The naval variant of the problem-plagued Shenyang J-31 "stealth" fighter will likely become the main air superiority fighter aboard China's aircraft carriers.

Privately funded by Shenyang Aircraft Corporation (SAC), the J-31 or FC-31 was first unveiled on Nov. 12, 2014 at the Zhuhai Air Show. Two prototypes have been built since then, and the fighter is expected to join the People's Liberation Army Air Force (PLAAF) in 2019, but only after Beijing approves funding for its serial production.

The version that will fly from the two aircraft carriers of the People's Liberation Army Navy (PLAN) is expected to begin development after SAC receives government funds. Chinese state-controlled media reports an accelerated pace of test flights for the J-31, which looks remarkably like the Lockheed Martin F-35 Lightning II stealth fighter.

Chinese military pundits say this stepped-up pace of flight tests indicates SAC will develop a carrier variant of the J-31. SAC is known to have developed a third J-31 prototype and this one might be the naval variant.

There is strong speculation among military pundits, however, that SAC has already received funding for the carrier version of the J-31. Rumors are the naval J-31 will be much larger than the PLAAF variant in order to increase range, payload and structural strength to meet the intense demands of carrier flight operations.

The J-31 looks like a clone of the F-35 and it's long been widely held in the West the reason for this is the theft by Chinese spies of top secret F-35 plans in covert operations spanning over a decade.

The J-31 is powered by two Russian-made Klimov RD-93 turbofan jet engines. During its first test flight in 2012, the first J-31 managed to stay airborne for only 11 minutes.

The second J-31, a new aircraft, has a number of improvements over the first one. Chinese aerospace experts said the second J-31 saw changes to the airframe, wings and vertical rudders.