# Paul Weston Sea-Era

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#### billyvray

##### Well-Known Member
I stumbled upon this video again of a neat amphibian built by Paul Weston in Washington. Nice looking pusher design, single seat. Unfortunately he crashed it in on the second flight (which the video shows) - looks like a stall on landing. I haven't been able to find where he has it back flying again.

I submit it here for cogitation.

[video=vimeo;5364455]http://vimeo.com/5364455[/video]

~Bill

#### Dana

##### Super Moderator
Staff member
It's an attractive design, but from the one point where you can see the planform as it flies overhead, I suspect it may have had inadequate elevator authority (insufficient tail volume to compensate for all the area forward of the wing).

-Dana

I have a hard time deciphering the fine line between boredom and hunger.

#### BBerson

##### Well-Known Member
HBA Supporter
Weston gave a nice forum talk at Arlington 2011.
I asked about the short tail. He said it worked fine in his opinion. But Weston did not hold a pilots certificate at the time of the flight...
and this story was explained.

The prop blast could help with elevator authority, when power is on.
He is working on a two-seater.
BB

#### pwood66889

##### Well-Known Member
Since the crash, probably due to stall of the left wing near landing, was in 2009 and the forum was in 2011, Mr. Paul musta survived! And I guess that was him paddling at the end of the video.
Neat design, though. Did he ever get a pilot's certificate?
Percy in SE Bama

#### jjbaker

##### Well-Known Member
Holy Schmoly! Dizzying landing procedure! Looks like an otherwise stable machine...

#### skeeter_ca

##### Well-Known Member
He probably felt that in his seatbelts.

#### Himat

##### Well-Known Member
A strong hull it look like!

Studying the video it look like the hull is "unconventional" with a step/steps placed well forward at the wing leading edge.
The forward part also look like it have quite a bit V-form with a "flat" aera behind.
Do anyone have pictures drawings of the hull?
It look to work OK on the water.

The variable incidence wings are another interesting point.

#### litespeed

##### Well-Known Member
Wow

What a awesome design.

I have never seen such a wingstall come out so well.

That appears a inherently very tough sea plane.

Most planes would have had big damage and probably tear apart with that landing.

Very cool design- note how it just spins on its axis when it hit the water and took all the force in its stride.

Love it.

#### Propshaft

##### Well-Known Member
EAA - EAA Experimenter - Arlington Fly-In Has That Summer Feeling
Perhaps the most unique feature of Paul’s creation is the variable angle of incidence (AOI) mechanism he developed to take full advantage of the high stall angle of the lifting body. In short, the center section of the plane produces approximately half the lift, but it stalls at a higher angle of attack (AOA) than the outer wing panels. So at the highest AOA of the wings, the center section is hardly working. Paul’s answer was to lower the AOI of the wing to keep it from stalling while the AOA of the center section is increased. This way, while in slow-flight, the center section can be made to stall before the wings, leaving the ailerons in full control.
In theory that's nice talk, however, when watching that video, to me it looks like the wingtip stalled first though.

ps: there are a couple more pictures that also show some of the mechanics of the wing. (about 2/3 down on the page)

#### orion

##### Well-Known Member
I seriously doubt that the body creates that much lift. Yes, it does have a substantial amount of planform area but it is inefficient for lift generation so given the small angles of attack, I'd guess its lift contribution is much smaller than the designer thinks it is.

As far as the accident is concerned, it does not look like a stall. Although flying slower, the airplane and its wing were at a relatively low angle of attack. Furthermore, there was no indication of the typical nose-down motion that one would see during a stall of that magnitude. To me it looks like he was maneuvering for his final approach and misjudged the height at which he was flying. The turn looked to be a bit steeper than it probably should have been given the surface proximity - it almost looks like the airplane slid out of the turn, maybe due to a wind gust.

But got to give the airframe credit - very few airframes could withstand a tip impact of that magnitude without causing much more substantial damage.

#### Holden

##### Banned
Orion,

I know Mr Weston (1998 to present) and worked on the high wing version of the airplane. He did stall it at about 40 mph. He was enjoying the flight and, like most 20 hr novice pilots, got fixated on the approaching water and forgot to watch the speed. Woops. The plane had to have some repairs to the booms and under fin after of the step, but is now flying.

The lack of pitch down was due to the aerodynamics. The delta (hull) and wing panels cancel each other leading to a near neutral pitch. This works well with WIG issues. The design allows you to get close to the water and hit the water without the risk of a crash at high speed, except for the wing tips. The high-wing version solved the problem seen in the video. The wing tip would not have touched with the high-wing version and the airfoils were corrected on the high-wing to eliminate the stall roll. Basically on the high-wing version you can hold it up to 31 degrees with full wing down "pitch" (rotation with flaps) and maintain control with the correct wing foils. It will vertical drop straight down and recover. Kind of fun... Paul knew the wing foils on the Low-wing were not ideal, but he decided just to use them to save time. I doubt it would have rolled with the proper foil, IMHO.

