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22 hp V Twin Predator engine ultralight Aircraft (IDEA/project) ICON A5 REPLICA

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Tdwalker

Member
Joined
Dec 7, 2015
Messages
5
Location
Monett, Mo United States
Hey guys, new to the forum here. So I've been planning on building my own ultralight for quite some time now. And although I wouldn't mind just buying a used one, I really just want to design one myself. I would like to post my idea for what I'm doing here and see if I can get some useful feedback on the project, and hopefully this information can help others with similar experience as well.

So the idea I have, Is to in a way, replicate the shape and style of a plane called the icon A5 while at least attempting to keep it around 300-375 lbs. Most elements from the plane I would be leaving behind, such as the option of being amphibious, most of the electronic systems, the folding wings, and of course the luxurious style. Basically, I would like to build an extremely simple ultralight that has the shape of the icon a5.

The motor I would like to use is a new 22 hp (670 cc) V Twin Predator engine. It is 125 lbs. I may end up using two of them rear facing, just behind the wings or just one of them just behind the cockpit and center of the wing just like the Icon A5. A question I have about this is: Can I order a propeller online that will fit this motor? If so, are there specific fittings that need to be in place or will that come with the propeller? Also, is the engine simply too heavy for use in aircraft? I mean... Dual motors would be 250 lbs. dry, BUT that would also mean 44 hp and I plan on building extremely light, so I'm not sure how that would balance out.

The frame would be mostly wood, with the exception of things like landing gear, and control arms, etc.

I would like to keep the 2 seat configuration, but move the passenger seat behind the pilots seat. The only reason I would want to do this is so that instead of the cockpit being over 4' wide, it would be 3' or less and therefore be a little more efficient, and might actually better allow for it to work as a two seater. (Less likely to work with less aerodynamic properties). I just want to eventually be able to do cross country trips with my wife.

I plan on building the cockpit enclosed using a material similar to a heavy duty tarp that you can buy from a place like Harbor Freight. Then for windows, also use a non-rigid clear plastic material. I also thought it would be a good idea to cover the enclosure materials with some sort of clear vinyl paint that will harden and seal the material, as well as making it less rough and more aerodynamic. (On the other hand, this would make it slightly heavier).

So the specs on the icon a5 are as follows:

Interior Cockpit Width: 46 in (116.8 cm)Wingspan: 34.8 ft (10.61 m)
Aircraft Length: 23 ft (7.01 m)
Aircraft Height: 8.1 ft (2.47 m)
wing chord: 4 ft



The specs on my aircraft would be estimated at:

Interior Cockpit Width: 3 ft
Wingspan: 32 ft
Aircraft Length: 21 ft
Aircraft Height: 8 ft (With landing gear)
wing chord: 4 ft (Would be a non tapered fixed wing)



The plane would have a tricycle landing gear style, and would be non-retractible. Another question about the propeller: Is a small aircrafts propeller length entirely based on horsepower? With this motor, the maximum speed is 4000 rpm's. I feel that is too low and that the best setup would be two of these engines. If I could I would put the two motors in line with each other so that if one failed, the main propulsion would still be in the center, but I'm just not sure if that is possible or if the flow of air would be disrupted between the two.



If you have ANY advice for me, please don't hesitate to tell me your thoughts. For me, this is likely a long term project and will involve a lot of time learning and optimizing after building. I plan to be extremely safe, but I am a dreamer and I have high ambition for things like this. Thanks for reading my thread, feel free to leave input!!
 

Tdwalker

Member
Joined
Dec 7, 2015
Messages
5
Location
Monett, Mo United States
Hey guys, new to the forum here. So I've been planning on building my own ultralight for quite some time now. And although I wouldn't mind just buying a used one, I really just want to design one myself. I would like to post my idea for what I'm doing here and see if I can get some useful feedback on the project, and hopefully this information can help others with similar experience as well.

So the idea I have, Is to in a way, replicate the shape and style of a plane called the icon A5 while at least attempting to keep it around 300-375 lbs. Most elements from the plane I would be leaving behind, such as the option of being amphibious, most of the electronic systems, the folding wings, and of course the luxurious style. Basically, I would like to build an extremely simple ultralight that has the shape of the icon a5.

