Cessna 208 Electric Conversion

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12notes

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Well, it said "roughly" one tonne. (could be 3000 pounds)
And, the other article said 2 tons (with cooling system). So details matter.
3000 pounds is not roughly one tonne, by any reasonable measure .

Yes, details matter. But this company doesn't have a history of making unrealistic claims, and currently claims the weight capacity for 4-5 passengers. The article that says 2 tonnes is by the Seattle Times and would result in a plane whose empty weight is way over the maximum landing weight, the article that says one tonne is by Flight Global and results in a plane that has enough useful load to carry 4-5 passengers, exactly what the company claims. Flight Global also publishes the weekly "Flight International" magazine, which has been in publication for 111 years (not a typo, started in 1909). Which one do you think is more likely to have it wrong?
 

stanislavz

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Coul anybody point me to better Rutan boomerang specification, than is available on wikipedia or here ? https://www.google.com/url?q=http://www.rutanboomerang.com/Flight%20Test%20Development%20of%20a%20New%20Generic%20Configuration%20the%20Boomerang.pdf&sa=U&ved=2ahUKEwjuv_OaxefpAhVPr4sKHamJDcgQFjACegQIBBAB&usg=AOvVaw26x8UXOnJvaPaMZyfBX5hv

Its looks much better converted to electric, than anything else.

On napkin it looks like this 2359lbs empty, 4200lbs full, 1000lbs load (846 lbs fuel ? )

So its gives 846 + 250lbs (lighter engines ) 1100 lbs for batteries. Going for tesla - 20 packs with 100kwh capacity.

And if boomerang cruise is correct - using 143kw at 250mph - we are covering 170 miles using today tech.

How much reserve we must left ? And how to compare climbing/descent of used energy ?

And yes, i still like assymetric electric airplane safety.
 

Mad MAC

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details matter
Its a bunch of press releases of an aircraft in early flight test, its not a quality data source.

  • It could be operating over gross weight at this point.
  • They don't state they are using the final battery type (statements somewhere suggest they expect better ones to be available within the time frame they expect certification)
  • The batteries could be ton and batteries plus associated systems (cooling heating, packaging, power management etc) could easily be closer to 2 ton.
  • They also state they want it certified by 2021 that seems optimistic.
 

Dan Thomas

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That doesn't excuse you when the physics and math works out, and there is an actual, physical example of it, and the company isn't making any claims of it doing anything but exactly what it does. You're entitled to nothing in this case.
It can't carry passengers yet because sufficiently light and powerful batteries don't exist. They hope they'll have those batteries someday. That doesn't justify some skepticism?
 

12notes

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It can't carry passengers yet because sufficiently light and powerful batteries don't exist. They hope they'll have those batteries someday. That doesn't justify some skepticism?
It has the weight capacity to carry 4-5 passengers with currently available batteries. They have stated this multiple times. They currently have those batteries where the seats would go, but they have been open about not optimizing the location yet. They hope to increase that to 9 passengers with improvements in batteries. They have given no date for those improvements, as it's impossible to know, but at no point have they said they need new battery technology to carry any passengers.

No, skepticism isn't justified, they are not making claims for anything they can't do right now.
 

12notes

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Its a bunch of press releases of an aircraft in early flight test, its not a quality data source.

  • It could be operating over gross weight at this point.
  • They don't state they are using the final battery type (statements somewhere suggest they expect better ones to be available within the time frame they expect certification)
  • The batteries could be ton and batteries plus associated systems (cooling heating, packaging, power management etc) could easily be closer to 2 ton.
  • They also state they want it certified by 2021 that seems optimistic.
They could be operating over gross, but going roughly 1000 lbs over maximum landing weight (which is lower than gross) would require structural changes to the landing gear at least, if not the entire airframe.

They stated the battery system ways 1 tonne. Not just the battery.

