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 - FLYING Magazine

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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