# Fauvel AV-36 and 361 project - comment page

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#### Aesquire

##### Well-Known Member
The Fuavel uses a reflexed airfoil. With a fairly long root chord, it should be decent in damping as well.

#### Bille Floyd

##### Well-Known Member
I looked , and they say it's good for 10-G's ; that would be good enough for
me , (along with a ballistic reserve).

Not quite light enough for 103 compliant ; could it maybe
go on a carbon diet, to get the weight down ?

Bille

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
I looked , and they say it's good for 10-G's ; that would be good enough for
me , (along with a ballistic reserve).

Not quite light enough for 103 compliant ; could it maybe
go on a carbon diet, to get the weight down ?

Bille
That 10G is ultimate so it is a bit misleading. The 10G is also for the long wing -361. The -36 goes to 12G ultimate.

I believe that it will be possible to get the weight for a minimally powered version down to part 103 weight using carbon, but it won't have a folding wing or retractable gear at that weight.
Part 103 weight for a pure glider at 155 pounds is just fantasy.

#### blane.c

##### Well-Known Member
HBA Supporter
It don't need to fold, just stand it on its nose and point a wingtip forward on the trailer.

#### Hot Wings

##### Well-Known Member
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Log Member
It don't need to fold, just stand it on its nose and point a wingtip forward on the trailer.
It doesn't need to fold but it does make the tow-able package a lot more compact.
*

Hangar storage for the one piece wing can be small:

*There is some evidence that this type of trailer can damage the structure during transport.

#### blane.c

##### Well-Known Member
HBA Supporter
I see glider trailers grouped up in tie down spots. Very few of them look like they have moved recently. Mostly used as sheds.

#### Bille Floyd

##### Well-Known Member
...
Part 103 weight for a pure glider at 155 pounds is just fantasy.
I agree !!
And if Ya add a Moster 185+, (@ 35Lb) , the machine can go to 254 Lb
and still be legal ; "I Don't get the analogy " ?? Doesn't make any sense
at all , (to me) ??? The same organization, is gonna make it illegal, for
a kid to fly a foam RC airplane, in the park, (soon) !!!

Bille

#### Erik Snyman

##### Well-Known Member
I fly hang gliders, and paragliders , so
I should probably leave this Thread ; lots of GA pilotes
would call me nuts !

Bille
S true. Many would!
Erik in Oz.

#### Dennis K

##### Member
I seem to remember at the Elmira Flying Wing Symposium in1997 to determine the feasibility of towing the Space Shuttle to altitude held at the museum an owner of an AV-36 (Jack Lambie ?) describing how comfortably it flew in bumpy conditions. He said (Or I read it in another report) it responded to gusts by dipping its nose into them and so decreasing the severity. He also mentioned once trimmed hands-off he could eat his lunch and correct for minor altitude excursions by simply leaning forward or back. His only derogatory comment concerned its fast and high ground looping tendency if either lower fin caught so much as a dandelion upon touchdown which resulted in gluing the sub fin back on.

#### Bille Floyd

##### Well-Known Member
S true. Many would!
Erik in Oz.
Call me Nuts for flying a PG ; and for Very Good reason .
Hope i quite that sport , before it kills me ; it's just kinda
addicting !!

I'm : William Erich in USA ; thus the user-name Bille .

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
Double post from y project page:
+++++++++++++++++++
After another nights sleep I've come to the conclusion I've been wasting time on trying to adapt the B+S 810 to the AV.

No one besides me would/should even consider this motor. It needs to be converted from vertical to horizontal. The factory mounting pads, while fairly easy to adapt to a normal firewall/engine mount configuration, just aren't suited to the AV which needs an extension shaft. A more practical solution would probably be an off the shelf horizontal shaft industrial engine - if one wants to use an industrial engine. I do have a Harbor Freight HZ V-twin setting at the shop. The ONLY advantage of the B+S 810 is that it can be inverted (still more work) leaving room above it for a BRS.

It seems I'm stuck in the same place a lot of others are. There just isn't a mass produced engine that is easily adaptable in the power and weigh range needed for the AVs. Paramotor power packages are light and powerful, but they still need to be adapted to function with an extension shaft. And a lot of people don't like the sound of 2 strokes. I know I don't so they aren't an option, for me. They may be the most practical solution?

The model turboprop that HBA member Arfang is working on is another option. That is more \$'s than I, and probably others, would like to spend and the future availability is not secure.

From the start of this project I've thought that the ideal power package would be a hybrid electric one. Unfortunately I don't know of a developed system that could be bought mostly complete and adapted to the AV. If I go down this path that means developing one, and that takes time.

The point of all the? I'm at a point where I need to make a decision on the path forward. Options:

Forget the engine for now and just finish the plans for a glider version - but with some good hard points built in for future engine mounts. (not really an option for me personally)
Decide on an off the shelf motor to adapt and get on with the project.
Decide if the hybrid path is practical or more of a "want" of mine. If it makes sense from a cold dispassionate engineering point of view - am I prepared to spend the time to develop it?

I'm open to thoughts and opinions.............

