Quantcast

Raptor Composite Aircraft

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Status
Not open for further replies.

Pilot-34

Well-Known Member
Joined
Apr 7, 2020
Messages
661
We beat up on Peter every day here but I have to hand this to him for somebody’s first try at building who has a huge amount of money to be able to make big mistakes with He really isn’t doing too bad.
I don’t think he’s the guy that had a lot of big failures I’m not sure he knows how to deal with that
I suspect at some point he’s going to quit adding and start subtracting
When I’m inventing /building a major item of machinery I figure I can make four major modifications to it before I have to go back and start fresh again
If I can be ready for the first production model after four restarts I think I’m doing OK that’s 16 major modifications
Peter hasn’t even gotten to the first restart yet.
Remember Peter isn’it building airplane he is inventing one.
 

pictsidhe

Well-Known Member
Joined
Jul 15, 2014
Messages
8,812
Location
North Carolina
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.
Aha, so Peter did indeed take an engineered design and 'fixed' it.

Now all he needs to do is peel off the extra layers and have everything he designed redesigned by experts then built.

Did he upgrade the spar and other structural parts to take all the weight he added?

Oh, that's a complete new aircraft, because he is smarter than people who do this every day.
 

GotWake

New Member
Joined
Sep 21, 2019
Messages
3
$ 130 K complete...and 230 kts cruise.

Power to weight ratio 0.16 hp/kg.

I think they might pull that out.

I assume 150 K is closer to truth.
The problem is all the pieces and parts are going to cost that. He has already stated he doesn't know much about getting the kits produced. So, best case scenario is the thing flies perfect, he gets the redesign done with reduced weight with the $2.5 million escrows and some investor(s) comes in with help to fund production. The business side is where all this falls...... well, except physics. No one is handing you $5 million and turn around and selling kits at costs. They are going to want to make their investment back in a reasonable timeframe. Pretending this thing worked, it's an easy $300k kit. Just look at what a Lancair Mako costs, a loaded up kit without the engine is $430k.
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
3,985
Location
Calgary, Alberta, Canada
$ 130 K complete...and 230 kts cruise.

I think they might pull that out.

I assume 150 K is closer to truth.
The plane weighs around 1600 pounds more than Peter's initial projection. It will have about 30% more drag than he thinks. The engine will burn 50% more fuel than he projected, make 50% less hp than he thinks he has, range will be 75% less and it will cost at least 100% more than his projections- all in round figures. It will never go into kit production with the Audi diesel engine, the scary PSRU and nonsensical turbo system. This says nothing of the likely stability, handling, control and structural issues that will need serious sorting and time consuming and costly modifications.

I hope that doesn't sound too negative.
 

BoKu

Pundit
HBA Supporter
Joined
Aug 15, 2013
Messages
2,811
Location
Western US
We beat up on Peter every day here...
For the most part, we are not beating up on Peter. We are beating up on what he's doing, which is screwing up.

...for somebody’s first try at building who has a huge amount of money to be able to make big mistakes with He really isn’t doing too bad...
Raptor isn't bad. It's terrible.

Pretty much since the dawn of aviation, the first step of every successful new design is to survey all that has come before it to assess their strengths and weaknesses inside and out. You might even take rival aircraft apart and see what makes them work, and reverse-engineer their basic structures. Car makers always do this. General aviation manufacturers used to do it a lot. Boeing and Airbus do it to some degree. I did this for a couple decades before trying to design my own sailplane.

The Raptor as it now stands is a testament to what you get when you leave out this step. When you decide you can ignore customary practice for layup schedules of airplanes of similar size and shape, and just throw on a bunch of extra plies, you get extra weight. When you ignore the idea that every part must do more than one job, you get extra weight. When you are on your third iteration of the primary control systems and they still aren't stiff enough, you get extra weight.

...I don’t think he’s the guy that had a lot of big failures I’m not sure he knows how to deal with that...
I suspect he's had a lot of failures. But in the realm of software development (not to be confused with computer science), failures are normal and expected. You find bugs and fix them. For the most part they are frustrating but harmless. And if your patches are somewhat cumbersome, no worries, the next generation of processors will speed them right up.

In the realm of aeronautics, things are different. It plays for keeps, its history is written in blood, and Moore's Law never ever comes to your rescue.

...I suspect at some point he’s going to quit adding and start subtracting...
The time for that is long past. You can't subtract layers of carbon. Well, you can, actually, but it is more troublesome than just starting over.

...When I’m inventing /building a major item of machinery I figure I can make four major modifications to it before I have to go back and start fresh again...
We've been over this a bunch. If Raptor had started as a proper development project, it would have been done with a minimal proof-of-concept airframe with a known engine. No pressurization. No air conditioning. One door. Get it in the air, get a bunch of data, figure out where to go next. With the crew that Raptor started with, that would have taken about six months. The performance data would show that there is no "subsonic area rule" free lunch, and that all Raptor has to offer over a Velocity is a big roomy cabin. But, hey, that's something. You're only six months into it, you've got a bunch of money left, you can work with that.

Instead, the project sank a ton of money (actually, about three tons of money if you're counting dollar bills) into the development of an engine and PSRU and into a pressurized cabin that doesn't even hold air. And now it fairly well reeks of desperation.
 

TarDevil

Well-Known Member
Joined
Jun 29, 2010
Messages
765
Location
Coastal North Carolina/USA
The plane weighs around 1600 pounds more than Peter's initial projection. It will have about 30% more drag than he thinks. The engine will burn 50% more fuel than he projected, make 50% less hp than he thinks he has, range will be 75% less and it will cost at least 100% more than his projections- all in round figures. It will never go into kit production with the Audi diesel engine, the scary PSRU and nonsensical turbo system. This says nothing of the likely stability, handling, control and structural issues that will need serious sorting and time consuming and costly modifications.

I hope that doesn't sound too negative.
No, it sounded conservative! :p
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
13,969
Location
Memphis, TN
Here is a VK-30 project. Kit bought by the owner from the factory back in the day. Somewhat close to flying. It’s very complex. Over $250k in it. Gave up a pressurized Saratoga to build it.
Think what 500K complex kit would drag out after the support dies.
 

Attachments

BBerson

Light Plane Philosopher
HBA Supporter
Joined
Dec 16, 2007
Messages
14,299
Location
Port Townsend WA
The composite fuselage aircraft that I have flown (Glasair and Sportsman) have foam cores.


BJC
That's one company. I believe the majority of German gliders and motorgliders have solid fuselages. Ask Boku? I think pressurized dictates solid core less, at least the cockpit.
I don't know what Peter's initial projection was, but I doubt that any hired engineer would neglect to first check the actual weights of existing Velocity and Orion and then add another 500 pounds (2300) total) for the pressurization, compound turbos and A/C, parachute and whatever else the dreamer wanted at that time.
The website does say it caters to "dreamers" (or something similar). What does that imply?
.
 
Last edited:
Status
Not open for further replies.
Top