China showcase 6T H-VTOL (a 6 propeller eVTOL) using hybrid propulsion

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pdf27@reddit

That has very strong "artist's impression" vibes to it. It feels like a mashup between Joby and CityAirbus NextGen, enlarged beyond what is practicable and then with a gas turbine air inlet added on top of the tail to make it a "hybrid". There are lots of details to it that just look suspect and aren't the way you would normally do a hybrid eVTOL - hence my suspicion that it's an art project not an engineering one.

For a credible Chinese eVTOL, take a look at TCab Tech and start noting the detailed differences. https://www.tcabtech.com/en

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DuelJ@reddit

I wonder how vibration issues work out on these. You've got two sets of three somewhat axial props, on 6 arms, and they have transitory positions.

Maybe the electric aspect helps?

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East-Plankton-3877@reddit

We don’t even have quad-propeller VTOLs yet.

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DarkArcher__@reddit

It was done in the 60s

https://en.wikipedia.org/wiki/Bell_X-22

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East-Plankton-3877@reddit

So, why don’t we have like, big heavy lift quad VTOLs in operation?

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DuelJ@reddit

Helicopters

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no-more-nazis@reddit

https://en.wikipedia.org/wiki/Bell_Boeing_Quad_TiltRotor

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PsychoTexan@reddit

That’s a 26 year old design proposal, I think they’re asking why none are in service currently given proposals go as far back as the 60’s.

The answer is a combination of things. The first is the technology, pure and simple. Flight transitions are very complex and without the advantages of modern tech were even moreso in the past. Next, while the V-22 is a pretty stable craft now, its development from 1988-2007 was pretty fucking rocky. This in and of itself likely would’ve halted other development till it matured but add to that the lack of doctrinal need for a quad tilt rotor vs the V-22 vs a Chinook or equivalent vs a conventional plane.

Its niche would likely be plane speeds required for things that are too heavy for the V-22 but also have to land VTOL. Which as a very new unique capability there really isn’t a doctrinal call for. Even if it were, only superpowers would likely be able to reasonably budget for it.

And for pretty much everyone besides the US in the 90’s and early 2000’s, the russians were falling apart, china was catching up, everyone else had a front row seat to the V-22 project and peacetime budgets to watch. After all, if the US was struggling with two tilt rotors and a budget the size of a third world GDP then why try for 4 rotors on a niche use case?

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Wolffe_In_The_Dark@reddit

Uh... yeah, we do. We have quite a lot of them, actually, albeit none ready for widespread use.

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A3bilbaNEO@reddit

Hybrid as in, gas turbine generator driving those electric motors?

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DuelJ@reddit

If you want it to gun on jet fuel, and want it to have 6 props spaced like that, I can't imagine there being an easier way.

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PresentationJumpy101@reddit

Death trap

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Gullible-Guarantee90@reddit (OP)

Side face

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Western-County4282@reddit

How does it look bigger than the osprey, while being able to carry even less

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Re0ns@reddit

And being way more mechanically complex as well, 3X as difficult to maintain to carry less than the Osprey, and is hybrid propulsion even proven to be viable yet?

Most likely a propaganda piece than a real aircraft project imo, all the flashy words and no substance.

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tadeuska@reddit

Nothing is mechanically more complex than an Osprey. That transmission system is some madman's idea.

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Saul_Firehand@reddit

They kept trying to see if they could, they never stopped to think if they should, because there was so much so much money.

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tadeuska@reddit

Yeah, almost like that was the point. Let's do something next to impossible just to see how much money we can put on the side. And it worked.

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Saul_Firehand@reddit

No no it is cutting edge technology that doesn’t crash and kill its passengers repeatedly.

Nothing bad can happen, it can only good happen.

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Dpek1234@reddit

To be fair

It has good reliability (when compared with other helicopters, the problem is that helis have a bad crash rate)

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Seawolf571@reddit

I wish the NCD Osprey man was here... (he tragically died in one of the most recent Osprey crashes that grounded the entire fleet for a year or so, no im not joking)

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Saul_Firehand@reddit

Helicopters are an affront to gravity.

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KokoTheTalkingApe@reddit

This Chinese model uses electric motors, so there's no transmission shaft between the props. It's probably mechanically simpler than the Osprey, not more complex.

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Farfignugen42@reddit

The Osprey uses helicopter rotors that also tilt relative to the engines.

This looks like it uses simple drone rotors that do not tilt at all.

Helicopter rotors can move individually and collectively in all 3 dimensions, as well as being able to spin faster or slower.

Simple drone rotors can go faster or slower but are otherwise fixed to their axles. They are far less complex.

Using six simple rotors powered by electric motors is way less complex than an Osprey. This won't need a transmission at all since it is electric.

