Electric and Hydrogen aeroplanes - feasibility and issues

GTX said:
www.abc.net.au

How close is Australia's aviation industry to going fully electric?

Multiple Australian companies are pioneering the country's electric aviation industry. So how are green planes powered, how safe are they, and what will it cost?
www.abc.net.au www.abc.net.au
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I think one big misconception about electric engines is that since they have fewer moving parts people assume they must be simpler and inherently trouble free. But the electronics and software needed to manage them is incredibly complex. This is an old but good interview that sheds some light on these engines:

MagniX Seeks Retrofit Certification Path | Aviation Week Network

The company is focusing on the retrofit market as the easiest path to market for its electric propulsion units.
aviationweek.com aviationweek.com

“People say electric motors are much less complex than gas turbines,” Armesmith says. “And that is true physically, but functionally, and in software, I would say [motors] give [turbines] a run for their money."

“Controlling permanent magnet machines is complex,” she continues. “And the software around extremely fast-acting protection systems that can get ahead of an electrical fault is very complex. A lot of our development recently has been around that.”
 
The Fully Charged channel was originally about electric ground vehicles but has expanded its scope to all things electric, including aircraft and infrastructure. Here's one video from 2022 about the first commercial electric plane, the Pipistrel. Some may recognise Robert LLewellyn as Kryten from Red Dwarf.

View: https://www.youtube.com/watch?v=YdfYXlUK6is


This is a recent update the first public charging network, Aerovolt, featuring the Pipistrel again. At the nine minute mark the discussion looks at other aircraft, then charging technology and growth of the company.

View: https://www.youtube.com/watch?v=_hmEjconLyA
 
Scott Kenny said:
Electric power works tolerably well for small scale aircraft, up to something maybe the size of a Beaver or Otter/Twin Otter, and as long as you're flying short distances of less than 100nmi/190km.
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The farce that was Alice in wonderland proved that it doesn’t “work(s) tolerably well.”
 
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Scott Kenny said:
Electric power works tolerably well for small scale aircraft, up to something maybe the size of a Beaver or Otter/Twin Otter, and as long as you're flying short distances of less than 100nmi/190km. Bigger loads or longer distances, and you can't carry big enough batteries to make the trip.
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I agree. For short haul travel, the only viable option with the technology currently available, is hybrid electric propulsion.

www.ainonline.com

Heart Sets Up U.S. R&D Hub for ES-30 Hybrid-electric Regional Airliner | AIN

Heart Aerospace will base development work for its hybrid-electric 30-passenger aircraft in California as it works towards type certification in 2028.
www.ainonline.com www.ainonline.com

www.flyingmag.com

12-Hour Hybrid-Electric Flight Sets New Endurance Record

Manufacturer Ampaire this week took its hybrid Electric EEL demonstrator on its longest flight yet, eclipsing its own endurance record.
www.flyingmag.com www.flyingmag.com
 
Scott Kenny said:
Electric power works tolerably well for small scale aircraft, up to something maybe the size of a Beaver or Otter/Twin Otter, and as long as you're flying short distances of less than 100nmi/190km. Bigger loads or longer distances, and you can't carry big enough batteries to make the trip.
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Connecting islands with small populations seems to be a good niche. The advantages are essential and the disadvantages don't matter.


www.orkney.com

Electricity in the air above Orkney | Orkney.com

The first hybrid-electric plane in Scotland has taken to the skies above Orkney.
www.orkney.com www.orkney.com

Hybrid Air Vehicles is in on it too.

news.stv.tv

Electric aircraft reserved for Highlands and Islands as plans progress

Sites in Orkney, Shetland, Western Isles and the Highlands are being proposed as part of the plans.
news.stv.tv news.stv.tv
 
The big problem with operating many short frequent flights is that you would wear out the batteries so fast that the economics of constantly replacing them wouldn't work out. That is the reason Tecnam cited when they ceased development of their 9 seat all electric aircraft.

