A hybrid plane based on Cessna Skymaster

MountainDude

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MountainDude
The Dutch are getting serious about this (it has already flown).
I really like the shape of it. We'll see what the price and cost of ownership will be.
It should be safer, since it has 3 motors, and they are all electric. If the ICE fails, the battery can take you to an airport.

Here is the best video of it flying I could find.
https://www.voltaero.aero/en/feature-stories/voltaero-flight-video/
 
I think weird crap like this is cool, but it really makes no sense other than a novelty. Carrying both ice and electric engines as well as batteries and fuel leaves you nothing to spare for people or cargo. You end up with most of the cons of both worlds.
 
I think weird crap like this is cool, but it really makes no sense other than a novelty. Carrying both ice and electric engines as well as batteries and fuel leaves you nothing to spare for people or cargo. You end up with most of the cons of both worlds.

The reason that hybridization works for cars is that in city and suburban driving they spend a good bit of time decelerating and stopped, so there's kinetic energy that can be captured during that deceleration, and fuel to be saved while the car is stopped. The only time that light GA airplanes have extra kinetic energy to be shed is during final and rollout, and for the most part spend little time idling on the ground, so there's not that much energy to save in a battery.

If they're looking for a low-carbon way to fly, I'd look towards biofuels. I don't see any battery technology on the horizon that's going to work for airplanes.
 
The reason that hybridization works for cars...

Somewhere in Volt’s marketing material I found this description of their hybrid concept.

“The VoltAero propulsion concept is unique: Cassio aircraft will utilize their propulsion system’s electric motors for all-electric power during taxi, takeoff, primary flight, and landing. The hybrid feature (with an internal combustion engine) comes into play as a range extender, recharging the batteries while in flight. Additionally, this hybrid element serves as a backup in the event of a problem with the electric propulsion, ensuring true fail-safe functionality.”

Sounds like the ICE motor is a generator, which is novel.
 
Somewhere in Volt’s marketing material I found this description of their hybrid concept.

“The VoltAero propulsion concept is unique: Cassio aircraft will utilize their propulsion system’s electric motors for all-electric power during taxi, takeoff, primary flight, and landing. The hybrid feature (with an internal combustion engine) comes into play as a range extender, recharging the batteries while in flight. Additionally, this hybrid element serves as a backup in the event of a problem with the electric propulsion, ensuring true fail-safe functionality.”

Sounds like the ICE motor is a generator, which is novel.
Novel for aircraft, yes.
 
Somewhere in Volt’s marketing material I found this description of their hybrid concept.

“The VoltAero propulsion concept is unique: Cassio aircraft will utilize their propulsion system’s electric motors for all-electric power during taxi, takeoff, primary flight, and landing. The hybrid feature (with an internal combustion engine) comes into play as a range extender, recharging the batteries while in flight. Additionally, this hybrid element serves as a backup in the event of a problem with the electric propulsion, ensuring true fail-safe functionality.”

Sounds like the ICE motor is a generator, which is novel.

OK, that's more like a range extended battery electric vehicle. So, maybe all electric for burger runs, and battery+engine for cross country. That still seems like a lot of complexity for the amount of gain. The nice thing about that setup would be in a single motor airplane. Electric motors are more reliable than ICE engines, if you always had 30 minutes worth of battery in reserve that would take the sting out of an engine failure.

I see they're planning on providing service to regional airports in the Netherlands. Considering that the Netherlands is about the combined size of Vermont and New Hampshire and has an extensive passenger rail network, I'm not seeing the need.
 
OK, that's more like a range extended battery electric vehicle. So, maybe all electric for burger runs, and battery+engine for cross country. That still seems like a lot of complexity for the amount of gain. The nice thing about that setup would be in a single motor airplane. Electric motors are more reliable than ICE engines, if you always had 30 minutes worth of battery in reserve that would take the sting out of an engine failure.

