Raptor Aircraft

3393RP said:
Clean sheet? It's a poor copy of aircraft that already exists. Muller did add nice features, like windows and doors that would blow out if the fuselage was actually pressurized, an orphan junkyard engine that has badly mismatched compound turbos, an inadequate cooling system that is always on the edge of a meltdown emergency, an empty weight that's double the initial projections, and the crowning jewel, a set of performance specifications that will never come close to realization.
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I was trying to be nice after being so critical for so long. The best thing he can do is go dark and work on it in silence. Social media pressures people into doing dumb things because fans want more and you feel the need to prove naysayers wrong.
 
iamtheari said:
What is your source for the 25 miles until 10 hours and 50 miles thereafter limitations? I don't remember those being mentioned before but I mostly watch the Raptor videos while I'm doing something else around the house so I miss a lot.
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donjohnston said:
According to the current operating limitations, it's 25nm until it expires after 12 months. Then he has to reapply.
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Marc Zeitlin obtained them from the FAA and posted about it at HBA. He didn't post the doc itself, just reported what it said, but I trust him to get it right:
In the case of N352TD, the test area is defined as a 25 mile radius around Valdosta Airport (KVLD) for the first 10 hours of flight [...] and as a 50 mile radius around KVLD after the first 10 hours
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https://www.homebuiltairplanes.com/forums/threads/10-23-raptor-video.34652/page-98#post-587941
 
I think Peter is coming to the end of his journey. "Sometimes life has a way of moving you past wants and hopes." - Jeff Bridges
 
Agreed, sounds like this is about over. I hope he makes it out of the next few hours of flying with all his limbs.
 
Racerx said:
However, he created a relatively clean sheet plan, stuffed an automotive engine in it and made it work, sort of. The thing flew. And faster than a large portion of GA planes, if the ADS-b data is valid. Ain't no dummies pulling all that off.
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He didn't do it though. He hired experts to get him just far enough, then dismissed them when they didn't agree with his ideas. Without them he'd still be sitting at his computer dreaming.
 
DaleB said:
Personally... I hope the guy is successful. At least to the degree possible. There’s no way in hell that he’ll come anywhere near his original claims, and personally I don’t think he’ll ever have a viable product. But I hope he at least either ends up with a usable airplane, or a valuable set of lessons learned. I think the chances of that last one are pretty low; he doesn’t seem to really be open to seeing things that disagree with his plans or desires.

But a viable commercial product? Ummm... nah.
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Didn’t he mention he had a company on the west coast that were going to take over the development after he flys of his hours and takes it to Komnifornia?
 
1RTK1 said:
Didn’t he mention he had a company on the west coast that were going to take over the development after he flys of his hours and takes it to Komnifornia?
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He said pretty clearly his plan is to fly 40 hours, and then take it to CA and hand it over to another company. I’m guessing if that’s true, they told him to cut out the videos.
 
I don't know why the hours would even matter at this point. Its going to take significant work to get it to something that is marketable and that will require a completely new flight test regime. Seems pointless to keep flying this one.
 
Salty said:
He said pretty clearly his plan is to fly 40 hours, and then take it to CA and hand it over to another company. I’m guessing if that’s true, they told him to cut out the videos.
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“We will give you $7 and a souvenir t-shirt for the prototype, molds, and any documentation.”

Peter: “Deal!”
 
Possibly the goal is to fly off the hours and switch it to E-AB so he can then fly it west. Not sure if the DAR would credit hours flown prior to the new airworthiness certificate, but if that's the plan he probably already got the DAR to agree to it.
 
How can it be "switched" to E-AB when it doesn't meet the requirements for E-AB? The major portion was not fabricated for recreation/education. Way too much hired help.
 
231TC said:
Possibly the goal is to fly off the hours and switch it to E-AB so he can then fly it west. Not sure if the DAR would credit hours flown prior to the new airworthiness certificate, but if that's the plan he probably already got the DAR to agree to it.
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He just needs to get his geographic restriction changed if he wants to fly it to the west coast. A stroke of the pen for the FAA (or a DAR).

Personally, I think he's either found an out, or will take one shortly. He's done. The airplane is an unfolding disaster and him shouting down helpful advice has left him in a corner. None of the Wile E Coyote fixes he's tried have really worked, so either he takes the advice of the people he's told to hush (and eats a serving or 3 of crow) or he finds a way to exit the project, maybe by selling it for little more than the sum of the value of a G3X system, a used Audi engine, and a set of wheels and brakes. There isn't much else of value there unless someone thinks the molds are worth something.
 
