What do you think about "e-soaring"?

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claude.bouzerand

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Yes, it is this craft. I am aware of this pusher configuration and of the risk of tail flutter ,the surface and volume of the vertical fin is rather important, but the vertical fin and stabilator are wire braced both together... maybe a reason of the limited VNE... But such a little light plane can be interesting to illustrate the thread of these captivating pages. My first intend was to electrify a Mitchell Wing B10 (I have the last one plans) but the design of the Bagalini Bagaliante is so seducing...
 

claude.bouzerand

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Here is a better tail boom! The boom of the B.Bagaliante is a simple aluminum tube ,but with a doubler at the pod's area. I think it is a good concept, with the correct calculations.
 

John.Roo

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Yes, it is this craft. I am aware of this pusher configuration and of the risk of tail flutter ,the surface and volume of the vertical fin is rather important, but the vertical fin and stabilator are wire braced both together... maybe a reason of the limited VNE... But such a little light plane can be interesting to illustrate the thread of these captivating pages. My first intend was to electrify a Mitchell Wing B10 (I have the last one plans) but the design of the Bagalini Bagaliante is so seducing...
Pusher configuration is good for simple electric propulsion installation.
20kW electric motor + folding prop (like from Helix) would be nice.
Small problem is with designed MTOM - only 185 kg.
If EW is 110 kg and you remove 30 kg for engine....
.... than airframe weight is arround 80 kg.

Typically you need to have reserve for pilot at least 100 kg (I suggest 110 kg - lets be realistic) :cool:
So 75-80 kg for airframe + 100-110 kg for pilot.
You need also 20 kW electric motor (10-12 kg) + controller (2-3 kg) some wiring and... battery.
Min. battery size would be 5-6 kWh = arround 30 kg weight.

"Optimistic" summary...
75 kg airframe
100 kg pilot
10 kg motor
2 kg controller
30 kg battery
==========
Airframe should be designed and tested for at least 220 kg.
However for "real life use" and flying also in harder conditions I would recommend to design airframe for MTOM above 250 kg.

For comparizon - technical parameters of EXEL from Alp-Aero:
1633514671839.png
Wing span: 13.74 m (45.1 ft)
Length overall: 5.90 m (19.3 ft)
Propeller diameter: 1.28 m (4.2 ft)
Wing area: 11.62 sq.m (125.1 sq ft)
Aspect ratio: 16.2:1
Weight empty*: 190 kg (432 lb) - *incl. ICE engine with approx. 20 kg installation weight
Max T-O weight: 310 kg (683 lb)
Max wing loading: 26.67 kg/m2 (5.46 lb/sq ft)
Cruising speed at 75% power: 120 km/h ( 65 kt, 75 mph)
Max speed: 180 km/h ( 97 kt, 112 mph)
Stalling speed: 64 km/h ( 34 kt, 39 mph)
Max rate of climb: 2.2 m/s (434 ft/mn)
Endurance: 3 hours
T-O run: 150 m (492 ft)
Landing run: 140 m (459 ft)
Best glide ratio: 30:1
Min rate of sink: 0.75 m/s (148 ft/mn)
G limits (operational): + 4.4 / -2.2 G
Seats: one pilot
 

John.Roo

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Philosophy of Claude Noin - why he designed EXEL.
In my opinion, it's really nicely written....
1633515390225.png
"Flying a sailplane is certainly one of the most enjoyable aeronautical activities. But it is also a very restrictive leisure process : you need a ground crew, a tow-plane, and the waiting usually associated with gliding activities. The motorglider frees the pilot from the tyranny of the tow-plane, and also allows recreational glider pilots to soar much further afield from home base with confidence, because it pratically eliminates the risk of outlanding and the time-consuming hassle of a retrieve. Landing in other people's fields is increasingly unpopular and frustrating. If you run out of lift at the end of the day, just start the engine and cruise home. Or if you miss the wave on the first try ? Instead of dashing back to the airport, try another place, until you get it right.
The motorglider is the solution to a more modern soaring experience, not only turned towards competition but also leisure... and pleasure.

Motorgliders are the ultimate recreational vehicle and will modify the sort of flying that is done. Being less thermal dependent, they will give pilots more flying time. Nowadays sailing a cruising boat on the sea without an engine is impossible, and even the entry to some marinas is prohibited to unmotorized boats. Is it so different with sailplanes ? There is nothing wrong with the use of an engine if it gives more flying on more days, because the need to understand and use weather will still be there both for fun and economy. It won't change the way you soar, but allow you to do it more conveniently and more often.

