# 10/23 Raptor Video

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#### malte

##### Well-Known Member
My best guess would be ICON Aircraft . They are good at convincing non-pilots to buy the A5 (40 units/year?). They would get an instant customer base of position holders and they have experience with composite manufacturing. Not sure how many position holders are left but to ICON it could be 50 years worth of A5 buyers. Time will tell I guess.
If ICON builds 40 aircraft per year with 200+ people and has one LSA "certified. Alexander Schleicher builds 100 aircraft with 100 people per year and has a current choice of 15 Models/Versions with 10 powered gliders among them, two of which are electric and 4 of the models having their first flight in the past 10 years. I think if I were in need of a manufacturer who has experience in efficient production of complex composite aircraft with a high quality standard, I'd talk to Schleicher (or Schempp-Hirt, HpH, Jonkers...). ICON doesn't spring to mind directly.

Why can't folks designing new aircraft just wait until the prototype is built, flown and tested before they open their mouths? Usually they are forced to eat their words or revise their overly optimistic predictions- performance downwards, weight and cost upwards...
They do. But they don't make the big and loud threads in the forums, because "went as planned" is boring, except for an engineer.

#### rv6ejguy

##### Well-Known Member
I don't know any more than anyone else about his production plans, but I learned that a guy named Kevin Halverson is part of "the team on the west coast." He's involved in several startups, mostly unrelated to aviation. But he is also CTO of a company called RPR Aero. Almost nothing about the company online and nobody I know in aviation or venture capital has ever heard of it, but he/they have a patent application involving wing spars with "integrated power cells." I didn't look too closely at that, but at first glance it looks like investor bait. Anyway, that invention is unrelated to Raptor, but the guy is part of the team so I'd guess his company is involved, too.
Peter has kind of hinted that he has some new plans- maybe that includes electric? Range would drop from 3600NM to 136NM though...

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#### TarDevil

##### Well-Known Member
Peter has kind of hinted that he has some new plans- maybe that includes electric?
I'd guess (hope, actually) he's been convinced by "investors" to throw in the towel on that Audi and go with proven propulsion. Could be why he stubbornly refuses to correct engine deficiencies (then again, that would be a wise choice, and wisdom has yet to be evident in the Raptor project) . I don't know engines and I'm not smart enough to participate in any investor group but I certainly can discern a hopeless cause when I see it.

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#### BoKu

##### Pundit
HBA Supporter
My best guess would be ICON Aircraft...
I'd considered that, and I'd be quite surprised if it were so. I think that if they wanted an airplane in the Raptor's design space, they would design and develop it themselves. They have (or have had, at least) some top-notch engineering talent, and they would see in an instant that Raptor's claimed performance metrics are entirely fictional, and that what _could_ be achieved with its OML is not particularly compelling. But as you say, we will see.

#### BoKu

##### Pundit
HBA Supporter
...Kevin Halverson ... RPR Aero ... wing spars with "integrated power cells."
Here's their patent. It looks like a typical $600 jobbie that any decent IP lawyer could bust over lunch. #### Vigilant1 ##### Well-Known Member Lifetime Supporter Here's their patent. It looks like a typical$600 jobbie that any decent IP lawyer could bust over lunch.
I am not a lawyer, but that appears to be some very weak sauce. Has the "not obvious" patentability requirement been rescinded?

#### 231TC

Here's their patent. It looks like a typical $600 jobbie that any decent IP lawyer could bust over lunch. Yeah, I kind of got the impression it was only intended to present to ignorant potential investors to part them from their money. #### rv6ejguy ##### Well-Known Member Here's their patent. It looks like a typical$600 jobbie that any decent IP lawyer could bust over lunch.

The last place I'd want to place batteries would be inside a spar from structural, volume and accessibility standpoints...

#### 231TC

##### Well-Known Member
Peter has kind of hinted that he has some new plans- maybe that includes electric? Range would drop from 3600NM to 136NM though...
Haha, 136nm would be an improvement at this point....

#### Malish

##### Well-Known Member
I did hear that "knocking" sound when engine at idle and notice vibrations on this video - this did't happened on video before engine replacement.
Problem with the engine?

#### Geraldc

##### Well-Known Member
Not to worry about production. That's years away, if ever, given the current state of the design...

So many companies fall into this same old trap:

1. Promise the moon without even having built or flown the airplane.

2. Somehow come up with a kit price before step 1 is complete.

Peter was talking about training, air taxis and certification way back in 2013. Completely naive.

