The Aviationist
This sense of the capabilities of the J-31 are largely based on the successes China has had in industrial espionage against US targets.
"I think they'll eventually be on par with our fifth-gen jets - as they should be, because industrial espionage is alive and well," an unnamed senior US fighter pilot familiar with the F-35, the US's fifth-generation stealth fighter, told USNI News.
Chinese hackers have been noted for their frequent success at obtaining sensitive information relating to US
In July, a Chinese entrepreneur was arrested in Canada at the request of the FBI after he allegedly stole information for 32 military projects, including the F-35.
The stolen information on the F-35 has likely made its way into the designs of China's J-31 stealth fighter. There are reports that China may be looking to make the J-31 capable of landing on aircraft carriers, giving them a role similar to the F-35C's, which will serve as a naval aircraft. This similarity between the planes has placed China and the US in a race to develop the first aircraft carrier-borne stealth jet.
If the J-31 actually does deliver on its promise of being able to match the F-35, China could counter some of the strategic effects of the US's pivot to the Pacific. Speaking to USNI News, one former pilot said that the K-31 would likely out-perform a handful of US fourth-generation fighters, such as the F-15 and the F/A-18E/F Super Hornet.
However, the technical proficiencies of an aircraft does not determine its overall capability. The skills and training of pilots play a significant role in determining the effectiveness of a fighter jet.
"[I]t is safe to say it's not always a matter of technology, armament or on-board equipment," David Cenciotti, a military aviation expert and founder of The Aviationist, told Business Insider via email. Early warning systems, intelligence, and training all are vitally important.
The J-31 is about the same size as the F-35. But the Chinese airframe has smaller engines and a flatter fuselage, implying a focus on air-to-air combat. The J-31's design necessitates a smaller weapons bay than the F-35, although this would increase the plane's overall fuel efficiency and speed as it would suffer from less drag.