My colleague Greg Waldron from our office in Singapore is reporting that China's "new" carrier--the former Soviet vessel Varyag--has been spotted with a number of aircraft embarked. Among these are a Z-8 airborne early warning helicopter and a Shenyang J-15 copy of the Russian Su-33 carrier-variant of the Flanker.
The version of the J-15 spotted on the former Varyag is significantly different than the original Su-33 or even previous versions of the J-15 that have been photographed. The cockpit canopy is shortened/cut-off, and--at least to me--the forward fuselage and radome looks shorter and fatter.
Why the Chinese would alter the design in such a manner is anyone's guess--it's not like they're going to tell us. But it's standard practice to build flight sciences aircraft to evaluate flying characteristics and separate jets to test the avionics. We do it; the Russians do it; and the Chinese mostly likely do so also. It might be a new radar in there. But designs also evolve as flight testing progresses and problems are found...
The original Sukhoi T-10, which was the prototype for the Su-27, changed considerably after problems were discovered in test. There were also revisions to the Boeing (McDonnell Douglas at the time) F-15A Eagle--the developmental aircraft lacked the notched stabilator and raked wingtips of the production aircraft. More recently, the Lockheed Martin F-22 Raptor had all sorts of developmental problems which had to be corrected... The same process is happening today with the F-35--which has also had all manner of discoveries in flight testing. No doubt, there will be many more discoveries before it finishes its flight and operational testing. Bottom line, problems are found and an engineering fix is designed and implemented.
But, for the J-15, it is also possible that this could just be some sort of deck handling mockup which the PLAN is using to gain experience. The reason I say that is because the nose landing-gear door appears to be missing. If I were to place a bet, it would be on a mockup.
So here is picture that Greg found...
Whatever the case, the Chinese are clearly making progress with developing their naval aviation capabilities. It's also a safe bet that the J-15, having been reverse-engineered decades after its progenitor, is probably fitted with better avionics than the Su-33s that are in service with the Russian fleet.
The J-15 seems to have an infrared search and track sensor mounted, but there is no way to tell what kind of radar it has. It could have a passive electronically-scanned array (PESA) radar--which has a single large transmitter and receiver coupled with a single large fixed electronically-scanned antenna. Or it could be a more advanced design, an active electronically-scanned array (AESA) radar--which consists of hundreds or sometimes thousands of smaller transmit/receive modules making up the aperture.
We just don't know.
Here is a white paper compiled by EMS Technologies in Atlanta, Georgia, that explains the differences in the two different approaches to building a phased-array radar-AESA vs. PESA. EMS does come down on the side of passive phased arrays due to cost reasons though.