I see they're planning on providing service to regional airports in the Netherlands. Considering that the Netherlands is about the combined size of Vermont and New Hampshire and has an extensive passenger rail network, I'm not seeing the need.
All electric has yet to be able to do a burger run - without the weight of an ice engine and fuel on board because it’s all used up in batteries.
I think the pipistrel is something like 18 minutes with reserves ?

On this plane the ICE is doing all the work. The batteries are just to get you back to the ground if it shuts off.
 
All electric has yet to be able to do a burger run - without the weight of an ice engine and fuel on board because it’s all used up in batteries.
I think the pipistrel is something like 18 minutes with reserves ?

On this plane the ICE is doing all the work. The batteries are just to get you back to the ground if it shuts off.

So, closer to a diesel-electric locomotive.

Unless batteries become a lot lighter and more compact, an electric airplane is just a dream. I could see an electric self launching sailplane, but that's about it with today's technology.
 
Unless batteries become a lot lighter and more compact, an electric airplane is just a dream.
And unless there's a demand for lighter and more compact aviation-rated batteries, no one will develop them. Technology/concept demonstrators and R&D test and evaluation are one way to spur that development. There seems to be an opinion here that when something flies or is being readied for flight it should be ready to go to market. Research and development doesn't work that way. There also seems to be a tendency here to denounce marketing hype but not recognize it as what might be technology development that has been misinterpreted or oversold for PR purposes. R&D does work that way, for better or worse. If you believe hype equates to 100% reality you're going to struggle with advertising in general.

Nauga,
who couldn't run faster or jump higher with Keds
 
The Cessna Skymaster famously had the capability to fly in the flight levels on the rear engine alone, and far greater distances than would have been possible with both engines running. One engine at max continuous is much more efficient then two, each at half that power.

With a relatively modest lithium battery pack, charged on the ground with solar or wind energy, taxi to departure could be done on electric, then start and runup on the ICE rear engine for the departure and augmented climb to cruise altitude in less tan 15 minutes. There, the electric could be shut down, remaining battery saved for emergency use. Cruise at altitude is much more efficient than at near sea level.

Returning to the lower altitudes, the pilot could determine how much of the remaining solar/wind energy he should use before landing, thus reducing the carbon use to the extent that safety was not reduced.

Battery capacity for 15 minutes at 150 HP equivalent would meet these requirements, and a significant reduction of the gasoline tankage to correct for the lower fuel burn climbing and cruising up high, and the weight penalty would be more modest than assumed here. This plane doubtless cannot go 800 plus NM at 10,000 feet and 125 Knots, but may do near that.

Power out approaches to airports often fall just a little short of the runway due to miss judging the energy remaining in altitude and speed, with this plane, even 5 minutes of cruise power in the airport vicinity would make a huge difference in the last minutes of flight.

This seems to be a hybrid that can work, as opposed to a primarily electric airplane. This should reduce fossil fuel burn by at least 20% on most flights, and more on shorter flights. The passenger/cargo capacity should still be quite good. Most GA flights have only 2 people on board, so typical travel would not be constrained.

Those of you who have made a GA business or pleasure flight with more than 2 persons on board this year, chime in and tell us how many of your flights did have more than 2 adults, and how many had 2 or one.

The train system within the Netherlands is quite fast and convenient, but the trip to England, Spain, Portugal or Italy is via Paris. The Scandinavian countries are not easy to reach. All of these are an easy flight in a Cessna Skymaster.
 
This seems to be a hybrid that can work, as opposed to a primarily electric airplane. This should reduce fossil fuel burn by at least 20% on most flights, and more on shorter flights. The passenger/cargo capacity should still be quite good. Most GA flights have only 2 people on board, so typical travel would not be constrained.
How do you figure carrying 2 extra motors and the inefficiency of converting fuel to electrons with a small ICE engine is going to result in a 20% increase in efficiency? I’d wager it’s closer to a 20% decrease.
 
