According to the PLAAF 60th Anniversary Warplane Show, the J-11B conducted its maiden flight on December 2003 and entered service with the 1st PLAAF Fighter Division on December 2007. The initial batch of the J-11B was powered by the imported Russian AL-31F turbofans engine instead of the delayed WS-10A.
In addition to the engine, the J-11B differs from the J-11A in other areas; it features a new quadruple-redundant digital fly-by-wire flight system with mechanical backup, a new multimode pulse Doppler radar for indigenous armaments against land/sea/air targets, and a new cost of composite material to reduce weight. It's redesigned cockpit is equipped with a new set of instruments ranging from a holographic HUD, four LCD MDFs, to a new missile warning system.
J-11B with PL-12 MRAAM and WS10A