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homebuilderfan

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Feb 22, 2015
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Some time ago there was a thread on this forum (I am no more able to find it-it looks like it is no more available-) talking about a new fast light aircraft.
Now the designer is going to set a new record.
http://www.sea-avio.com/
Nice to see this news because is one of the few good news coming out of my country (Italy) these days...
Fabri
 
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tspear

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Oneida
I like the look of the plane. But a 23:1 glide ratio screams light wing loading. That must make for some bumpy rides.

Tim
 

Victor Bravo

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But a 23:1 glide ratio screams light wing loading.
As Cab Calloway used to sing... "It ain't necessarily so..." :)

The DC-8 airliner had a 20-1 glide ratio clean. This was told to me by a retired DC-8 captain. I have to assume that more modern airliners have a slightly higher L/D than a 50 year old DC-8.
 

Himat

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I like the look of the plane. But a 23:1 glide ratio screams light wing loading. That must make for some bumpy rides.

Tim
Minimum sink rate relate close to wing loading. I can't remember to have seen an aerodynamics book that show a relation between high L/D and low wing loading. I'll check the books I have later if I remember.
 

Victor Bravo

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L/D is mostly independent of wing loading; the L/D of high performance gliders has been shown to remain the same as wing loading (water ballast) increases. Sink rate, on the other hand, is affected and increased by wing loading.
 

BoKu

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...But a 23:1 glide ratio screams light wing loading...
When Mythbusters called me about the Concrete Glider episode, I shot down their original idea of a man-carrying part 103 glider flown by Adam or Jamie. My counterproposal was a 75-lb RC glider made of solid concrete, with rebar wing spars, launched off a tall bridge with a catapault. The magic that this would have demonstrated is that, once you got it up to its best L/D speed (estimated at around 150 MPH), it would have the exact same glide angle as a styrofoam glider made in the same molds and weighing only a couple pounds. Because until you start bumping up against compressibility, it's all about the p*v^2. Heavier just means faster, the angles stay the same.

Of course, what we saw in the episode they actually made was them just demonstrating that it is possible to make a model airplane out of concrete. Meh.

--Bob K.
 

homebuilderfan

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Feb 22, 2015
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Italy
The Risen, and its pilot/designer, has reached Natal ( Brazil) !!!
This was not a "simple" task: this is just a great goal that Mr. Porto has been able to accomplish. Hat off! He deserves all my respect. And also he deserves the title of "homebuilder", truly. Because he designed and built his own plane.
Somebody might tell that this is an extreme advertising campaign: it's ok, surely this epic trip add also a big value to the aircraft.
But the courage and the skills of the man are still there, intact.
I believe also he is a honest designer: the customers are often involved involuntarily in the development of the aircraft; piloting an aircatft in this situation means that the designer has got a lot of trust about his Risen, I believe. Only a crazy man could think to cross the ocean in an untested plane.
Clearly he has already done the hard work before.
Again, hat off Mr. Porto.
The trip is not over: but on my mind the scariest part of it is already a souvenir.
 

Aesquire

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Gorgeous plane. The stall speed to cruise speed ratio is exceptional ( there's a thread on that subject that someone should post this to )

re: wing loading.

That is Not a low wing loading plane. The Fowler flaps are a clue that great effort was made to optimize small wing area & high lift devices for landing.

L/D changes with wing loading in a very complex way, but generally not much if at all. Flexible wings like a Hang Glider or Paraglider are affected as the wing distorts under higher than normal loads, generally hurting L/D. For Sailplanes, that carry ballast in the wings, almost no effect with wing loading within design limits. A swept wing subsonic airliner has some change in L/D at gross overloads, but not enough to notice.

Sink rate, OTOH.... even Parachutes are greatly affected by wing loading. I Know I don't like the Sink Rate on a small reserve chute.
At 270 pounds with WW2 Surplus Paratrooper gear, under Reserve chute the term is "Anvil" ( beep beep )
 

choppergirl

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297 Kilograms = 654.772919 Pounds

472 Kilograms = 1040.58188 Pounds

Not particularly light...

Can you bench 1040? And I don't mean a can o greasy spray
 

saini flyer

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Dallas, TX
The overall package is brilliant. All of that performance with a 52" wide cabin!!
It was designed with the US population in mind :gig::gig:

I wish them well and hope to see them enter the US market.
 

gtae07

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Dec 13, 2012
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Savannah, Georgia
297 Kilograms = 654.772919 Pounds

472 Kilograms = 1040.58188 Pounds

Not particularly light...
Useful load is apparently about 386lb. With a full tank of gas it's a single-seat airplane for me. But it's very pretty.

Scale it up till I can carry 400-425lb with full tanks and we're talking.
 

homebuilderfan

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Feb 22, 2015
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Italy
Useful load is apparently about 386lb. With a full tank of gas it's a single-seat airplane for me. But it's very pretty.

Scale it up till I can carry 400-425lb with full tanks and we're talking.
I believe it is a matter of burocracy: the Risen is in the ultralight(european) category; it means that the max weight allowed, ballistic parachute onboard, must be about 470 kg.
Since the designers are not silly guys (usually) they (usually) design the very light aircrafts keeping in mind the LSA category; just in case...
So, I believe this aircraft is ready to accomplish that regulations, that is in the 600 kg. region.
Ok, I know what you are thinking about: the Risen can't be a LSA. I saw a fixed gear, simpler version (simpler flaps, etc...) on their website. If the more complex Risen has showed to be effective I am almost sure the development of the Siren will be flawless...
 
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