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Raptor Composite Aircraft

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malte

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I couldn't find this one online. However, it's odd that the last four of its registration is identical to the previous French accident: F-PRIQ vs. HB-PRIQ. Is the Swiss registration a typo, or is this actually the same airplane?

Ron Wanttaja
It is most likely the same aircraft. The swiss have three letters after HB. F-P indicates a french experimental. A swiss experimental would have HB-Y, followed by two other letters.
 

Doggzilla

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I see this Raptor saga as an ongoing puzzle. We have several pieces missing to solve for how it got to this point.
Clearly to me, the website specs have been misleading or just not updated.
But how can a professionally built airframe be 900 lbs heavier than comparable airplanes? Must be some pieces of this puzzle still missing.
I already suggested the parachute for which the comparable airplanes don't have, so deduct 100 pounds for a large chute as one piece of the puzzle. The comparable airplanes don't have pressurization so what should all that add up to if well engineered, for another piece of the puzzle. What else? Leather seats? Avionics? A/C?
Maybe it has extra long range fuel tanks? What does that weigh? What airframe part was too heavy?
Jeff's plane was about 2100-2200 pounds. So maybe the 1800 pound number is suspect. Who knows?
It should be possible to locate all of the overweight items.
It is obvious to me the the original website estimates were flawed or at least not updated as options were added.
Just an interesting unexplained mystery to me.
Someone else who has worked with composite aircraft stated that Raptor crew used thicker carbon than anything else he's ever seen, including thicker than full size turboprops.
 

Scheny

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But how can a professionally built airframe be 900 lbs heavier than comparable airplanes?
Someone else who has worked with composite aircraft stated that Raptor crew used thicker carbon than anything else he's ever seen, including thicker than full size turboprops.
I started and was part of that conversation. I noticed, that the keel is solid carbon and about as thick as my thumb... Normally you would construct solid parts only 1/10 inch thick. Also the hull is normally built with three layers on both sides of foam. Cirrus and Diamond even use only 2 except for high stress areas.

The Raptor rather looks like having at least 8 layers but without any foam giving it stiffness. If pressurized, this would be less a problem.
 

lelievre12

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Whoever told you that "canards don't stall" didn't know what they were talking about.
The mechanics of the canard stalling first are easy to understand. However the more insidious aspect of Raptor is what I would call 'fuselage width creep' whereby the aerodynamic effects of the 'fat' fuselage plays a larger role in forward of CG aerodynamic lift than I think Rutan ever anticipated. His tandem designs had a very narrow (fighter) style fuselage. The later 'wider' versions such as Cozy et al found that the canard needed to be 'cut short' to combat the increasing lift from the fuselage.

Raptor takes that problem to a whole new level and so flight tests will need to carefully examine/avoid deep stall (where the main wing stalls) as I expect the CG range will need to be further forward and/or the canard 'cut short' to find an acceptable balance between stall resistance and CG range. Fat fuselage wants to fly too.
 
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pictsidhe

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I wouldn't be surprised if Peter had decided to up the layup schedule to make the Raptor 'better'. Perhaps Jeff could chip in? There are also all the non engineered parts he TLAR designed. None of which seem to have weight as a consideration. I wince every time I see those rudder pedals.
 

TarDevil

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For those of us who have watched the majority of Raptor videos, every fix or issue was corrected not by redesign but by throwing on pounds and pounds of band aid fixes. It would take more time than I will ever have to go back and document the weight gains from incremental add-ons.
As already mentioned, this in additional to overkill CF layups, the mess spinning the propeller, the vault-like doors, etc. etc.
 

BBerson

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I started and was part of that conversation. I noticed, that the keel is solid carbon and about as thick as my thumb... Normally you would construct solid parts only 1/10 inch thick. Also the hull is normally built with three layers on both sides of foam. Cirrus and Diamond even use only 2 except for high stress areas.

The Raptor rather looks like having at least 8 layers but without any foam giving it stiffness. If pressurized, this would be less a problem.
I did see the thick as your thumb video where he said that was only a small fit up area. That is the sort of thing that could be corrected on another try. Typically composite fuselages are solid laminate without foam core. My Grob fiberglass fuselage is solid laminate and seems incredibly heavy with 1/4" laminate in some places.
I would need the individual weights of each part to give a proper assessment. Mostly I want to know what the weight penalty for pressurization is or should be.
I watched the majority of videos and didn't see comments about excess weight until the aircraft was completed and weighed and Peter was making repairs by himself on a few parts. If the entire aircraft was built with TLAR then it wasn't just his fault.
 
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cheapracer

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The Raptor rather looks like having at least 8 layers but without any foam giving it stiffness. I
But how can a professionally built airframe be 900 lbs heavier than comparable airplanes? Must be some pieces of this puzzle still missing.
It wasn't professionally built, it was built by professionals employed to build it to an amateur's design and directives.

Jeff Kerlo has stated in this thread that Raptor Guy continually insisted on continually adding many extra layers of carbon against his, and other's advice, but Raptor Guy signs the paychecks, so you only argue so far....

Search for his posts.
 

Jay Kempf

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Is the pressurization system even installed? Or is it just the structural penalty you are talking about? I guess the only way to assess that is find a 5 seat airplane that is offered in a non pressurized and a pressurized version...

I was just reading an article about the Lancair 4P that the pressurization system was a 125lb add over the 4.
 

BBerson

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Jeff Kerlo has stated in this thread that Raptor Guy continually insisted on continually adding many extra layers of carbon against his, and other's advice, but Raptor Guy signs the paychecks, so you only argue so far....
He didn't tell me that. Jeff said he didn't design it. If an IT guys hires an engineering firm to assist with the design I would expect the engineering firm would advise about weight. Is there evidence that the IT guy insisted that the engineered plans and layups be made heavier?
Or is there a conflict in that the website listed the weight at 1800 pounds for years? Then it was changed to 2300 now. Should be listed at least 2800 pounds.
How could any engineering firm work with that 1800 pounds number if they had knowledge that the IT guy wanted features far beyond similar Velocity weight?
The engineering firm should have worked with an empty weight estimate around 2600-2800 pounds, is my guess.
 
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