Clearer views of the Chinese "Bohai Sea Monster" ekranoplan, now with visible hardpoints.

Posted by JeantheDragon@reddit | WeirdWings | View on Reddit | 29 comments

Sourced from Chinese social media, shared by [Andreas Rupprecht](https://x.com/RupprechtDeino/status/2058445237907837413)

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Yari_Samurai@reddit

I highly doubt this is an Ekranoplan.

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Zombificus@reddit

If it’s not one, what do you think is the reason for such an oversized tail? Seems way overkill for an ordinary flying boat, personally, but it is a feature present on known ekranoplans.

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GrafZeppelin127@reddit

I would consider it pretty likely this is a flight-capable WIG seaplane. Cruises efficiently in the ground effect for most of the time, but capable of flying outside of it with higher power settings.

The Americans have investigated similar concepts before with things like the Pelican and Liberty Lifter.

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Pretty sick and very weird. What would be really neat is if you had like a boat-hull modular payload container so that you could do super heavy lifts if the sea is flat but you could safely cut-n-run if the swell picks up too much for WIG and you could do it all with a single power setting.

Course then you'd be limited to payloads that aren't going to erase your advantage if they get captured while waiting to be picked up. Its always something with the ekranoplan idea!

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GrafZeppelin127@reddit

Eh, having the ability to drop the payload would likely be far more work, compromise, and opportunity cost than just having enough reserve power to scoot out of the ground effect. That additional power requirement pretty much halves your range due to the higher fuel use, but it’s better than being smashed to bits by an… overly enthusiastic sea state.

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Trevski@reddit

To the drawing board!

I mean idk either way is a lot of work, I guess I'm thinking too much in the efficiency regime and not enough in the military "lets go ~~kill~~ save those people no matter how much fuel it uses" regime

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GrafZeppelin127@reddit

Well, even from an efficiency perspective, consider what it would entail to have a fully separable payload module and versus a fully structurally integrated cargo bay. You would need more weight and built-up structure in order to have a compartment that could drop off, because then the remaining structure would have to be able to handle all relevant aerodynamic and structural loads in a much narrower package (which means even more structure and weight in order to resist bending and buckling due to the unfavorable geometry), as well as the cargo compartment itself having enough structural integrity to not fall apart when sitting in the water or on the beach on its own.

By comparison, consider just how little extra weight and structure would be involved in just having extra engine power that you could tap into when needed, since modern engines have absolutely gigantic power-to-weight ratios. Operating more powerful engines at a lower power setting (say, 50%) still increases efficiency enormously, even if it’s not quite as efficient as operating smaller engines at their ~70% peak efficiency (at the cost of lacking much extra oomph when necessary).

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Trevski@reddit

Good points, especially the 50%/70% power-efficiency tradeoff. I wonder if that might be why the "Bohai Sea Monster" has quad engines, can WIG with 2 at 70, fly with 4 at 70, or freakin SCOOT with 4 at 100. I don't think the extra weight problem is as drastic as you think it is simply because the payload module could be a stressed member and without it the structural loads would be a lot smaller. I think the bigger problem is how to incorporate a deployable fairing so that the plane is still aerodynamic without the payload.

Practical considerations aside, now I'm thinking of a WIG craft that deploys RIB drones like the tank-dropping gunship in the clone wars. WIG is so cool.

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GrafZeppelin127@reddit

I don't think the extra weight problem is as drastic as you think it is simply because the payload module could be a stressed member and without it the structural loads would be a lot smaller.

Ah, but don’t forget that we’re not just talking about payload weight, but also aerodynamic loads, and the drag forces involved increase exponentially with linear increases in speed. Flying in the ground effect, something like the Pelican is only doing 240 knots, but flying outside of it, it’s going 400. That, paired with the inherent structural disadvantage of a much thinner fuselage segment, would require considerable reinforcement to withstand, even accounting for the lost weight of the payload and payload module.

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404-skill_not_found@reddit

I think you have a point there

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Huskarlar@reddit

It's wing to engine ratio is also odd. It has a lot of engine for a pretty small wing.

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Hellothere_1@reddit

Isn't that kind of a given for any kind of flying boat? I'd imagine launching out of the water takes a lot of power.

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thrashmetaloctopus@reddit

Not just the oversized tail but the engine placement as well, neither make sense separately or togoether otherwise

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ts737@reddit

Probably because the engines are on top and they generate a noticeable pitch down momet

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Yari_Samurai@reddit

Look, I am no expert, but from my understanding erkanoplans have wings as low as possibe to be as close as possible to the water to maximise ground effect. This aircraft has regular high-placed wings.

I have doubts this is conceptialized as an ekranoplan, or at least as "pure" ekranoplan meant to never leave the ground effect.

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GrafZeppelin127@reddit

Yes. The aspect ratio and wingspan of a pure ekranoplan’s wings are also both very, very low:

This aircraft has a high aspect ratio and a wingspan commensurate with planes of similar-sized fuselages. If it’s not capable of flying out of the ground effect, then I’ll eat my hat.

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Is that a GEV? Yes. Is it an ekranoplan? No, but only because it's not Russian. Similar to how you can go into space, but you won't be a cosmonaut.

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