231TC said:
Marc Zeitlin obtained them from the FAA and posted about it at HBA. He didn't post the doc itself, just reported what it said, but I trust him to get it right:

https://www.homebuiltairplanes.com/forums/threads/10-23-raptor-video.34652/page-98#post-587941
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I just skim read through the last 10 or so pages of this thread and was surprised to see that Marc Zeitlin acts as whether he is only an interested observer.
I was under the impression that he was the designer of the Raptor airframe and also the person who came up with these unrealistic performance and weight predictions!? Am I mistaken? Do you know more about his exact involvement in this project?
 
German guy said:
I just skim read through the last 10 or so pages of this thread and was surprised to see that Marc Zeitlin acts as whether he is only an interested observer.
I was under the impression that he was the designer of the Raptor airframe and also the person who came up with these unrealistic performance and weight predictions!? Am I mistaken? Do you know more about his exact involvement in this project?
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Marc posts on the Homebuilt Aircraft forum. Best I can tell, his involvement was being part of the Wasabi team's initial visit where he did failure mode analysis and maybe did a gross double-check of the aero to make sure it wasn't crazy far out of bounds aerodynamically. He was not engaged when the aircraft was designed.
 
I believe a different Mark helped Peter in the early stages.
 
martym said:
How can it be "switched" to E-AB when it doesn't meet the requirements for E-AB? The major portion was not fabricated for recreation/education. Way too much hired help.
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Good point, maybe exhibition then.
 
German guy said:
I just skim read through the last 10 or so pages of this thread and was surprised to see that Marc Zeitlin acts as whether he is only an interested observer.
I was under the impression that he was the designer of the Raptor airframe and also the person who came up with these unrealistic performance and weight predictions!? Am I mistaken? Do you know more about his exact involvement in this project?
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That was not Marc Zeitlin. He did a condition inspection at the request of Wasabi. I believe he was there one day and wrote up a report of things needing fixing, and no other involvement.

Mark Bettosini did some engineering work on it but I don't know how much.

kyleb said:
Kerlo.
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That's Jeff Kerlo. He did most of the carbon fiber.
 
Cooling is always a problem when trying to convert automotive engines to aircraft ... by the time larger radiators , oil coolers , and airflow are increased many of the original attractiveness has been lost ... not to mention auto specs may state 300 hp but it is always at high rpm thus a gear reduction is required . Which of course adds even more complexity and weight. All of a sudden those forward looking plans start to go backwards.

Lycoming were not fools in the 1940's .... they used lots of cubic inches to produce low rpm power , hemispherical combustion chambers and dual plugs for best combustion , a hefty crankshaft for direct drive prop flange , and air cooled for simplicity.

The single biggest problem has always been the high cost of those certified engines , thus innovators turn to automotive power as an alternative .... and then trick themselves into thinking they have accomplished something .... and YES ... they may have solved a financial issue ... but that is about it.
 
Automotive engines typically use only about 15% to 20% of rated power cruising down the freeway. They run forever and can be very efficient.

Take (Peter's) excellent Mercedes diesel in a car or SUV ... hook a heavy trailer behind it .... point it up a long steep mountain road .... it will require 80% of rated power to make the climb .... within a short time that excellent car & engine will be overheating , boiling over , hot oil will be thinning , engine life will be drastically reduced.

Automotive engines adapted to aircraft always demand 70-80 % of available power. Same thing as climbing the mountain.
 
A Martin said:
Cooling is always a problem when trying to convert automotive engines to aircraft ... by the time larger radiators , oil coolers , and airflow are increased many of the original attractiveness has been lost ... not to mention auto specs may state 300 hp but it is always at high rpm thus a gear reduction is required . Which of course adds even more complexity and weight. All of a sudden those forward looking plans start to go backwards.

Lycoming were not fools in the 1940's .... they used lots of cubic inches to produce low rpm power , hemispherical combustion chambers and dual plugs for best combustion , a hefty crankshaft for direct drive prop flange , and air cooled for simplicity.

The single biggest problem has always been the high cost of those certified engines , thus innovators turn to automotive power as an alternative .... and then trick themselves into thinking they have accomplished something .... and YES ... they may have solved a financial issue ... but that is about it.
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I'd be willing to bet most guys that throw an LS motor in an airplane have spent more to make everything work than they would have if they just went straight to lycoming to begin with. And it's probably heavier than the lycoming after all the accessories
 
A Martin said:
Automotive engines typically use only about 15% to 20% of rated power cruising down the freeway. They run forever and can be very efficient.

