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11-27-2011, 11:33 PM
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Join Date: Jul 2009
Location: Bonney Lake, WA
Posts: 295
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Quote:
Originally Posted by aerhed
That explains why I have to use up-rudder on takeoff.
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It also explains why airplanes just spin around when power is applied and never move forward. 
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Ryan Winslow
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11-28-2011, 12:27 AM
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Join Date: Apr 2011
Location: Melbourne, Victoria, Australia
Posts: 211
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Good Panel guy
Quote:
Originally Posted by SteinAir
I'm with Peter....this just makes me go "hmmm"...I have sorta the same reaction to the Tripacer I saw with a T-Craft wing scabbed on the bottom of it a couple years ago - and yes, it still had it's top wing!
I guess I can't say too much without being sort of a hypocrite since I'm building something about the size of an RV with 500hp engine (that also hasn't been built for 50+ years) on the front!
Cheers,
Stein
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Hey Stein,
Cool aircraft... if you have trouble with the Panel I know this really good panel guy you go to ;-)
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Gus Bisbal
RV7
Obsession only exists when someone else isn't doing it too.
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11-28-2011, 06:55 AM
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Join Date: Jul 2007
Location: Keller, TX
Posts: 1,553
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Yes yes yes
Quote:
Originally Posted by B25Flyer
I want to see somebody build a twin fuse RV-3,4 or 8 like a P-82...
(or Rocket ;-) )
Tailwinds,
Doug Rozendaal
F-1 EVO Rocket
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So do I. That would be impressive!
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RV-8 180 hp IO-360 N247TD with 10" SkyView!
VAF Donations Made 8/2019 and 12/2019
"Cum omni alio deficiente, ludere mortuis."
(When all else fails, play dead.)
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11-28-2011, 08:57 AM
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Join Date: Jan 2005
Location: TX32
Posts: 1,891
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However comma...
Man, you have to admire their ingenuity, resourcefulness and tenacity. However comma, for practicality sakes (Good Lord forbid) some very successful light twins are already out there in large quantities. They have produced some impressive numbers of their own including Max Conrad circling the globe several times in twin Comanches and Aztecs. My Dad flew F-82's and said a stock single engine P-51 could keep right up with it. I think that would apply to this aircraft as well. So, the mission of a light twin RV is, improved reliability? Redundancy? Load? Range? Prove a point? All the above? Oh well, what can I say about one-off's, I bolted a set of RV4 wings on a Six fuselage and built a Rocket
Having quite a few hours in a single engine engine Jet and seen twin engine counterparts alongside I noticed: We burned less gas when gas was in critical supply, more bang for the taxpayer buck, greater overall efficiency. This was Lindberg's thinking when he designed the Spirit. There are great arguments for and against but Van himself designed the RV's to provide the greatest efficiency for the least dollar. So, Why re-invent the wheel?
It is intuitively obvious that some really smart guys with slide rules have been there, done that. They even sent men to the moon without calculators or cell phones.
All that said, I still applaud their efforts.
Smokey
http://www.aviastar.org/air/usa/piper_pa-30.php

Wing Derringer designed by John Thorp
Last edited by smokyray : 11-28-2011 at 09:37 AM.
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11-28-2011, 09:07 AM
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Join Date: Dec 2007
Location: Flagstaff, AZ
Posts: 2,653
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Neither for or against the project but in response to the previous post: what if Van had taken that mindset. Lots of successful low-wing singles out there; why reinvent the wheel? I'm not saying this twin will be a refinement like Van's RV series has been, but just because something has been done before does not render a new take valueless.
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Patrick Kelley - Flagstaff, AZ
RV-6A N156PK - Flying too much to paint
RV-10 14MX(reserved) - Fuselage on gear
http://www.mykitlog.com/flion/
EAA Technical Counselor #5357
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11-28-2011, 10:50 AM
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Join Date: Jan 2007
Location: LI, NY
Posts: 409
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Twin RV ?? Yes it's true. Pictures.
My friend told me he saw it with his own two eyes and I didn't believe him. So we flew into Mattituck and I saw it for myself. I'm sorry I forgot the builders name, I'm sure he'll chime in here, but I figured I'd post a couple of pictures. It was a flying 6A that is being modified. It is not flying, yet but the work is progressing.
This not my RV, I have no idea about the engineering of this thing, I just took a couple of photos. Interesting for sure. I don't know that it's something I would want to build, but then again to each his own.