And unless there's a demand for lighter and more compact aviation-rated batteries, no one will develop them. Technology/concept demonstrators and R&D test and evaluation are one way to spur that development. There seems to be an opinion here that when something flies or is being readied for flight it should be ready to go to market. Research and development doesn't work that way. There also seems to be a tendency here to denounce marketing hype but not recognize it as what might be technology development that has been misinterpreted or oversold for PR purposes. R&D does work that way, for better or worse. If you believe hype equates to 100% reality you're going to struggle with advertising in general.

Nauga,
who couldn't run faster or jump higher with Keds

According to the GAMA, its members shipped 1261 piston and electric single engine airplanes, 148 twins, and 181 piston helicopters. That's less than 2000 powerplants installed in new aircraft. There's not enough money spent here for anyone to commit to R&D for a battery technology that is light enough to power a light GA airplane. If the airlines or the military show interest, that's a whole 'nother box of bananas.


The train system within the Netherlands is quite fast and convenient, but the trip to England, Spain, Portugal or Italy is via Paris. The Scandinavian countries are not easy to reach. All of these are an easy flight in a Cessna Skymaster.

I don't doubt that is true, but the routes that VoltAero proposed are all within the Netherlands.
 
They claim three modes, with the longest range at 1200 KM, which will take you well out of the Netherlands, but that mode is mostly ICE.

Up to 200 KM is all electric, charged on the ground from normal airport electric power mains.

They do not seem to plan to charge the batteries with ICE power of the ICE propulsion engine except when at an airport without a charging station.

Their proof of concept is on the Skymaster model, with electric motors at the front of each tail boom. The production version is a very sleek design with three relatively small electric motors driving the same shaft as the ICE engine, and using three small ones, the assembly fits inside a relatively small, streamlined cone at the tail end of the fuselage.

The production design is much more slippery than the Skymaster version. Wisely, they are building the central structure of aluminum, for lightning protection.
 
How do you figure carrying 2 extra motors and the inefficiency of converting fuel to electrons with a small ICE engine is going to result in a 20% increase in efficiency? I’d wager it’s closer to a 20% decrease.
I’m not going to argue their numbers, but I’d bet a small generator with modern engine controls that is optimized to run at a narrow rpm range might be more efficient than a large bore lycosaur. Cooling ducts could be done better than the typical cowl as well.
 
I like the hydrogen powered Malibu better. I read somewhere the skymaster clone had a max weight of 11,000 lbs! Surely that's a typo or for a larger version?
 
I like the hydrogen powered Malibu better. I read somewhere the skymaster clone had a max weight of 11,000 lbs! Surely that's a typo or for a larger version?

Those that hype hydrogen as a clean fuel with the potential to become a primary source of power for automobiles, trucks, trains, and aircraft almost without exception fail to mention an inconvenient reality. Producing hydrogen in large quantities is an expensive and energy consuming proposition that is not economically feasible.

If that fact happens to be addressed by its proponents, they assure the easily fooled green energy media that a breakthrough in methods to produce hydrogen cheaply in the vast quantities required for widespread adoption are just over the horizon.

Also left unsaid is that using hydrogen, the lightest element, to produce motive power will require manufacture, transport, and dispensing of the highly combustible product in large quantities at extremely high pressures. This will be expensive, and considering the average motoring public's lack of any sort of technical aptitude, dangerous.
 
I’m not going to argue their numbers, but I’d bet a small generator with modern engine controls that is optimized to run at a narrow rpm range might be more efficient than a large bore lycosaur. Cooling ducts could be done better than the typical cowl as well.

Our current GA engines have pretty good specific fuel consumption:https://en.m.wikipedia.org/wiki/Brake-specific_fuel_consumption

Light passenger vehicles need things like variable valve timing because they are mostly run at very low throttle openings, where they are not very efficient. I could see a 10 percent or so bump in efficiency if we adopted the pseudo Atkinson cycle technology that hybrid cars use, but I can't see anyone investing the money to do that for the small size of the market.
 
Having driven a Volt for eight years now. I'm not seeing this as a win. Even the volt clutches in the gas motor direct to the wheels in hybrid high speed operation. It runs the engine at high speed into the generator only for the lower speed ops.
 
