Bye Aerospace Electric Updates

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rv6ejguy

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Seems much of this is premature and the performance specs listed here are incredible given the current state of battery development. I don't see how the E-Flyer 800 twin could possibly come anywhere close to the performance goals stated here.

"Aerodynamic efficiency is over twice that of a typical legacy aircraft of similar size" Quite a bold statement. Does that mean half the drag? Sorry to be skeptical but that sounds a lot like Raptor. There is this disclaimer however-"Note: Performance metrics are projections only and subject to change".

People are signing up for aircraft which haven't even flown yet which hardly seems prudent unless you can cancel if it doesn't meet goals.

However, good on them for getting the ball rolling and getting so many pre-orders. Can they deliver? The E-Flyer 2 hasn't moved much since 2018. Battery supplier TBA. It appears as though no production aircraft have been built to date.
 
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rv6ejguy

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Bye has a great team and they are farther along on the E-Flyer 2 than it appears on the surface.

May be but the 800 numbers are pure fantasy with today's battery tech. This is a Cheyenne sized plane, needing at least 1000KW to achieve this 3400 fpm of ROC. Let's say it needs 400KW to cruise at that published 320 knot speed at 35,000 feet, 500NM including the climb would take around 1.8 hours. 1.8 X 400= 720KWH. Divide that by .8 for battery longevity, throw in an IFR reserve and you're looking an 1100KWH battery pack. Using current Tesla battery energy densities, that battery would weigh around 8400 pounds and would have a volume of around 50 cubic feet, which isn't going to fit well in this airplane.

Surely the engineers at Bye have run this simple calculation? Even doubling the energy density of current batteries doesn't make it viable.
 
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Rhino

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Seems much of this is premature and the performance specs listed here are incredible given the current state of battery development. I don't see how the E-Flyer 800 twin could possibly come anywhere close to the performance goals stated here...
So in other words, it's no different than the other thousand electric airplanes we keep hearing about.
 
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John.Roo

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I don´t understand system of pre-orders...
On the website you can see info that for example KLM Flight Academy signed up for 14 eFlyers. Sky aviation orders 15 eFlyer 800 etc.
So without to see real flight test results of at least prototype they just order so many pces?
Of course I can understand that investors (or bank) wants to see real interest for product.
However what if performance will be lower, final cost higher or unknown delivery time etc.?
Is there some "deposit" or "order" is just something like "letter of interest"?

Sorry for "what if" but I have real problems to believe performance based on "future" batteries. And true is that with actual generation of batteries (cca. 5 kg per 1 kWh) will be performance definitelly different.
Don´t misunderstand me - it is not "hate" of Bye Airspace. Bye Airspace do a very nice work. For example eFlyer 4 design is nearly "TMG" design 👍
1637564883456.png
However Bye Airspace is not develeping or producing battery cells so their statements are based on info from battery cells producers. And reality... reality is that (as usually) we have to use well known and well tested cells - especially in aviation.

And is not only about safety, but also about lifetime. Without info about lifetime of batteries you just can´t calculate costs for 1 hour of flying and this seems to me important especially for flight schools.

For example...
Actually you always "pay" some advantage with some other "disadvantage".
LTO - Lithium Titanate Oxid. Interesting cells.
30 000 cycles to 80% capacity, safe technology - wow. But weight / capacity ratio is approx. same like LiFePO.


From my posts you probably know that I realy believe in electric sport aviation. But reality shows that we have to start with light and very efficient one / two seaters. Simple to use, safe and we have to accept actually lower performance in compare with ICE engines. Seems to me that only acceptable "compensation" for lower performance is.... lower price for flight hour (incl. lower price of electric airplane). Arguments about enviromental friendly flying are not working if price for airplane and price for flight hour will be same or higher in compare with airplanes powered by ICE engines. That is reality...
 

EzyBuildWing

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new electric paramotor 45 minutes flying-time.....comments below vid are interesting: brilliant instant torque(no ICE lag), quietness etc ....some nice flying along the beach.....
Seems any breakthroughs in energy-density will show up immediately in such applications as motor-paragliders, motorcycles, mountain bikes, etc....