www.ainonline.com

Tecnam and Rolls-Royce Stop Work on P-Volt Electric Aircraft | AIN

Current battery technology is not cost-effective for commercial flight operations due to useful life limits, according to Tecnam and Rolls-Royce.
www.ainonline.com www.ainonline.com
 

Why Hybrid-Electric Aircraft Developers See Their Moment Coming | Aviation Week Network

Developers of turbo- and diesel-electric generators offer flexibility.
aviationweek.com aviationweek.com

This article has a paywall but here are the main points:

* Battery density is not improving fast enough for even short commuter flights. As a result battery electric fixed wing aircraft will be confined to limited niche roles for the foreseeable future.
* The best battery right now offers 200 Wh/kg but just started the FAA certification process.
* Any small commuter aircraft incorporating today's batteries with IFR reserves factored in would get less than 100nm of usable range.
* A hybrid electric powerplant would utilize a simpler thermal engine, reducing wear and tear. That could possibly lead to the FAA extending time between overhauls (TBO) giving it a competitive advantage.
* The Electra 9 seat eSTOL project is going to use a 600kW electric turbo generator developed by Safran.
* The TBO can potentially be tailored to each operator depending on what type of mission profiles they fly with their aircraft. I don't know if the FAA would go for that but we'll see how that pans out.
* Ampaire projects that their diesel electric Caravan could create operating costs savings as much as 25 to 40% through lower fuel burn and reduced MRO expenses.
* These aircraft can shut down their thermal engines and fly on battery power alone for a short period, such as during an approach to a noise sensitive airport.
* Hybrid electric aircraft will not require to be plugged in and charged while on the ground, giving them an advantage as they do not require new infrastructure to be built to accommodate them.
 
alberchico said:
* These aircraft can shut down their thermal engines and fly on battery power alone for a short period, such as during an approach to a noise sensitive airport.
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The primary noise source from a propeller-driven aircraft is the prop, not the engines.

Best example is the B17, you can hear those droning overhead at 200hz from miles away. But that's not the engine noise, you don't hear that at takeoff.
 
It doesn't make sense to shut down any power when it is needded most. A direct drive turbocharged Diesel engine will be almost unhearable at take off.

It could make sense to replace starter and generator with an electric mashine which could provide additional power during take off, so that a Diesel powered plane (like the M500) would have the same take off power like a turbine powered plane. With a two stage charging system, the Diesel engine could provide more power at high altitude than a typical small turbine (talking about turboprops)
 
Pigeons are heavy for a fast spinning short span CFRP blade with a fixed pitch (the blade absorb the full momentum own + that of the pigeon)
 
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Missed this at the time. Rolls Royce did work on a prototype light electric aircraft, the beautiful ACCEL, but new management has decided to concentrate on biofuels. It's not that they think that electric propulsion is a dead end but that for the foreseeable future, it's going to be suitable only for light and general aviation. RR has decided to concentrate on its primary market, which is engines for large, long-range airliners. They're not shutting down the electric division but trying to sell it off and may even keep a minority stake.

It makes sense - very different market sectors with different economies and management/manufacturing/marketing needed. At one stage, the car maker Rolls Royce (with the Bentley brand) was owned by Vickers, a predecessor to BAE Systems (https://en.wikipedia.org/wiki/Vickers), which was not the best place for it.

www.carscoops.com

Rolls-Royce To Sell Electric Flight Unit To Focus On Jet Engine Business | Carscoops

The company believes that sustainable aviation fuel is the sole path for large airliners to achieve net zero climate targets
www.carscoops.com www.carscoops.com

(For anyone wondering, RR the aero-engine maker is a separate entity from RR the car maker and the two separated long ago. The aero-engine maker is an independent company and has the rights to the name, while the car maker, which is owned by BMW, uses the name with permission. It was a similar case with the car maker SAAB.)

Image of ACCEL attached.

51481062732_70fc127a8e_k.jpeg
 
There ! Somebody has finally seen the light and made a master study of ammonia for jetliners. A very good reading.

