YJ-6 is China's first air-launched anti-ship missile in large-scale service. It was developed from the land-based
HY-2 missile with a more compact airframe for aircraft carriage and a newer active-radar seeker. The missile used liquid fuel and a large warhead inherited from HY-2. It entered service in 1986. YJ-63, also known as KD-63 or K/AKD-63, was an air-to-surface missile developed based on the YJ-6. YJ-63 (KD-63) is an air-launched cruise missile with an electro-optical (EO) seeker, allowing man-in-the-loop terminal steering via a data link. ==Variants==