2 2
DJL

Electric Aircraft - The Thread

Recommended Posts

Posted (edited)

I've had my eye on this for a while and it looks like the industry is about to turn the corner of the magic ratio of energy density (energy to weight). There are already commercial airlines ordering electric aircraft in the short haul market and I have to believe that with the flight cost being 1/10th of an ICE aircraft that it's going to turn heads very quickly.  Once an air frame that works with skydiving hits the secondary market there's no doubt that small DZ's will start snapping these up. If big DZ's are getting hit hard NOW with C182 operations sprouting up around them, just wait until they can fly for $20/hr fuel cost.  Here are a couple on the current market.  The key elements are cost, operating cost, weight and power.

Bye Aerospance eFlyer 2 ($350k, $20/hr, XXkg, 90kW peak/70kW continuous) Company is testing a 9-seater

https://electrek.co/2019/04/11/norway-60-electric-airplanes/

Cessna Caravan - powertrain developed for existing airframe ($XXXX, $XX/hr, 50 kg engine, 250 kw)

https://www.flyer.co.uk/magnix-tests-new-electric-motor-on-cessna-ironbird/

Seimens SP260D engine ($XXXX, $XX/hr, 50 kg engine, 261 kw) Their goal is a 10kw/kg engine

https://en.wikipedia.org/wiki/Siemens_SP260D

 

Edited by DJL
  • Like 1

Share this post


Link to post
Share on other sites

I think there is way to go until electric aircraft will be usable.

On flyer.co.uk they say, that the range of the electric caravan is about 105 miles.

If I compare that to our Pilatus Porter, we need about 27 - 30 miles to get us on height. So lets say 40 miles per load (the plane has to get back on the ground).

Therefore every 2 - 3 loads a recharge is needed. I doubt that this is done in a couple of minutes like on conventional planes...

Share this post


Link to post
Share on other sites

One challenge is, as you mentioned, you have to wait for them to hit the secondary market.  A second challenge is that maintenance will be a big unknown for a while - and with skydiving operations tending towards the bare minimum of maintenance, that may result in some ugly problems early on, at least until A+P's get a similar level of understanding that they have now of Continental engines.

But once we reach that point, the change will happen quickly.  FBO rental organizations will be selling their eplanes because the battery capacity has degraded to the point where they're not safe for cross country flights, and it costs too much to replace it.  But for an organization going to 8500 feet and back all day - that's not really an issue.  If you can make it to altitude once, you're good.

Additionally, there are an awful lot of small DZ's out there who run their aircraft very occasionally during the week, and eplanes are ideal for that.  No issues with frequent start/stops.  I can see DZ's getting an eplane to run during the week for the occasional tandem or fun jumper load, then keeping it as a backup/overflow plane for their C206 on weekends.

Share this post


Link to post
Share on other sites
1 minute ago, frontloop33 said:

I think there is way to go until electric aircraft will be usable.

On flyer.co.uk they say, that the range of the electric caravan is about 105 miles.

If I compare that to our Pilatus Porter, we need about 27 - 30 miles to get us on height. So lets say 40 miles per load (the plane has to get back on the ground).

Therefore every 2 - 3 loads a recharge is needed. I doubt that this is done in a couple of minutes like on conventional planes...

State of the art right now is a 2C fast charge rate (in other words, a 30-40 minute charge, empty to full.)  If you assume you are using 30% of the plane's capacity, as you indicated above above, that's a charge in 10 minutes.  Smart operators will keep their aircraft at close to 50% charge average.

Share this post


Link to post
Share on other sites
(edited)
16 minutes ago, billvon said:

State of the art right now is a 2C fast charge rate (in other words, a 30-40 minute charge, empty to full.)  If you assume you are using 30% of the plane's capacity, as you indicated above above, that's a charge in 10 minutes.  Smart operators will keep their aircraft at close to 50% charge average.

And you can probably charge while you load since you're eliminating liquid fuel getting carted around.  There also shouldn't be an issue with a cool-down period for restarts.

It looks like regional people-carriers who use Caravans are very interested in this and can set the pace for how to run ground ops.

Edited by DJL

Share this post


Link to post
Share on other sites
47 minutes ago, frontloop33 said:

I think there is way to go until electric aircraft will be usable.

On flyer.co.uk they say, that the range of the electric caravan is about 105 miles.

