If that’s a real issue, then the obvious solution is quick-change batteries. The fact that nobody’s suggesting that indicates that the issue isn’t substantial.
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Nobody really has designed a quick change system yet for the batteries that is 1) ergonomic (ie easy to use & replace 2) Economic (ie enough energy to use effectively 3) the actual support systems to install and uninstall the batteries. Most battery systems are built in such a way they maximise battery capacity and aren’t generally designed for easy install & uninstalls as that normally compromises capacity.
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or they understand the difficulties of getting FAA/CASA approval of the electric airplane, the battery system (active and standby-replacement, and the housing-connection mechanisms and decided the economics vs technology do not yet meet the pub test to try.
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It is a shame it hasn’t occurred as it would remove one of the major achilles heal of a EV battery systems…charging times especially for long distance and frequently used vehicles.
I recall when EVs first hit the market, there were promising discussion about universal, exchangeable battery systems. The skeptic in me thinks that maybe as EV cars possibly have less spare parts which need replacing regularly from wear and tear/normal vehicle use, the manufacturers see battery replacement as a way to fill the spare parts voids EVs create (needing replacing every ~10+ years)…thus all have pursued EVs with built in batteries of different design, voltages, capacity and outputs to maintain existing spare part revenues.
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Which is my point. The issue, if there is an issue, isn’t worth addressing. Economies inherent in electric drive (energy, maintenance, etc.) more than offset costs associated with charging times.
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Or the effective capacity and weight of the battery system remains the most significant challenge, to delivering range and performance equal to a petrol engined aircraft.
Practical battery electric replacements for everyday light aircraft are still waiting for a high energy density light weight battery. Based on the DHC-2 payload and range a compact high energy density cell that delivers better than 1kWh per kg would be required. That is a big step change compared to the best Lithium Iron cells 250W per kg or typical BEV battery packs around the 150W per kg.
Some Simple Maths, assuming current best tech.
The standard DHC-2 Beaver weighs 1,361kg empty.
The maximum added payload weight is 953kg.
Power is by a 336kW radial petrol engine.
A substitute electric power plant is likely to save some weight. Specs say 296kg dry weight for the petrol radial Wasp Junior. The replacement electric motor
and controller may be as little as 100kg. I’m being lazy here on not finding the exact data.
A 500kg (125kWh est*) battery pack would leave a payload of approx 653kg. Or approx 20 mins flight time at full power zero reserve.
A 750kg (187kWh est*) battery pack would leave a payload of approx 400kg. (Pilot + 3 pass and light luggage) Or approx 30 mins flight time at full power zero reserve.
For comparison the standard DHC-2 has a range of more than 700km and endurance at cruising speed of more than 3 hours.
The engine maintenance savings, the simplicity of the battery energy system and the low fuel cost are all a plus.
What restrictions flight approval might place on an aircraft with such a short range might be a great question? Noting the electric conversion is a float plane version perhaps an all over water flight path is considered mitigation against always needing an alternate landing place within the range of the aircraft.
{* estimate assumes 250Wh per kg specific energy density for the lithium battery technology which is at the upper end of the data currently in Wikipedia)
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Factor in the reality that you are addressing VFR flight. An IFR flight must (currently) be able to fly to the destination and land with 45 minutes reserve fuel (eg airtime). That 45 minutes is in case of unexpected headwinds or an unexpected need to divert so will not just go away in the numbers.
Ignoring power settings you have an airplane capable of negative 15 minutes air time in instrument conditions using current regulations and safety norms. IFR commercial flights (eg charter or air transport) in prop planes must also be multi-engine although there are some single turboprops certified for IFR. Most IFR must also have a pilot+co-pilot,unless certified for single pilot IFR.
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Thanks for that reassurance. With more than enough passenger or brown paper bag time in Twin Otters and smaller I’ve often wondered about the plan B’s. Just how long will the pilot spend wondering where the F… are we? That cloud looks familiar, but that mountain poking up from the Owen Stanley’s looks different!
More Directly on Topic. (Battery vs Hydrogen vs Burning Stuff). 
Wikipedia has a graph that compares energy density of various fuels and materials. By volume and weight. It reveals the size of the technology gap science and engineering are trying to close in moving us to a low carbon transport future.
The further to the top right on the chart the more effective the energy source by volume and weight.
