Modified J-20 seen being prepared for maiden test flight
Richard D Fisher Jr, Washington, DC - IHS Jane's Defence Weekly
23 February 2014
A CAC J-20 undertaking high speed taxing trials. Source: via Chinese internet
Images emerged on 20 February of a modified prototype Chengdu Aircraft Corporation (CAC) J-20 fifth-generation fighter undertaking high-speed taxi runs.
These taxi runs are presumably prior to its maiden flight and suggest it may be a pre-production variant slated for formal testing by the People's Liberation Army Air Force (PLAAF).
Photographs of the prototype first appeared on Chinese military web sites in December 2013 and January, although some of these images appeared to have been digitally altered. The prototype carries the bort number '2011' and shows modifications intended to improve engine performance, combat capability and stealth.
Most noticeable are redesigned engine intakes featuring more of a sloped 'caret' design said to improve pressure distributions for the engine. The vertical stabilizers have been clipped in their outer aft corners and the main wheel doors and the internal weapons bay cover feature larger scalloping to aid low observability. The canopy also features a new brace.
A new electronic targeting system is located below the nose and just aft the radar. This and the J-20's distributed infrared sensor system points indicate Chengdu's ambitions to give the J-20 an optical and infrared targeting and warning system similar to that of the Lockheed Martin F-35 Joint Strike Fighter.
The new intake shape and electronic targeting system may also suggest multirole ambitions for the J-20, which has a larger internal weapons bay than the F-35.
On 16 February China's Securities Times Online reported that a demonstrator version of the 15-ton thrust WS-15 turbofan, the J-20's expected engine, may be completed in 2014. Other sources note the WS-15 may not be ready for service entry until 2020 and indicate that continued difficulties in its development will lead to the adoption of Russian engines for initial J-20 production.
If this is the case then the J-20 may be first powered by a version of the 13.5-ton thrust Saturn AL-31F-M1, with the 14.3-ton thrust AL-31-M2 or the 14.5-ton thrust Saturn 117S possible later options. In 2010 reports suggested that China was seeking the 117S turbofan for the J-20 but so far Russia has been reluctant to sell China this engine separately from the Sukhoi Su-35 fighter.
Fitted with Russian engines initial production aircraft could emerge as early as 2015 for testing by the PLAAF, with service entry following in 2017 and initial operating capability (IOC) by 2019.
Other sources have suggested that a tandem twin-seat 'J-20S' may also emerge in 2014, raising the possibility of an eventual dedicated fifth-generation strike fighter that could rival the Shenyang Aircraft Corporation's twin-seat fourth-generation J-16 attacker, now in testing.
COMMENT
Design refinements are an expected result of early aircraft prototype development although it is unclear whether these modifications represent the definitive pre-production standard for the J-20.
If the reported production time-line holds, then CAC is on schedule to fulfill PLAAF General He Weirong's 9 November 2009 prediction that China's fourth-generation (fifth-generation in Western terminlogy) fighter could enter service in "8 to 10 years."
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