The motor I would like to use is a new 22 hp (670 cc) V Twin Predator engine. It is 125 lbs. I may end up using two of them rear facing, just behind the wings or just one of them just behind the cockpit and center of the wing just like the Icon A5. A question I have about this is: Can I order a propeller online that will fit this motor? If so, are there specific fittings that need to be in place or will that come with the propeller? Also, is the engine simply too heavy for use in aircraft? I mean... Dual motors would be 250 lbs. dry, BUT that would also mean 44 hp and I plan on building extremely light, so I'm not sure how that would balance out.

The frame would be mostly wood, with the exception of things like landing gear, and control arms, etc.

I would like to keep the 2 seat configuration, but move the passenger seat behind the pilots seat. The only reason I would want to do this is so that instead of the cockpit being over 4' wide, it would be 3' or less and therefore be a little more efficient, and might actually better allow for it to work as a two seater. (Less likely to work with less aerodynamic properties). I just want to eventually be able to do cross country trips with my wife.

I plan on building the cockpit enclosed using a material similar to a heavy duty tarp that you can buy from a place like Harbor Freight. Then for windows, also use a non-rigid clear plastic material. I also thought it would be a good idea to cover the enclosure materials with some sort of clear vinyl paint that will harden and seal the material, as well as making it less rough and more aerodynamic. (On the other hand, this would make it slightly heavier).

So the specs on the icon a5 are as follows:

Interior Cockpit Width: 46 in (116.8 cm)Wingspan: 34.8 ft (10.61 m)
Aircraft Length: 23 ft (7.01 m)
Aircraft Height: 8.1 ft (2.47 m)
wing chord: 4 ft



The specs on my aircraft would be estimated at:

Interior Cockpit Width: 3 ft
Wingspan: 32 ft
Aircraft Length: 21 ft
Aircraft Height: 8 ft (With landing gear)
wing chord: 4 ft (Would be a non tapered fixed wing)



The plane would have a tricycle landing gear style, and would be non-retractible. Another question about the propeller: Is a small aircrafts propeller length entirely based on horsepower? With this motor, the maximum speed is 4000 rpm's. I feel that is too low and that the best setup would be two of these engines. If I could I would put the two motors in line with each other so that if one failed, the main propulsion would still be in the center, but I'm just not sure if that is possible or if the flow of air would be disrupted between the two.



If you have ANY advice for me, please don't hesitate to tell me your thoughts. For me, this is likely a long term project and will involve a lot of time learning and optimizing after building. I plan to be extremely safe, but I am a dreamer and I have high ambition for things like this. Thanks for reading my thread, feel free to leave input!!
 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
12,011
Location
97FL, Florida, USA
Td

Welcome. The first time that I looked at your question, I did not reply because there is just too much to be said, and I don't really know where to start. But here are a couple of thoughts:

Are you a pilot? What do you, have you, flown?

What do you know about aircraft construction? Design? Rules and regulations? (The weight that you mentioned will require that the airplane get an FAA experimental license, and you will need a pilot's license appropriate for the airplane.)

Have you joined the EAA? If you have no experience or background, my recommendation is that you join a local Experimental Aircraft Association chapter and start learning there. EAA Chapters | EAA

Good luck.


BJC
 

Tdwalker

Member
Joined
Dec 7, 2015
Messages
5
Location
Monett, Mo United States
Thanks for your reply BJC. I am not a pilot, but have given serious thought to becoming certified over the last few years. I have Zero experience flying, but I am a fast learner with anything I do, and I am committed once I have my mind set. As far as aircraft construction and design, I am familiar with the amount of hard work it takes to do so, and concepts such as center of lift, center of mass, MAC, types of wings, and have the ability to solve equations related to the process of designing an aircraft and optimizing it so that it is actually able to fly (Although I am not familiar with all of the formulas and how they relate to each other). Also, I have not joined the EAA or any similar organizations. Thanks for the link!
 

