Electric and Hydrogen aeroplanes - feasibility and issues

https://www.futureflight.aero/news-...ce=twitter&hss_channel=tw-1160922136632053766
Very interesting development. This is currently the only 19 seater in development that will incorporate a rear cargo ramp, so it might give the Cessna Skycourier a run for its money. It also might be a very useful as a light military transport. The only problem with this configuration is that you save fuel but you also add a lot of weight and complexity to the design.
 

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alberchico said:
https://www.futureflight.aero/news-...ce=twitter&hss_channel=tw-1160922136632053766
Very interesting development. This is currently the only 19 seater in development that will incorporate a rear cargo ramp, so it might give the Cessna Skycourier a run for its money. It also might be a very useful as a light military transport. The only problem with this configuration is that you save fuel but you also add a lot of weight and complexity to the design.
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"Desaer's planned hybrid electric ATL100 regional airliner will feature MagniX's electric propulsion system and a pair of turboprop engines"

How can additional weight and drag help to safe fuel?

ATL100Hibrid002.png
 
VTOLicious said:
How can additional weight and drag help to safe fuel?
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The peak power you need during takeoff is typically much greater than the level of power you usually need during level flight. The power-to-weight of an electric engine is dramatically higher than that of a turbine, so long as you only need that power for a minute or two. A hybrid aircraft that is provided with sufficient power for taking off by the electric engines, and has conventional engines sized to only provide the constant power needed for level flight or very slow climb can be substantially lighter and less draggy than a conventional plane that has turboprops sized for takeoff loads.

Of course, all engineering comes with tradeoffs, and in this case one of those is that if one of it's turboprops fails, a conventional plane that's in the air has plenty of power reserve remaining, while a hybrid plane that's at altitude with empty batteries wouldn't.
 
Tuna said:
VTOLicious said:
How can additional weight and drag help to safe fuel?
Click to expand...

The peak power you need during takeoff is typically much greater than the level of power you usually need during level flight. The power-to-weight of an electric engine is dramatically higher than that of a turbine, so long as you only need that power for a minute or two. A hybrid aircraft that is provided with sufficient power for taking off by the electric engines, and has conventional engines sized to only provide the constant power needed for level flight or very slow climb can be substantially lighter and less draggy than a conventional plane that has turboprops sized for takeoff loads.

Of course, all engineering comes with tradeoffs, and in this case one of those is that if one of it's turboprops fails, a conventional plane that's in the air has plenty of power reserve remaining, while a hybrid plane that's at altitude with empty batteries wouldn't.
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I'm aware of the basic principle.

What I question is the implementation shown in the picture I've posted.
It suggests they would put two electric motors (incl. nacelles, propellers) on the wings IN ADDITION to the Turboprops of the standard aircraft.
 

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alberchico said:
https://www.electra.aero/
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I switched off when I read “it will have in flight battery recharging”. Just where is the energy coming from? Having a fuel, electrical generator and battery makes no sense in a platform as weight sensitive as this. And at some point someone’s has to squirt something into it, be it liquid or electricity.
 
alberchico said:
https://www.motherjones.com/environ...rplanes-aviation-battery-research-technology/
This article is interesting because it explains the challenges that involve improving battery technology for use in aviation.
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Lithium is the third lightest element. It’s got just three electrons and can give only one up but that’s 33%. Any other alternative element is going to be heavier,i indeed much, much heavier. Lithium is also naturally reactive so is keen to give up its electron. I guess for a mass competitive chemistry, the reactivity has to out pace the increase in density, but too much just creates too stable a reaction product. Where next for the balance of density and reactivity?
 
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alberchico said:
If this company manages to meet it's promises regarding range and payload, this aircraft could prove to be a serious competitor to the Tecnam P2012. Considering that the USAF as well as Lockheed Martin are investing in this project they have a chance. The fact that it has extreme STOL capabilities could be very useful in the developing world.
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Speaking of Tecnam, what's the status of the X-57 programme? It's supposed to explore the feasibility of DEP.

https://www.nasa.gov/specials/X57/

Edit: Found a vid that was posted six months ago..."looking forward to first flight"...

View: https://youtu.be/2SP0PZws9jQ
 
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https://newatlas.com/aircraft/odys-evtol-interview-james-dorris/
One thing I love about this site is that when they conduct an interview, they actually ask meaningful questions instead of just writing some fluff piece like so many other sites that cover this industry often do.

This has got to be my favorite interview so far. I like how they hold this guys feet to the fire over his preposterous idea of creating an evtol the size of a small bus.

https://newatlas.com/aircraft/braeden-kelekona-interview-massive-evtol/
 
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aonestudio said:
Airbus and @CFM_International to pioneer hydrogen combustion technology https://fly.airbus.com/3h47foH
..................
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A lot of bla bla.