 

tallank

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May be but the 800 numbers are pure fantasy with today's battery tech. This is a Cheyenne sized plane, needing at least 1000KW to achieve this 3400 fpm of ROC. Let's say it needs 400KW to cruise at that published 320 knot speed at 35,000 feet, 500NM including the climb would take around 1.8 hours. 1.8 X 400= 720KWH. Divide that by .8 for battery longevity, throw in an IFR reserve and you're looking a 1100KWH battery pack. Using current Tesla battery energy densities, that battery would weigh around 8400 pounds and would have a volume of around 50 cubic feet, which isn't going to fit well in this airplane.

Surely the engineers at Bye have run this simple calculation? Even doubling the energy density of current batteries doesn't make it viable.
There are a lot of people who come up with schemes to entice Venture capital money. This how they make their living.
 

Jay Kempf

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May be but the 800 numbers are pure fantasy with today's battery tech. This is a Cheyenne sized plane, needing at least 1000KW to achieve this 3400 fpm of ROC. Let's say it needs 400KW to cruise at that published 320 knot speed at 35,000 feet, 500NM including the climb would take around 1.8 hours. 1.8 X 400= 720KWH. Divide that by .8 for battery longevity, throw in an IFR reserve and you're looking a 1100KWH battery pack. Using current Tesla battery energy densities, that battery would weigh around 8400 pounds and would have a volume of around 50 cubic feet, which isn't going to fit well in this airplane.

Surely the engineers at Bye have run this simple calculation? Even doubling the energy density of current batteries doesn't make it viable.
A Tesla can accelerate fast to a large top speed (not for long). A Tesla can carry a large load (at less distance than no payload). A Tesla can have a large endurance or range (if you don't use any luxury items and only have one light person in warm weather).

Try to use one formula to describe how all three mission cases can co-exist and it don't work.

Such is the marketing of electric vehicles.
 

John.Roo

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A Tesla can accelerate fast to a large top speed (not for long). A Tesla can carry a large load (at less distance than no payload). A Tesla can have a large endurance or range (if you don't use any luxury items and only have one light person in warm weather).

Try to use one formula to describe how all three mission cases can co-exist and it don't work.

Such is the marketing of electric vehicles.
I agree that ICE powered cars are more universal.
However like airplanes also cars are designed for some mission.
Pitty that politicians cannot see it and their "forced green way" is making a lot of people angry.

Example....
In many families are two cars.
Even if second car is used only to bring children to school, to work or to shopping (so in total it needs +-100 km a day) we use car with ICE. Why? (Please lets not open discussion about safety of big SUV cars) In cities is speed limit 50 km/h and now are discussing about 30 km/h. You often wait in traffic jams etc. All it means that affordable electric car would be ideal - except that price is much higher :(

It is important to have freedom to make this decission. And if governament wants to support electric transportation it should be done together with building the infrastructure (charging points), electricity production etc. I am not fan of subsidies. New technology should be finished until point where is competitive. Investments (money from investors)... well that is problem of investors, but governament subsidies are typically worst spent money ever (beside of money spent in weapons but that is another theme).
If I count all subsidies used to "develop airplanes ideal for pilot training" I can see that for same money we could let every young boy o girl to make PPL license for free. Or to buy trainign airplanes (and gliders) and give them to every aeroclub in EU :)

So what if you have a good idea and no money to make prototype? One of theoretically possible way could be to involve more Technical Universities and students. Governament money going to schools are in my opinon well invested money. And even "wrong (blind) way" is an experience that counts.

Actually seems to me that best you can do for your project is to hire Hollywood director. Don´t waste time with real prototype for testing - make beautifull 3D render, use it in nice video and you can get support. And that is pitty because new aviation projects starts to look very unreliable in eyes of public - many promisses and no real results.

Sorry for long post ;)
 

rv6ejguy

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BBerson

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It looks like the DC one hour quick charge is an alternative to battery switch out (like with RC models).
Truck fleet or flight school would still need a huge AC utility service capacity.
 

