What do you think about "e-soaring"?

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John.Roo

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=or involve best L/D with low weight and costs...

(BTW=constant chord K-wing is simple for HBAs...)
Why not? Every homebuilder can make his own decission ;)

Just to explain you a bit better my point of view....
The e-Glider idea is aiming to clubs and young or older private pilots.
Final result should be KIT of composite one seat "glider like" airplane with possibility to install electric propulsion. It should not be designed to one exact type of electric propulsion.
Maybe would be not bad to offer it like a pure glider (with done preparations for battery pack installation place, motor and controller holders, pre-wiring etc.) and make some recommendations about "tested" propulsion configurations.
Up to now seems to be not so hard challenge.... however real challenge starts with price and weight.

My dream would be to keep price of complete airframe arround 20K EUR (24-25K USD).
It means that airframe constructio should be simple. Materials are comming to be expensive, but even more expensive is human work.
If we consider actualy offered electric propuslion systems in our power range (arround 20 kW) we can get price from 10 000 USD (Aerolite system with 2 batteries).
Geiger Avionics or MGM system available in EU will costs arround 12-15K EUR (my estimation).
Builder experienced in electronics could probably make propulsion system for lower price (of course on his own risc and than he must convince inspector about safety of his system).

Weight....
Is interesting to see how the weight is affecting final price.
Low empty weight can safe a lot of money on certification / registration proces and pilot requirements (price of pilot license, requested or not requested medical checks etc.).
However low empty weight is also increasing price of materials. Is practically impossible to make light airframe without to use carbon fiber. In this case is not possible to make some compromises as the e-Glider should be able to fly also in mountains and wave conditions. This is by the way another reason to make design with relativelly "short wings" and keep possibility to "sponsor" L/D with electric propulsion.
Where could be possible to save some money is simplicity of construction. Is really necesary to keep production hours as lower as possible.

Another ways how to save money... (just "self brainstorming").
- to use parts already developed (possible for example for control lines, control lines connections etc.)
- keep low Vne. Vne is affecting necessity of expensive flutter testing. Of course cannot be too low - that would affect safety. Optimal Vne is 180 kmph (100 kts).
- use of back parachute instead of ballistic rescue system? I prefer BRS to save pilot and whole plane but this again affects price and empty weight....
- ... maybe other suggestions? ;)
 

henryk

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... maybe other suggestions?
=SECOND CHANTZ instead of BRS/ GRS...(typical chute,softpack+homemade pneumatic rocket)

=PARABEAM (3 mm, 0.5 kg/m^2) =low lamination time...
(f.e. auer Firma EKOLOT products=ELF, JUNIOR,TOPAZ)

=low AR<10 +rudders/winglets

=good China electric motor(1000 $) +VESC (England, 400 EUR) +battery from hybrid cars...

or pressing on Darek Lewek=organize GEKON KIT !
 

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John.Roo

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BTW=

"David Webb and the Brochocki BKB 1 "

in the end of PDF=
"...prototype BKB ended with a crash in 2013 that also killed pilot."
Please lets continue our discussion about airplanes with classic configuration (with tail surfaces).
I fully understand that on Kasperwing are done modification increasing safety, but true is that we are looking for airplane designed for non-experienced pilots or older conservative pilots. Thanks 👍
 

EzyBuildWing

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Seems there are 5 Schleicher 2-seater motorized Gliders being auctioned-off from the Australian Air Force soon.
Auction commences on 5th November.
Details are below.
Anyone care to guess what prices they might bring?

 

John.Roo

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Seems there are 5 Schleicher 2-seater motorized Gliders being auctioned-off from the Australian Air Force soon.
Auction commences on 5th November.
Details are below.
Anyone care to guess what prices they might bring?

That will be interesting. I also wonder what will be final price for the ASK 21 gliders.
"Bidding starts at just $1 with NO RESERVE."
That seems like good opportunity for Australian aeroclubs 👍
 

henryk

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henryk

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That is a nice glider 👍
Really only 60 kg Empty Weight?
Very good result!
70-60=10 kg reserve for repair works...and stay in 70 kg class.

BTW=first Zenon Pietruszka AXEL glider was equal to Him=55 kg !


(80 kg with 120 cc engine )

 
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John.Roo

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Empry weights of Axel / Gekon and "light version of Puchatek" are really very good.
I asked for more technical paratemers only to have an impression about achieved airframe strength.
At least MTOM and Vne would be interesting.
Well... I assume that realistic MTOM is anyway arround 280-300 kg.
Assuming 120 kg as basic EW + pilot weight up to 110 kg + batteries + small reserve (for example for light on board charger) = 280-300 kg ;)
 

henryk

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John.Roo

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ELF KIT is for 9 900 EUR?

Update...
ELF airframe KIT is for 9 900 EUR.
1632996366866.png
Control lines set costs 5 500 EUR.
1632996533601.png

Technical data:
wingspan10,73 m
wing area10,5 m2
length5,45 m
height208 cm
empty weight120 kg
maximum weight (with GRS)250 kg
take-off weight250 kg
cruising speed128 km/h
maximum speed142 km/h
stall speed55 km/h
climb speed3,9 m/s
 
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