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Why battery-powered aircraft will never have significant range

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pictsidhe

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Are you trying to piss me off ?

If I have a plane that has half the mass of Solair 2 and better/lower wingloading and lesser drag..I am certainly at better performance than the arofementioned Solair 2. It is that simple.

View attachment 104484
Your last specs did not align with reality by a very, very long way. You aren't going to design a decent plane if you can't even do basic sanity checks.
Now it is going to be half the weight of a 140kg 66' span carbon honeycomb special? Still thinking you can fly fast in that? I can't see it even flying, myself.
You need to do some basic maths before making outrageous performance claims, or you will just get ridiculed.
 
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Speedboat100

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Your last specs did not align with reality by a very, very long way. You aren't going to design a decent plane if you can't even do basic sanity checks.
Now it is going to be half the weight of a 140kg 66' span carbon honeycomb special? Still thinking you can fly fast in that? I can't see it even flying, myself.
You need to do some basic maths before making outrageous performance claims, or you will just get ridiculed.

I only see you ridiculing.

Rochelt sets a benchmark...flying at 755 watts.

SLAIR2_Rochelt.jpg
 

Dan Thomas

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I only see you ridiculing.

Rochelt sets a benchmark...flying at 755 watts.

View attachment 104490
So I looked it up. 755 watts in level flight. 1352 wH of battery. Two hours. In a really light glider that normally sinks at 0.35 m/s, or about one foot per second, or 60 fpm. The motor is contributing VERY LITTLE. If the pilot encounters sinking air he's in pretty much as much trouble as the guy with no power.
In the climb it uses 5742 watts at max power, meaning the batteries are good for no more than 14 minutes, and the climb rate is 2 m/s, or 394 fpm. Subtracting the capacity to overcome the acceleration and air and ground drag forces in the takeoff roll, you wouldn't end up with much altitude before the batteries died.

This is what you call a practical electric airplane?
 

pictsidhe

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So I looked it up. 755 watts in level flight. 1352 wH of battery. Two hours. In a really light glider that normally sinks at 0.35 m/s, or about one foot per second, or 60 fpm. The motor is contributing VERY LITTLE. If the pilot encounters sinking air he's in pretty much as much trouble as the guy with no power.
In the climb it uses 5742 watts at max power, meaning the batteries are good for no more than 14 minutes, and the climb rate is 2 m/s, or 394 fpm. Subtracting the capacity to overcome the acceleration and air and ground drag forces in the takeoff roll, you wouldn't end up with much altitude before the batteries died.

This is what you call a practical electric airplane?
But topspeed is going to make it fly fast!
 

Dan Thomas

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But topspeed is going to make it fly fast!
Yes. I should have mentioned the speeds:
Operational velocities:
Stall speed vs: 44 km/h (That's 27 MPH)
Maneuver speed vA: 96 km/h
(59 MPH)
Max. speed vNE: 120 km/h (74 MPH)
Operational top speed vD: 111 km/h
(66 mph)
Optimum level flight airspeedt: 51 km/h
(31 MPH)

Blistering performance indeed.
 

pictsidhe

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Yes. I should have mentioned the speeds:
Operational velocities:
Stall speed vs: 44 km/h (That's 27 MPH)
Maneuver speed vA: 96 km/h (59 MPH)
Max. speed vNE: 120 km/h (74 MPH)
Operational top speed vD: 111 km/h (66 mph)
Optimum level flight airspeedt: 51 km/h (31 MPH)

Blistering performance indeed.

We'll se I am pretty far in my project and I just test the electricity..as the cells are very expensive. 10 m2 cell area ought to be able to sustain a flight....best new have 37% efficiency at high at noon that makes 5 kw continuos.

Elektra One manages to fly at 3 kw but is almost twice as heavy as my spartan ship. At high ( and I don't mean marihuana ) with suitable aerodynamics with longer wings it ought to soar at 150-200 km/h.

Where is the problem ?
So, not marijuana. Perhaps something stronger?
 

Speedboat100

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So I looked it up. 755 watts in level flight. 1352 wH of battery. Two hours. In a really light glider that normally sinks at 0.35 m/s, or about one foot per second, or 60 fpm. The motor is contributing VERY LITTLE. If the pilot encounters sinking air he's in pretty much as much trouble as the guy with no power.
In the climb it uses 5742 watts at max power, meaning the batteries are good for no more than 14 minutes, and the climb rate is 2 m/s, or 394 fpm. Subtracting the capacity to overcome the acceleration and air and ground drag forces in the takeoff roll, you wouldn't end up with much altitude before the batteries died.

This is what you call a practical electric airplane?

No so much, but think about it...if just 600 watts will change the glideratio into 70:1 then you can glide really far...from very low altitude...and solar rays does not has to come from above.
 

Speedboat100

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Now I get it. It will be powered by search lights. Very clever!

Could that be possible..to have 2 m2 high grade panels on the side and powerful beam of light would follow it at nite time....and energize it ?

In a bigger ship like 20 m2 ?
 

blane.c

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Re-link the Pyramids into a world wide power grid. Likely impossible because of a shift in the earths magnetic field has the Pyramids no longer in a useful pattern ... move the Pyramids into re-alignment ... yes that's it ... .
 

pictsidhe

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Why are we even talking about stuff with wings? All we need is an antigravity device powered by ZPE (zero plausibility energy). Simple.
 

Dan Thomas

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Why are we wasting our time on this nonsense? We should just ignore him until he builds his impossible airplane. I am too easily sucked into trying to teach the unteachable.
 

Speedboat100

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Phantom of the opera did contact the local FAA about the needed G-forces the craft has to endure in Finland...if sold to masses.
 
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