
Bye lands orders for nearly 300 electric planes - gscott
https://www.aopa.org/news-and-media/all-news/2019/april/11/orders-for-eflyer-hit-300
======
Alupis
This is cool indeed, but don't get too excited - this is a puff piece touting
(220, not 300) preorders that aren't yet real orders and might never be.

The plane is not FAA certified yet (the first and only prototype flew in
February), and the 4 seater (which accounts for half of the 220 preorders)
won't fly until 2022, and then will have to seek FAA certification too.[1]

Electric motors and batteries have a long way to go to even come close to
power density and weight of kerosene or gasoline aviation engines.[2]
Batteries also don't get lighter with reduced charge - something most aircraft
rely on with designs and efficiency (ie. 500lbs of batteries weigh the same
when nearly empty).

It's also notoriously difficult and extremely expensive to certify new engine
types for general aviation commercial pre-built's - which is part of the
reason majority of modern GA aircraft still use very old engine designs (just
not worth the investment from the manufactures). You can't just show it
works... it has to be proven to work in a number of extreme situations and for
very long duration with extreme reliability.

Getting a new engine type into an Experimental Type Aircraft is much, much
easier...

I'd also hope the motor electrical system is fully isolated and separate from
the aircraft's other electrical systems (maybe I missed it, but I haven't seen
anything discussing this so far). Electrical problems happen, and losing all
systems plus the motor at the same time would seriously jeopardize the safety
of this aircraft.

I wish Bye and his company the best, but I'm skeptical.

[1]
[https://en.wikipedia.org/wiki/Bye_Aerospace_eFlyer_2](https://en.wikipedia.org/wiki/Bye_Aerospace_eFlyer_2)
[2]
[https://aviation.stackexchange.com/a/26919/2294](https://aviation.stackexchange.com/a/26919/2294)

~~~
Tuxer
This is wrong on many levels:

1) General aviation doesn't rely at all on the weight difference from fuel
burn for flight planning (I am IFR certified and fly Cirrus SR22s). My fuel
not burning in my wings wouldn't change anything, as I'm constrained by
takeoff weight not by landing weight, and I don't climb into the flight-levels
high enough for my current weight to matter (that would require FL22 or above,
and I like my breathable oxygen).

2) General aviation certification, while expensive, is far from the cost of
commercial cert, especially for VFR aircraft. There is no reason why they
can't certify an electric aircraft, and they have funding from Subaru's
investment fund. Pipistrel (electro) did it for their ultralight.

3) Of course the motor's electrical system is separate from the aircraft's
other electrical system, that's aircraft certification 101 (being able to
through the master switch deactivate alternator but not battery power). On top
of that 12v instrumentation is (obviously) on a different power level than an
electric engine, so the batteries will be different.

IFR certification will require 2 instrumentation power source backups (like
BAT1/BAT2 on my cirrus) which really isn't a problem, when you've put a 92kWh
battery on a plane you can put 2 0.5kWh batteries as redundancy.

(for what it's worth, I'm currently waiting to buy an eFlyer 4).

~~~
AWildC182
1) Ignoring actual question, electrics will likely benefit from flying
extremely high as the motors don't care about atmosphere. Fuel burn won't
really matter here though.

2) GA certification has sunk so many companies it's become a running joke.
It's entirely fair to question their approach of using a heavily modded
Lancair Legacy with an ipad for EFIS/EMS.

3) Yea, but again, they said they want to use an iPad as primary EFIS. Seems
like a good way to piss off the FAA to me...

Enjoy your 20 mile finals :)

~~~
bluGill
Motors rely on air for cooling, so they do care about atmosphere. Propellers
rely on air density to "push". I don't know how this plays out in the real
world, but atmosphere matters.

~~~
AWildC182
Motors came be 99% efficient, compared to ICE at 20%. Cooling isn't that huge
of a deal. If a wing can operate at a given altitude you can design electric
propulsion that will also work there. The U2 operated on a turbine at
70,000ft. A turbine is just a very complicated prop at the end of the day so
in theory a large cord/diameter prop or a high speed ducted fan would also
work. The actual altitudes were're talking about for GA are far lower though.
Most GA aircraft top out below 18,000. Electrics will likely prefer operating
at 20,000+.

~~~
outworlder
Not sure if the 99% figure is correct, but it is certainly above 80%. Electric
motors run quite cold compared to motors that are burning things. Cooling is
unlikely to matter.

Now, wouldn't the cold air at higher altitudes present a much bigger problem
for the battery? FL20 and up you can easily reach temperatures where current
batteries are no longer usable.

~~~
YUMad
90% is the usual assumption.

------
spaceheretostay
These are small, low-altitude, low-capacity planes - because this is a hard
problem and you have to start small.

