At least 30 J-8Bs have been converted by the PLA Navy to J-8D standard, with an aerial refuelling probe for use with Xian H-6DU tankers in addition to newly built J-8Ds. The most significant difference between the J-8B and J-8D is the use of the new Type-02 airframe that was heavier than the J-8B and featured uneven length wing fences. The heavier 'Type 02' airframe is able to carry a larger payload and can tolerate higher G-loadings. The new airframe also has a stiffer radome. A few minor differences between the later J-8B batches and the J-8D are the J-8Ds slightly improved avionics. The use of the KLJ-1 pulse-Doppler radar was used through the J-8Ds entire production run. The J-8B and J-8D both suffered from China's difficulty in developing a MRAAM. Although the Type 208A was theoretically capable of using semi-active radar homing missiles and the KLJ-1 was certainly capable; no such missile, semi-active or active, were available at the time. Both variants were only initially armed with SRAAMs such as the PL-2 and PL-5, and the more advanced infrared-homing PL-8 SRAAM.