[Jeroen]

Originally Posted by V.Narayan

That’s because such a powerful motor commands the need for extremely high-capacity batteries. It needs a nominal voltage of 540V and the juice is said to have been supplied by a lithium-ion battery pack weighing about an insane two tonnes. The battery pack is so big that it basically occupied all the passenger space in the aircraft, leaving room only for the pilot.

The second photo clearly shows the size of the engine bay of the Cessna Caravan 208 showing the volume occupied by the turboprop and the much smaller space needed by the electric motor.

Very interesting to see that engine bay. But the batteries are a problem giving the size and the weight. It must also be a problem from a weight and balance point of view. Not sure how they deal with it. Normally the weight of the fuel would be distributed mostly across the wings.

Not sure if variable prop would still be advantageous on an electrical driven unit?

If anything it would allow you to reduce drag in case of an (electrical) engine failure by weather vaning. It could provide braking (assist) during landing and even reverse power on the ground.

its probably not the highest priority for them. I wonder what the pilot requirements are for this modified plane? Anything special?

Jeroen

[V.Narayan]

Originally Posted by Jeroen

But the batteries are a problem giving the size and the weight. It must also be a problem from a weight and balance point of view. Not sure how they deal with it. Normally the weight of the fuel would be distributed mostly across the wings.

Not sure if variable prop would still be advantageous on an electrical driven unit?

Exactly my thoughts. Just the way the advent of jet power altered the layout of aircraft, both limitary and civil, similarly electric aircraft will gradually evolve different configurations. Fuel consumption as we fly plays a big role in how aircraft are designed today. It's different with batteries!

With regard to this flight my understanding is that the designers are really testing the motor so they dumped the batteries at the CoG within the cabin as a rough and ready solution. I think they are working on their battery solution. For utility machines like the Caravan one solution for the battery would be to fit them in the ventral pannier which usually carries extra luggage or courier parcels. It has the volume, it is at the CoG and it doesn't take away space in the cabin. {illustrative photo below}

[sandeepmohan]

What is supposed to be very busy nose section looks almost empty with that one electric motor and what appears to be a couple of heat exchange units and an air dryer. Should also reduce some time around regular maintenance or pre flight checks.

[V.Narayan]

World's first hydrogen fuel cell powered commercial aircraft takes flight.


https://newatlas.com/aircraft/zeroav...ectric-flight/

On 24th September, 2020 six-seater Piper Malibu aircraft took off at Cranfield Airport in England. Usually, a 15-minute, 32 kms flight wouldn't be noteworthy -- but this was the world's first hydrogen fuel cell powered flight for a commercial-size aircraft, albeit a small one.

The plane's powertrain -- the mechanism which drives the plane, including fuel tanks and engine -- was built by ZeroAvia, a UK-based company developing hydrogen-electric engines. Using liquid hydrogen and oxygen from the atmosphere to feed a fuel cell electric battery, the technology eliminates carbon emissions during the flight.

A conventional flight today produces half the CO2 generated by flights in 1990, largely thanks to an increase in fuel efficiency. However, due to record traffic growth, driven by increasing passenger numbers and trade volume, the aviation industry is creating more emissions than ever before -- accounting for 2% of global manmade carbon emissions. This percentage is set to increase as other industries, like road transport, are decarbonizing at a faster rate while aviation is lagging behind.

While the spotlight has been on electric aviation for the past decade, the limitations of current battery technology restricts its expansion. Currently, lithium ion batteries are around 48 times less energy dense than aviation fuel. Hydrogen on the other hand mass for mass has 3X the energy density of aviation fuel but volume for volume has 6X lower energy density. This means scaling up is a problem for electric aviation. The largest electric plane flown to date is the 9-seater eCaravan {see post number #15}. It has a range of only ~150 kms -- for which it requires a battery weighing 900 kgs.

ZeroAvia's next step is to carry out a longer test flight to showcase its powertrain's capacity, by flying the six-seater on a 400 kms journey from an airbase in Orkney. Scotland.