Though I like what the guys at Dark Aero are doing, they are following this same path with step 1 and 2. No way this plane will meet the cruise speed specs they are forecasting IMO either.

Why can't folks designing new aircraft just wait until the prototype is built, flown and tested before they open their mouths? Usually they are forced to eat their words or revise their overly optimistic predictions- performance downwards, weight and cost upwards...
Vickers Wave seem to be doing this.They have now registered the plane but no update on website.
They appear to be developing the plane as a sideline to an existing business.

#### rv6ejguy

##### Well-Known Member
I did hear that "knocking" sound when engine at idle and notice vibrations on this video - this did't happened on video before engine replacement.
Problem with the engine?
That's classic torsional vibration. It was there before but at a slightly different rpm. Many geared engines have a period right around the idle range. Rotax specifies idle above 1400 rpm for this reason- you should see what happens around 650-1000 rpm on a 912- scary on a test stand...

You can usually live with this by changing the idle rpm either up or down slightly however having high amplitude TV in the cruise or high rpm range isn't acceptable- you'll soon shed some parts.

#### Kiwi303

##### Well-Known Member
I am not a lawyer, but that appears to be some very weak sauce. Has the "not obvious" patentability requirement been rescinded?
Any lawyer worth his expense account would point at wet wings and integral spar fuel sorage. it even gets mentioned in Wikipedias spar page for crying out loud. Fuel and batteries, no difference. It's existing concept so not patentable as a novel solution.

#### Malish

##### Well-Known Member
That's classic torsional vibration. It was there before but at a slightly different rpm. Many geared engines have a period right around the idle range. Rotax specifies idle above 1400 rpm for this reason- you should see what happens around 650-1000 rpm on a 912- scary on a test stand...
I understand this and understand that may be some resonance vibrations on certain RPM's. On our aircraft we have increase idle RPM's to 1600 and we're have to avoid ruining engine on 3400-3600 RPM's because of that. But i think Raptor didn't have that sound and such vibrations with old engine.

#### rv6ejguy

##### Well-Known Member
If you watch some of the older videos and listen carefully, you'll hear the same "clucking" sound that is characteristic of TV, just below and above his typical idle rpm.

You can also see another period here at higher rpm:
from a run about 11 months ago at 4:55 and 5:14 and likely 6:16. If you watch carefully, as the engine is throttled up, it goes through several minor TV periods as well. Most people won't notice these unless they were pointed out.

As I pointed out right after he installed the 2nd engine, the TV periods have changed with noticeably more amplitude in at least 2 places- a cause for concern and investigation IMO but I'm sure Peter will just forge ahead, saying he's ok with that...

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#### TarDevil

##### Well-Known Member
For those more knowledgeable than me, what is the likely scenario should the PSRU fail in flight? Just prop stoppage! Prop loss? If he sheds the prop and maybe a bit more hardware, will Raptor be controllable with a sudden CG shift?

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#### BJC

##### Well-Known Member
HBA Supporter
Two of the dangers of losing a prop: vibration that removes the engine from the airframe, resulting in an uncontrollable CG location, and damage to the wings as the blades depart.

I know of conventional configuration airplanes that were controllable in flight after losing a propeller.

BJC

#### SuperSpinach

##### Active Member
Is there a way to reduce TVs ?
@rv6ejguy @Malish You are talking about restricting the RPM range. How common is this when designing a new aircraft ?

#### BoKu

##### Pundit
HBA Supporter
For those more knowledgeable than me, what is the likely scenario should the PSRU haul in flight? Just prop stoppage! Prop loss? If he sheds the prop and maybe a bit more hardware, will Raptor be controllable with a sudden CG shift?
I suspect that the most likely scenario is belt or torsional damper breakage that allows the prop to freewheel independently of the engine. If it isn't driving the engine, the prop drag shouldn't be too great.

#### Kyle Boatright

##### Well-Known Member
HBA Supporter
I suspect that the most likely scenario is belt or torsional damper breakage that allows the prop to freewheel independently of the engine. If it isn't driving the engine, the prop drag shouldn't be too great.
I think he'd be better off if it was driving the engine. It would spin more slowly, and possibly stall. Letting it spin up would be bad, I think. I relate this to helicopter autorotations. Faster blade rotation produces more lift (drag in that world) than a slow rotation.