Raptor Composite Aircraft

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bmcj

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There should be a picture of Raptor in the Wikipedia article on Sunk Cost Fallacy.
I think gambling addiction is another example of this behavior... the person who can’t tear themself away from a slot machine because they are sure that the machine is “bound to hit soon” and make up for their losses because it hasn’t hit yet.
 

TMann

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Aug 15, 2011
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This largest problem with the Raptor is Peter's ego.
Yeah, well I think you need some ego (self confidence) in spades to even try something of this scale.

Mohamed Ali used to brag and talk trash all the time and people would say he was all about ego.
Imagine if you would, climbing into the ring thinking you were the second best boxer in the world.:eek:
 

BoKu

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Yeah, well I think you need some ego (self confidence) in spades to even try something of this scale...
Some, definitely.

When it closes your ears and mind to good advice, it's too much.

When it makes you think that you are going to outperform your better-funded and more experienced competition by double-digit percentages, it's too much.

When it drives a program like this, it's too much.
 

swoodman

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Dec 28, 2016
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There is a saying in the UK:
"There's one born every minute"
Well gents I would be one of those people. And until a few months ago I was definitely on the Raptor bandwagon. An old but newly minted 100 hour pilot who has always dreamed of a Velocity and saw this carbon pressurized version and went wow! As you guys have pointed out about Peter - I think it is true that we all don't know what we don't know. Moreover, because Peter is passionate and believes so much in what he is doing, we were easy to convince. We didn't know about the complexity of doing all of this at once - or we chose to ignore it until we were hit over the head with it 20 times. So I thought, maybe I should park a couple thousand and risk my $65 and get in - this is so cool. Which is what I did. I was still on the bandwagon even as I began reading all 35 pages of this forum. It took a long while for me to slowly let the facts and arguments, fairly presented, sink in. Lo - there really are a lot of potential problems here.

What sent me way over the edge was when Jeff came in and said he and Mark had been voicing concerns forever and at some point they had to throw up their hands. I mean really? You are not going to listen to the guy that had a big part in the rebuild of the friggen Velocity and has been doing this for like 20 years??? The thing that really bothered me in the most recent video is that nothing - not a word - was said about the weight problems that are well documented here. I mean, if you're going to come clean, then get it all out there man. And I was surprised, I don't think anyone commented on Youtube that the biggest loss of all was likely that Jeff and Devon were leaving - people vote with their feet sometimes.

I do have a ton of empathy for Peter and respect for his tenacity and work ethic. He put it all into the plane and all out there for us to see. I agree with the "bit off more than he could chew" comment. Not listening to his learned team members though, that's not ok with me.

Francis Bacon said something like - If a man will begin with certainties, he shall end in doubts, but if he will be content to begin with doubts, he shall end in certainties. I try to remind myself to be the second guy. Thank you for educating me so much on so many things I didn't want to know about the Raptor. I think I may know what a rehabilitated member of a cult feels like. To be clear I didn't jump into the $20k pool and obviously no way I would do that now based on the education I received here. If I lose the $2k in escrow - I'll be ok with that. I felt like a kid in a candy store waiting for those videos to post.
 

Deuelly

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Nov 6, 2012
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My biggest concern now is that Peter is so swept up in this he's about to drink the Kool aid. I'm worried if his high speed taxi testing goes well, in his mind, he may convince himself that he could probably be the test pilot.
 

foolonthehill

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Aug 30, 2015
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This program, and much of this thread, remind me so much of the time I spent at Commutercraft last year. The lack of real design drawings at C/C, and so many unkowns in just the overall design itself, were a major drawback to that project, add to that the constantly moving goal posts as to what was going to be included in the aricraft, and there's a recipe for failure. Commutercraft never took a dime from any of the people that signed up to buy an aircraft, though. But they did make unfounded performance claims that I continually took exception to with Richard Hogan. In the end, he decided he could test fly his own aircraft, and three minutes later his life, his dreams, and over $4 million in investment, and about 14 jobs, were all lost. Richard Hogan was one of the kindest, most generous men I've ever had the pleasure of working with. He had a great number of friends, and now he's lost to us all. Damned shame.
I wish Peter well with this project, as we all should. I hope he gets it sorted out.
 

Chuchuf

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Dec 10, 2015
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Alpharetta
IMO the worst thing that Peter could do now is taxi the plane. Especially high speed taxi which leads to hopping and then flight.
Test pilots are motivated by different things (self preservation) than company owners (product preservation) so the decisions made by each are made for very different reasons.
A test pilot will have no problem putting the plane down in a field if needed or bail out if required, whereas the owner might want to stretch it a bit to get back to the airport and preserve his or her creation.
We recently lost a good man because of the financial pressure he was under to get the plane flown before Sun n Fun when he was NOT the right person to fly it. The same holds true here.
 

