weight wise yj83 should fit, i don't think the air launched variant without the booster is significantly heavier than kh31.
wingspan wise - it's a very, very tight fit. bltizo, it's easier to just use total wingspan and apply 45 degree turn to it. one gets 865 mm. that's more than your calculation because you ommited the other wing and the distance between wingroots on a 45 degree rotated body isn't total body diameter but 230mm instead of 360 mm.
I omitted the other wing, because I was under the assumption that the other wings/top wings wouldn't need to be considered, because after all, the pylon attaches to the missile fuselage rather than the missiles wings. I also made an assumption that any pylon on the aircraft designed for YJ-83K would have sufficient clearance space for the top side missile wings to not touch the aircraft's wing or air intake or wherever the pylon is located.
But I did overlook the additional distance of the diameter of a circular body on the overall missile to ground distance.
That should be half of missile wingspan*sin45 - half of missile diameter
So 610mm*sin45 - 180mm = 251mm, so not 304mm
Btw I get 862.7mm instead of 865mm
I'll do a quick Microsoft paint sketch later to visualize it. Describing this is quite difficult. I think I'm complicating matters by pointing out all the individual smaller dimensions and then adding them together, but I think it's easier to divide it out and add them back together so everyone can agree on the final thing.
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Here we go:
In my mind, the
minimum height that the J-15's (or any other aircraft's) pylon will need to allow the missile to sit, is 360mm + 251mm + wingtip/ground clearance. This is already assuming that the pylon in question is attached to the aircraft in such a way where there is both sufficient missile wing tip/aircraft clearance distance, but also so that it is minimal at the same time.
Because we can't know what the wingtip/aircraft clearance is, we have no real way to really eyeball the pictures of J-15's under intake pylons and judge if there is sufficient distance for the overall vertical distance of the missile (2H + diameter). That's the reason I didn't use total wingspan. However, we can try to judge whether the distance between the under intake pylon and the ground is equal to a diameter + height + wingtip/ground clearance, assuming that the pylon is deep/high enough to allow for the missile to be carried with minimal sufficient wingtip/aircraft clearance.
(I should note that I was trying to judge whether the missile could sit on the under intake pylon on Deino's picture rather with sufficient clearance rather than trying to estimate whether there was enough space under the J-15's air intake for a YJ-83K to sit at all, because I think there clearly is enough volume for that).
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One way of reducing the wingtip/aircraft clearance is by "recessing" the missile and allowing the wingtips to protrude outside of their space under the nacelles. Of course, this will reduce the space between the nacelles, potentially reducing the horizontal clearance of any missiles under there, and may also impact the rear landing gear, but the horizontal distance that will protrude out doesn't have to be very much, only enough so that the missile can have a few more centimeters of clearance. Chump change.
Looking at the relatively small height of the under intake pylon in Deino's picture, I presume that is how YJ-83K is meant to sit -- with wingtips protruding slightly out.
Overall, I think the prospect of hanging YJ-83Ks under J-15's air intake/nacelles has a lot going for it.