This was the first hydrogen fuel cell powered flight of a regular commercial aircraft capable of carrying a practical payload, in this case 6 pax for this Piper Malibu modified for hydrogen fuel cells. The first ever hydrogen fuel cell powered flight that could carry a passenger other than the pilot was the ultra light HY4 of Germany that flew in 2016. The Soviets had experimented, in 1989, with a Tupolev Tu-154 180-seat commercial airliner converted to burn hydrogen in its jet turbofans with the fuel stored in cyrogenic tanks.




First hydrogen fuel cell powered commercial aircraft taking its first flight in September 2020.


The HY4, first hydrogen fuel cell powered aircraft designed as a super light but passenger carrying experimental

[V.Narayan]

From rags to the runway. Japan Air Lines operates regular flight using Sustainable Aviation Fuel {SAF}

https://simpleflying.com/jal-saf-first-flight/amp/
Excerpts from the article....

Flying on fuel made from used clothing, February 4th, 2021, marked a special day for Japan Airlines (JAL). The carrier operated its first commercial flight using a made-in-Japan SAF, or Sustainable Aviation Fuel. While SAF can be made from non-edible plants or agricultural and forestry waste, the SAF used by JAL comes from a more unconventional source: used cotton clothing.

Back in October of 2018, JAL embarked on a project to convert cotton clothing into SAF. The project involved 50 local companies helping to collect upwards of 250,000 pieces of clothing and included technical support from the Green Earth Institute. The process itself was developed by the Research Institute of Innovative Technology for the Earth (RITE). In March 2020, the final result of nearly two years of work was a domestically-produced SAF.

The flight took place on February 4th as flight JL319, taking passengers from Tokyo Haneda (HND) to Fukuoka (FUK) using a Boeing 787-8 registered JA849J.

Data from USA indicates that American solid waste landfills receive about 11.3 million tonnes {yes you read that right} of clothing related waste each year of which only 2.5 million tonnes of which gets recycled.

Flying on SAF does not reduce air pollution but it does contribute to reduce organic solid waste. If this could be developed on an industrial scale it would help reduce organic waste as well as need for petroleum. As some one from the industry I can say it will be a long time till airliners can make even medium range flights on electric power. SAF can be a viable interim solution to use flights to cut solid waste albeit accepting that carbon dioxide and other gases continue to be added.

Photo is of a JAL Boeing 787-300 the type of aircraft used in this experiment

[ariesonu]

Whenever I read about EV or others similar concepts, one thing that really bugs me at back of my head is the source of electricity. If we take a look from that viewpoint then the EV does not sound that GREEN.

Even if we talk about the alternates like windmills or solar energy, the sheer ground space required for them to generate healthy amount of power will be humongous.

Every one acre Solar fields requires about 2-3 tons of water to keep the cells clean and working at 100% capacity, so we are back to wastage of water and hnec cannot imagine solar projects in deserts, where the cells will get covered with sand dust & there is not much water to clean them - EVERYDAY.
Windmills on other hand can only generate power when there is some wind, else they are just idle fans.

World, first, needs to figure out GREENER way of generating enough power to feed the ever growing power needs of the world & should then think of green vehicles.

Regards.

[V.Narayan]

Originally Posted by ariesonu

Whenever I read about EV or others similar concepts, one thing that really bugs me at back of my head is the source of electricity. If we take a look from that viewpoint then the EV does not sound that GREEN.

Even if we talk about the alternates like windmills or solar energy, the sheer ground space required for them to generate healthy amount of power will be humongous.

Every one acre Solar fields requires about 2-3 tons of water to keep the cells clean and working at 100% capacity, so we are back to wastage of water and hnec cannot imagine solar projects in deserts, where the cells will get covered with sand dust & there is not much water to clean them - EVERYDAY.
Windmills on other hand can only generate power when there is some wind, else they are just idle fans.

World, first, needs to figure out GREENER way of generating enough power to feed the ever growing power needs of the world & should then think of green vehicles.

Regards.