Okay, for an A350 it cuts the range from 16 000 km to barely 6500 km. That's... bad. Yet still enough to cross the Atlantic, or the Pacific with a stop in Hawaii. Just ask Concorde.
Then I wonder, how did people air travelled in the early 1960's, when largest airliner was DC-8-61 ? Scoop: they made refueling stops. If that's the price to pay for de-carboning of airliners, I'm all for it (plus 9200 km Paris - Réunion Island BY NIGHT in an A330 is complete hell, particularly with a 2.5 years old kid.)
 

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Archibald said:
There ! Somebody has finally seen the light and made a master study of ammonia for jetliners. A very good reading.

Okay, for an A350 it cuts the range from 16 000 km to barely 6500 km. That's... bad. Yet still enough to cross the Atlantic, or the Pacific with a stop in Hawaii. Just ask Concorde.
Then I wonder, how did people air travelled in the early 1960's, when largest airliner was DC-8-61 ? Scoop: they made refueling stops. If that's the price to pay for de-carboning of airliners, I'm all for it (plus 9200 km Paris - Réunion Island BY NIGHT in an A330 is complete hell, particularly with a 2.5 years old kid.)
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Very similar proportionate results to my/our A320 study, except we extended the range with some sizeable wingtip mounted tanks;- max bending relief. Our other study was a mixed fuel Ammonia/SAF A321 which allowed recovery of range and also offered flexibility of fuelling at destination;- to ease the fuel type transition. It’s ammonia’s compatibility with wing storage that’s the key difference with LH2 which has a massive improvement in platform aero efficiency. Despite these advantages over LH2 these were all soundly rejected by the Airbus Hydrogen mafia.
 
SAF + NH3 ? Excellent ! Do you published a tech paper somewhere ?
It’s ammonia’s compatibility with wing storage that’s the key difference with LH2 which has a massive improvement in platform aero efficiency.
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This. A hundred percent. Can still remember 1st time I saw a LH2 airliner project in a magasine 20 years ago. Had an 8-shaped fuselage 2 lobes with the LH2 on top of the passenger cabin.
I instantly hated the compromise.
NO.WAY.
Airliners have stored their fuel in wings since WWII bombers pioneered it. For good reason. It's a perfect bargain ! Safe for passengers, uses the wing or even makes it better.
If LH2 can't do that then screw it. Plus the dismal density, 0.25 of water rather than kerosene 0.8. Thrice lower ! Not only LH2 screws wing tanks, but it bloats the fuselage while endangering the passengers.
No. Thanks.
 
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No the study can’t be published but the Patent is now public…. Oh bugger you might be able to figure out who I am!
 
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This unveiling took me by surprise. I had no idea this company was secretly working on a full scale prototype. I assumed they would take the cheaper option of converting a small aircraft like a Twin Otter into a testbed to see if their hybrid tech worked as expected. This project is making some rapid progress compared to other outfits like Eviation.


newatlas.com

Full-scale demonstrator paves the way for hybrid-electric airliner

It was just this July that we heard about the ES-30, a hybrid-electric airliner being developed by Swedish firm Heart Aerospace. Well, the company has now unveiled a full-scale demonstrator version of the plane, which should fly next year.
newatlas.com newatlas.com

https://twitter.com/x/status/1834290323737981156
View: https://x.com/Allplane/status/1834290323737981156


https://twitter.com/x/status/1834483407989977120
View: https://x.com/heartaerospace/status/1834483407989977120
 
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www.flightglobal.com

No let-up in sight as Heart attacks ES-30 development

Having unveiled its first flight-test prototype, Heart Aerospace is now working to get the HX-1 airborne next year while also overcoming the multiple engineering and production challenges on the path to developing its ES-30, a hybrid-electric airliner targeted for service-entry by the end of...
www.flightglobal.com www.flightglobal.com

Some key points:

"Unveiled on 12 September at the company’s Gothenburg Save airport facility, the HX-1 will perform its first flight in the USA"

"Prior to its disassembly, the all-composite prototype will be subjected to a ground-test campaign to validate its systems."

