Electric Regional Aircraft in Service by 2026?
 

Saw this today.

https://www.stuff.co.nz/travel/green...ric-plane-deal

This is the company who is making the aircraft. https://heartaerospace.com

Frankly I think they are being a tad optimistic with their 2026 operational date. Right at the moment I see it as just attention grabbing headline pie in the sky stuff. It could happen one day but not this decade in my opinion. I wonder what other people think.

Certifying an new airframe and new propulsion technology along with having to develop all electric systems for air con/pressurisation etc will be a challenge.

Might work in NZ for the hop across the Straits or over their steep hills. The 750m runway length sound a little optimistic for a 19-seater, though?

As 27 September says above, the time line for certification seems pretty brave.

Electric engines are light and high torque, and with that arrangement across the wing would all lead to good field performance. One huge advantage to electric is you can have multiple motors for very little weight penalty. Downside, the batteries more than make up for the loss of engine weight, and don't get lighter as you fly either.

750 metres does indeed seem a little optimistic. Though that's pretty much in line with all the other optimism they show about what it'll be capable of and when it will fly.

Interestingly there's an outfit in the US doing a hydrogen fuel conversion on a couple of Dash 8's. They already have a proven airframe and their projected certification is towards the end of the decade and yet Heart is spruiking 5 years away for a brand new airframe and propulsion system. I really think they have their ambitions and abililty in the wrong order.

I agree it's ambitious, but 750m is achievable for that size of aircraft if the wing and lift devices are right for it. Do 228 is around 800m at MTOW and the Dash-7 which is a similar layout using propwash to aid lift production is under 700m.

The logical solution (and I believe Boeing are working on this) is a hybrid. We all know most energy is used during taxi and climb to cruise. Having an APU to generate electricity to power the motors also means you don't need fully charged batteries (and you have to consider how long they would take to recharge).

At cruise and descent the APU would be off, relying only on batteries

https://www.stuff.co.nz/business/976...market-in-2022

Zunum are no longer. I think their concept had a better chance of success than Heart's EP19. I wonder how long Heart will survive.
https://en.m.wikipedia.org/wiki/Zunum_Aero

Charging rate for batteries is dropping dramatically each passing year, there's talk of 5 minute car chargers in the next few years. Some are already down to 15 minutes. That aircraft they are talking 40 minute full charge.

Battery technology is really advancing at a massive rate, that will be the main driver of everything electric from aircraft to farm vehicles, trucks, cars and ships.

Hybrids just carry too much weight of having the two systems combined, the whole trip you are paying the fuel price of the extra weight of whatever is not being used.

I'm not sure everyone agrees about the use of batteries.

Hydrogen aircraft being developed here https://www.seattletimes.com/busines...-lake-venture/

Wouldn't it be cheaper and perhaps more sensible to take say a Dash-7 and create a hybrid job out of it with electric engines for number 1 and 4.

But if you did go fully electric, could you redefine fast charging by flying near a Cb looking for a lightning strike. Don't laugh, current fast charging for cars is looking at pumping 600kW into their batteries in just a few minutes which is quite a bomb of energy.

Ho-hum, yet another glossy CGI rendering of the future, yawn.
To paraphrase Yogi Berra, "The future ain't what it used to be."

Hydrogen would be the natural go to for the big companies, you can then control the fuel like oil now. It might be clean burn energy but it still costs a lot of energy to make mass amounts of hydrogen. Pure electric you can charge off the wind, sun, tide, thermal for free once you set it up. Great for the masses but not so great for collecting taxes and supporting infrastructure.

You could make your own hydrogen, but why bother when you can just power your vehicle with the energy directly without complicating the situation.

Not quite the same, but the RNZAF P-3 Orions use two engines to increase endurance on patrol

I wonder how you'd carry 30 minutes holding in an electric powered aircraft? Carry an extra powerbank in your nav bag? :confused:

How do you carry it now? In a Jerry can?

Think hard. Imagine a battery being just like your fuel tank, and the charge on the battery being the fuel that you put in the tank :hmm:

As did Nimrod.