Edit:
More questions:
Is the average home-builder going to be comfortable enough with the complexities of a hybrid system that they would consider installing and maintaining a package system?
We as a group seem to be getting comfortable with home-built avionics using Arduinos and Raspberries and open source software. To me, both seem equally simple. Are they perceived that way by others?

#### Vigilant1

##### Well-Known Member
Lifetime Supporter
An ancillary question:. Would >you< be in the business (literally) of making/selling whatever power package you decide on? That takes things from the theoretical to the concrete: which power package will have the greatest market acceptance and be most economically advantageous to you? My gut tells me that the B&S 810 might be a good candidate because the base engine ( your raw material) is availabile expensively, appears unlikely to change soon, and has worldwide parts and maintenance support. After your first conversion or two it will be simple, and the power to weight is attractive. A hybrid approach will be a lot more expensive for you and for customers. The HF engine might work, but surely requires more "selling" to prospective buyers, and its construction reflects the cost-conscious market it serves. Substitute forged conrods, etc and the B&S would be cheaper to start with, and many are already flying.

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
An ancillary question:. Would >you< be in the business (literally) of making/selling whatever power package you decide on?
Potentially - Yes. But I don't want to get into a position where builders are dependent on my business to get/keep their plane flying.

The HF engine would only be for myself. A more mainstream engine would be a better choice for others - IMHO. A HZ shaft B+S/Kawasaki/Honda should be pretty much a bolt in swap with for aircraft modifications.

I'm not so sure about the hybrid being all that much more expensive. It is now but may not be in the near future. Being a modular system a hybrid is actually more resistant to becoming obsolete than the industrial engines. Battery packs can be sourced from several vendors as can other components of a hybrid system. These sub-components may not be straight swaps but can be adapted pretty easily.

Thanks for your thoughts and insights!

#### Peter Mican

##### New Member
HBA Supporter
I would set on a Honda or Kohler ...available in most countries of the world.
B & S and Kawasaki not so popular and in many places difficult to find.
• HONDA´s are definitely everywhere to find and spare parts for it at every corner ...
• all over the place in South America, Asia, Europe ... have lived in these countries for a long time and always found Honda´s and spare parts everywhere, and I believe in the USA they are very common too ... (used 10 HP Honda´s as inboard engines in my Dinghies, which were used very hard and in the harsh saltwater environment, the only problem was a rusty carburetor bawl which I had to change every two years...rusted out from inside !!!)
B & S outside of the USA has horrible service, no spare parts ...

I use lawnmowers with B & S for 30 years, the newer ones never start, on one the engine block cracked, on another the carburetor got on fire, all plastic inside... no way for me to use such an engine on an aircraft...
The old B & S were bulletproof and real workhorses, this time is over, looks to me that they are made in China...

#### blane.c

##### Well-Known Member
HBA Supporter
Hi;

How much power does it really need? I mean it fly's pretty well without an engine.

Look at this Cri Cri

http://www.rotexelectric.eu/products/bldc-motors/rex-series/

https://emrax.com/products/emrax-188/

From the what do you think about e soaring thread https://www.homebuiltairplanes.com/forums/threads/what-do-you-think-about-e-soaring.17114/page-25#post-517431 you can link to the following.

https://www.sunexelec.com/phoenixelec

I don't think electric is here yet for airplane, but for glider it has definitely arrived. The diameter and weight of an electric motor would allow you to mount it nearer where you want the propeller and so a shorter shaft.

Electric is the future. Why design for the past?

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
Hi;

How much power does it really need? I mean it fly's pretty well without an engine.
<< >>
Electric is the future. Why design for the past?
The AVs require around 7hp (~5k watts) for level flight with zero lift. More lets it cruise at higher speeds and/or climb. A motorized version needs about 20 hp (~15K watts) for reasonable climb rate. If you use glider launch methods even 5 hp would significantly extend the glide range for a "save".
<< >>
Why? There are still a lot of potential builders that either don't trust or understand electric/hybrid systems. And this:

I would set on a Honda or Kohler ...available in most countries of the world.
Industrial engines of one brand or another are available most everywhere and they are pretty well interchangeable. Each will need it's own personalized modifications but the basics are all similar.

#### blane.c

##### Well-Known Member
HBA Supporter
If the rex 50 would do it, about 20hp continuous and 37hp for a short duration the motor weighs less than 20lbs and could be mounted on the end of a shaft and with a folding prop could be streamlined in.

#### blane.c

##### Well-Known Member
HBA Supporter
The rex 30 less than 12lbs over 10hp continuous and around 24hp for short period of time.

#### blane.c

##### Well-Known Member
HBA Supporter
You can use regenerative power for some or all of the drag, thereby reducing or eliminating the weight of that portion of the control system.

#### Hot Wings

##### Well-Known Member
HBA Supporter
Log Member
If the rex 50 would do it,
And it could work direct drive unlike a lot of the model electric motors that spin too fast. I also like the fact that they are using more voltage than the model motors.
I do have a problem dealing with companies that don't publish their prices.

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