Take (Peter's) excellent Mercedes diesel in a car or SUV ... hook a heavy trailer behind it .... point it up a long steep mountain road .... it will require 80% of rated power to make the climb .... within a short time that excellent car & engine will be overheating , boiling over , hot oil will be thinning , engine life will be drastically reduced.

Automotive engines adapted to aircraft always demand 70-80 % of available power. Same thing as climbing the mountain.
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But, but Lycosaurus!
 
He’s in the air again. Sure looks like he’s just running out the clock. Climbed to 3,300, then descended a bit and is just flying in circles at about 120 knots.
 
He burned another hour of gas going in circles. Down safe.
 
Salty said:
He’s in the air again. Sure looks like he’s just running out the clock. Climbed to 3,300, then descended a bit and is just flying in circles at about 120 knots.
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I think his out is going to be to fly the 40 hrs then ship it to this company in California and post a video saying his part in the project is done and it's now in the hands of the California company.
Then, the company cancels the project and he saves face by not cancelling the project himself.
 
MacFlier said:
I think his out is going to be to fly the 40 hrs then ship it to this company in California and post a video saying his part in the project is done and it's now in the hands of the California company.
Then, the company cancels the project and he saves face by not cancelling the project himself.
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Well, he doesn’t say how he is going to transport it, but he does say he’s going to “video it along the way because it should be interesting”, which lead me to believe he plans to fly it. Maybe I’m wrong.
 
He said a couple times before that he plans to fly it out there. Seems unlikely it'll make it without another serious incident.

And of course his current airworthiness cert won't allow it without a ferry permit. Current cert expires in August anyway, so it could be modified then. No idea if it can be modified to unlimited area and still remain R&D.

The physical capabilities of the aircraft are probably far more limiting than the paperwork anyway. I hope he does show the trip, but wouldn't be surprised if he edits it creatively. In this last video he made it look like those two flights were back to back rather than a week apart. I could see him doing that if his trip out west takes weeks or months, making it look instead like a couple days.
 
Salty said:
It would be a challenge to make it to CA from GA without going above 4K.
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Damn near impossible. I spent a few minutes flight planning when he first mentioned it. There's really only one realistic route, and even that requires a bit over 4000 just to clear terrain. *Might* be able to do it just fine if he takes off from a higher field after letting the engine cool overnight, but getting *to* the higher field will probably be dicey without climbing higher. If he cruises at 4000, he won't need to descend much to land, just let the field elevation come up almost to cruise altitude. He might consider that a feature, not a terrifying flaw.
 
Dumb question about the Raptor “wing” - if the airspeed stays the same and the plane can’t currently climb beyond 4k, does that mean the wing can’t produce any more lift with the given horsepower beyond that altitude? If so, the only answer is more airspeed and therefore needs more horsepower, right? The only other option would be a wing redesign for the current hp?
 
455 Bravo Uniform said:
Dumb question about the Raptor “wing” - if the airspeed stays the same and the plane can’t currently climb beyond 4k, does that mean the wing can’t produce any more lift with the given horsepower beyond that altitude?
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No, it means there is no excess power available at that airspeed. The fix is more horsepower or less drag, or a different climb speed where there is more excess power available.

Consider also that there may be other, possibly arbitrary, reasons for staying low besides insufficient power.

Nauga,
who knows it's press to test, not guess to test.
 
nauga said:
No, it means there is no excess power available at that airspeed. The fix is more horsepower or less drag, or a different climb speed where there is more excess power available.

Consider also that there may be other, possibly arbitrary, reasons for staying low besides insufficient power.

Nauga,
who knows it's press to test, not guess to test.
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Thanks.

Fo’fiddy Fife,
They told me to get in the plane and fly...
(...insert movie title, win a free POA post)
 
455 Bravo Uniform said:
Dumb question about the Raptor “wing” - if the airspeed stays the same and the plane can’t currently climb beyond 4k, does that mean the wing can’t produce any more lift with the given horsepower beyond that altitude? If so, the only answer is more airspeed and therefore needs more horsepower, right? The only other option would be a wing redesign for the current hp?
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Maybe Peter is afraid of heights. :)
 
nauga said:
No, it means there is no excess power available at that airspeed. The fix is more horsepower or less drag, or a different climb speed where there is more excess power available.

Consider also that there may be other, possibly arbitrary, reasons for staying low besides insufficient power.

Nauga,
who knows it's press to test, not guess to test.
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Might it also have something to do with the weight?
 
I thought he was pulling back power to keep the temps down.
 
Salty said:
I thought he was pulling back power to keep the temps down.
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The airplane has a poor rate of climb because of the power to weight ratio. But there's also a temperature constraint where it is under-cooled. He's bounded by both.
 
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