All that Airbus and CFM will do is take an existing jet engine, modify the burners and fuel system, mount that engine at the rear fuselage of an A380 and put a couple of LH2 tanks inside the A380.

First flight is scheduled for the end of 2026.

So it will take Airbus/CFM at least 4.5 years to achieve that.
Either they are incompetent, or, more likely, they don't really care and do this only for green publicity and drag it on as long as possible.
 
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https://www.bloomberg.com/news/feat...hes-delays-put-bezos-s-delivery-dream-at-risk
This article details how despite spending almost 2 billion dollars over a period of 10 years, Amazon still can't get their dream of delivery drones off the ground.

"A Bloomberg investigation based on internal documents, government reports and interviews with 13 current and former employees reveals a program beset by technical challenges, high turnover and safety concerns"

"A serious crash in June prompted federal regulators to question the drone’s airworthiness because multiple safety features failed and the machine careened out of control, causing a brush fire"

I wonder how many of these upstart eVTOL companies have designs that simply can't be certified for commercial use but don't realize it yet because they completely underestimated how tough regulatory bodies are when it comes to aviation as opposed to other fields.
 
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alberchico said:
This article details how despite spending almost 2 billion dollars over a period of 10 years, Amazon still can't get their dream of delivery drones off the ground...
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This reminds me a bit of the story of Samuel Pierpont Langley vs Orville and Wilbur Wright.
 
https://evtol.com/news/eve-enlists-thales-develop-evtol-aircraft/
https://www.flyingmag.com/embraers-eve-air-mobility-partners-with-thales/
"The companies announced on Wednesday that they have been partnering since January to conduct joint studies to examine the technical, economical, and adaptable feasibility of Eve’s aircraft. The study will run until the end of the year, the companies said."

"In addition to developing avionics, the Eve/Thales partnership includes extensive joint research on the overall feasibility of an eVTOL aircraft"

I'm a bit confused by these statements. Considering the large number of orders this aircraft has received, I assumed that Embraer had already committed themselves to see this project through all the way to certification. But they're still evaluating whether or not designing an eVTOL is feasible ? So does that mean that they could suddenly pull the plug and scrap the project if they feel like the business case is not strong enough ?
 
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Charlesferdinand said:
Not sure if it qualifies as an airplane, but there is the Regent seaglider, an all electric WIG craft that was presented recently. According to the press release, they already have 334 on order.

https://www.prweb.com/releases/2022/4/prweb18626378.htm
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Related to that,

https://www.stuff.co.nz/business/12...ctric-seagliders-to-connect-nz-cities-by-2025
2025 looks pretty optimistic, to put it mildly. Certification of an aircraft would take longer than that. However, supposedly...

Ocean Flyer had begun discussions with Maritime New Zealand which was likely to be the safety regulator for seagliders rather than the Civil Aviation Authority, he said.

Caveats: "begun discussions" doesn't mean much, the reporter has a good CV but his areas are business and technology (that is, gadgets, not aviation).

At first glance, ekranoplans would make a lot of sense in New Zealand - most of the population is in coastal cities and there's be a demand for fast, flexible, and frequent transport across the strait between the two major islands as well around the Auckland area.
 
Rhinocrates said:
Charlesferdinand said:
Not sure if it qualifies as an airplane, but there is the Regent seaglider, an all electric WIG craft that was presented recently. According to the press release, they already have 334 on order.

https://www.prweb.com/releases/2022/4/prweb18626378.htm
Click to expand...
Related to that,

https://www.stuff.co.nz/business/12...ctric-seagliders-to-connect-nz-cities-by-2025
2025 looks pretty optimistic, to put it mildly. Certification of an aircraft would take longer than that. However, supposedly...

Ocean Flyer had begun discussions with Maritime New Zealand which was likely to be the safety regulator for seagliders rather than the Civil Aviation Authority, he said.

Caveats: "begun discussions" doesn't mean much, the reporter has a good CV but his areas are business and technology (that is, gadgets, not aviation).

At first glance, ekranoplans would make a lot of sense in New Zealand - most of the population is in coastal cities and there's be a demand for fast, flexible, and frequent transport across the strait between the two major islands as well around the Auckland area.
Click to expand...

I'll be honest, I got excited when I saw that image of the prototype but then I realized it was just a small radio controlled sub-scale model. They have a long way to go.

"They are being designed to carry up to 100 passengers at speeds of up to 540 kilometres-an-hour, "

The battery tech to carry that many people on an electric craft at that speed for any meaningful distance is just not there yet.
 
https://twitter.com/x/status/1111314689932308480
View: https://twitter.com/hervepmorvan/status/1111314689932308480


A bit old but an interesting set of images from a presentation given by an ex Boeing engineer who explains what is actually achievable when it comes to designing an electric aircraft. Very interesting that even a basic no frills design that can carry 9 passengers can expect to have a realistic range of only 200nm.

