The electric way to fly.....

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woodgeek

Minister of Fire
Jan 27, 2008
4,373
SE PA
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. :p

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

Minister of Fire
Nov 18, 2018
5,945
Downeast Maine
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. :p

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.
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.
 

ABMax24

Minister of Fire
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

Minister of Fire
Jan 27, 2008
4,373
SE PA
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).
 

ABMax24

Minister of Fire
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.
 

semipro

Minister of Fire
Jan 12, 2009
4,023
SW Virginia
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.

 
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semipro

Minister of Fire
Jan 12, 2009
4,023
SW Virginia
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"?

 

SpaceBus

Minister of Fire
Nov 18, 2018
5,945
Downeast Maine
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"?

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

Minister of Fire
Fender benders are probably much more interesting at 3000 ft.
 

woodgeek

Minister of Fire
Jan 27, 2008
4,373
SE PA
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.
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,198
South Puget Sound, WA
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.
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,198
South Puget Sound, WA
GM is even playing around in this space.
 

begreen

Mooderator
Staff member
Nov 18, 2005
88,198
South Puget Sound, WA
More entries, including Boeing.
 
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begreen

Mooderator
Staff member
Nov 18, 2005
88,198
South Puget Sound, WA
Then there is the Celera. It's not electric, yet, but it is efficient. The Celera 500L carries 6 passengers at 18-25mpg.
 
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EatenByLimestone

Minister of Fire
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?
 

woodgeek

Minister of Fire
Jan 27, 2008
4,373
SE PA
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

Mooderator
Staff member
Nov 18, 2005
88,198
South Puget Sound, WA
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.
 
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walhondingnashua

Feeling the Heat
Jul 23, 2016
388
ohio
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.