The second aircraft is conducting a flight test programme at SAC's Shenyang-Beiling airfield, still unpainted. Even after two years of flight testing, only a few clear images have been released.
The first FC-31 demonstrator was unveiled during the Zhuhai air show 2014 proving China had become the second nation after the United States to have two stealth fighter designs in flight testing at the same time.
The FC-31V2 aircraft undergoing pre-flight checks on December 23, 2016, the date of its maiden flight.
Only a few images of the FC-31V1 under construction have been released.
A rare glimpse to the FC-31V1's cockpit showing a modern layout with large multifunction displays and a wide-angle head-up display.
The future variant's form is unknown though several artist impressions have been posted on Chinese forums. The most credible source is a black coloured model of the naval variant featuring folding wings and an arrestor hook exhibited in SAC's showroom.
An artist's impression of the revised second aircraft was first presented at the Zhuhai air show 2014.
An artist's impression of a People's Liberation Army Naval Aviation J-35.