Global warming

[corduroygt]

Electric helicopters work because they only have 5-10 minute flight time. They can't make one with higher endurance because then it wouldn't be able to lift the weight of its required batteries. Electric energy is great, it's just that electrical energy storage tech sucks big time.

 

[AlphaWolf]

Electric helicopters work because they only have 5-10 minute flight time. They can't make one with higher endurance because then it wouldn't be able to lift the weight of its required batteries. Electric energy is great, it's just that electrical energy storage tech sucks big time.

Actually they can get quite a bit beyond 10 minutes. There's versions with 30+ minute fly times that carry sophisticated surveillance equipment (gps/cameras etc). They are ridiculously expensive and it in no way means they are scalable to human sized craft. Battery tech is progressing fairly rapidly, I wouldn't say never for full sized craft.

edit

perhaps closer than I thought.

 

[Grall]

500 kilos of batteries gives ~15 mins flight time? Somewhat impressive, but not THAT impressive! Especially considering that helicopters pretty much can't glide down to the ground, should it run out of juice...

Then again this could probably be improved somewhat by custom tailoring the aircraft instead of just doing a 1:1 replacement of the powerplant like in this demonstrator. Still, I doubt it'll be workable, except for very niche tasks perhaps.

 

[WhiningKhan]

Especially considering that helicopters pretty much can't glide down to the ground, should it run out of juice...

Errrr... No.

 

[Grall]

Its capabilities in that regard are much more limited than fixed-wing aircraft. That's just the way it is.

 

[KimB]

500 kilos of batteries gives ~15 mins flight time? Somewhat impressive, but not THAT impressive! Especially considering that helicopters pretty much can't glide down to the ground, should it run out of juice...

Then again this could probably be improved somewhat by custom tailoring the aircraft instead of just doing a 1:1 replacement of the powerplant like in this demonstrator. Still, I doubt it'll be workable, except for very niche tasks perhaps.

Well, it's an interesting proof-of-concept, at least. I'm a bit skeptical as well that the power densities will ever be sufficient for a useful helicopter, but you never know.

 

[WhiningKhan]

Its capabilities in that regard are much more limited than fixed-wing aircraft. That's just the way it is.

Well, if head-on crashing is your preferred method of deceleration, fixed-wing emergency landing probably does make you feel safer.

 

[Gubbi]

Its capabilities in that regard are much more limited than fixed-wing aircraft. That's just the way it is.

Google "dead man's curve".

Also known among helicopter pilots as "The money curve"

Cheers

 

[corduroygt]

Actually they can get quite a bit beyond 10 minutes. There's versions with 30+ minute fly times that carry sophisticated surveillance equipment (gps/cameras etc). They are ridiculously expensive and it in no way means they are scalable to human sized craft. Battery tech is progressing fairly rapidly, I wouldn't say never for full sized craft.
perhaps closer than I thought.

Am I supposed to be impressed by that? Unmanned helis have 10 times the 30min+ endurance you've quoted running on gas, and manned helis have 10 times the 15 minute endurance you've quoted running on gas. Aviation is a different world where every pound counts, and battery energy densities are just not cutting it.

I am also unaware that there were battery technology advancements after li-ion and li-po cells. I certainly don't see it judging by the battery capacity/size in cell phones or laptops.

 

[Sxotty]

There are future battery advancements on the horizon. Both the simple and the large steps.

 

[Grall]

Well, if head-on crashing is your preferred method of deceleration, fixed-wing emergency landing probably does make you feel safer.

As opposed to falling in a more or less controlled fashion (less, if the pilot doesn't know how to do an autorotation landing or is just bad or scared out of his pants), you bet your ass I'd prefer it...

Now add if there's an electric tail rotor and no power to drive it...you'd spin uncontrollably and crash and die. Yeah that sounds like a real smash hit!

 

[KimB]

Personally, I strongly suspect that biofuels will be the only viable answer to the power requirements for aviation any time soon. Still, a workable electric-powered helicopter would be intriguing.

 

[Sxotty]

Personally, I strongly suspect that biofuels will be the only viable answer to the power requirements for aviation any time soon. Still, a workable electric-powered helicopter would be intriguing.

BTW I agree with this. I just disagree that batteries have plateaued. There will be significant improvements in the future, but the idea that they will replace biofuels in aviation seems a tad crazy to me.

 

[hoho]

Personally, I strongly suspect that biofuels will be the only viable answer to the power requirements for aviation any time soon.

I wonder at what speeds can zeppelins travel.
[edit]
Quick googling told me that stuff from early 20'th century reached speeds up to 140km/h. I wonder what could be done today. It will certainly not rival planes going at some 500-800km/h but could probably be a reasonable alternative as biofuels WILL be rather expensive once they aren't as massively subsidized as they are today.

 

[WhiningKhan]

As opposed to falling in a more or less controlled fashion (less, if the pilot doesn't know how to do an autorotation landing or is just bad or scared out of his pants), you bet your ass I'd prefer it...

Now add if there's an electric tail rotor and no power to drive it...you'd spin uncontrollably and crash and die. Yeah that sounds like a real smash hit!

Riiight, How was this relevant to the topic anyway? What kind of moron waits for fuel/power to run out before landing?

 

[zed]

zeppelins cause of their massive size and unstreamlinedness? will have huge wind resistance to overcome.

What I'ld like to see are massive 'floating city' ships made. Like 1km long

Travelling between say europe + the US, in ~3days, very cheap travel. Everyone gets a cabin.
Not everyone needs to get from point A -> B in under 10 hours

pros -
- more relaxed
- more comfortable
- cheaper
- less fuel etc used per person

cons -
-slower

 

[hoho]

Yeah, that's exactly my point
Faster than ships, slower than "real" aircraft, require relatively little fuel to travel but can still lift a whole lot of cargo.

Another point I tried to make was to think outside the box a little. If we can't make planes to fly on electricity then perhaps we should not only look for alternative fuels but also alternative methods for travelling.

 

[KimB]

What I'ld like to see are massive 'floating city' ships made. Like 1km long

Travelling between say europe + the US, in ~3days, very cheap travel. Everyone gets a cabin.
Not everyone needs to get from point A -> B in under 10 hours

pros -
- more relaxed
- more comfortable
- cheaper
- less fuel etc used per person

cons -
-slower

I'm not really convinced that such ships would be cheaper. Sure, transport by ship is fantastic for inanimate cargo. But the moment you add people to the mix, the costs go up tremendously, because you need food and water for the people, adequate living accommodations, and a staff to ensure the passengers' needs are met. For really long distances, my money's on aircraft continuing to be quite a bit cheaper due to these concerns. We'll just have to switch to biofuels in the future.

 

[hoho]

Considering they can take off with tens if not hundreds of tons of extra cargo I don't think having a few hundred people living in them for a few days would be too much of a problem.

 

[gamervivek]

because you need food and water for the people

and this is the bane of human existence, if only we could see the immense value in genetically modifying humans to carry out photosynthesis; farts of pure oxygen are the just the tip of endless possibilities.