Edit: Found a video of the actual presentation

View: https://www.youtube.com/watch?v=9ZvK4YyoCmg&ab_channel=RoyalAeronauticalSociety
 
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There is even some errors. The conversion from lb/hp to kg/kw is wrong.

Then the pictures doesn't highlight the surrealistic mass figures when it comes to empty weight Vs loaded weight and the nbr of passengers.
Example
Eco210: max difference is 1000kg for crew, catering, baggage, fluids and... 9 passengers. Targeted airline: AnorexiAir...
 
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To be fair, we don't know yet what will be the loaded noise imprint of Joby's design. Neither do they. Probably.

But they certainly know what that should be in approach and final configuration. :rolleyes:
 
https://www.avweb.com/aviation-news/diamond-predicting-20-minute-charge-for-electric-da40/
This comment sticks out at me: "The 90-minute endurance won’t be achieved immediately but will be possible as battery technology evolves".

It would be nice to know what the exact endurance will be when this thing enters service in 2024, not what they hopefully plan to achieve someday. As the comments in the article point out, taking into account that a typical flight lesson is usually 1 hour, plus the time it takes to fly to and from the practice area, as well as the legally required VFR reserves, 90 minutes endurance is simply not enough. At least for the U.S. market.

I had no idea that EASA actually reduced the required reserves for electric aircraft like the Velis Electro down to just 10 minutes to promote the industry, but so far the FAA is not budging on the 30 minute VFR reserve. The article below that discusses Textron's purchase of Pipistrel discusses the poor endurance of these electric trainers with reserves factored in.

https://www.flyingmag.com/did-textron-get-a-good-deal-when-it-bought-pipistrel/
 
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https://www.ainonline.com/aviation-...easyjet-partners-gkn-aerospace-hydrogen-power

https://www.flightglobal.com/aerosp...-hydrogen-fuel-cell-powertrain/147006.article
With all the money Europe is spending on hydrogen research, we might actually see a small commuter aircraft powered by hydrogen enter service at some point in the future. The article below does a good job discussing the pros and cons of hydrogen and electric powered aircraft.

https://interestingengineering.com/...ts four,comfortable for passengers and staff.
 
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alberchico said:
The article below does a good job discussing the pros and cons of hydrogen and electric powered aircraft.
Click to expand...

Sorry to disagree;- the article is widely optimistic, bias and factually incorrect where it suits the narrative- take for example its claims of LiS power density where it claims OXIS energy Ltd are about to deliver at battery at 450Whr/Kg , except OXIS is bankrupt.

”Many of hydrogen’s properties make it safer to use than gasoline, according to some experts”. What … Seriously? Hydrogen inherently leaks, had the widest flammable mixture range (4-74%) of any gas and a minimum ignition energy (0.019mJ) below that of a visible spark. What qualifies these guys to be experts worthy of quoting and why not just tell it as it is?

No mention of the global warming caused by hydrogen infrastructure leakage, which has the potential to be a fundamental hydrogen concept killer.

“Lithium-ion-powered planes are theoretically very well suited for regional flights carrying 30-200 passengers and traveling within around 310 mi (500 km).” Not even close..

“Currently, most of the electric planes on the market today are small……….”duration”.up to around two hours and have a range of at most 300 mi (483 km). Please show me a single commercial available e-plane that can stay aloft today for 2hours with the engine running (sole source of propulsion) or has a range of 300mi? The Alpha is the only one that’s really available on an order basis which has an advertised endurance of 50 mins, others are really gliders where the power is not continuously applied so I’m calling this out as factual incorrect.

It’s poorly researched commentary like this which is miss-directing investors and government research funding.
 
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Speaking of the Pipistrel's Alpha Trainer, ICE- vs. E-Version:

Cruise Speed (75%): 108 kts / 85 kts
Endurance: 3.1 h (incl. 30 m reserse) / 1 h (plus reserve)
Range: 324 NM / 75 NM

Best comparison due to same gross weight and aerodynamic layout. That's the current status of technology.
 
And we can see why Pipistrel choose the elementary trainer as its grand entry into the market. Most of the missions are under 1hr and doesn't involves cross country flying.

If I was manager of such school or service, I would do circuits & basic flight with such a/c, switching to their ICE version for the rest of the syllabus.

The advantages are that wear with power changes are null, mass variation is void (early training involves the trainee mastering the trim, something not always easy when you have no clue what a plane is), there are no limitations with the engine (temperature), not much variation in performances (OAT), not much of takeoff checklist, holds on taxi time can be done engine shut-off, engine behavior during stall is next to perfect (spin could then be safely reintroduced) etc...

Once again Pipistrel proves that Brain is still at the center of aerospace design.

Bravo. I hope they are successful also with that one.
 
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Didn't Australia just elect to use Pipistrel's Alpha Trainer, E-Version for it's basic flight trainer?
 

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