The reason that hybridization works for cars is that in city and suburban driving they spend a good bit of time decelerating and stopped, so there's kinetic energy that can be captured during that deceleration, and fuel to be saved while the car is stopped. The only time that light GA airplanes have extra kinetic energy to be shed is during final and rollout, and for the most part spend little time idling on the ground, so there's not that much energy to save in a battery.
Yup. It's a result of the same old problem: a lack of recognition that cars are not airplanes. It's just that simple. They both have pistons and wheels, but that's about it.
 
Their initial goal is a minimum of 3.5 hours at 200 Knots, with optional long range configurations.

Not much of a comparison to cars, but interesting as a concept...
 
I read this article somewhere- maybe here?? but it gives a good physics lesson on the practicality of electric flight.
https://www.wired.com/story/how-far-can-you-fly-a-battery-powered-jumbo-jet/amp
Yup. The battery technology is nowhere near adequate for anything but really short flights in small airplanes. Airplanes are not cars. They require high power output pretty much the whole time except for taxiing and approach. Flying is an energy-intensive business.

The same problem will prevent electric farm machinery such as tractors and harvesters from ever becoming a reality unless we come up with some completely different way of storing electricity. The John Deere 9560RT tractor I drove for a farmer during harvest a few years ago had a 560 HP engine. I wasn't working it too hard while pulling a grain cart, maybe as much as 50% power, but when it's cultivating, that engine is maxed out. For many hours each day. The same 560-hp engine was in the combine harvester, and it was at redline the whole time it was working. And it was working from about 9 AM to after dark. 12 hours a day sometimes. Just imagine the battery needed for that. Over 5000 kWh. Isn't that about 100 Tesla batteries?

And our governments want electric tanks and fighter planes for the military. Insanity.
 
Well, we could start out by making more electric ships. The carriers have been doing great with that, and submarines, too.

I don't know that I love the idea of farmers working on nuclear reactor powered tractors, though. I do think it would be cool to present one as a prototype 'zero carbon' solution, though.
 
I think many GA people do not realize for the small feeder lines; how much time is lost in taxi, takeoff, and being held low around major airports.
For example, I did a Cape Air flight a few years ago into Boston Logan. The flight time was maybe 20 minutes, the taxi time was at least 30 minutes. This is fairly typical of the target local regional flights. These planes will need to occasionally go farther, but that will not be the bread and butter of the market.
With all that idle time on start and taxi; there is plenty of opportunity for range extender model to make sense.

Tim
 
Well, we could start out by making more electric ships. The carriers have been doing great with that, and submarines, too.
Yup. Big stuff that doesn't crash (or sink) when its engines die. Ships are about the most efficient means of transportation, in terms of weight transported, distance and fuel burn, on the planet. It's why they were easily wind-powered up until the late 1800s. It's why I could have heavy stuff shipped from Japan to Vancouver, 4700 miles, for much less than it cost to transport the same weight between Vancouver and Kamloops, about 280 miles, in the 1970s.
 
[QUOTE="tspear, post: 3348392, member: 8389"
With all that idle time on start and taxi; there is plenty of opportunity for range extender model to make sense.
[/QUOTE]
I'd like to see a summary of the complete savings of range-extender technology, including mining, manufacturing and environmental costs, as opposed to the current ICE engine-only affairs. Remember, there's only so much lithium on this planet, and getting at most of it means a huge mess and either lots of pollution or lots of costs. We're going to need much better battery tech before any of this makes much sense at all.
 
I think you'll see the interim solution will be turbine/electric burning 100% SAF fuels and diesel/electric burning biofuels considering they are in use right now. Its also the reason behind the hydrogen fuel cell technology mentioned above as battery technology is not there for all markets. That said, current battery technology is starting to take a back seat in the larger markets as we speak.
 
I've always wondered why they don't just use electric-powered wheels to drive the aircraft around the large airports, especially for taxiing and similar. Seems like it would make a lot of sense and seems like you could easily add an electric-driven nose wheel to just about any aircraft.
 