"The HX-1 will be followed in 2026 by the next prototype, the HX-2, the first to be quipped with its “independent hybrid powertrain”: a pair of turboprop engines on the outboard part of the wing and twin inboard electric motors."

"Although flights under 108nm will be flown almost entirely on electric power, the turboprops will be brought on line during landing in case a go-around is required."

"Heart is promoting the ES-30 as a 30-seat aircraft but is also contemplating a 34-seat option – removing the lavatory and instead installing an extra row of four seats at the rear of the cabin while largely maintaining a 30in pitch."

"Having a vertically integrated production system will allow Heart to incorporate changes faster, avoiding the long lead times these can introduce when dealing with external suppliers, Forslund argues."
 
I’ve been studying at the few very short views given of the aircraft structure during build and it doesn’t look to be a normal flight standard;- there’s squared off holes in the wing ribs (I’d guess these are MDF), there’s no bolt holes or spar extension to take the wing bending loads. no fuel tank sealing, no signs of any flight systems components or mounting points for them, no provision for electrical cables, no signs of strengthen points for higher flight/ground loads (the rudder spar is looks like a piece of thin gauge Al with no hinge points, or driving points). No flanges on the tail fin ribs, so what does the skin attach to? Additionally despite the “all composite” claim, the structure looks typically aluminium but without any signs of rivets. And they’re attaching the skin without a supporting fixture for the ribs & frames? It reminds of the combined wooden/metal mock up (air show standard) we used to make in the late eighties. This is really gonna fly….right?
 
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Yes, it´s a bit dodgy. I do concur that we are not given the appropriate visuals to understand it as a flying prototype.
If my mem stands right, Heart Aero has the same backer/owner as Northvolt who is facing hard time at the moment. There might be something there to explain the timing and what´s rolled out. But once again, the visuals and hardware might not be synchronized. (?!)

If we compare it to other startups and their similar said so prototypes, the quality of the execution here is well represented and the design maturity palpable (see how it evolved during the multiple iterations). But still, what´s on screen is more a big mockup than a flying airframe.

Also, IMOHO, there is still a big NoNo with the battery pack supposed to absorb the severity of the impact during a gear-up landing (dynamic compression of the batteries would generally be thought to have catastrophic consequences that you would want to avoid, not even accounting the heat generated by the scraping along the runway). Batteries runaway and fire are things you don´t want to expose the poor passengers, adding that severity to the already factor of a CFRP fuselage.

Here are some pictures to illustrate your remark:

HearthAerospace_240912.jpg

HearthAerospace_240912b.jpg

HearthAerospace_240912c.jpg

So let´s wait & see what comes next from them because at this stage it is hard to be 100% convinced, given the pre-existing behavior of the overall aero startup industry. Better communication is indeed needed.

Oh, and, if any of their employee happens to read this, the swearing was not fun.

EDIT:

Seems they are moving their business unit from Gothenburg/Sweden to LA/USA.
 
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From the link above:
With a commanding 32-meter wingspan, the demonstrator, named Heart Experimental 1 (Heart X1), will serve as a platform for rigorous testing and development of Heart’s ES-30 aircraft.

Initially, the HX-1 will be used for ground-based testing, focusing on charging operations, taxiing, and turnaround procedures. It is scheduled to undertake a fully electric first flight in the second quarter of 2025. In preparation for this flight, Heart will over the coming months, test critical systems by running hardware tests both on and off the airplane.
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Hard to see that plan fully executed as stated above but that their say...
 
Zoo Tycoon said:
I’ve been studying at the few very short views given of the aircraft structure during build and it doesn’t look to be a normal flight standard;- there’s squared off holes in the wing ribs (I’d guess these are MDF), there’s no bolt holes or spar extension to take the wing bending loads. no fuel tank sealing, no signs of any flight systems components or mounting points for them, no provision for electrical cables, no signs of strengthen points for higher flight/ground loads (the rudder spar is looks like a piece of thin gauge Al with no hinge points, or driving points). No flanges on the tail fin ribs, so what does the skin attach to? Additionally despite the “all composite” claim, the structure looks typically aluminium but without any signs of rivets. And they’re attaching the skin without a supporting fixture for the ribs & frames? It reminds of the combined wooden/metal mock up (air show standard) we used to make in the late eighties. This is really gonna fly….right?
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At least the empennage section looks like they're hand laying composites over the structure there and maybe allowing them to glue to the formers.