The first commercial electric aircraft -

https://www.aopa.org/news-and-media/...lectric-beaver

So yes using old airframes has been proven to work.

It works yes, good to prove a point and get things rolling. A long lasting successful design will need to be optimised for the technology, therefore offering much better efficiency and operating costs. Using the technology to its full extent means you can save a lot of weight and offer better performance over the present machines.

If you look at cars simply retrofitting a petrol design works, but it is increased weight and poor weight distribution. A purpose built car with in hub motors, batteries set low along the chassis and low weight structure that does not have to carry the forces of engine torque and transmission makes fro a much more efficient vehicle. Hence when you weigh up hybrids, the technology is eco consumer appealing but doesn't achieve much in actual cost savings.

Dash-7 is a 40+ seat aircraft, and limited airframes remaining. Not really sure it would make a great test bed, to carry the two outer heavy turbine engines and accessories the wing structure has to be heavier, wasting weight on structure that's not required.

BTW engine efficiency for electric is very different to turbine or petrol. So switching off engines in flight is not really any better than keeping them running at low power/drain, it's probably worse, as the dormant engine will just create drag.

Read an article a few years back from RMIT IIRC about Aluminium ion batteries in development. They didn’t hold much MORE charge than a Li ion battery but you could plug them in and fully charge them up in a few minutes……that would be a game changer!!

That doesn't solve the issue of energy density which is the other big stumbling block which I'd argue is more of an issue than the charging time.

Everything I've seen so far on the electric aircraft front whether it be small like the Pipstrel, or Beaver/C208 size, is there's about 1 hour of endurance. That's a long long way short of the normally accepted endurance. Sure 1 hour is OK for niche markets but it doesn't cut the mustard for most routes and especially IFR where alternates are required. A long way to go yet. One article I read said up to 20 years before commercial services with electric aircraft became common place.

I think it quotes 400km range, so yep about 1 hour. Not applicable to virtually anything in Australia especially with alternate concerns. As said earlier battery technology still needs about 10 years of advancement at current pace to get to a reasonable range. So 20 years is probably a good mark.

Technical rip-apart at ;
https://leehamnews.com/2021/07/08/th...rcraft-part-2/

TLDR; "Tell 'em they're dreamin"





(also has articles on hydrogen fuel)

Leehamnews is a trusted and reliable source for all things aviation. That article drives a nail in the coffin me thinks…..

The energy density for lithium-ion batteries seems to be very much understated in that article. The author writes,

So he is calculating the required battery weight using 0.250 kWh/kg, a figure he purports to be a 56 percent stretch improvement over current technology of 0.160 kWh/kg. However, current technology, the Panasonic 2170 battery used in the Tesla 3, is already delivering 0.260 kWh/kg. A 56 percent stretch on that would be 0.405 kWh/kg, pretty much bang on what Musk was predicting a year ago.

I would normally agree wholeheartedly but his assumption on energy density seems to be out of whack on this. I think that he is overstating the requisite battery weight by about 50 percent.

8 tonnes of battery did sound an awful lot……….

4 tonnes is still a lot, we're just talking degrees of awfulness. Make no mistake, when trying to apply electric propulsion systems to aviation, battery weight is the most significant impediment by a long margin.

-> MickG0105 ; the "(the energy density on a system level)" caveat is important.
An individual cell might have an impressive energy-to-weight ratio but on its' own it is of not much use.
Cells need to packaged into robust battery stacks and battery-monitoring/charging/protection must be added, all of which will reduce the energy-density of a usable 'battery'.

I dunno.....
If I cannot consign Li-ION batteries in the cargo hold because of the fire risk, why oh why would you want to put them internally within the wing or fuselage area?
Oh, I know, tow them behind by the power cable...well clear of the aircraft....Turn them 'ORF' on landing and wind them in......so they don't get caught on the fence....or the ILS.....

An electric beaver? Do you need dark glasses and your collar turned up when you go into the dealer and ask for one? For a friend, of course.

