Fisher Flying Products Announces New Electric Propulsion Systems

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pictsidhe

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Batteries weigh a good chunk more than just the cells. You need to physically and electrically connect them together and the aircraft. The latest Pipistrel pack is 154lb and 12.3kWh. Tesla model S 85kWh pack is 1200lbs. Those are actual production packs built by real engineers, not internet 'paper' packs from keyboard experts.

The battery weight is why you cannot have a drop in electric GA engine.
 
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Bigshu

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Electric motors can last between hours and decades. We have a 30yo 100hp BLDC that doesn't look like it has ever been opened. Bit heavy for a plane though. Seen some BLDC die in hours.
The pump station I work at has 4, 900 hp Westinghouse pumps and a couple of 600 hp Seimens. All of these electric powered pumps were installed between the 30's and 40's. Still run most of them for days or weeks at a time, without issue. The ones that we don't run that much are because of line utilization, not equipment issues.
 

User27

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Before saying all current electric aircraft are a waste of time it pays to look really carefully at the aircraft's mission. If the mission now requires an RV-6 or C172 then an electric aircraft will not be a substitute for a similar upfront cash outlay.
There are some (quite particular) missions where electric aircraft can be successful today, not may but some. As the price of batteries reduces, and the availability of off-the-shelf battery packs increases, the scope of those missions may well increase. If no-one starts now there will be no motor/controller/integration technology in place when batteries improve. Outside of the US, under different certification rules and in different operating environments, electric propulsion is perhaps more attractive. Its the only area of this business/industry/sport/hobby where there is any significant innovation going on, don't knock it!
 

cluttonfred

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Well, if a typical fixed-pitch propeller GA piston single engine installation weighs at least 250 lb firewall forward, plus 25 gallons of fuel @ 6 lb/gallon makes 150 lb, plus the weight of the fuel tank itself, plumbing, wiring, controls, instruments, you're talking a weight allowance of about 450 lb for a typical GA application. If the electric motor, redrive, and propeller weigh 100 lb and you allow 50 lb for wiring and controllers and instruments and controls, that still leaves 300 lb for batteries. Mount half the batteries with the engine for weight and balance, the other in the wings or fuselage wherever the fuel tanks would have gone. The issue is energy density, how many pounds per kWh, once the battery technology gets to the point that the energy density of the batteries is even 50% that of gasoline, then we'll see some real change. We're not there yet.

Batteries weigh a good chunk more than just the cells. You need to physically and electrically connect them together and the aircraft. The latest Pipistrel pack is 154lb and 12.3kWh. Tesla model S 85kWh pack is 1200lbs. Those are actual production packs built by real engineers, not internet 'paper' packs from keyboard experts.

The battery weight is why you cannot have a drop in electric GA engine.
 

12notes

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You have to start somewhere...
I agree. I'm a big fan of electric aircraft. They are practical for some small niche applications right now. These should be promoted and encouraged.

However, unrealistic claims for an aircraft that hasn't even been designed yet aren't helping. Projections of performance based on hopes and dreams aren't helping. Unrealistic projected advances in battery technology aren't helping. When these are continuously promoted and fail to deliver, interest and investment will decrease, even for those projects that are realistic with achievable goals.

Lithium sulfur batteries should be available in the next year, and I expect them to have a battery density approaching 400W/kg when released. This is a big improvement over Li ion, but not even close to what is needed for a typical GA application. And improvements after that will revert back to the steady 3-5% per year typical of battery development.
 

BJC

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I agree. I'm a big fan of electric aircraft.
Yep, I want one. But, even for my modest sunset flight mission, they aren’t available yet.

However, unrealistic claims
Nor are suggestions that they will, in any reasonable time frame, reduce coal, natural gas and nuclear power generation.


BJC
 

pictsidhe

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Yes, way too many people wanting or 'planning' electric GA type planes. Newsflash: those aren't happening for many, many years, if ever.

What IS possible now, is to electrify something along the lines of a motorglider. Do a decent job, people won't laugh hysterically when you mumble it's range and flight duration. GA electric is going to have wait a few decades. Meanwhile, do the maths, repurpose some ground EV tech and learn to live with the span and low drag that it requires.

I bet BoKu could build a good one...
 

Tornado Flyer

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I have argued that developing electric aircraft is a complete waste of time until the battery tech allows for comparable range to gas engines. I stand by that. I don't thing that many people are going to put 900-2000 hours into building an aircraft only to hobble it with an hour of range.
AND thousands of dollars on a new setup when used engines are widely available.
 

Foundationer

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As someone that flies gliders in the very fickle conditions of the UK the idea of e-soaring is a very attractive one. There's always a gap that's a bit too big even with my 40+ to one glide ratio. That's before you hit the inconvenience/potential danger of not getting home.
 

Tiger Tim

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Yes, way too many people wanting or 'planning' electric GA type planes. Newsflash: those aren't happening for many, many years, if ever.
Moore’s Law applies to the rate of advancement of most technological products that most people will handle daily. I think it’s just human nature to expect that same advancement applies to whatever they want it to.
 

Cy V

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Fisher just put out an update to their new electric propulsion systems. Only the first 2 1/2 minutes of the video is about the update. The rest is unrelated.

 

BBerson

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Electric for ultralights has been proven.
A marketable electric kit price has not been proven.
 

BoKu

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Moore’s Law applies to the rate of advancement of most technological products that most people will handle daily...
I think one could make a good case that Moore's Law applies specifically to the technologies of electronic data processing. It may have some application outside that narrow realm, but as you note it mostly just raises expectations precluded by basic science and the periodic table of elements.
 
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