The world is already headed in that direction. Well on its way infact. We cannot say that till we have perfect technology to generate green electricity we won't make any efforts in that direction. Whether wind or solar the efficiency rates have grown significantly over the last 15 years. Building electricity from renewable sources has to go hand in hand with improving the technology. Your argument is like saying in 1950 that unless we have the perfectly safe car with all the features of a Volvo of 2020 we wont make any cars and continue on horseback. Or that till we find the perfect cure for cancer we wont treat patients with what we have. You may be looking down the wrong hole. You may want to read up on progress in solar cells and wind turbines. We will agree to disagree on this matter.

[volkman10]

New Airspeeder Mk3 revealed as world’s first electric flying racing car.

The Airspeeder Mk3 flying racing car will compete in remotely piloted events during the second half of 2021, before pilots are dropped into the cockpit in 2022.

The company has called on the experience of some big names for the EV’s development, including McLaren, Tom Walkinshaw Racing and Brabham for the motorsport aspect. Brett Hill is leading the aerospace side of the project, thanks to his experience as a flight dynamics specialist on the Boeing 747-8 programme.

The races will also play out in much the same way as a Formula One event, only taking place in the air rather than on the ground. Each octo-copter will also have to take regular pit-stops for battery changes, which Airspeeder says have been trimmed down to just 14 seconds thanks to its new quick-release battery mechanism

Link

[RM Motorsports]

At the 2019 Paris Air Show, Eviation, an Israel-based startup company, introduced a revolutionary prototype for an all-electric aircraft called Alice. This would be the world’s first fully operational, electric passenger plane, having the capacity to take on board nine passengers.

Eviation’s in-development all-electric aircraft completed a low-speed taxi run in recent days, marking what Eviation calls another step leading toward the prototype’s first flight.

Alice will have 440nm (815km) of range, 1,134kg (2,500lb) of payload and maximum cruise speed of 250kt (463km/h). Maximum take-off weight is pegged at 7,484kg, according to Eviation.

Eviation is offering Alice as a nine-passenger commuter aircraft and as a cargo aircraft. Cape Air is launch customer for the commuter, and DHL has ordered the freighter.

[srini1785]

A More technical discussion can be found here :

https://www.eng-tips.com/viewthread.cfm?qid=490403

Superconducting motors are now the new thing in Electric Powered Aviation. You cool the conductors of the motor to such an extent that they loose all resistance thereby producing enormously high magnetic field which in turn provides enough thrust to lift a full sized aircraft. Straight out of a 007 movie but real.

[mpulztrack3r]

Originally Posted by V.Narayan

The world is already headed in that direction. Well on its way infact. We cannot say that till we have perfect technology to generate green electricity we won't make any efforts in that direction. Whether wind or solar the efficiency rates have grown significantly over the last 15 years. Building electricity from renewable sources has to go hand in hand with improving the technology. Your argument is like saying in 1950 that unless we have the perfectly safe car with all the features of a Volvo of 2020 we wont make any cars and continue on horseback. Or that till we find the perfect cure for cancer we wont treat patients with what we have. You may be looking down the wrong hole. You may want to read up on progress in solar cells and wind turbines. We will agree to disagree on this matter.

I agree with you. I also think the way we are thinking about renewable sources of power today may actually be transitory. We are headed to a future with super efficient power sources (such as safer Fusion/Fission). Solar (PV based) will be relegated to rooftops and other decentralized applications. The idea of large solar farms like we see today is not only environmentally a bad idea but also suffer from poor economies of scale.

[V.Narayan]

Rolls-Royce breaks all-electric aircraft speed record

https://www.whatcar.com/news/rolls-r...lectric/n23881
https://eurasiantimes.com/british-en...ectric-planes/

In November 2021 Rolls-Royce tested a new all-electric aircraft, which it says could be the fastest plane of its type in the world. The Spirit of Innovation aircraft achieved a top speed of 623 kmph during one of three test runs in Wiltshire, which is believed to be a new world record. It then achieved a sustained 531 kmph over a 15km circuit. another first. The previous fastest speed for an all-electric plane was 411 kmph held by a Siemens made machine. Spirit of Innovation has a 400kW battery, with a power output of just under 500bhp. Rolls-Royce says this is the most power-dense propulsion battery pack ever assembled in aerospace.