Or the closer to the bottom left, the greater the weight and volume for the same stored energy.
The Lithium Ion battery wins the fat and heavy prize.
Why do we use them? They can be recharged readily and direct conversion to mechanical or thermal energy is efficient (50-90% depending on application). The other common fuel options such as diesel, LNG etc are in comparison inefficiently converged to mechanical or electrical energy (15-40%).
Still for weight and size critical applications, the gap between battery electric power and combustion of hydrocarbon fuels is very large. There are various published assessments. To compete in critical applications on weight and volume current rechargeable batteries need to decrease in weight by up to 20 times for the same energy capacity.
It’s worth noting as an energy source, liquified hydrogen or when contained as anhydrous ammonia is by weight and volume many times more effective than current battery technology. Although both require 2-4 time’s the storage volume compared with hydrocarbon based fuels.
Hydrogen based fuel is still lacking a high efficiency (80-90%) practical conversion technology that would put it on a level playing field with hydrocarbon fuels by volume.
What do those regulations say about extreme short-range (say suburban) commuting?
As I said:
Follow that link and you’ll find other examples.
[edit]
Then, there’s this:
[end edit]
Meanwhile, on ABC News Radio this morning, there was a piece on airships. The interviewee pointed out that airships operated for about four decades. Failures, when they happened, were spectacular but the overall safety record was pretty good. Perhaps better than heavier-than-air aviation at the time.
For anything but niche applications, helium is not a realistic option. Hydrogen wasn’t terribly unsafe in the first half of last century and we could probably improve on that record now. One great advantage is that the lifting gas can also be the fuel for (for example) fuel cells.
I presume you meant this as your premise?
It does not address weather issues and current regulations differentiates between visual (VFR) and instrument (IFR) flight rules, and ‘private’, commercial (charter), and airline transport (commercial aviation) operations.
Ignoring the latter, VFR is akin to jumping in your car and going. Not so with IFR where you are flying through clouds with zero visibility, with other airplanes.
Given road ragers I can imagine air rage being pretty special if airplanes replaced ground vehicles, and do you fly on the left or right, or over or under? The complexities of avoidance in flight, especially in high density areas, is not a 
matter; plus one cannot just pull over to the side to get one’s bearings in flight, especially in instrument conditions.
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No, that was an edit (ie. added later). I was referring to this:
You might find it less confusing if you follow the links in the order presented.
Perhaps if I followed links in order rather than just thinking about it and noticing the first related one I saw? But
The Sydney ferries would be an analogous reason. It works most of the time, except in severe weather. Then how does it go?
Air traffic (volume)? The practicalities of ‘traffic control’ and parking (ramp space, arrival and departure slots, et al)?
Disclaimer: As a certificated pilot I may be overly sensitive to current practicalities as well as safe distances between flying machines, how few aircraft are as stable as a Segway or similar especially when they bump, or drone technology. Re the latter distribute the noise cancelling headsets - a flock of cockies would be almost innocuous compared to a few hundred drones. And ‘our flying machines’ would never impact a cocky for one or the others demise, right? Suburb to suburb would be low level with its attendant issues, even if managed like a bus service.
What technology enables is not always practical in practice.
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There have been occasions when extreme weather has forced me to pull to the side of the road and stop driving. By your logic, that makes driving impractical. Obviously, when conditions are unfavourable, the activity is best halted.
This is not a new concept, even in this thread:
I’m surprised that you’re surprised.
Anyway, I reckon the airship thing is far more interesting.
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It might be worth considering the options and how well they harness current “low carbon” technology?
The DHC-2 example suggests a service that uses 1.0kWh# of battery energy per 0.6km# travelled. (# edit to correct calc)
A road limited modem BEV with similar Passenger and cargo capacity will travel between 5km and 8km on the same battery capacity of 1 kWh.
A BEV bus makes even better use of the same battery capacity/investment due to the greater load capacity and overall effeciency.
Should we be staying with what is best current technology and considering the long lead times for proven new tech to be common place?
In respect of passenger mile per dollar invested in battery of hydrogen or bare wire electrical services what is going to be the lowest up front cost, and demand the least in new resources?
Investment today in:
- High speed electric trains,
- battery or hydrogen buses,
- long haul freight on ammonia/hydrogen cycle powered trains or trucks,
- shared commutes in a guided BEV,
- local shopping in an oversized electric golf cart.
