The testers at Chengdu are making some progress on their mammoth J-20 fighter. It looks like the concept has moved from a technology demonstration phase to a more missionized and refined prototype state. Here are the changes I can identify:
First off the canopy has gone form a single piece design, almost identical to the canopy found on the F-22, to a simpler two piece design with a bow separating the windscreen and the canopy. Reliably manufacturing a highly quality, optically uniform, single piece canopy with low observable properties, like the F-22’s, is not an easy or cheap task. With this in mind it looks like the Chengdu design team has opted for a simpler and less costly design, one that is also similar to the configuration found on the F-35.
The diverterless engine inlets hqve been tweaked to more closely resemble the F-35’s inlet design and shaping.
The control surface actuator “humps” below the wings have been streamlined.
Maybe most interesting of all of the J-20’s new design refinements is the inclusion of a gold-plated aperture for an electro-optical targeting system (EOTS) under the nose. This is a huge deal as clearly the Chinese are trying to build an analogue to the F-35’s cutting edge optical/IR targeting and visual situational awareness system and this window looks like an almost direct copy of the F-35’s. We know that a ton of the F-35’s design was stolen via cyber espionage by the Chinese and the J-20 is beginning to really illustrate the fruits of the China’s hacking adventures.
The vertical tail surfaces are also of a new design, with the corners “notched off” significantly.
Finally, the paint/surface application is a new design which appears to almost be a hybrid of the F-22’s and F-35’s schemes. Seen with this new paint job/radar absorbent material application, are differences in tone on the composite leading and trailing edges of the aircraft. As with fifth generation US aircraft, this usually means that antennas are contained inside these structures and/or they are high-priority radar defeating structures.