Originally Posted by mpulztrack3r

I agree with you. I also think the way we are thinking about renewable sources of power today may actually be transitory. We are headed to a future with super efficient power sources (such as safer Fusion/Fission). Solar (PV based) will be relegated to rooftops and other decentralized applications. The idea of large solar farms like we see today is not only environmentally a bad idea but also suffer from poor economies of scale.

Thank you for your comments. Where technology goes I never say never. In the 1930s we thought we could not fly faster than sound and that the only way a flying machine could fly trans-continental long distances would be in a lighter than air machine! Energy density is the huge hurdle in the path of all electric aircraft. But as you correctly point out super conductors can be one solution.

Where aviation propulsion goes we have not seen something so exciting since high bypass turbofans evolved from turbojets. With Airbus and Rolls Royce having thrown their heft behind this path it is only a matter of a decade till all-electric or hybrid short hop regional airliners start scheduled operations.

Photo of Rolls Royce's test aircraft 'Spirit of Innovation'.
Photo Source- Rolls Royce.

[mpulztrack3r]

Originally Posted by V.Narayan

Rolls-Royce breaks all-electric aircraft speed record

Photo of Rolls Royce's test aircraft 'Spirit of Innovation'.
Photo Source- Rolls Royce.

Must say both Eviation's Alice and Rolls's Spirit of Innovation are such beauties

Offtopic :
I'm a huge fan of propped plane designs in general especially from the early 30's when racing was a big phenomenon. Early Messerschmitts, Hughes H1, F4U Corsair etc.

[GutsyGibbon]

Originally Posted by mpulztrack3r

I agree with you. I also think the way we are thinking about renewable sources of power today may actually be transitory. We are headed to a future with super efficient power sources (such as safer Fusion/Fission). Solar (PV based) will be relegated to rooftops and other decentralized applications. The idea of large solar farms like we see today is not only environmentally a bad idea but also suffer from poor economies of scale.

Solar thermal plants have got to do with a lot of water usage, wet cooling, chemicals for dust suppression, spillage etc. With PV water usage is greatly reduced when we can accept the lower efficiency, and wait for the rains, and take care of run off. I have never washed my rooftop solar in 5 years, rain takes care of it.

We have an abandoned nuclear reactor with spent fuel sitting in our backyard. (San Onofre) The reactor is rated for an earthquake of 5.0, and we regularly have 7+ earthquakes. No insurance company has the money to pay for damages in Southern California. Nobody has the will/money to move the spent fuel to the desert. While operating it used a billion gallons of water a day. This is why they locate these plants next to rivers and lakes. After Fukushima, most countries are committed to the nuclear phase out. https://en.wikipedia.org/wiki/Nuclear_power_phase-out

[V.Narayan]

Airbus tests A380 on 100% SAF

Airbus has performed the first A380 flight powered by 100% Sustainable Aviation Fuel (SAF).

Airbus’ A380 test aircraft MSN 1 took off from Blagnac Airport, Toulouse, France on Friday 25 March. The flight lasted about three hours, operating one Rolls-Royce Trent 900 engine on 100% SAF.

27 tonnes of unblended SAF were provided by Total Energies for this flight. The SAF produced in Normandy, close to Le Havre, France, was made from Hydroprocessed Esters and Fatty Acids (HEFA), free of aromatics and sulphur, and primarily consisting of used cooking oil, as well as other waste fats. A second flight, with the same aircraft, took place from Toulouse to Nice Airport, on the 29 March to test the use of SAF during take-off and landing.

This is the third Airbus aircraft type to fly on 100% SAF over the course of 12 months; the first was an Airbus A350 in March 2021 followed by an A319neo single-aisle aircraft in October 2021. All Airbus aircraft are currently certified to fly with up to a 50% blend of SAF mixed with kerosene. The aim is to achieve certification of 100% SAF by the end of this decade.

Most in the aviation see Increasing the use of SAF as the key way by which the sector will reduce its carbon emissions in the short to medium term while engineers develop and test electric and hydrogen-powered aircraft.

https://www.aerospacetestinginternat...n-100-saf.html