I wonder though - does Bye have ambitions in creating larger ones that fly at
higher altitudes? I've thought about this ever since Elon speculated that
high-altitude electric planes could be insanely efficient: they don't require
the intake that normal jet engines do, so they can fly in thinner air and thus
require less power to overcome air resistance.

The main problem being battery density, IIRC. I wonder how that has changed
since the ideas were floated some years ago.

I want the super-fast, high-flying, supersonic electric planes please! That
could do more to alleviate greenhouse gas emissions than even electric cars
might!

~~~
Retra
A propeller works by pushing off of the air. A jet works by exploding fuel.
It's not clear how you'll get super-fast in thin air without the exploding
fuel part?

~~~
Robotbeat
That’s not true. You’re describing a rocket, not a turbofan or even a
turbojet. Fundamentally, modern high bypass turbofans are just shrouded
propellers. Could reach supersonic speeds in the same way using electric.

Lift to drag is about half as good at low supersonic speeds as transonic, so
cut your range in half, but fundamentally there’s no reason you can’t achieve
supersonic electric flight. Just need good batteries to get that range...

------
AWildC182
Spoiler: These aircraft are almost entirely useless outside of limited pilot
training applications. You might get 1-1.5 usable hours of flight time per
charge. Battery density _is not there yet_ and this is another fake it till
you make it play.

To further expand, these will cover about 90% of the hours needed for a part
61 private pilot licence and and another 80-90% for instrument and commercial.
The issue is you'll still need a ICE aircraft for some of the XC flights which
complicates training somewhat.

Edit: Also, 3.5 hours is at barely-staying-aloft airspeeds riding the bottom
of the drag curve. If you're maneuvering, doing practice landings, or actually
trying to go somewhere you will not get anywhere near those numbers. The FAA
also requires minimum 0.5 hours of reserve upon landing.

~~~
djsumdog
How many students drop out after the first class or two, or how many just take
a class for fun?

Flight schools could still make this work depending on those ratios.

~~~
AWildC182
Don't get me wrong, these will be great for schools, but I don't think that's
what the average HN reader is thinking about when looking at these. Bye is not
publishing the important numbers so this whole thing looks a little too much
like an attempt to say they're changing the entire aviation landscape when
they're just another electric trainer (in a market that already exists and has
more realistic contenders).

------
ortusdux
Impressive stats on the 2-seater: 3.5hr flight time at 1/6th the hourly
operating cost of a Cessna 172. Perfect plane for flight school.

~~~
repiret
You think so until you look at TCO. A used 172 equipped for a superset of the
training scenarios can be had for 1/5th the initial investment. You can buy a
lot of operating costs with the savings.

~~~
VectorLock
Comparing a new 172 to a new eFlyer the price seems competitive ($300k vs.
$350k it looks like?)

~~~
repiret
Indeed, which is part of why most flight schools don’t buy new planes at all.
I was mostly trying to refute the grandparents assertion that it was a
“perfect plane for flight school.”

On the other hand, the discontinued Cessna 162 sold for $150k and is more
similar to the eFlyer’s capabilities.

------
sremani
I am curious, the aero-engines are know to be reliable but electric engines
are considered to be good too. What kind of complexity variation does a
battery introduce in providing reliable power vs gas tank. What can be
possible weaknesses if any with electric planes?

~~~
ccleve
I remember reading that electric motors are much lighter than gas engines for
the same amount of power. This difference can at least partially offset the
added battery weight.

Also, it's possible to have multiple, small electric motors with no loss of
efficiency. That isn't possible for a gas engine. Multiple motors could add
some redundancy, and therefore reliability.

I think we're going to see a lot of interesting designs over the next few
years.

~~~
mikeyouse
Smaller motors unfortunately means smaller propellers which means smaller
swept area and a large decrease in available power.

~~~
thrill
Propellers are generally limited by torque, which is something that electric
motors excel at.

------
JMTQp8lwXL
Title is confusing until you understand "Bye" is a company/CEO's last name,
and "lands" as in orders.

~~~
NullPrefix
"Bye Aerospace lands orders..." would be easier to parse, given no prior
knowledge of Bye.

------
Robotbeat
Shout out to EMRAX, manufacturer of the motor for the prototype eFlyer2.
According to the FAA filing:
[https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?N...](https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=502SF)

[https://emrax.com/products/emrax-268/](https://emrax.com/products/emrax-268/)

Up to 98% efficiency. Up to 10kW/kg. Pretty impressive motor, and few electric
motor makers like to compare their motors to this high of a standard.

~~~
Alupis
> Shout out to EMRAX, manufacturer of the motor for the prototype eFlyer2

Doesn't seem to be true.

