(H-6U image). China began developing air tankers in the late 1980s, during a period of modernization of its Air Force and also due to an incident with Vietnamese forces known as the “Johnson South Reef skirmish.” This armed incident took place on March 14, 1988, and was the culmination of a long territorial dispute between Brunei, China, Malaysia, the Philippines, Taiwan, and Vietnam. In this confrontation, China was aware of the need to be able to deploy its combat aircraft beyond its continental territory, something that PLAAF could not achive adequately.(RDC-1 pod image). Initially, the PLAAF contacted different foreign manufacturers with the idea of reaching an agreement for the licensed manufacturing of aerial refueling systems. However, after the harsh repression of the 1989 Tiananmen Square protests, the West imposed an arms ban that forced the cancellation of all contacts, so the only alternative left was to develop completely indigenous system. In 1986, the Chinese authorities had signed an agreement with Flight Refuelling Limited (FRL Ltd) in the UK to convert an H-6 bomber into a tanker aircraft by installing an indigenous pylon mounted RDC-1 hose/drogue pod under each wing. The RDC-1 pods were to be designed by the China Research Institute of Aero Accessories and can be said to be a copy of the old “Mk.32B” pods manufactured by the British firm FRL Ltd.(FRL Mk.32B pod image). According to other sources, in the early 1990s, China obtained some Western air refueling equipment from the 1960s and 1970s, through third countries, which it intended to use as a basis for its own design, but certainly, the RDC-1 pod is practically a copy of the British model, so the information referred to above seems more plausible. Once the fuel transfer system was achieved, all that remained was to install it on the chosen aircraft and start the test program.(H-6U image). Development progressed at a good pace and during 1988, an aerial tanker based on the H-6 bomber was exhibited at a technology fair held in Beijing. According to some sources, this first tanker aircraft was designated “HY-6” and maintained the PV-23 fire control system and could perform bombing missions if necessary. Probably this aircraft was more an experimental prototype than an operational aircraft. Later, in 1990, an aircraft called Xian HY-6U or H-6U performed its maiden flight, this being considered the first operational variant, since the PV-23 fire control system and Type 244 radar were removed, in such a way which became a dedicated refueling aircraft.(H-6U image). The new HY-6U/H-6U tanker aircraft was almost identical externally to the H-6 bombers, although its airframe was of new construction. The nose of the H-6U was different, lacking glass and being completely solid, with weather radar inside. New flight control and navigation systems were also installed, including an inertial navigation system (INS), a GPS and a tactical air navigation system (TACAN). An electronic warfare suite was included with a radar warning receiver (RWR) and a chaff/flare dispenser. Additional lights were installed under the pods and in the fuselage to allow night refueling, although this was not considered common practice as the refueling system was not compatible with night-vision goggle (NVG).(H-6U image). The refueling equipment consisted of two RDC-1 hose/drogue pods installed in the wings, two large fuel tanks installed in the bomb bay and the refueling operator station located in the tail gunner compartment. The fuel capacity for refueling is 18,500 kg, but for refueling at a maximum radius of 2,200 km the amount is reduced to 10,000 kg. The H-6U can refuel two aircraft at the same time and in one sortie it can refuel a maximum of 6 fighters, extending its combat radius by around 50%.(H-6U image). The Xian HY-6U/H-6U performed the first successful aerial refueling operation in 1992, when it supplied fuel in flight to a pair of J-8D Finback fighters. In 1999, two H-6U tankers could be seen along with several J-8 fighters during the National Day military parade, so it was assumed that these tankers were already fully operational at that date. The H-6U tankers began refueling J-8 Finback fighter aircraft and currently can support the J-10 fighter and perhaps the JH-7 fighter-bomber but not the Russian Su-27SK and Su-30MKK fighters so the PLAAF has other tanker aircraft such as the Ilyushin Il-78 MP or the new Xian YY-20A. Currently (2024) the PLAAF has 10 HY-6U/H-6U in service with the 8th Bomber Division stationed in Southeast China, with a view to possible operations in Taiwan and the South China Sea.(H-6DU image). Once the PLAAF HY-6U/H-6U were in service, work began to provide the PLA Naval Air Force (PLANAF) with an aircraft to support its combat aircraft. On this occasion it was decided to convert someH-6D maritime bombers by installing the same electronics, ECMs and refueling equipment as in the Air Force tankers. The new naval tanker received the designation “H-6DU” and kept the glass-in nose and the Type 245 search radar radome under the nose, although the remote control gun barbettes, tail turret and mid-wing harpoints were removed. Currently (2024) there are 7 H-6DUs in service distributed in the 6th and 8th Divisions within the PLANAF, based in Changzhou and Guiping respectively.