These people are away with the fairies when it comes to commercial EP aircraft but sure does make for amusing reading! -)

I had a hearty conversation, recently, with a gentleman who already has an electric powered GA training aircraft in operation. The aircraft has a one hour duration with a one hour charge time which makes it OK for typical pilot training missions. There are also a few airfields withing the one hour circle of Damyns Hall, where the aircraft is based, which have on airfield charge points. He did come out with some gems from airfield operators when he approached them with a view to getting more on airfield charge points such as:

"why would I want to supply free electricity to aircraft when I am still trying to build up customers for my Avgas supply?"

Because the cost of the battery charge is only a couple of pounds and your landing fee is 15 quid!

"but what about the loss of Avgas sales?

Doh, the electric aircraft users are not going to be buying your Avgas and so won't be flying in and paying your landing fee.

Interestingly most of the on airfield charge setups are using solar power and recycled truck batteries to provide charging from off grid solar systems. This removes many of the restrictions imposed on the feed in grid tie familiar to most of us domestic solar installation owners and thus also gets them away from paying for grid supply and the tax associated. It would seem to be win win for airfield and aircraft operators.

Rans6......

If only it were as simple as the battery charge being only a couple of pound v the 15 quid landing fee. What about the cost of setting up the charging system? Why would you invest in a system that will be only used sporadically and you'll very likely never get your money back on?

For the time being I don't think any airfield owner is going to lose sleep over any electric aircraft that don't visit.

Can we draw an analogy with supermarkets, pubs and other businesses who are installing EV charging points?
I assume they are doing it to attract custom but they are probably getting subsidised too.

What happens if you land an electric aeroplane at an airport that doesn't have a proper charge point (say as a precautionary emergency - passenger sick)? I guess you'd be stuck there for a while until somehow you find a way to get enough charge to fly out and make it to somewhere that does have a proper charge point.

Roll out a diesel GPU

The same as when your battery goes flat now, from what I read batteries are not integral and are "plug and play". So you can add/remove batteries to control range vs payload. Just roll up with a charged battery set and fly out, or possibly they can be charged from a normal socket in the wall albeit a much slower rate, which would just require the adapter and extension cord.

Same thing that happens now if I land my jet at an airport that doesn’t have the correct stairs or refuelling facilities….. you be stuffed.

Plenty of obstacles for the dreamers of EP pax carrying commercial Ops. A/C have lots of elect gizmos to support their operation, lights, avionics, retractable U/C (if the pie in the sky stuff ever got that far!), flaps, AC & or fans, ice protection all cutting into that precious batt supply! Even sitting in a cue awaiting to T/off is eating into yr reserve of FF!

I hope I am around to see these in service, maybe in my next life -)

There is no logic in making electric airliners until all land based transport is running on renewable fuel, that is going to be a very long time, all electricity has to be converted to renewable or nuclear first. For aviation low pollution high density liquid fuels for turbines is going to be the norm for decades yet.

Guess we should just convert all the city trains and trams to diesel then.

That's like saying there's no point going to mars until we develop faster than light travel to make it quick. Technology does not advance without purpose, so waiting until you have perfect conditions for the technology to start developing it means you start years behind where you could be.

Now we all know the issues like an electric train running off coal fired generators. Does not mean there are additional benefits, like that pollution can be limited to one area rather than distributed around where you live by smaller less efficient personal systems, also easier to capture and prevent release of polution from a large static power plant than individual mass produced especially mobile units. Also electrical power does not really care for altitude etc, not so much reliance on optimal altitudes and optimal ranges. The example of the aircraft waiting in line for take off, the electric engines just switch off and don't consume any power, yeah some power is still drained by AC and fans and system but this is minute compared the energy an idling turbine consumes.

Simplistic arguments of electric vs fossil fuel is not possible as there are vast differences of operation between the two technologies.

The main hindrance to electric vehicles in general is weight and volume of batteries required to make range effective. As that is solved the technology will flourish and not just from ecological point of view but they are far cheaper to run.