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Rodot@reddit

Not to mention the extra rotors probably provide more failsafes than points of failure

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Frostwick1@reddit

This mentality is why china will surpass the US. There is nothing mechanically complex about electric motors connected to a generator. Jesus it’s embarrassing reading these sinophobic comments.

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highcommander010@reddit

was thinking this

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Lui_Le_Diamond@reddit

The engine isn't the only part that matters

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okonom@reddit

Yeah, there's also the inherent redundancy of a hexacopter allowing the designers to do away with gearboxes and driveshafts, as well as the ability to rely on differential collective instead of cyclic allowing the designers to do away with swashplates and blade flapping.

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Lui_Le_Diamond@reddit

Cool, but it still has higher maintenance than an Osprey and can't even carry as much. I have serious doubts this thing can do it's job reliably

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okonom@reddit

While I also have considerable doubts that this thing will ever get built due to the constrained performance stemming from a heavier hybrid propulsion system and power limitations of current electric motors, I think you're significantly underestimating how much less maintenance an electric motor powered directly driven variable pitch propeller requires when compared to a pivoting turbine, gearboxes, and a flapping rotor. It's easily to the point where the two of the V-22 would require more maintenance than the six of this thing, and that's before we get into the V-22's pivoting wing and folding rotor blades. The issues around lubrication and seals in the pivoting turbine alone were enough for Bell to design an entirely new pivoting gearbox when it came to the V-280. The maintenance tradeoffs are most comparable to how RC multicopters have largely displaced RC helicopters when it comes to hovering toys. Despite being inherently less efficient and having more motors and props than helicopters had motors and rotors, multicopters were overall less mechanically complex due to the simplicity of each direct drive motor-propeller unit.

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Lui_Le_Diamond@reddit

So why need 6? Why NEED the extra extra redundancy?

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okonom@reddit

If your only form of control is by varying the thrust of the individual propellers (so motor speed or collective pitch, no cyclic) and you don't have driveshafts linking the engines, then six propellers is the minimum you need to be able to have one engine out and still control pitch, roll, yaw, and altitude in the hover mode. I suspect the propeller tilt mechanism is simply too slow to act as part of the primary flight controls, so six propellers is the bare minimum of redundancy.

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Lui_Le_Diamond@reddit

I mean most get away fine with 2. So that is demonstratively false.

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okonom@reddit

What do you mean by "most get away fine with two"? With the exception of obscure drone curiosities that use the temporally cyclic variation of power to mimic cyclic rotor control there are no vehicles capable of controlled hovering flight where the only primary flight controls are the variation of thrust of two propellers. It would either require one of the thrusters to be a rotor with cyclic control as in a conventional helicopter, or thrust vectoring whether via pivoting motor mount or via blown flaps.

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Lui_Le_Diamond@reddit

Look up ANY other tilt rotor aircrafy I beg of you

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okonom@reddit

You mean the tilt rotor aircraft that all have driveshafts traveling through their wings linking the engines so that in the event of a single engine out one engine would power both rotors? The tilt-rotors that all have tilting rotors with thrust and cyclic control instead of tilting props that only have thrust control? Notice how if you read my comment on redundancy I specifically prefaced the hexacopter configuration being the minimum number of props needed for single engine out redundancy on the case where there were no such interconnecting driveshafts and the vehicle used propellers instead of rotors?

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Lui_Le_Diamond@reddit

If you NEED 6 to be redundant and still can'tcarry as much as your competitorswho use ⅓ as many, then your design is horribly inefficient.

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okonom@reddit

And now we're back to my even earlier comment agreeing that this won't get built "due to the constrained performance stemming from a heavier hybrid propulsion system and power limitations of current electric motors" but arguing that despite having six propulsion units vs a conventional tilt-rotor's two it still represented less overall mechanical complexity and less maintenance burden when compared to a conventional tilt-rotor due to each of the six propulsion units being dramatically simpler.

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Lui_Le_Diamond@reddit

Sure on paper, but not in practice by virtue of there being 6 of them. That's a LOT, and it removes that inherent redundancy of one powerplant being able to run both rotors if one fails. It's a really shitty idea with today's tech. Maybe something like this could be practical in a few decades, but with today's tech? This is just shitty propaganda at best.

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highcommander010@reddit

dude they took a cargo drone and made it big.

it'll fly

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Lui_Le_Diamond@reddit

That's not how avionics works

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Lui_Le_Diamond@reddit

Doubting CCP tech isn't sinophobic.

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Re0ns@reddit

It's not the motor issue, it's the whole mechanism for the tilt, just because it doesn't have fuel lines doesn't mean that it is less likely to fail, the Osprey used a transmission shaft to ensure an engine failure doesn't immediately crash it. How would the system look like on the triple tilt sextuple engined thing? Or just forego the mechanical backup and crash if one of the motors fails?