"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." Which lines up with the 1 tonne battery system weight.
 

dog

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The more experienced here might concede that this project is useing a very strait forward aproach to getting an electric plane in the air as
quickly as possible,motor,on front,batteries, in the middle,on floor,electronics, on floor, now fly.
Carravan is a shoe in.
In this market, they could have scooped it at auction and MADE money selling the pt 6 on the next bounce.
The full scale of current battery manufacturing is
huge and growing at double digit rates.
There are a large number of very promising new
battery technologys, the rub bieng how for investors to choose, AND everybody scared of what elon got up his sleeve, like watching spiders in a jar
ALL of the worlds care makers are "anouncing"
new models,trucks ,vans,etc.But again,which
battery teck and elon and his sleeve.
He is likely going to wait till his crew is back on the planet and the other situations provide a
suitable intro.
Northern europe is now selling more than half of new cars as electrics ,and in that market there is
major interest in electric aviation.There are now electric charging stations north of the artic
circle in finmark,etc.
All the pieces are in place.
Physics is fun.
The future is here now, its just not evenly distributed.
 

BJC

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Northern europe is now selling more than half of new cars as electrics ,and in that market there is
major interest in electric aviation.
The last time that I was there, there were huge tax benefits for buying / owning an electric car. Is that still the case?


BJC
 

dog

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The last time that I was there, there were huge tax benefits for buying / owning an electric car. Is that still the case?


BJC
The whole benifits and rebate system is in constant flux.Depends on what car(there was backlash over subbsidies on exotic hypercars with hybrid drive trains), certain special privlages for electrics(bus lanes, city center free parking),depending on municipality,etc.
Still there is huge public support and every indication that the electric vehicle trend will continue to take over.
And as to aviation, there is already mention of the
noise factor, which as we all know is plaguing countless airports.
It wont take long for an inner city comuter airport
somewhere to start getting pressure to go electric,
and saying it here means that its already bieng put forwards by homeowners under the aproach,looking at the resale value of there homes
 

Dan Thomas

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And as to aviation, there is already mention of the
noise factor, which as we all know is plaguing countless airports.
It wont take long for an inner city comuter airport
somewhere to start getting pressure to go electric,
and saying it here means that its already bieng put forwards by homeowners under the aproach,looking at the resale value of there homes
It's really too bad that most of the noise comes from the prop, unless the airplane has straight exhaust stacks.

Homeowners have been buying homes under long-established airport approaches for 50 years, then complaining about the noise. Paul Poberezny once wrote an article about visiting a particular city where the homeowners near the airport were trying to shut down the airport due to the noise. As he drove through that neighborhood he was surprised at the numbers of noisy lawnmowers and other yard machinery, guys revving up their dirt bikes and snowmobiles and hotrods in their driveways while tuning them up, noisy music and so on.
 

autoreply

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The last time that I was there, there were huge tax benefits for buying / owning an electric car. Is that still the case?


BJC
Yes. A new Toyota Hilux costs about 20K before and 40K after taxes.
A Tesla model 3 is about 40K before and 50K after taxes.

Were I to drive both as a company car, I have to add a fictional 25% of the cars new value to my income and that's taxed, unless it's electric, then it's 8% (used to be 4%).
For the Hilux that's 25% of 40K taxed at 52%, so 5200 Euro's/year in extra income taxes.
For the 3 that's 8% of 50K taxed at 52%, so 2080 Euro's/year in extra income taxes.

Gas and diesel is heavily taxed here, so an electric MJ costs about a quarter of a gasoline MJ. (about 6.5 US$/gallon for gas now)

So yes, the amount of subsidies/benefits are and will remain enormous for the near future.
 
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BJC

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Thanks, Auto.

That is in line with what I remembered. There was something about free recharging, too, although that may have been in another country.


BJC
 

dog

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It's really too bad that most of the noise comes from the prop, unless the airplane has straight exhaust stacks.

Homeowners have been buying homes under long-established airport approaches for 50 years, then complaining about the noise. Paul Poberezny once wrote an article about visiting a particular city where the homeowners near the airport were trying to shut down the airport due to the noise. As he drove through that neighborhood he was surprised at the numbers of noisy lawnmowers and other yard machinery, guys revving up their dirt bikes and snowmobiles and hotrods in their driveways while tuning them up, noisy music and so on.
Come on.
Reality isnt part of the noise equation.
Its a blame game and public perception will instantly fall in line with anything that gives them
a sense of victimization and the juicy goodness
of forcing there contradictions on others, preferably safely in another tax bracket and postal code.
Sore spot as one of the very few airports got the ax here a while back and the shut it down folks used every little twist to do it.
 
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