I've seen automotive widebody fenders made the same way.

That is NOT how I would make a flight-worthy article directly, but it appears to work on relatively small items like canoe fairings. Also, there's that composite fuselage X-plane that was originally laid out like that for the master, then had the tools made of fuselage halves that were then glued together.
 
That´s much better.

There are no more batteries in the sponsons for example and CGI are more refined and decoupled from the mockup/Iron bird.

I don´t know you but there is a bit too much people in ectasia for my own taste (see the time ratio b/w information and people nodding frantically in closeup shots) ;)
 
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Probably a game changer to mitigate the serious risks that have been so far put aside in the name of rapid progress; Li batteries get shortcuts and runaway protection akin to what are self sealing tank lining.

Here, we introduce a scalable approach to fabricating the safety reinforced layer (SRL), designed to provide LIBs with an immediate shutdown capability in the event of internal short circuits, thereby minimizing the risk of overheating and explosions. The side chains of conductive polymers within the SRL have been tailored to trigger the PTC transition around 100 °C, while also ensuring the polymer’s high solubility in a commercially viable solvent, toluene, as opposed to chloroform. We uncover an unexplored phenomenon that incorporating carbon additives into the SRL facilitates the doping/de-doping kinetics of the conductive polymer, maintaining the high conductivity of SRL under standard battery operation. Despite constituting <0.5% of the total cathode weight and thus preserving the battery’s power and energy densities, the SRL efficiently interrupts current flow when a short circuit occurs, or the temperature surpasses 100 °C by elevating the resistance fourfold. Utilizing a 500 L reactor for the mass production of the polymer and a roll-to-roll (R2R) coating system designed for 1700 mm-wide current collectors, we have achieved a production capacity of 5 km per day. Impact tests on 3.4-Ah pouch cells have statistically shown that the SRL decreases the rate of battery explosions by 53%.
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www.nature.com

Thermal runaway prevention through scalable fabrication of safety reinforced layer in practical Li-ion batteries - Nature Communications

The authors present a scalable method for implementing a thermo-responsive safety reinforced layer (SRL) in batteries, which enables immediate shutdown during internal short circuits and reduces the risk of overheating and explosions.
www.nature.com www.nature.com
 
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www.ainonline.com

Electra Launches Hybrid-electric EL9 Short Takeoff and Landing Aircraft | AIN

Electra is hoping to create accessibility to air travel with its EL9 aircraft that will be able to take off in 150 feet of runway.
www.ainonline.com www.ainonline.com

The definitive version of this aircraft has been unveiled. I wonder how this will compete in operating costs with something simpler like the Tecnam P2012. I guess it depends on just how big of a demand there is for an aircraft of this size with extreme STOL performance.

https://twitter.com/x/status/1857131391861026929
View: https://x.com/ElectraAero/status/1857131391861026929
 
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alberchico said:
www.ainonline.com

Electra Launches Hybrid-electric EL9 Short Takeoff and Landing Aircraft | AIN

Electra is hoping to create accessibility to air travel with its EL9 aircraft that will be able to take off in 150 feet of runway.
www.ainonline.com www.ainonline.com

The definitive version of this aircraft has been unveiled. I wonder how this will compete in operating costs with something simpler like the Tecnam P2012. I guess it depends on just how big of a demand there is for an aircraft of this size with extreme STOL performance.
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Interesting concept indeed, but complex/expensive systems. AEH+SW, DEP+batteries+turbo-generator, etc...
It remains to be seen whether this type of aircraft can establish itself in the targeted market segments. Operating cost is definitely an important factor as well.
 

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