I'm from Hong Kong, my hatred for china runs as deep as the Mariana trench. The things they do are practically mockery of the city.

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okonom@reddit

Hexacopters with sufficient excess thrust have enough redundancy to maintain control and safely land after the loss of a single motor. With less power you can't maintain yaw control but still have enough control over pitch and roll for a fly by wire system to direct the craft to an uncomfortably spinning but likely survivable landing.

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IndorilMiara@reddit

With 4+ motors and a sufficient safety margin of thrust to weight in hover mode, a multirotor craft like this can land safely with a complete rotor loss. A reasonably balanced quadcopter can land no problem with a motor out, and with 6 rotors this thing is even better off for that safety.

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Euphemisticles@reddit

Can't wait to see these fall out of these sky 3 times as often as the Osprey if they are ever rolled out. They will crash more often than the Pelicans from Halo.

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Marionettework@reddit

3 times as often than an Osprey

And still safer than a helicopter

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redmercuryvendor@reddit

How does it look bigger than the osprey, while being able to carry even less

Because volume filled with air doesn't weight much. For a military craft you may care more about how many tonnes of materiel you can carry and if the crew and ~~squishy cargo~~ embarked personnel end up shoved up against the walls then tough for them. For a commercial aircraft, having space for people to stand up and stretch their legs is more valuable than having the spare lift capacity to sling a truck underneath.

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PatchesMaps@reddit

It's an eVTOL. No battery tech (even the hypothetical stuff) gets even remotely close to the energy density of petroleum derived fuels. Even if you did have magical batteries that had the same energy density, you'd still have to carry the dead ones around with you. With jet fuel we just ditch the used fuel into the atmosphere. It gets even better because we only take half the chemical reaction with us and pull the oxygen from the air.

It hasn't worked out so great for the atmosphere but it makes flight possible.

Traditional battery powered fixed wing aircraft might be plausible but eVTOLs are still going to struggle with the math quite a bit.

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Ace_389@reddit

That's probably why it's a hybrid, you only carry enough batteries to bridge the power needed for landing and takeoff while using the engine for cruising, also they probably go for full electric motor driven props to reduce mechanical complexity. Although I can't really find anything on that model anyway so maybe hybrid in this case just means a generator driven by a turbine.

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IndorilMiara@reddit

If it’s a hybrid anything like the one from Electra Aero, then yeah - the motors are 100% electric, and the gas turbine charges the batteries.

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Havoccity@reddit

Doesn’t seem to be designed at transporting cargo

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Western-County4282@reddit

People are cargo

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guardianone-24@reddit

I think a certain captain says otherwise.

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Western-County4282@reddit

Fair, but I think you get my point, carries less passengers than the V22

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amaze_childhood4@reddit

flying cars are closer than my lunch break

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Echogolf4991@reddit

Oh did they steal Osprey plans at the same time they stole plans for the HIMARS?

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tlawrey20@reddit

What? How tf did you even get that?

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Echogolf4991@reddit

Idk man, my mom must have taken too much Tylenol when she was pregnant with me. My only other defence is that it was prior to coffee, but the more I look at it the less I see osprey. 😂 dunno guess I got the tism

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tlawrey20@reddit

Owned up to it like a champ.

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Chennyboy11@reddit

Dude you need to get your eyes checked out, in what world does Osprey have 6 propellers.

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Echogolf4991@reddit

No no I get that, it just looks similar to me. Fair point though

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Urkot@reddit

The idea of innovating is cool, but what need exactly is this addressing? Aren't existing helicopters just as capable? Is operational cost supposed to be far lower than those to justify more of them? I also don't get how the idea here is to integrate what looks like a *ton* of rotors. Shouldn't this be achievable with something a little more advanced than basically a super sized camera drone with a small passenger cabin.

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okonom@reddit

Normally the big benefit of a tiltprop/tiltrotor would be range, but this is only claiming a range of 600 km carrying 600 kg, which is pitiful compared to their Blackhawk derivatives. Maybe they're selling it to the brass as having a higher top speed, or maybe they're just desperately pivoting from the VC-funded urban air mobility grift to the MIC exploratory development contract teat.

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tadeuska@reddit

Why on earth do people compare it with Osprey? They can fly vertically and horizontally, so what? I mean they are mechanically not even remotely related.

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Uniturner@reddit

With a fraction of the design budget of Osprey, this would be so much simpler and more reliable to build and operate. Dare I say it, with the six rotors, it probably has the redundancy to successfully force land with one or even two opposed rotors inop. I agree with you, they’re completely different machines with vastly different design requirements.

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