Airworthy

Active Member
Joined
Nov 23, 2015
Messages
42
Location
Florida
The Buccaneer SX is probably the closest to the A5 as far as looks and affordability in the UL class. I am not sure if the company still exists but it's a good starting point for a design. Your engine is heavy and under-powered, two of them would already put you over the UL weight.


buccaneeramphib-1.jpg
 

StarJar

Well-Known Member
Joined
Sep 6, 2011
Messages
1,723
Location
El Centro, California, USA
There is a relationship between power and gross weight and your plane appears to have those two elements too far apart. I would suggest looking at those number relationships on other planes to get a feel for what could work.
The Xplane simulator program can also give you a feel for this, and some limited flying skills.
That would be my next step, if I were in your shoes. Good luck :)
 

Dana

Super Moderator
Staff member
Joined
Apr 3, 2007
Messages
9,448
Location
CT, USA
Welcome,

I can't give an in-depth reply as I'm away from home with no keyboard, but some comments:

"Ultralight", by definition, means single seat. Two seats or more puts you in the experimental category.

125# is a lot for a 22 HP engine, and too much for an ultralight. Also 22HP is marginal for an ultralight, and completely inadequate for a 2 seater.

For a similar configuration aircraft (not amphibious), look at the Kolb Firefly (ultralight, 40HP) and Firestar (experimental, 50+ HP).

Forget about harbor freight tarps for covering material.

Dana
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
13,833
Location
Memphis, TN
It is a cool idea but it is a stretch that you can build it with the engine and weight. The difference in size is small between yours and the A5. With the weight you want, most two seaters are going to be this Challenger - Light Sport, Experimental Amateur-Built, Advanced Ultralight & Part 103 Aircraft or a knockoff. If it needs to be wood you might look at RagWing Aircraft Design, plans for proven replica models How about this VOLMER VJ-22 AMPHIBIAN from Aircraft Spruce if you want it to act like an A5 and be wood. The engine is way too heavy for the horsepower. A 125 lb engine should be making 65 hp in aviation or better.
 

Hot Wings

Grumpy Cynic
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
7,369
Location
Rocky Mountains
You may find these 2 threads relevant to your engine choice?

https://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/20227-22-hp-525-dollars-4.html

https://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/21130-22-hp-harbor-freight-engine-evaluation-other-v-tiwns.html

I purchased and tore down one of these Harbor freight 22Hp engines. After looking inside I decided on a B+S engine. They may still make an acceptable aircraft engine with some work but I don't have the time to invest in such a speculative project right now.
 

Aviator168

Well-Known Member
Joined
Sep 21, 2012
Messages
2,214
Location
Brookville, NY. USA
Seriously. Can a 22hp engine power an ultralight? Also, how useful is an ultralight anyway other than flying around the field. IMO, that's the reason that people not wanting to pay too much for them.
 

clanon

Well-Known Member
Joined
Jun 6, 2007
Messages
1,101
YUP , a REALLY efficient one (Low drag) with the optimum PSRU and Propeller ; very light and Large Wing Area (LOW Wing loading) a very efficient airfoil and Tail...
But it is usually a 2 strokes ...so weight ya know :
https://en.wikipedia.org/wiki/Zenoah_G-25
 

jedi

Well-Known Member
Joined
Aug 8, 2009
Messages
2,225
Location
Sahuarita Arizona, Renton Washington, USA
The "Configuration Design Proposals Wanted" in this section and "Norms Flying Boat" in the Float plane section should be interesting reading for your project. The 125 # engine allowance can give you 50+ hp at a much better rpm range. The V twin 4,000 rpm would require a PSRU to swing an efficient prop for your application. Even for the 50 hp you would possibly be limited to single seat operations. The Adventura Two seat Ultralight had difficulty meeting the increased weight limitations of the two seat training exemption that is no longer an option. It had much more power than your proposed 22 hp.

Good idea though. I like the concept. Keep working on it. You will need to "horse trade" on some of the numbers unless you can pull off some game changing concepts however.
 
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