We also believe that climbing performance is more important for recreational soaring than gliding performance. When we compare gliders, we often use one criteria: Lift/Drag ratio. Yet it's strange that of the characteristics that we use when we fly a glider, l/d is one of the least important (are you really a world record hunter ?). For the true recreational flyer (not the competitor), climbing capabilities are more important than glide ratio. And if you want to have more flying time you need to stay up even on weak days. You want a light sailplane that can stay up when the birds are flapping their wings. You want to be able to fly even when the day dies, or when the heavy gliders are on the ground. That takes low wing loading, low stall speed and low sink rate.
Sink rate defines an important parameter for soaring flight, as it is that measurement that determines whether you can get up, stay up and climb high. While good glide essentially means to run between thermals with little altitude loss, it doesn't mean that you can effectively work the lift to gain altitude. For a recreational glider pilot, climbing capabilities, based on low wing loading, low stall speed and low sink rate, are more important than being able to fly fast between thermals.
We don't believe that the very heavy all-plastic motorgliders are a good solution to recreational soaring. Lightness gives more flying time, lower speeds for more security, ... and more affordable gliders !

Our motorgliders are not designed for the few glider pilots addicted to competition flying, who need the best high-tech sailplanes. Our products are designed to satisfy a great majority of pilots who do not need the expensive technology of the top world glider manufacturers, but only easy-to-fly and enjoyable light sailplanes... with full independence.
" 👍
 
Last edited:

opcod

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Aug 28, 2010
Messages
101
Location
Canada
Can't agree more ! The Excel and the Choucas are very nice one. And the Excel in hydrogren and E was look into 17yrs ago.

*On the black paint, it was a vari-ez build near TX i think about 7yrs ago and fully paint in black. So yes, it's real, just as mention.. But i think i could seat in it in within the first year if it flew 1 time per week, all time in hangar and with special cover sheet put over. But not more.
 

claude.bouzerand

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Feb 2, 2020
Messages
35
Location
Toulouse France
I reakky well know Claude Noin, and I flew the Choucas when they did first certification flights ! It is a very good and efficient flying wing , very stable ! and I remember the pilot going close the stall and letting the stick go ,the Choucas did 3 damped "phugoids" to come back to a straight flight.
 

claude.bouzerand

Active Member
Joined
Feb 2, 2020
Messages
35
Location
Toulouse France
Pusher configuration is good for simple electric propulsion installation.
20kW electric motor + folding prop (like from Helix) would be nice.
Small problem is with designed MTOM - only 185 kg.
If EW is 110 kg and you remove 30 kg for engine....
.... than airframe weight is arround 80 kg.

Typically you need to have reserve for pilot at least 100 kg (I suggest 110 kg - lets be realistic) :cool:
So 75-80 kg for airframe + 100-110 kg for pilot.
You need also 20 kW electric motor (10-12 kg) + controller (2-3 kg) some wiring and... battery.
Min. battery size would be 5-6 kWh = arround 30 kg weight.

"Optimistic" summary...
75 kg airframe
100 kg pilot
10 kg motor
2 kg controller
30 kg battery
==========
Airframe should be designed and tested for at least 220 kg.
However for "real life use" and flying also in harder conditions I would recommend to design airframe for MTOM above 250 kg.

For comparizon - technical parameters of EXEL from Alp-Aero:
View attachment 116556
Wing span: 13.74 m (45.1 ft)
Length overall: 5.90 m (19.3 ft)
Propeller diameter: 1.28 m (4.2 ft)
Wing area: 11.62 sq.m (125.1 sq ft)
Aspect ratio: 16.2:1
Weight empty*: 190 kg (432 lb) - *incl. ICE engine with approx. 20 kg installation weight
Max T-O weight: 310 kg (683 lb)
Max wing loading: 26.67 kg/m2 (5.46 lb/sq ft)
Cruising speed at 75% power: 120 km/h ( 65 kt, 75 mph)
Max speed: 180 km/h ( 97 kt, 112 mph)
Stalling speed: 64 km/h ( 34 kt, 39 mph)
Max rate of climb: 2.2 m/s (434 ft/mn)
Endurance: 3 hours
T-O run: 150 m (492 ft)
Landing run: 140 m (459 ft)
Best glide ratio: 30:1
Min rate of sink: 0.75 m/s (148 ft/mn)
G limits (operational): + 4.4 / -2.2 G
Seats: one pilot
I jnow all Claude Noin's works, Thry are very well done and the EXEL is a state of the art , Claude's art ! I thak you a lot for your suggestions, I have same considerations I will do some extra calculation using Jim Marsje's book , his method seems affordable , and rather simple ,If I can get good strength without too much weight ....It will be good !
 

PiperCruisin

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Jan 17, 2017
Messages
276
Location
Idaho
I jnow all Claude Noin's works, Thry are very well done and the EXEL is a state of the art , Claude's art ! I thak you a lot for your suggestions, I have same considerations I will do some extra calculation using Jim Marsje's book , his method seems affordable , and rather simple ,If I can get good strength without too much weight ....It will be good !
The EXEL is tempting. Wish I had gone to see it when I lived in France. Another one is Manfred Ruhmer's eSwift as an economical means of flight. Maybe the Aeros AC-21 if that ever gets commercialized. I saw the predecessor at the Coupe Icare (St. Hilaire, France) and the disintegration of an Archaeopterix doing aerobatics (I don't think it was designed for that).