If I compare that to our Pilatus Porter, we need about 27 - 30 miles to get us on height. So lets say 40 miles per load (the plane has to get back on the ground).

Therefore every 2 - 3 loads a recharge is needed. I doubt that this is done in a couple of minutes like on conventional planes...

Electric aircraft can also have something like regenerative braking for cars, and recover some energy on the descent, reducing the recharge needed between lifts and reducing total fuel cost even further. Regular engines can't do that.

The charging time is still a problem for quick turnarounds common in skydiving, but battery tech is improving quickly.

  • Like 1

Share this post


Link to post
Share on other sites
35 minutes ago, sundevil777 said:

I would figure that easily changed batteries would be a design goal for e-planes. Whether the cost would work out to have multiple batteries getting recharged and swapped, I hope it will.

Problem there is that it has to be very well integrated into the aircraft because they are big and heavy - and aircraft loads are pretty extreme.  No EV battery swap scheme has worked out yet.  (Other than Nio, which is still in its infancy in China.)

Share this post


Link to post
Share on other sites
(edited)
13 minutes ago, billvon said:

Problem there is that it has to be very well integrated into the aircraft because they are big and heavy - and aircraft loads are pretty extreme.  No EV battery swap scheme has worked out yet.  (Other than Nio, which is still in its infancy in China.)

Seems like that's a problem worth solving since you can't have an aircraft sitting on the tarmac not making money and rapid charging is bad for batteries.  If you can secure cargo adequately for flight I have to imagine that you can do the same for a design built element of the aircraft.

Edit:  And when you're talking about a comparison to the complexity of fueling, holding fuel and pumping fuel to the engines I have to imagine a purposed build module is quite an improvement.

Edited by DJL
  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, frontloop33 said:

 

If I compare that to our Pilatus Porter, we need about 27 - 30 miles to get us on height. So lets say 40 miles per load (the plane has to get back on the ground).

I'm not sure that's accurate.

#1 - The plane can deadstick back to the airport after dropping the jumpers. I know the Otter pilot at my current DZ says he pulls the throttles back to idle and glides all the way in. 

 

#2 - Current electric/hybrid cars use regenerative braking. Applying the brakes results in converting that power back to electricity that is added to the battery. No clue at all if this is going to be part of the electric plane, but I would strongly suspect it to be. 

Put the motor in 'windmill charge' mode (or what ever the real name is) and use the forward speed of the airplane descending to spin the prop and charge up the battery.
I know that the hybrid cars are very efficient in recapturing energy when driven in stop and go traffic. I can see the plane doing something similar. I don't have any idea how much charge they would be able to recapture on a descent, but if it's half of what they used on the climb (again, pure guess), that would result in a 'cycle use' of 13 - 15 miles. With a 105 mile range, that is up to 7 loads without charging. Although smart operators wouldn't let the charge go super low. 

Share this post


Link to post
Share on other sites
1 minute ago, wolfriverjoe said:

#1 - The plane can deadstick back to the airport after dropping the jumpers. I know the Otter pilot at my current DZ says he pulls the throttles back to idle and glides all the way in. 

I think part of this issue is that (Talking out of my Ass) that there's a requirement to have enough fuel for a certain quantity of flight beyond the planned flight.  In reality, yes you can reclaim some flight time.

Share this post


Link to post
Share on other sites
1 hour ago, SkyDekker said:

Local airline recently announced their plan to go all electric

https://www.harbourair.com/harbour-air-and-magnix-partner-to-build-worlds-first-all-electric-airline/

They are a quite successful operation and I look forward to see how this develops.

Seems like it's still leaving the aircraft (Beaver) underpowered considering the current plant is 450hp (336kw):

"The first aircraft to be converted will be the DHC-2 de Havilland Beaver, a six-passenger commercial aircraft used across Harbour Air’s route network. Harbour Air and magniX expect to conduct first flight tests of the all-electric aircraft in late 2019.

This partnership follows significant milestones for both companies, including the successful testing of magniX’s 350 HP all-electric motor and the addition of a Vancouver to Seattle route in Harbour Air’s destination roster."

However, the economics of flight are all about fuel cost and weight so if it costs less then you can fly less weight.