The "lifting body" does produce around 50% of the lift as Paul claims, based on wind tunnel tests that I performed on the high-wing version (below), 1/4 models by Paul of the low-wing (full size is seen in the video) and computer models validated by Darcorp that mix data from both with assumptions. The forward section of the hull produces a LOT of lift with a slight positive pitch which is cancelled by the negative pitch of the main wing. Kind of clever. This leads to a near zero or low pitching moment airframe and low trim drag. All the vortexes follow the lower hull keeping flow attached on the lower hull. Very low drag...from memory...around 2.5 sft FPD

You can read the patent 6264136 for yourself, or just Google Paul H. Weston. He is a very nice gentleman about 84 years old and lives on the lake. The low wing has no gear, BTW.

I was going to make a Kitplane of the high-wing version of the airplane shown here

,

but pulled the plug when I realized it was a $140,000 airplane, or about what an ICON would cost. I did not see a real market at that price. Wish ICON luck... Walking on the "delta" section would require a lot of reinforcements and by extension weight. The high wing was a "theater seating" for three people and 1600 lb gross. When the Sport plane rule came out we changed to 1430 and two seater, but by that time I was off the project. After about 4 years of work, I found a better way. The high wing is iteration 2 and I am on 5 now. Paul spent at least 20 years playing around with RC models. He learned by reading and a lot of trial and error. He is an excellent modeler with great workmanship and attention to detail. He does it all by hand drawings, the old fashioned way. He is not an engineer like I am, but he is fun to work with. Lots of common sense. He has a lot of talent in art and he did a good job in making it look good, IMHO. A Boeing engineer with Chinese connections is thinking about producing it with low cost labor in China. I gave him all the data, models, prototype hull (partially complete), gear, etc. About$500,000 in value. My new design will be lower cost and much better, so the more the merrier. I will not be doing the "wing pitching" as a primary means, only as one of three options.

There are a lot of little "tricks" the average guy does not see in the airplane. I would not call it revolutionary, but it does have clear safety and performance advantages demonstrated by the "accident" shown in the video. It sure was fortunate to get it on video. I have landed a float plane in that same lake. If I did that with a C-172 on floats, it would have been a total loss...

That said, I am not interested in advancing the design as shown other than to help someone (Chinese guy) who wants to get it going. I am taking what I learned and applying it to a new design.

Compared to an ICON, I would say the ICON has a LONG way to go to get to the level of a Sea-Era. The High wing is a much better and safer airplane than an ICON, plus it can be built in weight and with gear. Funny that Google CEO and former Boeing CEO would spend \$25 million on the ICON which cannot even meet the sport plane rules, nor is anything safe.

The high wing Sea-Era should be around 3.5 sft flat plate drag, which is good for a three place 1600 lb, 700 lb useful, amphibian seaplane. Again, there is a better way.

Some day all three version may fly together. Low-wing, High-wing, and a roadable version. Full time on it.

Hope that helped.

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#### orion

##### Well-Known Member
Thanks for that info - it's always better to have someone who is "in the know" chime in since all the rest of us can do is try to make judgement calls from a brief video clip. And it looks like you're right - a second, closer look at the video seems to show a left wing tip stall. It does look interesting in the air though, doesn't it?

And I agree, I think ICON has aways to go, despite the millions spent so far. Like many of that ilk, I'll be surprised if they make a go of it at all. Last I heard they were trying to eliminate the wing fold option since the mechanism just added too much weight. They've been on a pretty serious weight reduction kick some time back but I don't know the current status. It's pretty but I think they would've been much better off making a real airplane out of it rather than an LSA toy.

##### Well-Known Member
Man, I want the Icon to work, and I've been tempted many times to drop a deposit on one... it just looks like too much fun. But I can't quite convince myself that they'll accomplish their goals. But ooh, do I ever want one.

#### Holden

##### Banned
Orion,

I hope too that ICON can make a go of it. Maybe with all the money they have they can get the engineering to make it light enough. The basic configuration of the ICON has been tried by many, but the limit of 1430 lbs is very difficult to make work, as you stated, especially with landing gear AND a wing pivot system. The Sea-Era has some advantages, but it too is not enough, as I see it, to make it a very useful piece of equipment. A toy, ok, but not something that can justify the expense. Both ICON and Sea-Era are good looking airplanes, but looks are not enough for me. The ICON guys really know how to market!

