The maiden test flight of the J-31 was made over the Shenyang Aircraft Company airfield on Oct 31. The first Chinese stealth fighter, the J-20, was test flown in 2011. The two prototypes use Russian motors.
"The big Achilles heel for Chinese aerospace generally and particularly for both of these two programs is engines. They still rely very much on foreign technology and their progress on developing domestic high-performance engines for combat aircraft has been frustrating and slow," said Sam Roggeveen of the Lowy Institute in Sydney.
According to Greg Waldron of Flightglobal magazine in Singapore, the J-31 seems to be a smaller version of the J-20. The former could be assigned a fighter-interceptor role and the latter could be a more attacking option, he told The Associated Press.
"I think it is a fairly straight forward evolution to develop advanced fighters at this time, but you can't read too much into it in terms of capabilities," he said.
Telegraph.co.uk quoted Chang of the Kanwa Information Centre as saying that "In terms of design, it appears the J-31 is inferior to the latest US planes. The layout is similar but the material and quality are inferior. It will take at least seven or eight years before it can be commercially sold."
In a report on the test flight, the Washington Post noted: "The technical barriers and development costs for such aircraft are enormous and the US has struggled for years to deliver on their potential."