# Raptor Composite Aircraft

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#### Jet787

##### Active Member
The refundable deposit holders like you have only lost about $60 escrow fee. But they also lost about 5 years waiting with the missed completion promises and wildly inaccurate performance claims, so some might be angry and critical. But like I said, I don't see it. The$20,000 supporters? gifters? could be more disappointed and loose it all. But I have not heard anything from them either. Seems bizarre. This whole open and public story is bizarre and I wonder if someone is looking at a book project.
As for the $65 it cost me, it was worth the entertainment value. As for the investors, I wouldn’t be surprised to see a suit but I don’t think there are any assets or value to recover. I’m sure there will be some that are angry if not at Peter then themselves. #### Speedboat100 ##### Banned I’d be curious to see what Peter Sirpol could have done with the$+2.5 mil.

He'd have lots and lots of new batteries.

This is very intereresting thread. I like the way he is able to convince himself and investors......hopefully arrangement around the duct and outlets now really will cool the engine.

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#### BBerson

##### Light Plane Philosopher
HBA Supporter
As for the $65 it cost me, it was worth the entertainment value. As for the investors, I wouldn’t be surprised to see a suit but I don’t think there are any assets or value to recover. I’m sure there will be some that are angry if not at Peter then themselves. Maybe they figure that Peter lost vastly more than$20k of his own money.

#### pictsidhe

Maybe they figure that Peter lost vastly more than $20k of his own money. It's more likely that the CEO of Raptor Aircraft, Inc has been amply recompensed for all his work. #### BJC ##### Well-Known Member HBA Supporter I’d be curious to see what Peter Sirpol could have done with the$+2.5 mil.
He could have made lots more YT videos. He doesn’t seem to be very interested in designing and building a useful airplane.

BJC

#### pictsidhe

##### Well-Known Member
He could have made lots more YT videos. He doesn’t seem to be very interested in designing and building a useful airplane.

BJC
Like PM, then. Just with a far smaller budget and a lot more talent?

##### Active Member
I've casually followed PM's Vblog off and on for several years during which I've had various questions but never wrote to Peter about them because I'm just a simple mechanical engineer and nothing close to an aerodynamicist. I have very much enjoyed the range of comments and insights provided in this forum by clearly skilled engineers and pilots. So thank you all.

That said I am surprised by a couple of things that I feel have not been commented on. It's likely just my lack of specialized experience but I want to continue learning from you folks and so would appreciate some clarifications if and when any of you have time.

I've watched the Raptor 1st flight video several times attempting to notice any visual correlations between the aircraft's attitude, PM's control inputs, and the clear porpoising present throughout the flight. I cannot see the roll – yaw coupling implied by the many “Dutch Roll” references. That is made more difficult by the fact that he is in a near-constant right turn negotiating his way back to the airport but it even seems in a couple of frames that the pitch cycle decreases with increased roll input. I've tried locking my few to a point on the edge of the windscreen and cannot detect any periodic yaw. Again, very hard for my less skilled eye to know what is happening from the video. Perhaps the increased roll input just changes the phase relationship of the (proposed) Dutch Roll but I never see any Yaw motion coupling with the pitch.

My larger concern, as has been I believe at least partially shared by a few of you, is that in the Vblogs I watched PM seemed to casually modify fight control design and balance without ever referring to how his changes impacted his aeroelastic design calculations. This was especially apparent when he had to change the sliding elevator hinge on the canard and when he added the significant aileron balances. He never discussed verifying the impact of the changes to his Flutter calcs.

Then when testing the aileron balance by shaking the wing I was nearly sickened to see the ease of excitation, its apparently significant structural under-damping, and what looked like slightly out of phase excitation of the far wing and winglet.

I fear that if he didn't have significant cooling and power problems and could accelerate at anything near his estimates he would have very quickly found resonate modes of his structure that he would not have recovered from. So, am I just naive or should there be a real intervention? Thanks.

#### Speedboat100

##### Banned
I am very for this kinda direct affecting via youtube and blog....as long as the hero stays alive.

I wonder if a twin engine let's say 12-16 passenger plane of similar kind could be constructed just by getting the money from eager funding capable people ?

Let's put 350 kts cruise speed for it for starters.

Kinda like a new Starship...but with lifting fuselage ?

#### TarDevil

##### Well-Known Member
RaptorMan's calcs show the engine producing 425 hp. I guess the lack of acceleration and climb rate didn't budge the needle on the cluemeter. 5 more gallons of coolant = another 50 lbs?
Yeah, like when, if ever, will he acknowledge that noisey mess behind him isn't developing power?
RE the 50 lbs.. he said he'll be removing weight under the seat.. net zero weight gain.

#### Alessandre

##### Active Member
I'm asking me about if Peter is right about of the effect of the big hole of the landing gear almost in front of the wing isn't the cause of the weird behavior of the airplane. I think this prototype could have non retract landing gear and a lot of issues would be avoided.
I saw that he improved the air flux, but the engine still overheating, the engine is generating more heat than the radiator is able to eliminate, it's a bomb waiting for explode at the worst hour, I think is time to give up of this engine, he could switch for a gasoline engine like LS1 gm and maybe would be more lighter with more power and no turbos and intercoolers. Diesel engines generates a lot of heat, see the size of the truck's radiators.

#### rbarnes

##### Well-Known Member
I think is time to give up of this engine,
PM is in the depths of Sunk Cost Fallacy. I'm not sure he has the personality to pull himself out of it until the plane is destroyed in an incident.

Individuals commit the sunk cost fallacy when they continue a behavior or endeavor as a result of previously invested resources (time, money or effort) (Arkes & Blumer, 1985). This fallacy, which is related to loss aversion and status quo bias, can also be viewed as bias resulting from an ongoing commitment.

#### Richard Schubert

##### Well-Known Member
or should there be a real intervention
There will be no intervention. He has already left the building, the only question now is how high the bounce will be off the pavement.

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#### proppastie

##### Well-Known Member
Log Member
This fallacy, which is related to loss aversion and status quo bias, can also be viewed as bias resulting from an ongoing commitment.
Certainly.....but ......can what are glaring errors be fixed and an aircraft of his own design and development be made safe to fly? The consensus here is he will not meet his design goals, but backing up a moment ,....can the engine problems be fixed?,.....can the aerodynamic problems be fixed? Is it possible that a somewhat heavy aircraft with a Jet A or Diesel burning engine will develop?

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