# The electric way to fly.....



## woodgeek (Apr 7, 2021)

We had a discussion around here awhile back about how electric propulsion would enable more efficient and smaller aircraft... green flight.

When I crunched the numbers a couple years ago, I worked out that an electric flying car could have similar energy usage per passenger mile to a ICE SUV.  While flying is more energy intensive, lightweighting the aircraft, versus armoring the SUV (for collision survival) + the inefficiency of the ICE engine made it a wash.  After all, a full 747 has a mileage per passenger better than a Prius, perhaps close to my 2015 Volt.    

The latest entry is the Beta Technologies ' Alia-250' Electric EVTOL.



I've been following this tech pretty causally, and it is still evolving.  

One approach is to scale up a quadcopter drone, like the EHang 184:



The problem with this is that it can't 'glide' or even autogyro in case of power failure (a chute is possible), low horizontal speeds and fairly high energy per mile consumption, limiting range.

For this reason, major Aerospace Cos have looked at designs like the tilt rotor Osprey (that has a poor safety record).  Vertical takeoff and landing (VTOL), but flies like an airplane, for better range, safety and speed.  The trick is in stability and control.

The nice thing about the  Alia-250 is that they skipped the tilt rotor.  They have 4 lifting rotors for VTOL, and a pusher prop with its own motor for horizontal flight (when the lifting rotors are locked forward for minimum drag).  This greatly simplifies control and hardware, and seems very sensible to me.  And it can glide to a landing without power if need be (but needs a runway or road).

Early plans are for high value point to point rural cargo (like medivac, some rush packages, etc).

I'm excited.


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## SpaceBus (Apr 7, 2021)

woodgeek said:


> We had a discussion around here awhile back about how electric propulsion would enable more efficient and smaller aircraft... green flight.
> 
> When I crunched the numbers a couple years ago, I worked out that an electric flying car could have similar energy usage per passenger mile to a ICE SUV.  While flying is more energy intensive, lightweighting the aircraft, versus armoring the SUV (for collision survival) + the inefficiency of the ICE engine made it a wash.  After all, a full 747 has a mileage per passenger better than a Prius, perhaps close to my 2015 Volt.
> 
> ...



I think something like this would be great for people living in remote rural areas, like Newfoundland, Alaska, etc. Would be a lot faster and more efficient, perhaps arguably safer, to go to "town" in an electric plane than a big ICE SUV or pickup truck.


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## ABMax24 (Apr 7, 2021)

I like the idea of the quadcopter units. I think they'd be fun.

Just like with electric cars though, range will be the limiting factor in mass adoption.

We had a fellow snowmobiler flown out in a medivac flight a couple weeks ago with a broken hip, where he was picked up was close to the max service range of the BK117 helicopter. If we had to we could have hauled a barrel of Jet-A on snowmobile to give the chopper enough fuel to return to base, and that fuel could be stored for long periods in remote locations. I'm not sure what would be done though if it was an electric, very hard to add charge in a remote location.


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## woodgeek (Apr 7, 2021)

ABMax24 said:


> We had a fellow snowmobiler flown out in a medivac flight a couple weeks ago with a broken hip, where he was picked up was close to the max service range of the BK117 helicopter. If we had to we could have hauled a barrel of Jet-A on snowmobile to give the chopper enough fuel to return to base, and that fuel could be stored for long periods in remote locations. I'm not sure what would be done though if it was an electric, very hard to add charge in a remote location.



For kicks, I looked up the range and speed for the BK117.   Looks like 300 miles and 160 mph max.  So the target specs on the Alia (250 miles, 150 mph) are not that shabby by comparison.  And way better than the Ehang (25 minutes air time, 60 mph max speed).


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## ABMax24 (Apr 7, 2021)

woodgeek said:


> For kicks, I looked up the range and speed for the BK117.   Looks like 300 miles and 160 mph max.  So the target specs on the Alia (250 miles, 150 mph) are not that shabby by comparison.  And way better than the Ehang (25 minutes air time, 60 mph max speed).



I did see that is their targeted range. What remains to be known is how much that range decreases due to hovering to takeoff and land, which in this case requires 2 takeoffs and 2 landings.

It'll be cool if they can do it though, aircraft have long been thought to be the hardest machines to electricify.


