Why J-10 has a metal bar fixed above its air intake?

The J-10 (歼十, Jian-10) is a multi-role fighter aircraft was designed and produced by the People's Republic of China's Chengdu Aircraft Industry Corporation (CAC) for the People's Liberation Army Air Force (PLAAF). It is designed to be equally useful in both the fighter and light bomber roles, and is optimized for all-weather day/night missions.

The delta-wing, a triangular wing platform, offers two important aerodynamic qualities. First, the swept leading edge of a delta-wing stays ahead of the shock wave generated by the nose of the aircraft during supersonic flight, making the delta-wing a very efficient aerodynamic wing shape for supersonic flight. And secondly, the leading edge of delta-wing also generates a massive vortex that attaches itself to the upper surface of the wing during high angle-of-attack (AOA) maneuvers resulting in very high stall points. Additionally, the delta-wing offers increased survivability by having increased structural and airflow stability.

 

The airframe possesses a large vertical tail, as well as canards placed near the cockpit. The air intake is rectangular in shape, and is located beneath the fuselage. Construction likely incorporates much use of composite materials, as well as more conventional metals. Performance is generally speculated to be within the class of a late-model F-16, although maneuverability is thought to be superior (possibly within the range of some early fifth-generation Western fighters). A bubble canopy provides 360 degrees of visual coverage for the pilot.

 

The fighter aircraft J-10 impresses people most because of its aerodynamic look, though the metal bar located above air intake slightly disfigures its sleek shape.

The bar caused much speculation among people, some of whom believed the bar was actually a telescopic device, while some others thought it was for airframe reinforcement, and other thought it was simply a radar antenna.

Apparently, the bar couldn’t possibly be radar antenna since electronic signals would be seriously be obstructed by severe turbulence if electronic equipment were installed in the joint of air intake and airframe. Meanwhile the bar cannot be a telescopic device as there is no sign of sliding or overlapping sections. In all, as agreed by many international weaponry experts, this metal bar is most likely for structure reinforcement purposes.