The RF4UL would be amazing if that project could be resurrected. You're in France. Maybe you can go talk to them and we could put them in touch with the Experimental Soaring Association.

Marske's book is pretty good. It needs some more details, but worth the money.
 

John.Roo

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Oct 8, 2013
Messages
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Location
Letohrad / Czech Republic
Dear friends, I know (and I am sure you noticed) that I mentionned gliders EXEL, AXEL / GEKON and Sagitta many many times during last weeks in this thread. Why so?
Reasons are simple....
Important part of final price are not only production costs but also development and certification costs.
It is possible to affect (decrease) production costs making construction simple and from "affordable" materials.
Certification costs is possible to decrease a lot designing airplane in category, where are certification requirements as low as possible (one seat ultralight in Class 120, SSDR....).
And finally - development costs are lower if you use already existing parts ;) Of course it does not mean that using existing parts is "for free" but at least it safe time to make prototype etc.

Look to performance of above mentionned airplane types.
All of them are in category L/D 1:30+
All of them are in category with MTOM max. 300 kg.
All of them were already flown with electric propulsion.
Non of this projects moved to serial production - Exel has been produced in 9 pces, Axel / Gekon probably 1-2 pces (maybe Henryk knows exactly?), Sagitta exist in one prototype. And if I remember well - KIT of all these airpanes was supposed to cost arround 20-25K EUR.

Of course they are existing also other projects, but they have been not yet flown or conception is not standard (flying wings, "V" tail etc.).

Question is... is on the market between pilots interest for such an airplane? In short is about composite, electric, self launch, single seater in price range of 35-40K EUR (price for Ready To Fly version, KIT should stay in 20-25K EUR).
 

PiperCruisin

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Messages
276
Location
Idaho
Dear friends, I know (and I am sure you noticed) that I mentionned gliders EXEL, AXEL / GEKON and Sagitta many many times during last weeks in this thread. Why so?

Question is... is on the market between pilots interest for such an airplane? In short is about composite, electric, self launch, single seater in price range of 35-40K EUR (price for Ready To Fly version, KIT should stay in 20-25K EUR).
Seems to me there are a lot of stalled projects. For the US, I would want a kit/experimental rather than certified. Also, most being manufactured outside the US complicates things and it's hard to get info.

Folding wing or one that has mid span joints for easier storage and available engine I think are important.

The Xenos is nice, but you need a good size hanger and making those long wings looks like a chore. I would want it hangered or covered to prevent hail damage to those wings. If the outer wings folded or detached, I think it would be a real plus despite the weak L/D.

Electro Taurus is nice, but I don't like the drawbacks of the turtle deck propulsion storage (deployment and stowage time/drag). Not a bad price for the performance and RTF/certified?.
 

John.Roo

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Letohrad / Czech Republic
Seems to me there are a lot of stalled projects. For the US, I would want a kit/experimental rather than certified. Also, most being manufactured outside the US complicates things and it's hard to get info.

Folding wing or one that has mid span joints for easier storage and available engine I think are important.

The Xenos is nice, but you need a good size hanger and making those long wings looks like a chore. I would want it hangered or covered to prevent hail damage to those wings. If the outer wings folded or detached, I think it would be a real plus despite the weak L/D.

Electro Taurus is nice, but I don't like the drawbacks of the turtle deck propulsion storage (deployment and stowage time/drag). Not a bad price for the performance and RTF/certified?.
I agree that fast and simple dismantling is very important - it can save costs for hangar.
I don´t know situation in US but in EU are costs for hangar increasing every year.
 

PiperCruisin

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I agree that fast and simple dismantling is very important - it can save costs for hangar.
I don´t know situation in US but in EU are costs for hangar increasing every year.
I have a hanger that is 40 feet wide that I rent for about $200/mo. I consider myself lucky to have it but the door is a PITA (two rollup doors with a center track post you have to remove manually), it leaks, and its 40 miles from home, and its not big enough for a motorglider. In our area, inflation and demand mean hanger prices are much higher, rent closer to $450/mo IF you can find one. There are Facebook groups dedicated just to finding hangers.

Soooo, something compact/foldable would be NICE.
 

John.Roo

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I have a hanger that is 40 feet wide that I rent for about $200/mo. I consider myself lucky to have it but the door is a PITA (two rollup doors with a center track post you have to remove manually), it leaks, and its 40 miles from home, and its not big enough for a motorglider. In our area, inflation and demand mean hanger prices are much higher, rent closer to $450/mo IF you can find one. There are Facebook groups dedicated just to finding hangers.

Soooo, something compact/foldable would be NICE.
You are right - to keep airplane in hangar is more and more expensive.
I can´t imagine prices like 200 USD for hangar in my area (Czech Rep.), but I know that is common in Western Europe.
Owners of gliders are very often using their trailers and they have usually tools allowing to assemble the glider in one person in short time. I prefer to keep plane assembled, but true is that wing span bigger than 10 meters (30 ft = +- Cessna 150/152) makes problems everywhere because of difficult manipulation, hangar door size etc.
 
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