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## semipro (Apr 7, 2021)

What used to be called "urban air mobility: and is now being called "advanced air mobility" is what I think should be called "regional air mobility".   I believe it will definitely have its place flying routes that would take between 4 and 6 hours to drive; the same kind of trips that have one looking at flying versus driving and deciding it's a wash timewise.   I do a lot of that professionally - at least I used to.
As mentioned, multirotor aircraft are not very efficient and don't glide well.  Fixed-wing aircraft required too much space to take off and land.  I think the human mobility tech will evolve more towards what is used now for delivery services; a VTOL with wings much like the Google Wing unit in the video below.  
BTW, this operation is taking place in the area where I live.









						Google launches Wing drone delivery service in small Virginia town
					

Wing, a sister company of Google, is the only approved drone delivery service in the country and is in a test phase before getting FAA approval to expand. For now, ten pound drones deliver small packages in a 12 mile radius from Walgreens, FedEx, and a local store.




					www.nbcnews.com


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## semipro (Apr 8, 2021)

Came across this in my inbox this morning.  
4 lift props plus a pusher prop. 

"The eVTOL aircraft comes with 4 major benefits, 3 of which come with all electric vehicles:

Cuts pollution immensely.
Lowers operating costs.
Super quiet.
Reduces transit times."
I have my doubts about the 3rd claim above.  It probably quieter than a helicopter but "super quiet"?









						UPS Orders 10 Electric Vertical Takeoff & Landing Aircraft
					

UPS gives the eVTOL industry a boost, and especially startup Beta Technologies, by placing an order for actual eVTOL aircraft.




					cleantechnica.com


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## SpaceBus (Apr 8, 2021)

semipro said:


> Came across this in my inbox this morning.
> 4 lift props plus a pusher prop.
> 
> "The eVTOL aircraft comes with 4 major benefits, 3 of which come with all electric vehicles:
> ...



Compared to a helicopter with an ICE and giant rotors it would be considered super quiet.


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## EatenByLimestone (Apr 9, 2021)

Fender benders are probably much more interesting at 3000 ft.


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## woodgeek (Apr 9, 2021)

I think congestion is lower and collisions easier to avoid in 3d than one restricted roadways.  The lack of a road also reduces the carbon footprint of flight relative to ground transport.


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## begreen (Apr 9, 2021)

woodgeek said:


> I think congestion is lower and collisions easier to avoid in 3d than one restricted roadways.  The lack of a road also reduces the carbon footprint of flight relative to ground transport.


The lack of traffic, slowing deliveries and increasing idling time also would reduce fuel wastage.


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## begreen (Apr 9, 2021)

GM is even playing around in this space.


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## begreen (Apr 9, 2021)

More entries, including Boeing.


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## begreen (Apr 9, 2021)

Then there is the Celera. It's not electric, yet, but it is efficient. The Celera 500L carries 6 passengers at 18-25mpg. 








						Long-awaited Celera 500L 'bullet' plane is finally revealed
					

Finally, the mysterious bullet-shaped Celera 500L has been officially revealed. The super-efficicient six-person plane might hit skies by 2025 and could revolutionize private travel




					www.cnn.com


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## EatenByLimestone (Apr 9, 2021)

woodgeek said:


> I think congestion is lower and collisions easier to avoid in 3d than one restricted roadways.  The lack of a road also reduces the carbon footprint of flight relative to ground transport.




So those who have trouble operating trouble free with only 2 dimensions of travel are going to be better when you add another axis?


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## woodgeek (Apr 9, 2021)

Ofc not.  But conversely, autonomous flying in a large empty 3-d space is much easier to program than autonomous driving in 2d, with a mix of human drivers.

We might get flying robot ubers before we figure out robot ground ubers.  And they might be cheaper bc of it.


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## begreen (Apr 9, 2021)

Another not electric, yet, but interesting. It's a major redesign of large passenger aircraft. If it works as specced and gets off the ground it could be a game-changer. 








						SE Aeronautics Announces New Green Widebody Aircraft - Avionics International
					

SE Aeronautics announced a new widebody aircraft, the SE200, that promises 70 percent lower fuel consumption and the ability to lower CO2 by 80 percent with a light tri-wing design and short take-off and landing capabilities for long flights, the company said in a March 17 press release.  “Our...




					www.aviationtoday.com


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## walhondingnashua (Apr 15, 2021)

ABMax24 said:


> It'll be cool if they can do it though, aircraft have long been thought to be the hardest machines to electricify.