- Etc
All these and … are solutions that deliver so much more value per battery or invested dollar in low carbon alternatives than a 15minute commute in a float plane. Even the much flogged dream of Uber et al AI guided Air Taxis for now face a similar reality. They are a very energy intensive and battery wasteful solution. Who would purchase a car today that consumes 50-100l per 100km on the school run, and pay an extra $25k for the benefit of the extra high capacity hazardous goods registered fuel tank that might require? (There are such cars but they skimp on the fuel tank, while you might need to live on a closed test track to unleash the 300+kph high speed potential.)
P.s.
While it is fact we have a largish house dam, and the DHC-2 is renowned for short take off and landing, even the ducks need a bit of a run up to get off the water when disturbed. Yes, one day hydrogen or battery technology will make that ten to twenty fold leap and move powered flight to a different future. It still took 40 years to progress powered flight from a internal combustion engine to the first jet engines, and another decade for it to become a commercial reality (the British Comet and Boeing 707). In the interim electric flight is a field full of proof of concept examples with their promoters all hoping to be first in the field when the technology makes the next big step change.
Is that the only option? Read back.
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I have been reading forward.
It is all thought provoking in a positive way.
Simply put the economic argument for getting to a lower carbon future sooner and at the lowest added cost suggests electric powered flight should not be a priority. It is still waiting on better batteries or …
Even the link to Norway is talking about a goal for 2040, still 20 years away.
For Air NZ and others, talking about air taxis deserves a Gruen bullet. It is a simple distraction saying we Air NZ is a carbon friendly champion, look this way and not at how much CO2 our real business adds to the environment everyday.
I’ll offer some credit to the major airlines and Boeing and Airbus etc when they commit to making no new hydrocarbon fueled aircraft after 2025 or 2030. Commercial aircraft have lifetimes of 25-50 years. That takes builds from current new orders well past 2050.
It’s great that there are those as you note with different better goals for aircraft in the interim.
The Rattly Brain:
I personally can’t see how as a planet we can justify trying to decarbonise, transport in particular by continuing to try and keep everything as we know it by direct substitution of electric or hydrogen. The faster, less resource demanding and lower cost solution is to change how we do things to more Energy efficient solutions. A progressive change to lower energy housing has been one of the more effective solutions now happening at little added cost. Transport I’m suggesting faces the same challenge. Less airtime, more high speed mass transport. It is worth a longer discussion of the options and benefits vs waiting for some magic bullet (sorry Prime Ministerial miracle) that arrives too late to make any real difference.
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You obviously got my point. The backup mode would be used far more than from train or ferry disruptions because air travel is sensitive to the vagaries of weather; one has to wonder whether these proposals (demos) include IFR capability. Rain and cloud happens, especially around Melbourne 
We both know the concept has been around for decades. Both your stories include touches of reality that it is technologically possible, but not (yet) practical for numerous reasons.
we are showing people what is possible… Doing one or two is easy, taking it into operation is a giant step beyond.
Uber’s plan to trial an aerial taxi service in Melbourne is technologically feasible but needs to be well regulated to avoid “absolute chaos”…
The ‘flying it on a nice day’ is but a small bit to ‘get it done’.
Since you have bought into the concept I hope you have an opportunity to partake in your lifetime.
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Agreed. Interesting though.
Like pretending that present-day regulations will always rule?
I’ve “bought into” nothing. Just watching, with enthusiasm.
So, what do you think about the airships?
I have always been a fan but the problems putting them into widespread operation are well documented. In these days of instant gratification speed is problematic for long haul, and for short haul their bulk.
It’s a great observation.
Current regulations are one of the most significant road blocks to locals buying cheap electric golf carts in place of a second car for the trips down the shops, for the school run, etc.
The current ADR (design rules for Australian road vehicles) assume that every road vehicle must be capable of all things on all roads. We now allow battery electric bikes on our roads, electric scooters on some, so a just as fast golf cart with full lights and a reasonable speed could be common place on many urban streets. It may also need some other driver and road rule adjustments to get the best outcome. It only needs more of Australia to demand the change than to stay the same, and deliver the message to the politically powerful. Like most things.
Not only are smaller BEVs more affordable; they only demand smaller lower cost batteries.