Share this post


Link to post
Share on other sites
1 hour ago, DJL said:

Seems like it's still leaving the aircraft (Beaver) underpowered considering the current plant is 450hp (336kw):

"The first aircraft to be converted will be the DHC-2 de Havilland Beaver, a six-passenger commercial aircraft used across Harbour Air’s route network. Harbour Air and magniX expect to conduct first flight tests of the all-electric aircraft in late 2019.

This partnership follows significant milestones for both companies, including the successful testing of magniX’s 350 HP all-electric motor and the addition of a Vancouver to Seattle route in Harbour Air’s destination roster."

However, the economics of flight are all about fuel cost and weight so if it costs less then you can fly less weight.

That is just successful testing of that motor. Their magni500 model produces 751 HP.

Share this post


Link to post
Share on other sites
(edited)
10 minutes ago, SkyDekker said:

That is just successful testing of that motor. Their magni500 model produces 751 HP.

Good point.  Would like to see the battery pack associated with that. Continuous Power at 750 HP is no joke, we can start dreaming about putting them on Twin Otters.

Edited by DJL

Share this post


Link to post
Share on other sites
On 6/26/2019 at 11:30 AM, DJL said:

This is the power plant and drives referenced for the aircraft above.  They say they can be retrofitted into Caravans and King Airs.  However, this says nothing about the battery portion which is where the real weight is

Yep.  Motors/controllers are pretty easy by comparison.

Share this post


Link to post
Share on other sites

Another order on the books for an electric aircraft.  Not a type that benefits us but some help in developing the market and infrastructure.

Order for First All-Electric Passenger Airplane Placed by Massachusetts Carrier

https://spectrum.ieee.org/energywise/aerospace/aviation/order-for-first-allelectric-passenger-airplane-placed-by-massachusetts-carrier

Share this post


Link to post
Share on other sites

I dunno, a '9 seat regional aircraft' is pretty much what most jump planes started as. Caravan, Porter, Kodiak. Otters are 19 seat, but same basic concept.

First the regional airlines get them. They fly them a while and sell them to the cargo haulers. Then they go to the drug smugglers. Then, a DZO buys it, tears out the interior, installs a kick ass stereo and we jump from it.
Isn't that how it goes? ;)

 

I do, however find this interesting:

 

Quote

...the Alice has a maximum takeoff weight of 6,350 kilograms (14,000 pounds), but 3,700 kg of that is the battery. (And of course there is no fuel burned, so its takeoff weight is more or less its landing weight.)

Most big airliners have a max takeoff weight and a max landing weight. The latter is a lot lower. If there's a situation early in a long flight, it's typical that they have to fly around for a while, burning off and dumping fuel overboard.

Share this post


Link to post
Share on other sites
On 7/26/2019 at 7:08 AM, DJL said:

Another order on the books for an electric aircraft. 

Holy cow, a CONVENTIONAL gear aircraft sold to a regional airline?  That will see some interesting changes in pilot training . . .

Share this post


Link to post
Share on other sites
5 hours ago, billvon said:

Holy cow, a CONVENTIONAL gear aircraft sold to a regional airline?  That will see some interesting changes in pilot training . . .

Also quite unusual for a fuselage mounted pusher on a tail dragger.

the article is a bit loose with mechanical details, such as claiming about 10 moving parts for a 6 cylinder internal combustion engine.

Share this post


Link to post
Share on other sites
On 6/25/2019 at 1:07 PM, DJL said:

Seems like that's a problem worth solving since you can't have an aircraft sitting on the tarmac not making money and rapid charging is bad for batteries.  If you can secure cargo adequately for flight I have to imagine that you can do the same for a design built element of the aircraft.

Edit:  And when you're talking about a comparison to the complexity of fueling, holding fuel and pumping fuel to the engines I have to imagine a purposed build module is quite an improvement.

I think you'll find that the industry effort is directed at fixing the "rapid charging is bad for batteries" problem instead of the swapping problem.  

Share this post


Link to post
Share on other sites
21 minutes ago, chedlin said:

I think you'll find that the industry effort is directed at fixing the "rapid charging is bad for batteries" problem instead of the swapping problem.  

Share it.  This post is for learning about these developing methods.  For us that birdy needs to turn so that's what I'm most interested in.  For basic airline usage they may be able to afford a 30 minute to hour long sit on the ramp but we can't.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's free!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
2 2