Fourth known J-20 prototype makes first flight

The fourth known prototype of the Chengdu J-20 fifth-generation fighter made its first flight on the morning of 26 July, according to Chinese aviation websites.
The prototype flew for nearly two hours after having undertaken taxi tests since early July. The first hints on military web forums of a fourth J-20 prototype with the tail number '2012' emerged in late June, with clear photos emerging by mid-July.
Images show that '2012' features the refinements first seen in the third prototype, '2011'. These include an undernose faceted shape to hold a future electro-optical targeting system, adjusted air intakes to aid engine air flow and clipped tips on the vertical stabilizers.
The new J-20 prototype does not give any outward indication that CAC has installed an indigenous turbofan engine, despite much online speculation. The status of the J-20's intended WS-15 turbofan is not clear, and it is possible that initially deployed J-20s may use a Russian-made turbofan, perhaps an upgraded version of the Saturn AL-31 or the newer AL-117S.
In mid-June prototype 2011 reportedly left the CAC airfield to join its two other stablemates at the China Flight Test Establishment (CFTE) at Yanliang Airbase in Xian Province.
In late April an Asian government source told that 20 J-20s, or about one regiment, could be deployed by 2020.
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