I listened to Elon's most recent episode on the Joe Rogan Experience.  They get into electric planes.  In a long, super-intelligent person explanation, he basically explains how challenging it is and that he's considered it but it was not worth the effort.

I tell my high school students all the time how unique the period in history they live in is.  Yes, a lot of really bad stuff because of the generations before them, but they opportunities that seemed so "futuristic" and "sci-fi" are becoming actual realities in their life time.  I had them look up their future cars and design a reasonable "dream house."  They had to keep cost in mind.  Most had electric cars/trucks and solar because in the next 10 years when they buy a car and build a house, ITS ACTUALLY REASONABLE FOR THEM TO DO THAT!  As bad as things can be, I have high hopes for the future.  This new attempt at transportation is an example of that.


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## ABMax24 (Oct 24, 2021)

Starting at $92k USD


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## begreen (Oct 24, 2021)

Whee! That would have made my commute a lot easier, though the 20 minute flight time would have been anxiety provoking, especially in the winter.


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## woodgeek (Oct 24, 2021)

begreen said:


> Whee! That would have made my commute a lot easier, though the 20 minute flight time would have been anxiety provoking, especially in the winter.


Exactly.  I was floored by the vehicle weight including battery.  Its like a wrap around seated jetpack.


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## ABMax24 (Oct 24, 2021)

And the best (or worst) part is that it falls under the US ultralight regs and doesn't require a license to operate.


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## woodgeek (Oct 24, 2021)

ABMax24 said:


> And the best (or worst) part is that it falls under the US ultralight regs and doesn't require a license to operate.


Oh my.  I honestly thought it would be a fun 'beach rental' kinda machine.

At least until someone totalled it.


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## stoveliker (Oct 24, 2021)

begreen said:


> Another not electric, yet, but interesting. It's a major redesign of large passenger aircraft. If it works as specced and gets off the ground it could be a game-changer.
> 
> 
> 
> ...



I'd be a little concerned about the fuel stored above my head. Don't want to get rained upon when things are already dicey.

The remark about once thru air is plain dumb. It costs a boatload of energy to heat -65 F air up to 68 F.
Planes these days refresh the air about 20-30 times per hour (compared to office buildings, your grocery store, etc where that happens 4 times per hour or so). Yes, they do recycle some of that air (i.e. they mix), but overall air freshness is superior than anyplace we know of barring the good old outside (in the country). Not re-mixing any air therefore does not create any significant health benefits, but does cost a lot of energy - reducing the latter was the goal of this plane. Seems they can still improve on their impressive achievement.


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## ABMax24 (Oct 24, 2021)

stoveliker said:


> I'd be a little concerned about the fuel stored above my head. Don't want to get rained upon when things are already dicey.
> 
> The remark about once thru air is plain dumb. It costs a boatload of energy to heat -65 F air up to 68 F.
> Planes these days refresh the air about 20-30 times per hour (compared to office buildings, your grocery store, etc where that happens 4 times per hour or so). Yes, they do recycle some of that air (i.e. they mix), but overall air freshness is superior than anyplace we know of barring the good old outside (in the country). Not re-mixing any air therefore does not create any significant health benefits, but does cost a lot of energy - reducing the latter was the goal of this plane. Seems they can still improve on their impressive achievement.



I'm assuming it has to do with the bleed air that is currently used to heat and condition the cabin of an airliner. The air enters the engine is run through the compressor and then significant amounts are bled off to heat the wing de-icers and the cabin itself. It's an extremely inefficient process, but one that has been used since the beginning of jet travel. That compressed air is much better to be burnt in the engine, and run through the turbines to generate shaft hp. The Boeing 787 is the first aircraft to diverge from the bleed air architecture, instead the engines turn a generator and an electric compressor is used instead.

Here's a couple cool videos on it, the 787 and GENx engine powering it really are marvels of engineering. The engine runs a 23:1 pressure ratio and as such has one of a kind 3D printed lean burn fuel nozzles to reduce NOx emissions.


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## tlc1976 (Oct 25, 2021)

It would be great for emergencies or remote locations. As with electric-only cars or just about anything really, it seems like a great idea, until everyone starts doing it.


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## SpaceBus (Oct 25, 2021)

tlc1976 said:


> It would be great for emergencies or remote locations. As with electric-only cars or just about anything really, it seems like a great idea, until everyone starts doing it.


Which will make things better through economies of scale. The first automobiles were mostly electric powered until the military got on the fossil fuel bandwagon.


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