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-   -   Electric Rex (https://www.pprune.org/australia-new-zealand-pacific/648023-electric-rex.html)

43Inches 1st Aug 2022 08:27

Well designed batteries can be slung so that if they catch fire they can detach from the aircraft and fall on someone below. Anyhow a lot of commercial aircraft have been using NiCad which can suffer thermal runaway for years. They have a protection circuit to prevent overheat. As said before wading through tons of kerosene is far more dangerous following a crash than flash battery fires. Almost all cabin fires are from batteries that have been tampered with or broken/crushed, so have been compromised in their own thermal protection, which is why now they say to leave dropped phones and wait for an FA to come and search for it, lest you crush it and cause a fire.

In anycase first trial flights are supposed to be in under 2 years, so we will see soon if its realistic or not. In regard to SAAB and the TC, they will explore anything and help with certification, for a fee, lots of modifications have been done to SAABs, including airframe modifications and so on. Pretty sure SAAB would be heavily involved from a consulting point of view, you just have to read SAABs site regarding regional aircraft where they advertise how they will provide technical assistance for operators.

Jack D. Ripper 1st Aug 2022 12:32

Electrifying a SAAB, surely akin to lipstick on a pig.

Why on gods green would you invest in a new power plant for a 30 year old airframe?

Traffic_Is_Er_Was 1st Aug 2022 12:33


In 1903 we had the first powered flight. In 1969 man walked on the moon. Just 66 years later.
Two world wars and a political situation drove that. Without a decent war, or an ideology race, tech hasn't really progressed that fast since. We had pistons, turbines and rockets in 1945, we've still using them 77 years later. There is no pressing need for a massive technological leap. It's just incremental.

so there is most definitely an incentive for GE or EMD to continue their own R&D.
“Looking to the future,” Wabtec says it plans to “accelerate the shift to alternative clean energy solutions, through zero-emission hydrogen-powered locomotives.”

Their future is not with batteries.

josephfeatherweight 1st Aug 2022 18:17


Originally Posted by Jack D. Ripper (Post 11271217)
Electrifying a SAAB, surely akin to lipstick on a pig.

Why on gods green would you invest in a new power plant for a 30 year old airframe?

This. It’s surely a publicity stunt. If it can be done (which it can’t yet), you’re not going to do it on a Saab.

illusion 1st Aug 2022 21:45

There is an enormous amount of research going into this area. At the REX level one might be uncharitable and consider the possibility that the announcement is nothing more than a precursor to a government handout disguised as a research grant.
One would hope that with the change of government the chances are some what diminished of this occurring.

43Inches 1st Aug 2022 22:15

Zeroavia is about to test fly it's first DO-228 testbed, within the next few months. It has Hydrogen fuel cell on one side and normal combustion on the other for test purposes. You can look it up, most modification is in the engine nacelles, so no massive fuselage or airframe tweaking as suggested here, then there's the electronic side of things to manage the system. They are partnered with Bombardier and PWC to have a viable power system for the Q400 by 2025 or so. Both the SAAB and Q400 share large nacelle space for this technology and I assume some sort of tanks/batteries can be fitted where original fuel tanks were instead of AVTUR, or simply in the rear of the nacelles. Spreading batteries out through the wings would not be difficult either, which would aid cooling, and ability to bomb out through the lower surface of the wing should they meltdown, this would avoid ZFW issues with fuselage mounted stuff. If smart you could run the heat dissipation through the leading edges to assist deicing.

I do feel though that the major issue is more going to be pressurisation and de-icing in flight as some form of air pump/compressor will be needed obviously as it lacks bleed air systems. That being said there's some pretty neat low voltage kinetic deice systems that work without heating required, Russians have been using it for years (They hold the patent to it so the US has avoid it in favor of traditional boots).

Gne 1st Aug 2022 22:39

Did we miss these : https://www.bloomberg.com/news/artic...in-three-years
https://www.bbc.co.uk/news/uk-englan...shire-60068786

Gne

Icarus2001 1st Aug 2022 23:59

Thank you for the links, I found these quotes illuminating...


That range will keep improving with better battery technology, and may eventually be able to fly as much as 400 kilometers (250 miles) in the 2030s,

The aircraft uses a 400kW electric powertrain - the equivalent of a 535 BHP supercar.
I agree that progress will be made but the SAAB airframes will be out of service before the technology is available to electrify them.

Australopithecus 2nd Aug 2022 00:00

So the article linked quotes Rolls Royce as saying electric may, in the 2030’s, be able to power an 8 seater over a 400km journey. That's the reality of energy density.

kingRB 2nd Aug 2022 00:17

The part that concerns me with these delusions of grandeur is how increasingly institutions and corporations believe these lies (once repeated enough) - and just start instituting the "technology" and policies anyway - just like we've seen Western Governments removing baseload power generation all around the world.
The technology is not sufficient to replace what got us here in the first place - but that doesn't seem to matter anymore. Prices rise and first world reliability is falling. Is the same ESG madness that's taking over the world going to apply to transport category aviation now? Hope not. Prices rising is one thing, reliability when it comes to safety is another.