I've always wondered why they don't just use electric-powered wheels to drive the aircraft around the large airports, especially for taxiing and similar. Seems like it would make a lot of sense and seems like you could easily add an electric-driven nose wheel to just about any aircraft.
What for? An idling engine (that is already installed) does it far better, for less money, and with much less weight and complexity, than any nosewheel motor could. And if it was run by batteries so the engine could be shut down, you'd need to have those too, along with their cost and weight and volume.

Then there's the traction issue. Most of the weight is on the mains.

It would save nothing.
 
Well, those are damn good reasons!
I figured this more for jet airliners, who have lots of ground movement and waiting around at big airports. Driven wheels seen more efficient than props or jets, and an electric would let you use the power generated by the jet engines.
But, you may have just demonstrated why I am not an engineer.
 
I'd like to see a summary of the complete savings of range-extender technology, including mining, manufacturing and environmental costs, as opposed to the current ICE engine-only affairs. Remember, there's only so much lithium on this planet, and getting at most of it means a huge mess and either lots of pollution or lots of costs. We're going to need much better battery tech before any of this makes much sense at all.

I doubt you will ever see a complete study that you are advocating for. In terms of Li, there is a lot available in the world. The question is cost to access it. For example, there are huge amounts of Li in the USA, but currenting mining techniques for Li require massive amounts of water. Where we have Li, we have no water.... Therefore, we either need to bring in massive amounts of water and spend a lot of money on a closed loop system, or we will need a new mining technique.
It really is only a question of time before such issues are solved, and they are way outside the parameters in determining if Alice is technically feasible.

As for battery tech, I agree there will be changes to it. Question is when. From the stuff I read, I think we are getting close to replacing most of the NMC in large battery systems (things too big to hold in a hand); and for static systems I see we are probably cloose to moving away from LiOn completely due to cost.

Tim

edit #1. fix quote marks
 
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I think you'll see the interim solution will be turbine/electric burning 100% SAF fuels and diesel/electric burning biofuels considering they are in use right now. Its also the reason behind the hydrogen fuel cell technology mentioned above as battery technology is not there for all markets. That said, current battery technology is starting to take a back seat in the larger markets as we speak.

SAF for turbine will work and will likely be used for anything larger than a 9 person plane or something that goes more than roughly 200 miles. Outside of that, diesel has many implementation issues in a direct drive situation. There are a few certified diesel solutions (CMI, Austro), however they are very expensive and heavy. If you want want to utilize a cheap masss produced engine, the only solution will be to use the engine as a range extender. This is not as efficient, but significantly cheaper to develop.

I doubt you will see SAF for light GA. The problem is two fold; first is SAF for gas is based on alcohol. Alcohol is a solvent which breaks down most composite structures by attacking the resin. So, the most prolific plane produced in the past two decades cannot go near alcohol based solutions. Further, alcohol is know to attacks and degrade most glues and rubbers. Therefore, the super majority of the rest of the fleet is likely vulnerable to fuel systems coming apart.
And these issues would have to be figured out before you could even start to thinking about the second issue which is going for certification.

Tim
 
I've always wondered why they don't just use electric-powered wheels to drive the aircraft around the large airports, especially for taxiing and similar. Seems like it would make a lot of sense and seems like you could easily add an electric-driven nose wheel to just about any aircraft.

There have been a few attempts using the large plane tow vehicles to effectively do this. The few ones I have read about ran into a lot of logistic issues. I tend to think they did not do enough planning and spend enough time work out how this would work in practice. I saw a PR piece from I think United Airlines Investment, that discussed an automated solution which is being developed for EU airports. An electric tow, that hooks to both mains and is controlled by the pilot. Released near the runway and returned to a storage area to charge, near the landing zone for the next plane equipped with the control system. Eu has the regulatory structure in place to encourage a solution to be developed and for the issues to be worked out.

Tim
 
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