The motor is a Siemens SP70D[1]

[1]
[https://en.wikipedia.org/wiki/Bye_Aerospace_eFlyer_2](https://en.wikipedia.org/wiki/Bye_Aerospace_eFlyer_2)

~~~
Robotbeat
It IS true for the prototype. Siemens is really good at grabbing these orders
for production aircraft and getting their name in press releases, but the
actual motor used for the prototype according to the FAA (who I don’t
recommend lying to) is the EMRAX one.

EDIT: And EMRAX motors have shown up on lots of other electric aircraft. My
day job is making novel electric motors, and their motors are _incredibly_
tough to beat. I have much respect.

------
ChuckMcM
Interesting product. All the discussion about training airline pilots makes me
wonder if their value add is they can tune their fly by wire system to have
the flight characteristics of a larger jet for familiarity with takeoffs and
landings. That might make up for the relatively limited air time the plane can
achieve (you don't need a lot of time for training flights per say). Turn
around time would become an issue though in terms of how many you would need
to sustain a full training day for a given number of students.

~~~
bronco21016
The majority of flight training in the beginning is learning the basic ‘stick
and rudder’ flying skills. This is the basic characteristics and relationship
of pitch, power, roll, and yaw. Those basic skills and relationships help a
pilot learn how to get out of unfortunate situations. Training in an aircraft
artificially more similar to an airliner would not be productive as they tend
not to be as forgiving when pushing the envelope.

------
skanga
Why all the nay-saying? Give them credit for finding their niche and
delivering (on the orders at least)!

------
bronco21016
These aircraft may work as trainers because training aircraft come back to
home base the majority of the time. This doesn’t solve any type of GA point to
point transportation though until infrastructure is built out to accommodate
charging. Land at any FBO today and they’re going to laugh you away if you ask
for an electrical cord that charges these large batteries in any meaningful
amount of time. Your product may be killer (Tesla Model S) but don’t expect
any kind of uptake without the support infrastructure (arguably Tesla’s number
one strategic move).

~~~
curtis
Battery swapping and offline charging has not been successful in the
automotive realm, but it might be a pretty reasonable alternative for
aircraft. Even cheap aircraft are so expensive that the overhead of having two
sets of batteries wouldn't make that much difference on the overall price, and
you could probably rely on a shared pool of batteries anyway, since a lot of
light aircraft aren't flown that much.

If battery swapping works then that also opens up some interesting
possibilities like aluminum-air batteries that have much greater energy
densities than lithium-ion batteries but which aren't rechargeable.

~~~
bronco21016
I don’t disagree that there are many solutions to the problem. The issue isn’t
a lack of solutions though. It’s a lack of implementation. Swappable batteries
sound great but does say Million Air FBO at Chicago MDW have swappable
batteries for my aircraft? If someone wants to really make a dent in this
market they need to follow Tesla and build out the product and the
infrastructure to make it practical. I have yet to see anyone come up with big
enough investment to do that.

------
gmoore
Let's see how many of these 'orders' actually get delivered.

------
apo
> First deliveries of the $349,000 eFlyer 2 (the original price was $289,000)
> are anticipated in 2021.

There's a lot going on with DIY electric flying craft as well. For example:

[https://www.youtube.com/watch?v=J7ykW4zk-
Hk](https://www.youtube.com/watch?v=J7ykW4zk-Hk)

Fascinating to see this problem attacked from the top and bottom of the market
at the same time.

------
newhotelowner
What if the battery used in these planes are like my phone batteries.

After using my phone for a few hours, the remaining battery will be down to
25%. And in 5 mins, my phone will be off due to the dead battery.

Once it happened to my EV. The battery was down to 50%, and then suddenly drop
to 10%. Luckily, I was very close to my home.

~~~
davidrm
that’s because for those cases the power draw is hard to predict. in case of
your phone, the BMS might be lying and also the state of health of the cell
might not be accounted for, but it’s more likely that some apps are juat power
hungry. as for the EV, it’s doing the same thing as an ICE car, it predicts
the range based on your last x kilometers, if you step on the throttle your
range will deteriorate as you reach higher speeds and drag increases. a
traditional car will start reducing the estimated range as well. I imagine
that the aviation industry is much better at predicting and controlling the
power draw, therefore the range won’t be so unpredictable. it’s not the cells
that are unpredictable, it’s their end user.

------
Robotbeat
3.5 hour endurance translates to about 500-800km range.

~~~
AWildC182
Negative. 3.5 hours is at max endurance airspeed, probably 50-60 kts and only
3 of those is usable since the FAA requires you have 0.5 available upon
landing.

~~~
Robotbeat
About 400km range, then.

~~~
kgilpin
If you have a headwind, which is very commonly 30 knots or more, then in this
plane you are barely moving. So, it would be hard to reliably get anywhere at
all.

Training flights are mostly in the vicinity of the airport so speed and range
matters less. But you do still have to get places (eg the practice area and
back) and a really slow plane is going to make a difference in the number of
flight hours you need to accomplish the missions.

~~~
Robotbeat
It's unlikely you'd be moving at max endurance speed if you're going for
greatest range. Max lift to drag speed is probably higher, on the order of
70-120knots depending on altitude.