BJC

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Bye has a great team and they are farther along on the E-Flyer 2 than it appears on the surface.
Such is the marketing of electric vehicles.
I stood and listened to their spokesman (don't recall his name) when they first statically displayed their eFlyer 2 at Oshkosh. He told another pilot that, “It has a top speed of ... , an endurance of ... , a RoC of ... etc.” The pilot was duly impressed.

After the other pilot left, I asked how much flight time they had on the airplane. The answer: it had not yet flown.

They may well be onto something good. I like the airframe that they chose to start with, but I will wait for an independent, objective, competent flight review before deciding that they are credible.


BJC
 

BJC

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Truck fleet or flight school would still need a huge AC utility service capacity.
If they want it, they can get it. Excerpt from the Florida Public Utility Commission rules:
25-6.095 Initiation of Service.
(1) Anyone desiring service may be required to make application in writing in accordance with practices prescribed by the utility. Such application shall be considered as notice to utility that the applicant desires service and an expression of his willingness to conform to such reasonable rules and regulations regarding service as are in effect.
(2) Upon compliance by the applicant with the provisions governing utility service, the utility shall undertake to initiate service without unreasonable delay. To be effective, the policy adopted by each utility for the initiation of service shall have uniform application and shall be set forth in its filed tariff.
(3) When service is initiated, the utility may charge a reasonable fee to defray the cost of establishing service provided such charge is specified in its filed tariff.
Rulemaking Authority 366.05(1) FS. Law Implemented 366.03, 366.041(1), 366.05(1), 366.06(1) FS. History–New 7-29-69, Formerly 25-6.95.

Likely very similar rules in most free states.


BJC
 

BBerson

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If they want it, they can get it. Excerpt from the Florida Public Utility Commission rules:


Likely very similar rules in most free states.


BJC
Then the utility will need more reliable base load generation capacity, in most states. (not wind and solar)
 
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rv6ejguy

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There is no shortage of new electric aircraft designs waiting for a quantum leap in battery power densities. We see the usual obfuscation from the electric airplane fans and companies, listing top speed, endurance, range etc. But rarely at the same time. The reality is speed varies as the cube of the power and high speed demands massive power which results in low endurance and range. Slowing way down to get any sort of reasonable range and endurance defeats much of the reason we fly airplanes in the first place.
 
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tspear

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I agree that ICE powered cars are more universal.
However like airplanes also cars are designed for some mission.
Pitty that politicians cannot see it and their "forced green way" is making a lot of people angry.

Example....
In many families are two cars.
Even if second car is used only to bring children to school, to work or to shopping (so in total it needs +-100 km a day) we use car with ICE. Why? (Please lets not open discussion about safety of big SUV cars) In cities is speed limit 50 km/h and now are discussing about 30 km/h. You often wait in traffic jams etc. All it means that affordable electric car would be ideal - except that price is much higher :(

It is important to have freedom to make this decission. And if governament wants to support electric transportation it should be done together with building the infrastructure (charging points), electricity production etc. I am not fan of subsidies. New technology should be finished until point where is competitive. Investments (money from investors)... well that is problem of investors, but governament subsidies are typically worst spent money ever (beside of money spent in weapons but that is another theme).
If I count all subsidies used to "develop airplanes ideal for pilot training" I can see that for same money we could let every young boy o girl to make PPL license for free. Or to buy trainign airplanes (and gliders) and give them to every aeroclub in EU :)

So what if you have a good idea and no money to make prototype? One of theoretically possible way could be to involve more Technical Universities and students. Governament money going to schools are in my opinon well invested money. And even "wrong (blind) way" is an experience that counts.

Actually seems to me that best you can do for your project is to hire Hollywood director. Don´t waste time with real prototype for testing - make beautifull 3D render, use it in nice video and you can get support. And that is pitty because new aviation projects starts to look very unreliable in eyes of public - many promisses and no real results.

Sorry for long post ;)

John,

Every commercial endeavor is subsidized. They all depend on government investment to one degree or another. Everything from education (for the labor force), to roads, water, military providing safe zone....

Also, very few people realize how much foundational science is paid for by government investment. Such as the internet, email, forums, most vaccines (e.g. the spike protein used in all COVID vaccines was developed by NIH), X-Rays, Chemo and radiation therapy.... The list goes on.

Tim
 
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