Brumby
Major
I am curious. How can you tell from a photograph that the EOTS is functional as opposed to functioning?
J-20 5th Gen Fighter Thread V
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I don't understand your question -- what is the difference between "functional" vs "functioning"?
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If you mean how can we tell if the EO IRST (I prefer to avoid the word EOTS for J-20) is not a mock up and is a functional sensor, well that is by looking at the sensor itself. The mock up is an opaque, grey/black faceted stand-in, whereas the functional sensor (or suspected functional sensor) is a semi transparent glass housing with a gold tinge in the glass. It is easy to identify a functional sensor, when we have pictures showing the EO IRST sensor housing with the sky in the background, allowing us to ID the glass housing of the sensor as semi transparent, as well as partially ID the actual sensor itself within the housing via its dark shadow. The glass housing is also semi reflective.
Therefore the semi transparency of the housing, the semi reflective nature of the housing, and the partially identifiable dark shadow of the sensor itself within the housing are the key indicators to look for,
If you mean how do we know if the EO IRST is actually functional versus merely looking like it is functional, well that is something we obviously cannot prove, however it is also a very reasonable assumption to expect the aircraft to be equipped with representative hardware of its various sensors at the stage of prototyping it was at (i.e.: early 201X serials) when the first suspected functional EO IRST sensors were fitted.
Additionally, the fact that they go to the effort of replacing the grey/black mock up with the gold tinted glass housing suggests there is a significant difference between the two.
If we want to be really pedantic, we could say that during the prototyping and development stage each sensor would obviously gain additional capabilities and functions as the project progresses, in which case the word "functional" becomes a continuous rather than categorical characteristic.
Therefore, when I use the word "functional" to describe the EO IRST it is making the assumption that the hardware of the EO IRST is mostly or fully present (with whatever software that they had developed at the stage), compared to the "mock up" which is merely a piece of metal with the same shape as the EO IRST housing but without any of the representative hardware.
Over the last couple of years when the EO IRST has been described as "mock up" vs "functional" by various users I think that is the general thought process and understanding that people are using.
Brumby
Major
In my mind there potentially could be different representative state of existence such as mock up, non functioning, functioning, functional and fully functional. Functional to me imply meeting some basic capability mode as a qualifier whereas functioning does not need to. EOTS to my basic understanding is an optical tool that is able to provide image resolution with a quality track sufficient to provide a firing solution. Whether this information is fused with the other sensors or that it is integrated to its weapons system is still another matter. When you described it as functional, it imply that some basic capability is present which I was wondering how such a determination can be made from a photograph.
Right, well in that case it seems like you're thinking about the word more in terms of capability while I'm using it in terms of hardware.
Personally I think the word "functional" doesn't necessarily have any implications regarding the degree of function or capability, especially in terms of aircraft or an aircraft's subsystems. For instance, one could describe the first flying prototype of a new type of aircraft as a "functional aircraft" in the sense that it can fly and features certain basic hardware and that it is not a mock up, even though the first flying prototype would obviously lack certain sensors, subsystems and other capabilities necessary for "full functionality".
In the same sense, I use the word "functional" to describe the EO IRST system on J-20 in the sense that the hardware is assumed to be mostly present even if it may not be fully integrated into the aircraft's overall mission avionics architecture, but that it is not a slab of metal acting as a mock up.
That said, I can appreciate the potential for misunderstanding which is why I added the phrase "non-mock up" as an additional phrase in describing the sensor mount in my original post on the last page.
Brumby
Major
Thanks. I just wanted to understand the context of the word "functional" which you have adequately explained.
AssassinsMace
Lieutenant General
J-20 really does look quite unique from differing angles.
That last picture from the aft aspect makes it look like a star destroyer.
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Quickie
Colonel
Unless someone comes out with the proof to the contrary, those cars were likely from the same entourage that came for the production J-20 ceremonial sending off. The wall climbers are usually individuals and as far as I know do not have contact with one another and wouldn't have come in such a large group with their cars.
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