
So at this point flat nozzles can pretty much be confirmed (whether or not it has tvc). This new image isn't clear enough to confirm the nonexistence of the groove, however I think it's safe to say that it looks fairly different than the grey airframe. My personal theory is that if a groove or something similar exists at all, it may be the case that the center of the IWB is deeper than the sides, but there are no defined edges leading to a groove. It could just be a smooth slope. I think this makes more sense as a smooth edgeless surface will not impact stealth as much.