Shenyang FC-31 / J-31 Fighter Demonstrator

gelgoog said:

The body is supposed to be manufactured as a single large piece. So I would not expect panel lines and fasteners anyway.

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Of 31001? Surely not. There were plenty of panels and fasteners/rivets.

This should be a mockup. The landing gears are mockup ones and the surface is way too smooth to be the 31001 prototype.

The landing gears are very much not the original ones on the 31001 and are clearly mockup model kits.

As for the body being manufactured as a single piece, that's not doable and not a good idea with how current aircraft manufacturing tech is at. Maybe one day in the distant future aircrafts would be designed and manufactured using very different principles than they are today. I think you mean some bulkheads of the 31001 was 3D printed in entire sections.

And of course the 31002's stabilisers with 31001's paint scheme. It's almost definitely a mockup and can't expect it to not be. The 31001 prototype isn't going to be displayed like that.

siegecrossbow said it was a static test prototype in the first place. It is not 31001 since the tail section looks different. It could never be 31001 anyway since that is a flying prototype not a static test prototype.

Sure they use more than one part to build the airframe. But just look at this quote on Wikipedia FC-31 page (I also remember reading this elsewhere but do not remember where).

"Officials from AVIC claimed that additive manufacturing was extensively used on the aircraft, resulting in 50% reduction in components compared to similar aircraft. However, the resulting airframe cannot be disassembled, and the static test frame had to be transported in whole as a consequence."

There are plenty of skin fasteners visible if you look closely, it's just the matte black paint effect striking again. Where the additive manufacturing may come into play is internal load bearing structure, such as integrated wing spar bulkheads. This would prevent the wings from being detached from the fuselage, as the spar and bulkhead would form a continuous structure essentially from wing tip to wing tip.

While clearly advantageous in terms of strength/weight, I'm not sure it's ultimately such a clever idea, even disregarding the logistical difficulty of transporting it (which, to be fair, will not happen very often). What do you do if for whatever reason one wing is damaged (battle damage, collision with ground vehicle on the ramp)? Bin the entire airframe? Integrated structures of this kind of size (and much larger) have been feasible as machined forgings for a long time, albeit at very high cost. There is a reason why wings and fuselage were still implemented as separate assemblies even on fighter aircraft, despite money being less of an object.

As an aside, do I spot the J-8ACT in the background in one photo?

gelgoog said:

siegecrossbow said it was a static test prototype in the first place. It is not 31001 since the tail section looks different. It could never be 31001 anyway since that is a flying prototype not a static test prototype.

Sure they use more than one part to build the airframe. But just look at this quote on Wikipedia FC-31 page (I also remember reading this elsewhere but do not remember where).

"Officials from AVIC claimed that additive manufacturing was extensively used on the aircraft, resulting in 50% reduction in components compared to similar aircraft. However, the resulting airframe cannot be disassembled, and the static test frame had to be transported in whole as a consequence."

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even if the entire fuselage, skin, frame, stringers, bulkheads, etc we’re all 3D printed as one piece, there still need to be many access panels on the outside so it be possible to service the equipment inside.

In any case, there is no way to 3D print anisotropic high strength fiber reinforced composite, and 3d print of metal is by default annealed, lacking purposely aligned microstructure, and weaker than forged or cold worked metal components. So I doubt the airframe of a competitive high performance aircraft like a fighter where both strength snd weight are critical can be printed in one piece even in principle.

Maybe a cheap private recreational aircraft can be printed largely in one piece, but probably not a fighter.

Richard Santos said:

even if the entire fuselage, skin, frame, stringers, bulkheads, etc we’re all 3D printed as one piece, there still need to be many access panels on the outside so it be possible to service the equipment inside.

In any case, there is no way to 3D print anisotropic high strength fiber reinforced composite, and 3d print of metal is by default annealed, lacking purposely aligned microstructure, and weaker than forged or cold worked metal components. So I doubt the most of the airframe of a competitive high performance aircraft like a fighter where both strength snd weight are critical can be printed in one piece even in principle.

Maybe a cheap private recreational aircraft can be printed largely in one piece, not a fighter.

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Just look at the engine nacelles and you can see the outline of access panels. They are there, it’s just the paint job makes it hard to see, especially without super high resolution close up imagines.

Unconfirmed report of J-31/FC-31 sighting in Jinan, Shandong.

siegecrossbow said:

Unconfirmed report of J-31/FC-31 sighting in Jinan, Shandong.

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Jinan? Any idea what could be the reason for Jinan?

Deino said:

Jinan? Any idea what could be the reason for Jinan?

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No clue. I judged that the original poster is probably genuine because his thread initially stated that he saw a F-35/F-22 style plane in Jinan, meaning that he is not a military fan and probably didn’t have anything to get from faking it.

More construction details on the technology demonstrator.