One more reason I pulled the plug is that after the wind tunnel testing of the high wing, I was of the opinion, based on a desire to meet FAR 23 some day, that the upper wing position had to be moved forward and made larger than pictured. I wanted low landing speeds, or at least my desire for low landing speeds increased as I worked on the project.

This required a complete redesign of the load paths and I had already done all the hull lower prototype build with load paths. If you notice in the picture, the strut goes into the lower delta. Those loads had to go around the wheel arm as designed. To move the wing more forward, it made it difficult to still have the strut as a means, as the input was no longer at the maximum thickness and it became closer to the point of the leading edge and boom intersection. That made the strut not viable, which made the wing swing ability very heavy, just like the ICON.

A swing mechanism like a "kitfox" with struts is easy to do, but without the strut it becomes quite heavy as you well pointed out. The end effect was that the leading edge angle would have to be less or have a cantilever design. Basically I was "trapped" in a costly redo of the design, much like ICON now faces. I did not have the staying power and chose to regroup before all was lost.

I am back on my feet now, but it cost me dearly. I had one run at it and I knew that if it did not work the first time, I had to bow out. I learned first hand a lot of lessons. From these costly lessons hopefully I can go for it again in 3-5 years and build something useful. As you may agree, the fun is in the engineer and design. I look at it as twice as much fun...

As for the stall in the video, it looks like it "slid" to the left. The "flaps" were not down all the way and had they been, the stall would have happened in a more controlled manner. I fix this problem in the new design, btw. Remember, the low-wing was improved on with the high-wing design. Lessons learned were incorporated into the high-wing, but not into the low-wing. There is no desire to make a single place low-wing kit due to market issues. The low wing was nearly complete so Paul finished it hoping to learn from it and to get interest in the high-wing. He has a guy now working on the high-wing, so it may be in production some day. We'll see.

#### pcjr67

##### New Member
I personally met with Paul and I can say he is highly innovative. He has a history in hydroplane racing and boat building. The plane only had very minimal damage, a true statement about his ability to build strong aircraft.

#### Battson

##### Well-Known Member
Based only on that video (so a worthless opinion) it looks a little like a wing drop stall, but very slow and reserved.

That said, all in all the flight looked twitchy and I got the sense he might have been feeling a little gingery with the controls. The shape of the aircraft looks naturally unstable, quite a lot... my imagination leads me to think it'd be a tougher plane to control that more conventional designs.

#### Holden

##### Banned
your thoughts on " Box Wing In Ground"?
BWIG Box Wing In Ground - YouTube
I noticed you put the Sea-Era in the video. Since I am an expert on that airplane (did wind tunnel test on the high wing version) and know the designer, I might be able to add something with respects to WIG.

A WIG craft, as I understand it, can trim to height. If the airplane is trimmed to 10 ft, and it goes closer to the ground, it will pitch back up and if it goes higher than 10 ft it will then pitch down. Just as an airplane trims to speed, a WIG can trim to height.

Most airplanes pitch down as they approach the ground. This is caused by the pressure under the wing working more at the 50% as it approaches the ground, and not the 25% of chord location normally found on a wing.

The Sea-Era can be made to behave to act like a WIG (trim to height) but still fly like a real airplane. This is done by an accurate knowledge of the body Aero dynamic Center (AC) and the placement of the square wing relative to the body in height and for/aft displacement. For example, the low wing has the wing aft of the AC of the body and about the same height as the body, whereas the high wing is aft of the body and up high. The placement aft and height relative to the CG is the key.

The body is a Delt and the AC tends to remain at the center of area and as it approaches the ground the pressure works at the same area (center of area). On the wing, however, the pressure works at the 50% more and more instead of the 25%.

You can model this and get the plane to pitch negative, neutral or positive as desired with respects to height.

A use for this WIG effect in a seaplane would be to make it able to trim to height so that when you fly just over the water it will tend to be stable to height, otherwise flying close to the water becomes pilot control intensive and not as safe or fun. With the Sea-Era hull, if the airplane does impact the water, it will not crash. It will deflect off the water and the pilot will be safe. In contrast, a float plane is not safe if it hits the water at high speed and the pitching is negative and will dive into the water requiring the pilot to pull back and fly with careful attention. Basically, by designing with WIG in mind the airplane has a safe dimension that other airplanes don't have, namely skimming over the water without strong pitch attention to height required with a negative pitching airplane found with a typical square only design.

I will have this WIG effect in my new seaplane.

Holden

Q

#### qxev

##### Guest
in more detail this thought is stated hereyour thoughts on " Box Wing In Ground"? - Page 2sense of connection airplane + WIG

consists in creating on landing a powerful airbag...which gradually decreases and smoothly lowers our flying car before contact to a water surface

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