Velocity V-Twin

Morne

Morne

Line Up and Wait
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Morne
http://www.velocityaircraft.com/airplane-models-vtwin%20-%20updates.html

Saw this at Oshkosh. The bird really exists and really flies. Pretty impressive, really.

They have hung the same 160 hp engines that were on the Twinkie back in the day. Combined with the excellent aerodynamics they get good economy. Personally I would prefer 180hp per side and they did design the nacelles to accept such an option.

Much like the Cessna 337 this twin has no Vmc issue. In this case, it is because the canard will stall before the OEI yaw is insurmountable. Neat trick, really.

Currently it is configured the same as the Velocity XL (4/5). They are talking about making a 6 seat configuration.

All in all this bird impressed me. I am not one to drool over EAB aircraft but in this case I can't help it. Maybe next year at Oshkosh I'll have to attend some of those composite workshops and see if this could be for me.
 
Expected time and cost to build?
 
Saw it at Sun N Fun. They were really cagey about when anything would be available. Couldn't quite figure out the angle, what with the demise of light twin values. Then again, if they can get the project out the door I think they will have the only experimental twin design available in kit form.
 
steingar said:
Saw it at Sun N Fun. They were really cagey about when anything would be available. Couldn't quite figure out the angle, what with the demise of light twin values. Then again, if they can get the project out the door I think they will have the only experimental twin design available in kit form.
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All it takes is a buy out from the Chinese and that'll kick start production!:wink2:
 
steingar said:
Saw it at Sun N Fun. They were really cagey about when anything would be available. Couldn't quite figure out the angle, what with the demise of light twin values. Then again, if they can get the project out the door I think they will have the only experimental twin design available in kit form.
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Comparing prices to certified aircraft in this market is an exercise in futility.

I suspect that this airframe might be popular with folks who really want to wring out auto engine conversions. With two fans and no Vmc the downside to a lower reliability engine is not as bad. Why blow $55k for two brand new certified engines when for $10k you spin a pair of automotives? Besides, the required power is pretty modest at 160hp (again, 180hp for me, thanks).

Performance wise the comparison to certified aircraft is good. Show me a certified light twin that has the same economy as the V-Twin with anything close to the speed/climb numbers. You can't, because the Velocity is a very efficient and slick airframe that weighs a lot less than metal construction.

Add to that the comparative ease of entry/exit for this midwing twin compared to the old low wings and there's a lot to be said for it.

Of course the dedicated home builders will remind you that the same avionics in EAB are cheaper than in certified. Plus there are whole lines of avionics that are only experimental such as TruTrak.

Will it be a commercial success? Hard to say. The Defiant was not sold in large numbers and had many of the same advantages as this bird.
 
Morne said:
Will it be a commercial success? Hard to say. The Defiant was not sold in large numbers and had many of the same advantages as this bird.
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Far as I know, the Defiant never came in kit form. That's a lot to scratch build. I imagine the folks at Velocity are thinking to the uniqueness angle, the only twin in kit form.

They've sold 800 kits thus far for their singles. I imagine they though about the uniqueness angle there as well, since there's was one of the very few four-plance kits. They've sold 800, which really isn't that good if you think about it. How many RV10's have been produced in a smaller time frame?

Personally, I think the engine conversions are a Trojan horse of a different color. Many wind up costing what the airplane engine would have after the conversion, and lots come to grief.
 
Morne said:
Much like the Cessna 337 this twin has no Vmc issue. In this case, it is because the canard will stall before the OEI yaw is insurmountable. Neat trick, really.
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I think that's likely a bit of an overstatement. The asymmetrical thrust potential is lower than conventional twins due to the props being closer together but there will be no propwash assisting the rudder or aileron's effectiveness. But most importantly, the published Vmc being lower than Vs doesn't really mean squat because that Vmc is an artificially generated number which typically requires a 5° bank into the good engine and that's not an efficient condition of flight (few twins offer any climb then and most are sinking like a rock). Bank 5° the other way and "actual Vmc" (i.e. the speed below which the plane will roll over against full aileron and rudder input) typically goes up something like 20 KIAS and I'll bet that's well above the Velocity's stall speed.
 
gismo said:
I think that's likely a bit of an overstatement. The asymmetrical thrust potential is lower than conventional twins due to the props being closer together but there will be no propwash assisting the rudder or aileron's effectiveness. But most importantly, the published Vmc being lower than Vs doesn't really mean squat because that Vmc is an artificially generated number which typically requires a 5° bank into the good engine and that's not an efficient condition of flight (few twins offer any climb then and most are sinking like a rock). Bank 5° the other way and "actual Vmc" (i.e. the speed below which the plane will roll over against full aileron and rudder input) typically goes up something like 20 KIAS and I'll bet that's well above the Velocity's stall speed.
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But the canard will always stall first, lowering the nose. Barring aerobatics, that is, which can stall the main wing at which point you're hosed.

Perhaps you would like to contact velocity and offer to analyze the numbers for them?
 
Morne said:
But the canard will always stall first, lowering the nose. Barring aerobatics, that is, which can stall the main wing at which point you're hosed.
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While I understand that a properly installed canard will stall before the main wing, I fail to see how that would matter if the asymmetrical thrust overcomes roll and/or yaw control authority at a speed above the canard's stall speed when the sideslip into the operating engine is increased by letting the wing it's on get high. Vmc isn't directly connect to or related to stalling although it is true that any airplane with a published Vmc below it's stall speed is more forgiving than one that runs out of roll/yaw control well above the stall. That's why I feel the statement suggesting a loss of roll control is impossible due to canard behavior is an overstatement. IOW there's some validity but it's not likely to be completely true.

FWIW, thanks to the addition of VGs, my airplane is also supposed to stall before roll control is lost but I know for a fact that it's possible to get to a point where it's necessary to reduce power in order to regain roll control.

Perhaps you would like to contact velocity and offer to analyze the numbers for them?
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Why would I want to do that? It's more fun to take potshots on the internet.
 
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Morne said:
Performance wise the comparison to certified aircraft is good.
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Unfortunately it's still a canard, meaning "no flaps". I know a guy with LongEZ, and the stories he's telling about his exploits in unrefueled range are unreal. But then I can land at, say, E92 (and I have), and he cannot. I suppose V-twin is going to supply a tough competitor for Cirrus. Too bad it's not my mission.
 
Who wants to land on gravel?

Competition for Cirrus sounds fine to me.
 
I would think an aircraft with a rear mounted propellor would be ideal for gravel. You don't fling rocks into the airframe. That was explained to me as the idea behind the Piaggio.

1307943371-72.jpg
 
Problem is for most homebuilt canards anything that comes of the airframe (screws) usually goes through the prop. There's a saying that it's not if something goes through your prop it's when. Also I've had pebbles hit the leading egde of the prop and get deflected forward into the bottom of the wing chipping the paint. Pros and cons to both configurations.
 
steingar said:
I would think an aircraft with a rear mounted propellor would be ideal for gravel. You don't fling rocks into the airframe. That was explained to me as the idea behind the Piaggio.

http://www.auto-oglasi.org/wp-content/uploads/2011/06/1307943371-72.jpg[IMG][/QUOTE]

Gear kicks it up into the prop. The airframe is easier to protect than the prop. For example Cessna even saw fit to equip my plane with a rubber boot on the stab for just such a reason
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We're thinking about building one of these. Visited the factory and was impressed. Very cool
plane. I need another project and my hangar mate wants one.

RT
 
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