BBerson

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I had an unintended liftoff just doing what I thought was a routine fast taxi. It jumped to 12 feet, a result of being tail heavy. I knew it was tail heavy and had no intention to lift off but it caught me by surprise.
The Sanjay Dahl crash looked similar. Not sure how he is doing?
 

Marc Zeitlin

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But one thing I learned from the vid is that there is actually some sort of method to the madness of the elevator design. Apparently they want to preserve the possibility of having flaps or flaperons on the main wing, and balance the Cl increase with coordinated deflection of a flap-like elevator. I seem to recall that the Beech Starship does something similar, and I've not heard anything to suggest that it's necessarily a bad idea. But that would require more systems, more testing and tweaking, and more mass, in an already unreasonably bloated airframe.
So what the Starship did was have standard slotted flaps on the canard as elevators (in much the same way as the GU canard on VE's and LE's, not surprisingly) with the hinge line slightly below the bottom surface of the canard. So when the elevator is deflected downward, it VERY slightly increases the area of the canard, and VERY slightly moves the aircraft aerodynamic center. In order to balance the large moment increase when the main wing flaps were deflected, the SWEEP of the canard was changed in concert with the flap deflection, so that the movement of the canard forward would balance out the moment increase. This ONLY happened when the flaps were deflected.

The issue with the Raptor elevator is that the hinge line is FAR below the bottom surface of the canard, so the area change with elevator deflection is much larger, in proportion, than on the VE's and LE's, and it's NOT balancing out any moment change with flap deflection, as there are no flaps. Since the more you deflect the elevator, the more you move the AC forward at the same time as you're slowing down, you're losing stability AND making the airplane more susceptible to deep stall all at the same time. How much? Who knows... It's not going to be Len Fox, apparently.
 

Voidhawk9

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In my opinion, high-speed taxi testing should NOT be attempted unless the aircraft and pilot are prepared for flight. Many a high-speed taxi test has resulted in an unscheduled first flight, and not just among amatuers, even big-ticket aircraft have taken wing on such a test (the original YF-16 for example).

The fact that Peter has even talked about selling up is telling, I think. He is about done with this project, he can see no light at the end of the tunnel, he cannot fool himself any longer. That's probably a good thing for all concerned. Best-case, the project is sold to someone (or group) that can apply the lessons learned to build a new, simpler, improved prototype and proceed from there. The current one will make a great ground-based mockup that interested parties can see, touch, sit in, etc.
 

wsimpso1

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I had an unintended liftoff just doing what I thought was a routine fast taxi. It jumped to 12 feet, a result of being tail heavy. I knew it was tail heavy and had no intention to lift off but it caught me by surprise.
The Sanjay Dahl crash looked similar. Not sure how he is doing?
Talked with and shook Sanjay's hand last Thursday at his chapter's builder meeting. He looked good and moved around OK. I am sure he is still hurting somewhere, but he was social and friendly.

Billski
 

Andy_RR

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Sep 29, 2009
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Melbourne, Australia
OK so the latest video from Peter is positively scary! He's sliding down the slippery slope of DIY, talking about flying in ground effect and all sorts and then he loses all drive to the propeller by shearing this rubber thingy that seems to be a novel single-point-of-failure that needs to be engineered right into the rubbish bin!

Please, no-one test fly this thing without some serious re-engineering first!
 

Voidhawk9

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Another video!
As Andy states above, he is clearly intent on flying it himself now ("Just in ground effect" yeah right).
And then the drive fails. At least it happened on the ground. Hopefully it will keep the machine grounded.
The video showed them installing the airworthy nuts on the elevator hinges. Doesn't seem like something worth doing if you are going to redesign or substantially modify it before flying.
 

Marc Zeitlin

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Would you please explain this part? Thanks.
The further forward you move the AC, the further aft the CG is in relation TO the AC. This reduces the loading on the front wing (the area's getting bigger, remember) so it can reach a higher AOA. As the canard reaches a higher angle, it raises the angle of the main wing. Eventually, if it gets high enough ,the main wing will stall. This is a deep stall, and it's a bad situation if it fully develops. This can happen with ANY airplane, if the CG is too far aft (in relation to the aircraft's AC), and has happened a number of times in canards. The issue here is that the canard is getting bigger WITHOUT the CG moving at all. At least in a standard canard, if you have your CG within the approved range, a deep stall is almost impossible. Maybe not so here...
 
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