The recently revealed KD-63 is a derivative of the air-breathing HY-4 Sadsack. While it retains the delta wing and fuselage shape of the HY-4, it uses a new cruciform tail design, and includes a television / datalink terminal guidance package. It is thus a dual role weapon, capable of precision strikes against land and maritime targets. It is carried by the newly designed H-6H Badger variant, replacing the pair of Krakens carried by earlier variants. Range is cited at around 100 nautical miles.
http://www.ausairpower.net/APA-PLA-Cruise-Missiles.html
China is known to have illegally acquired, in a joint operation with Iran, several examples of the Kh-55SM Kent cruise missile from storage in the Ukraine, including some ground equipment. The cost of the investment suggests an interest in partial or complete reverse engineering of this missile.
The Kh-55 family of cruise missiles owes its origins to a series of internal studies at the Raduga OKB during the early 1970s. Raduga were unsuccessful initially in convincing the Soviet leadership of the value of their concept, but this changed as public knowledge of the US AGM-86 Air Launched Cruise Missile program became better known in the Soviet Union.
Russian sources claim that Raduga's early work on these weapons was opposed by many Russian experts who were deeply sceptical of the viability of such a complex new weapon.
The Kh-55 family of weapons most closely resemble the early US BGM-109 Tomahawk in concept, using a cylindrical fuselage with pop out planar wings, unfolding tail control surfaces, and a ventral turbofan engine, with guidance provided by a TERrain COntour Matching (TERCOM) aided inertial navigation system.
The most visible difference between the Tomahawk and Kh-55 families of missiles is the engine installation. The Tomahawk's Williams F107-WR100 engine is embedded in the tail and uses a ventral inlet duct and tailcone exhaust. The Kh-55's Omsk AMKB TVD-50 two spool turbofan is mounted in a nacelle which is stowed in the aft fuselage and deploys via a ventral door on a pylon after launch.
The TVD-50 is a critical piece of technology in the Kh-55 as it is a compact and fuel efficient turbofan in the thrust and size class required to power cruise missiles, standoff missiles and UAVs. The cited thrust rating is 400 to 500 kp (880 to 1,000 lbf), with a dry mass of 95 kg (210 lb), a Specific Fuel Consumption of 0.65, a length of 0.85 m (33.5 in) and diameter of 0.33 m (13 in).
The Tomahawk uses a four surface tail control assembly with anhedral on the stabilators, whereas the Kh-55 uses only three larger surfaces, with more pronounced anhedral, a configuration since adopted in the new Block IV RGM/UGM-109E Tomahawk Land Attack Missile. The largely symmetrical aft fuselage of the Tomahawk differs from the more pronounced sculpting of the Kh-55 aft fuselage.
The cylindrical fuselage configuration is essentially the same for both designs. The Tomahawk has a 21 in diameter, the Kh-55 a 20.5 in diameter, the Tomahawk weighed 2,700 lb at launch, the Kh-55 2,870 lb. The later blocks of the Tomahawk have a chinned 'Beluga' nose to reduce radar signature, the Kh-55 retains an ogival/spherical nose.
The baseline guidance package on both missiles is designed around a digital computer running Kalman filter and TERCOM software, with an onboard memory storing a digital map, coupled to a radar altimeter for terrain profiling and a low drift inertial unit. Tomahawks later acquired an optical Digital Scene Matching Area Correlator and GPS - the Soviet had DSMAC technology but it has never been disclosed whether this was added to the Kh-55 series. The cited designation for the Kh-55 guidance package is the Sprut and BSU-55.
Like the Tomahawk, the Kh-55 spawned a range of derivatives, unlike the Tomahawk the Kh-55 became the dominant air launched weapon. The first generation of Kh-55s appeared in three configurations, entering service in 1984. The 'Izdeliye 120' Kh-55 / AS-15A was air launched from the Tu-95MS using a MKU-6-5 rotary launcher and external pylons, the RKV-500A / SS-N-21 Sampson was tube launched from the Type 671 Victor, Type 945 Sierra and Type 971 Akula submarines, and the RK-55 / SSC-X-4 Slingshot tube launched from a MAZ-543M (MAZ-7910) 8x8 TEL, carrying six rounds.
The air launched Kh-55 was followed by the improved 'Izdeliye 124' Kh-55OK, which was supplanted in production by the most capable 'Izdeliye 125' Kh-55SM / AS-15B subtype in 1987.
The aim of the Kh-55SM design was to further extend the striking range of the basic missile, cited at 1,350 NMI (2,500 km). This was achieved by adding a pair of conformal fuselage fuel tanks, which increased launch weight to 3,750 lb (1,700 kg), but increased cruise range to 1,620 NMI (3,000 km) with a 200 kT warhead fitted. The naval variant of the Kh-55SM was designated the RKV-500B.
A conventional derivative of the Kh-55, designated the Kh-555, was recently announced. A lightweight shorter ranging derivative weapon, the Kh-65, has been actively marketed since the 1990s.
For all intents and purposes, the late model Kh-55SM is a heavier and longer ranging equivalent to the BGM-109B Tomahawk, with performance closest to the AGM-86B ALCM.