Greetings

[savaship]

Hello everyone, I've been lurking for a bit now, and thought I'd finally register and say hi! My name's Brent, I've been interested in flying since I was very young. The plane of my dreams does not exsist, so I was going to attempt to scratch build it, and would love to hear your comments or suggestions along the way. I've always wanted a 6 place amphibious twin. Below you'll find my preliminary 3D rendering. I'm using my skills as an accomplished R/C model airplane builder, but I know those don't all carry over to real aircraft design. I am beginning the process of making a working model for this plane. So far I've proposed to use 2x230HP Mistral engines. If anyone knows anything that could help me reach the goal of designing and building this dream, please let me know!

Thank you,

Brent

[Jon Matcho]

Hello everyone, I've been lurking for a bit now, and thought I'd finally register and say hi! My name's Brent, I've been interested in flying since I was very young.

Brett, welcome! There are a handful of modelers here, and that's always a good place to start w/dreams like these. There are a couple things in your design that should draw out some feedback from others, but I don't want to be the first to throw tomatoes -- it's a canard, and it's entirely allowed here.

 

Be sure to post more pictures when you have them.

[deronjthomas]

I love it. The only thing I would be worried about is the position of the engines & Wings. It looks like they might be too low. If you look at other amphibian planes, you will see that there is a lot of water spray, and their engines are mounted as high as possible. This is to prevent any water spray to get washed in to the preparers.

http://www.seawindsna.com/seawind/testimonials.htm

 

If you look at the OA-IOA “CAT” http://www.pbyrescue.com/Aircraft/catalina1.htm you will see that wings, and engines are mounted high on the plane. Good Luck with the build.

[savaship]

Thanks for that advice! I too was concerned about the engine height. my design until 2 revisions ago had this being a ducted fan, but the increased drag, and complexity and weight of the duct caused me to fall towards a more conventional propeller. The front wings are intentionally low, they will be at the water line until the plane gets up on step. The design process on this I think will take no less than 2 years with the amount of time I have currently to dedicate to it. so this forum will be great for all the suggestions, and hopefully I'll have a workable design pretty soon! Thanks for your comments and links!

 

-Brent

[Len Evansic]

The front wings are intentionally low, they will be at the water line until the plane gets up on step.

You will need some help here. Water provides a lot more drag than air, so it's not a good idea to have these touching the water, ever.

 

What I mean is that with a high mounted propulsion source, and the canard (as well as much of the hull) in contact with the water, you will find that you will more likely have a submarine than a seaplane.

 

You should mount your canard higher, and have pontoons extending down from the main wing for stability. It would also help if the front of your fuselage was a bit wider, and more shovel-shaped. Stability on water will depend on keeping the nose up until the wings can take over.

 

My senior design project for my undergrad degree was working on a flying boat project. The first design delivered by the aerospace students we were working with looked like a low-wing lear jet with stubby wings. A definite submarine. Our final design was a high-wing, high angle of attack, high aspect ratio pusher configuration with a floating hull and small pontoon wingtips. The model we built worked well.

 

-- Len

[Marc Zeitlin]

You will need some help here. Water provides a lot more drag than air, so it's not a good idea to have these touching the water, ever.

You may want to contact the Beriev corporation and tell them that their aircraft will never work. See:

 

http://www.beriev-usa.com/main/index.html

 

One of these was at OSH last year, parked in the North 40, IIRC.

 

This should NOT be taken as an endorsement of the OP's design, however.

 

What I mean is that with a high mounted propulsion source, and the canard (as well as much of the hull) in contact with the water, you will find that you will more likely have a submarine than a seaplane.

Apparently not, if the Be-103 can be believed.

 

 

My senior design project for my undergrad degree was working on a flying boat project..... The model we built worked well.

The fact that a scale model of your final design worked in no way speaks to the viability of a different design.

 

Existence proofs are hard to refute.

 

The Be-103 has some similar characteristics to the OP's design. The problems _I_ see with the OP's design is that the spray from the canard will go right through the prop/engine, while the Be-103 protects the prop/engine by having the prop above the wing. Another problem is that canards are not particularly suited to water ops, since they generally take more "runway" than other configs.

[savaship]

You should mount your canard higher, and have pontoons extending down from the main wing for stability. It would also help if the front of your fuselage was a bit wider, and more shovel-shaped. Stability on water will depend on keeping the nose up until the wings can take over.

 

Hi Len, thanks for the advice, and I completely agree with the main wing pontoons for stability. I was thinking about stealing a page from the Nazi's seaplane design book for the main wing pontoons. Remember the Do. 26? it had retractable main wing pontoons... I figure if they could do it in 1937, I could do it now. I do have good reasons to believe that the canard at water level will actually help the plane to NOT be a submarine, as opposed to making it into one... the taxi rules will be simple: always pull up. plus in flight it will be more efficient since lift vortexes will drift down and out, causing the rear wing to more efficient. I'm still designing before I commit to making a working model, which I know won't prove if the real thing will work, it's just supporting evidence.

 

Thanks Len!

Brent

[savaship]

The Be-103 has some similar characteristics to the OP's design. The problems _I_ see with the OP's design is that the spray from the canard will go right through the prop/engine, while the Be-103 protects the prop/engine by having the prop above the wing. Another problem is that canards are not particularly suited to water ops, since they generally take more "runway" than other configs.

Hi Marc

I originally was going to go ducted fan, to keep the props well protected, but like I said, the inherent limitations and difficulty to design a ducted fan lead me to more traditional routes. I rendered a quick fix using the Be-103's (thanks for the link) engine mount as the inspiration, and added a water line to the rendering, see if you think that would work better.

 

Thanks again!

Brent

[Len Evansic]

You may want to contact the Beriev corporation and tell them that their aircraft will never work... Existence proofs are hard to refute.

You're ignoring the fact that their wing configuration is not close to a conventional low wing and that I was concerned with submerged wings. The Be-103's leading edge is mid-fuselage (like a Cozy), while the trailing edge is at the absolute bottom of the fuselage. Likewise, the leading edge is designed to be above the waterline, so that the entire bottom surface of the wing is a planing surface. I'd like to see the Be-103 land with gusts, or with a pilot who comes in with one wing low, catching a tip.

 

I do concur that our model's success did not guarantee it's success when fully scaled up, but as a boat, I'm confident that it wouldn't have been a submarine. As for flying, it was only designed to 'fly' in ground effect and it used step foils to break free of water surface friction. Our design spec. was to design a boat that happened to fly, so that it would be under the jurisdiction of the state Fish and Game Commission, rather than the FAA. It succeeded in this regime. I know boats very well, and I'm trying to learn about planes. I know I have far to go.

 

-- Len