Xian H-8

The Xian H-8 bomber was a Chinese military aircraft and a possible successor to the aging twin-engined H-6 jet bomber. The prototype was reported to be an enlarged H-6 with underwing engines, but the project was canceled in the early 1970s before the bomber went into production.

Development
Originally proposed by Xi'an Aircraft Factory in June 1970 as a 4-engined version of Xian H-6, design begun in February 1971 after the proposal was granted by the state. In 1973, People's Liberation Army Air Force (PLAAF) issued additional requirement of incorporating capability against sea targets, and formally joint the project. By the end of 1977, the first sample was completed and the maiden flight was followed in January 1978.

The aircraft was able to climb 40% faster than H-6, and the range is also increased by a third to 8,000 km. More weapons could be carried, including bombs of various sizes, sizing from 100 kg to the massive 9-ton ones. The bomb bay was sized at 8.6 meter x 1.8 meter x 2.72 meter, capable of holding a maximum of 18 tons of ordnance, i.e. 2 of the 9-ton bombs, though to achieve maximum range, the payload had to be greatly reduced to 7 tons. Nuclear bombs could also be carried, as well as anti-ship and land attack missiles, and in the latter configuration, a total 3 missiles are carried, one under each wing, and a third semi-buried in the bomb bay. The permanent weapon of the aircraft is a tail gun mount incorporating a twin 23 mm gun.

The crew totaled 6, seated in two separate pressurized compartments. Pilot/mission commander, co-pilot/flight engineer, navigator/observer, and bombardier/flight mechanic were seated in the forward pressurized compartment, while the electronics warfare/communication officer and tail gunner/assistant communication officer seated in the pressurized compartment in the rear. The avionics of the aircraft borrowed heavily from the reverse engineering similar American systems obtained from the downed Boeing B-52 and other American aircraft provided by North Vietnam during the Vietnam War.

Variants

 * Xian H-6I - Prototype of Xian H-8. Powered by 4 Rolls-Royce Spey Mk 512 engines, originally purchased as spare engines for Hawker Siddeley Trident China had bought. Program first begun in 1970 and maiden flight was made in 1978, with state certification received in the following year, and the designation subsequently changed to Xian H-8 somewhere between 1978 and 1979, as it was prepared to entered series production. In comparison to the original H-6, the fuselage is lengthened and the engines are rearranged to be carried in individual pods under the wings. Ferry range is increased to 8,100 km (with standard payload), and combat radius is increased to over 5,000 km (with nuclear payload).
 * Xian H-8 - Follow-on of Xian H-6I, which replaces the Rolls-Royce Spey Mk 512 engines with Rolls-Royce Spey Mk 202 engines to reduce operational cost and to simply logistics. However, this was not enough to save the program and during the massive military downsizing in the 1980s, China canceled the program in 1980 before the start of the scheduled production.
 * Internet speculation has described the H-8 bomber as a new advanced Chinese stealth aircraft, but it is unlikely that China has such an aircraft in service.