The J-31 is a mid-weight, twin rudder and twin-engine jet with the typical configuration that is commonly shared by other 5th generation fighters such as Sukhoi T-50. J-31 incorporates certain stealth characters such as forward swept intake ramps with diverterless supersonic inlet (DSI) bumps, trapezoidal wings and a two-piece canopy.
The J-31 appears to be a smaller and more agile aircraft than the Chengdu J-20 that resembles a twin engine F-35C.
The reported maximum engine thrust figure of "88.29 kn" or 9 tons, does conform with statements made by Chinese officials to IHS Jane's at the 2015 Paris Air Show that China was testing a new 9-ton medium thrust turbofan on the Chengdu Aircraft Corporation FC-1/JF-17 fighter. Thought to be an improved version of the WS-13 Taishan turbofan reportedly developed from the Russian Klimov 8.29-ton thrust RD-33 turbofan, it will power versions of the single-engine FC-1 and the twin-engine FC-31. China is working on an improved variant named WS-13A with 100KN of thrust for use on the J-31.
The data posted online describes the FC-31 as "designed for high survivability, low radar detectability, low IR (infrared) signature, and excellent capabilities for electronic counter measures".
Avic said the fifth-generation fighter jet, which has a 1,200 km (750-mile) combat range and a top speed of 2,205 kph (1,370 mph).
The J31 has a maximum payload capacity of 8 metric tons.
Pakistan Air Force is looking to buy 30 to 40 J-31 aircraft.
Crew: one (pilot)
Length: 16.9 m (55 ft 5 in)
Wingspan: 11.5 m (37 ft 9 in)
Height: 4.8 m (15 ft 9 in)
Wing area: 40 m2 (430 sq ft)
Gross weight: 17,600 kg (38,801 lb)
Powerplant: 2 × RD-93 afterburning Turbofans, 84 kN (19,000 lbf) thrust each
Current domestic powerplant - 88.3 kN thrust each
Powerplant: 2 × WS-13A afterburning Turbofans, 100 kN (22,000 lbf) thrust each
Maximum speed: 2,205 km/h (1,369 mph; 1,190 kn)
Maximum speed: Mach 1.8
Combat range: 1,200 km (777 mi; 675 nmi)
Ferry range: 4,000 km (2,485 mi; 2,160 nmi)
4x PL-12 internally in stealth configuration.
SOURCES - wikipedia, ifeng.com, Janes.com, reuters