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Raptor - 300kts, 130k usd, 7gph jet-a1

Mooney_Driver wrote:

How can they even derive that it would work fine at FL250?

The approach is likely to be to fly it up there and see if it keeps working.

I think this should be a great project, and at the heart of it the true spirit of a genuine experimental, amateur built aircraft, and I wish them the best of luck!

There are only two things that I find problematic
– that he is taking other people’s money on the promise to turn that into a kit…
– that there are so many people falling for this

Last Edited by Cobalt at 04 Oct 09:08
Biggin Hill

HBadger wrote:

Do thorough test flights, step by step, with proper risk management?

Do they? I haven’t followed the blog, but for a proper aircraft engineering, you need to follow proper processes. Not everyone is willing to go that far for every detail, as it might seem unnecessary. In aircraft design, every little stringer needs the same attention as the main spar. Thus, certification from the external / governmental oversight is generally a good idea. However, if they open-source their processes, one might be able to see the data and judge onpon actual data and not upon marketing hogwash.

On a personal note: Noone who claims he’d build an aviation game-changer really did so. Words are just that and many claims collapse, when challenged by physics or economics. The real game-changers in aviation didn’t make a fuzz about being game-changers, they just delivered. Extraordinary claims need extraordinary proof. Having said that, I surely wish them well and would like to see their aircraft flying safely. Even if it’s not the 130k 5-seat-230KTAS-7GPH wonder. It might be a very nice aircraft nonetheless.

mh
Inside the sky.
EDXE, EDXF, Germany

230kt TAS at FL250 is easy enough to achieve with a plane which has a smaller-than-SR22 cockpit volume. It is only 155kt IAS at ISA. You just need a motor with a turbo on it which can do full power at FL250. This is why salesmen love FL250 Even a TB20 would do 200kt+ if you could push 300HP down the prop shaft.

And they are saying 240-310HP which would easily do it. I wonder however if the car engine turbo will still deliver the power at FL250. Cars don’t need to go that high. The highest they test them at is places like La Paz, about 14k.

Of course there is a lot of other detail but the basic physics seems possible. Every other novel design has indeed failed but that could be due to the innovators being much better used car salesmen evangelists (Eclipse being a great example) than project managers.

Administrator
Shoreham EGKA, United Kingdom

A bit of a bummer then. Audi/VW have stated they will stop producing diesel engines in the private car segment.

ENVA ENOP ENMO, Norway

And you can’t get 240-310HP on 7 USG/hr, short of inventing new physics whereby a lot more O2 molecules bind to each hydrocarbon one More like 15 USG/hr.

I wonder what impact on an aviation application the VW/Bosch software cheat would have? Actually most manufacturers were doing similar stuff. And the ECU software would be different.

Administrator
Shoreham EGKA, United Kingdom

The M20TN Manual describes in FL220/ISA 223 [email protected] GPH best economy. It goes down to [email protected] GPH. That’s hard to beat for an aircraft with an “extremely spacious” cabin suggested to be 1 inch higher and 13 inches wider than that of an SR22. And 230 KTAS [email protected] 7GPH is quite a claim.

  • Their homepage has a huge abstract devoted to the area rule, a concept only applicable to wavedrag in transsonic and supersonic flight. Even at 300 KTAS in FL250, the Rapotor is supposed to reach below M 0.5, way below Drag Divergence speed.
  • Their homepage talks about increasing lift force over speed (in the comparison of the Raptor vs. SR22). It is noted, that the raptor increases lift force from 2000 [email protected] to 5000 lbs @ 230 KIAS. That is nonsense on so many levels…

It is a nice concept and can be a nice plane, but my guess is that it will miss the performance data. I’d like to be proven wrong though.

mh
Inside the sky.
EDXE, EDXF, Germany

Yeah 230ktas at 7gph will not happen. And also the 130k usd price tag will not happen at least for many of the initial kits.

That being said, a 230ktas 14 gph plane for 300k usd including pressurization and big interior space would still be a game changer, especially if there is a big enough community around it, the value of which can be seen for Vans aircraft. Oh and it burns jet a1.

About the engine: they don’t use standard turbos but use bigger ones that apparently should deliver better power at altitude. But to be confirmed.
And also even if that engine goes out of production there will be enough supply because it is a standard engine in the VW/Audi universe.
Still it seems they are planning to push it too hard, and that concerns me for this application.

Switzerland

Cobalt wrote:

There are only two things that I find problematic
– that he is taking other people’s money on the promise to turn that into a kit…
– that there are so many people falling for this

How many buy lottery tickets every week with the dream of one day… a bit of the same thing. How many such options on pipe dreams have been sold in the past of which how many ever flew? I would not call it wrong if the intent is sincere and it’s not like the plot in “The Producers” (and if you have not seen that movie, do so, it’s worth it).

mh wrote:

Noone who claims he’d build an aviation game-changer really did so. Words are just that and many claims collapse,

Most of them I reckon. I would exclude Cirrus for obvious reasons, they did change the aviation game and were vocal about it before they did. But that had nothing to do with speed and econcomic performance, it had to do with the ingenious use of a parashute. All the other game changers have failed to change the world.

Another bit which will most probably make it impossible to use in Europe (apart from the fact that it is useless as a VFR – day plane, which it will be if it remains experimental) is the push prop. Those are usually VERY noisy. It is still beyond me how the Piaggio Avanti got certified, being the chain-saw-of-the-air it is. Also pushers use a lot of runway usually. Years ago, I was very interested in the Prescott Pusher, another one which looks even quite similar but never made it. There is only one flying today.


By FlugKerl2Own work, CC BY-SA 3.0, Link

LSZH, Switzerland

Mooney_Driver wrote:

I would exclude Cirrus for obvious reasons, they did change the aviation game and were vocal about it before they did.

But did they? They sell well enough, but isn’t their safety record basically an outcome of their training, rather their chute? And hasn’t Diamond a way better overall safety rate compared to the SR2x? How was Cirrus a game changer? In Marketing? No, they basically did design an aircraft pleasant enough to many people with a good marketing campaign and not bragging about stuff they didn’t were able to pull off.

Mooney_Driver wrote:

It is still beyond me how the Piaggio Avanti got certified, being the chain-saw-of-the-air it is.

Easy. They showed compliance against certification criteria.

Last Edited by mh at 05 Oct 14:30
mh
Inside the sky.
EDXE, EDXF, Germany

mh wrote:

But did they? They sell well enough, but isn’t their safety record basically an outcome of their training, rather their chute?

I think they did, not technologically maybe but they are the reason that today planes without a shute won’t sell in any numbers. The Single Engine market outside Cirrus is dead (with the exception of the C172), all other models sell in absymal numbers and mainly for training. Personal SEP’s, there is only Cirrus left. Despite the fact that they were neither the fastest, nor the most economical, nor (arguably) the most attractive option.

Yea, I think they were a game changer and if only in the fact that they managed to get a quasi monopoly out of the laziness of the other manufacturers who still think they can sell SEP’s without the shute.

When it comes to selling anything, people talk safety and other high motives. In the end however, they buy with their guts. Or, as that old sugarless chewing gum add showed in the 1970ties when it was the only one Mummy (the wife in this case) allowed.

mh wrote:

Easy. They showed compliance against certification criteria.

Yes of course, my mistake. I wonder how it managed to get a noise certificate which allows it to fly almost everywhere. It sounds a lot louder than most other planes.

LSZH, Switzerland
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