The two 1998 prototypes had their onboard missile fire-control systems installed and tested in November 1999 and the initial flight testing was completed in April 2000. Two missile firing tests were carried out in November 2002, with both missiles hitting their targets.
The H-6H carries two KD-63 (KongDi-63) air-launched land-attack cruise missiles (LACM) under its wings. The missile appears to be developed from the YJ-6 air-launched anti-ship missile, but with an X-shape tail. Its turbojet may be based on that of the HY-4 land-based anti-ship cruise missile. The KD-63 reportedly uses inertial/GPS mid-course with a TV terminal guidance seeker, carrying a 500kg warhead to a 150~200km range at a speed of Mach 0.9.
The H-6H has all of the 23mm cannon turrets removed. The bomber features an enlarged under-chin radome similar to that of the H-6D to accommodate the fire-control radar. It also has a distinctive black-colour radome located under the rear fuselage, possibly for command link between the missile and the bomber.