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Richard Fazio
LI, NY
N966RV
RV-6 Slider
O-360
FP Wood Prop
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11-28-2011, 11:08 AM
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Join Date: Sep 2006
Location: Douglas Flat, CA
Posts: 589
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Quote:
Originally Posted by flion
...what if Van had taken that mindset. Lots of successful low-wing singles out there; why reinvent the wheel?...
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Here's one thing to consider regarding that line of thinking: Van has always taken a very measured approach to sizing and configuring his airplanes.
Where we see this most directly is in the way they are designed for decently sized engines. All of the RVs are designed from the get-go to accommodate somewhere between a reasonable amount of power and lots of power, and still balance reasonably well. They may not accommodate the great gobs of raw brawn that the Rocket crowd demands, and they may not balance as well as someone with an RV7 and light prop would like, but they've all been in the ballpark.
What we haven't seen is a new RV design that comes out with a small engine, and then goes back to the drawing board for a power upgrade just to give it decent performance. Many airplane projects, the Wing Derringer included, have been there and done that.
I think that if Van were to dabble in a twin engine airplane, it would have a lot more horsepower on a side than the airplane we're talking about here. What I'd sort of guess at is that he'd start with the RV10 airframe, and mount 200 hp IO360s on a side. But that is a speculation for a different thread, and maybe a different forum.
For the twin we're talking about here, I think we will see that 2x110hp won't really be enough. According to www.flycorvair.com, the installed weight for a single 110 hp corvair motor ready to fly is 215 lbs or so. So for 220 horsepower worth of them, it is 430 lbs of weight, versus the single IO360s 300 lbs or so for 200 hp. And let's not forget that it has two engine mounts, two sets of fuel plumbing, two cowlings, two propellers, two sets of engine controls (cables, wires, etc). It also has about half again as much frontal area as an RV6. What it adds up to is an airplane with a bit more power than an IO360-powered RV6, but a lot more empty weight and a handful more drag. It will require greater workload to fly, but won't reward that workload with better performance or better handling.
And let's not forget that the usual selling point of the light twin is the improved safety of having an extra engine. At least that's what the brochures say, it too often does not work out that way. But anyhow, I don't see this airplane holding altitude very far above sea level on one 110 hp engine. I guess you can say that the extra engine gives you a lot more landing options, but I don't think that is worth the trouble.
Thanks, Bob K.
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Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
Last edited by Bob Kuykendall : 11-28-2011 at 05:09 PM.
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11-28-2011, 11:15 AM
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Join Date: Sep 2006
Location: Douglas Flat, CA
Posts: 589
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Quote:
Originally Posted by RFazio
My friend told me he saw it with his own two eyes and I didn't believe him. So we flew into Mattituck and I saw it for myself...
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I have to say, from what the pictures show it looks pretty impressive. It looks like a lot of thought and work has gone into it.
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Bob Kuykendall
HP-24 kit sailplane
EAA Technical Counselor
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11-28-2011, 12:02 PM
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Join Date: Jan 2010
Location: Hampshire, IL
Posts: 276
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Awesome
Nice to see some still think out off the box, best of luck.
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Ed Martin
Bluskydtl
RV7
DKB
Donations 1/19 & 6/19
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11-28-2011, 12:03 PM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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I think many people here are simply missing the point of this project and perhaps the essence of true experimental aviation. For many, they simply want to do something different or they have a dream. Projects don't need to be especially practical or efficient, just fun and educational.
Really, building a hole matched RV with a Lycoming up front, while still being a truck load of work and hours, isn't very "experimental" other than by category.
While many might question the practicality to add retractable gear, floats or another engine to RVs, I personally think these are all pretty cool mods because they are so different and involve a lot of independent thought and design/ fab work.
Dare I say, too many here have almost taken on a "sheeple" attitude, criticizing projects that stray very far from the flock. I say let's let the dreamers dream and build something unique that satisfies their desire for something different.
I seriously looked at doing almost the same thing before buying my RV10 kit. I was planning twin 130hp Suzuki 1.3 turbos with gearboxes on a modified RV7 airframe. I ran into design issues mounting the nacelles over the fuel tanks and couldn't get past not being able to source suitable full feathering props so I called it quits there.
I briefly considered a push/pull design like the Do 335 WW 2 fighter using RV7 wings and tail feathers and the same Suzuki engines until the design realities with the rear engine driveshaft system and a complete custom fuselage brought me to my senses!
Last edited by rv6ejguy : 11-29-2011 at 08:57 PM.
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