration, but fundamental energy density of battery chemistry is a bitch. Edit: why, for the love of god, would they include that ear-destroying audio with the showcase video clip?
- arcticbull 6y agoIMO this comment is pretty short-sighted. Gravimetric energy density of batteries tripled between 2010 and 2020 and in the same time period cost went down 87% [1]. By 2030, this plane could easily have a range of 300mi. [1] https://cleantechnica.com/2020/02/19/bloombergnef-lithium-ion-battery-cell-densities-have-almost-tripled-since-2010/ https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...
- jcampbell1 6y agoThere is a physics problem with carrying both fuel and oxidizer and not dumping spent fuel into the atmosphere. I suppose one could use lithium air batteries and then land heavier than takeoff. The reason petroleum fuel works so well is because you scavenge 2/3 of the fuel from the air.
- CrazyStat 6y ago
- siliconunit 6y agoNow a compact fast-neutron lead cooled reactor would come in handy... development has been done..like the Convair NB 36H, but with 1950 tech..I wonder with modern specs and upgraded safety protocols..
- yellowapple 6y agoThe Convair NB 36H wasn't actually powered by the reactor, though; its sole job was to validate that it was possible to shield the crew from the reactor's radiation (which it did). However, there were certainly successful tests of actual nuclear-powered jet engines, like General Electric's X39 (a modified J47, and slated to be slapped onto that NB 36H to make a Convair X-6) and J87 (a different design for a different nuclear-powered bomber project, the WS-125). A key issue is the shielding necessary to keep such an aircraft from irradiating everything around it (you think neighborhoods bitching about nearby airports are ornery now...); that shielding is heavy. Accidents also make such craft much riskier, which is indeed a cited reason (other than costs) why the USA and USSR both cancelled their nuclear-powered bomber programs.
- ggm 6y ago"The weight of the batteries makes swapping infeasible" comment makes absolutely no sense. Make them modular, In sub units which can be handled, mount them at the right points for C.G and design an airframe to permit module swapping with suitable equipment.
- swagasaurus-rex 6y agoIs there any room in the imagination for swapping these batteries mid flight? I'd imagine it makes even less sense than mid-air jet-refueling.
- rosywoozlechan 6y agoI imagine it would be mid-air recharging instead.
- ShorsHammer 6y agoTracking with lasers should be manageable for low level flight. https://en.wikipedia.org/wiki/Wireless_power_transfer#Lasers https://en.wikipedia.org/wiki/Wireless_power_transfer#Lasers
- PaulDavisThe1st 6y agoThis, by the way, has to be the future of electric ground vehicles too. A standardized external battery format, automated/mechanical battery replacement. In theory "filling up" vehicles like could be quicker than refilling a fuel tank with gasoline or diesel. And to ensure that I get marked down, I'll add that I'm fairly certain that only government(s) can make this happen (enforced standardization of the form factor across the industry).
- ggm 6y agoFlying is a fully regulated industry worldwide. Modular industry standard swappable batteries are achingly simple but so is regulated seat pitch and look how likely that is. Food cards? They did that. Intermodal containers? They did that.
- clueless123 6y agoFantastic Skydiving vehicle.. If you can get 9 people (+ gear) 12'000ft on a 30 minutes flight, then you can glide all the way down for the next load. at $6 worth of fuel it would be a game changer.
- MobileVet 6y agoSeriously, $6 for 30 min at ~100mph is pretty amazing. There are lots of cars that are less fuel efficient.
- bobly_today 6y agoHow much would that cost with conventional fuel?
- TylerE 6y agoA lot. Perhaps 75 gallons/hr. Jet fuel is currently a about $1/gallon. Even a much smaller plane like a 172 can easily burn $50/hr just in fuel. Much lower flow rate, but it’s leaded a gas at about $4.50/gal
- PunksATawnyFill 6y agoWay more than that these days. There’s only one supplier of 100LL, and even they don’t want to be in the business anymore.
- ReticentVole 6y agoIts not just the fuel cost, maintenance of electric motors is substantially cheaper. Plus, there's no need to transport and store specialty Avgas.
- deleted 6y ago[deleted]
- rmk 6y agoA lot of the expenses in flying arise out of regulatory requirements. Want to carry passengers? Pilot needs a license that take several hundred hours minimum to obtain. Want to use a part in an airplane? Getting it through the FAA certificating process will inflate its cost by several multiples. Want to operate an aircraft? You need to get it inspected every $fixnum number of hours of operation by a mechanic who in turn has to do everything the 'certified' way and is himself certified by the FAA. It's these costs, not fuel costs, that account for a big percentage of the cost of flying. There's no meaningful way to reduce the cost of flying without reducing them. Perhaps electrics will incur much lower costs in maintenance, reducing costs somehow.
- raverbashing 6y agoVery impressive The Grand Caravan is one step up your average "learner aircraft" and IIRC it's a turboprop (not a piston engine as most basic aircraft) > As configured, the Magni500-powered Grand Caravan can carry 4-5 passengers on flights up to 100 miles, taking into account the need for reserve power, says Ganzarski. Not bad, not bad at all
- GordonS 6y agoI know next to nothing about aviation, but I wonder if a "hybrid" would make any sense for planes, or if you'd end up with the worst of both worlds?
- todd8 6y agoWow, 2000 pounds of battery. About twice the weight of a Tesla battery. This suggests that a it could take perhaps an hour to recharge the battery for each 30 minute flight. This is just a guess extrapolating from the non-technical article.