Wizofoz 2nd Aug 2022 02:54


Originally Posted by Traffic_Is_Er_Was (Post 11271219)
“Looking to the future,” Wabtec says it plans to “accelerate the shift to alternative clean energy solutions, through zero-emission hydrogen-powered locomotives.”

Their future is not with batteries.

But near as we have it, the PRESENT is batteries. We're a good way down the path of rolling out electric vehicle infrastructue, which is not suprising given that it piggybacks off of the existing grid. There are applications (aviation being an obvious one) where hydrogen is definatlry a bettr fit- but you have to bear the set up costs which are enourmous, and so many applications will stick with what is rather than with what could be.

Icarus2001 2nd Aug 2022 03:02


We're a good way down the path of rolling out electric vehicle infrastructue
I completely disagree. There is no plan on even how to supply all the required electricty let alone where to put the charging stations. All those inner city units and houses with no driveway let alone a garage. Where do they plug in? Multi storey car parks in the city, who pays for the MASSIVE cost of charging stations and how do they power them with an "ageing grid"?

https://wattsupwiththat.com/2020/10/...-electric-car/

Wizofoz 2nd Aug 2022 03:33


Originally Posted by Icarus2001 (Post 11271535)
I completely disagree. There is no plan on even how to supply all the required electricty let alone where to put the charging stations. All those inner city units and houses with no driveway let alone a garage. Where do they plug in? Multi storey car parks in the city, who pays for the MASSIVE cost of charging stations and how do they power them with an "ageing grid"?

https://wattsupwiththat.com/2020/10/...-electric-car/

Sure, but there IS an electricity grid- that's a lot further down the road than hydrogen.

Icarus2001 2nd Aug 2022 04:28

https://cimg1.ibsrv.net/gimg/pprune....21c14eaec.jpeg
That would be location specific.

Wizofoz 2nd Aug 2022 05:01


Originally Posted by Icarus2001 (Post 11271551)

Now show a map of every electrical outlet in Europe...

Australopithecus 2nd Aug 2022 05:23

We ordered an electric car and figure to power it from our solar panels at home almost exclusively. My neighbours won’t let me set up my own H2 facility

43Inches 2nd Aug 2022 05:37

This H2 argument is ridiculous. H2 vehicles are electric vehicles that carry around their own generator powered by H2... So there is only very basic difference between one that carries around stored electrical energy in batteries or stored electrical energy in H2 tanks. Vastly different to a hybrid electric that has a petrol drive and electric drive combination. So you can easily make both vehicles and have the fuel source variation as the engine drive is identical. Its not even as complicated as diesel vs petrol as both cars have the same drive system, an electric engine or engines. H2 fuel cells just have better weight to range profile and faster charging at present. I mean H2 power is really just a 'battery' of H2 instead of lithium or whatever holds a charge. The big issue is that leakage of H2 has to be controlled in a way that it vents to the atmosphere readily and does not build up anywhere. But seriously, we've had LPG cars for ages and although the odd random explosion did occur it was not that dangerous.

A hybrid fuel source of batteries and H2 fuel cells is also a possibility, and that is what most airliner designs seem to be aiming for at the moment.

Foxxster 2nd Aug 2022 08:01

I heard him being interviewed on the radio last night or the night before.

a few points.

they are doing this in conjunction with Sydney seaplanes at rose bay who are going to convert one of their aircraft as a test.

it is NOT a Saab that Rex will be converting initially but a King Air 200. It will be done in Wagga. Initially one engine will be swapped then it it works they will swap the second. Not sure if they intend to extend it to the Saab fleet but I imagine it will take years as they need casa certification on the king air first then would need to repeat the process on the Saab.

given there are similar sized aircraft to the king air being built specifically as electric planes in the pipeline I am not sure what the point is. Although I don’t think those are using hydrogen to recharge the batteries inflight as Rex want to.

they see this being used on flights up to around one hour flight time.

anyway. I am not sure of the economics of it. Seems a fizzer to me.

Traffic_Is_Er_Was 2nd Aug 2022 11:37


Originally Posted by Wizofoz (Post 11271532)
but you have to bear the set up costs which are enormous, and so many applications will stick with what is rather than with what could be.

And in such a thin margin business as aviation, that's why we still have pistons and turbines after 3 quarters of a century. Efficiencies you gain are traded off selling the resultant product off cheaper to remain competitive. Thin margins are not going to change.

Rataxes 9th Aug 2022 01:39


Originally Posted by Captn Rex Havack (Post 11270972)
Couldnt even be like when they tried to put turbines on the old Caribou - un fixable C of G issues. Had to rebuild the airframe and call it a buffalo.

In fact the re-engined, PT6-equiooed Caribou flew perfectly well, could carry more cargo and was FAA-certified. I guess they had smart, qualified people working on the re-design. Shame it didn't 'take off.'


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