Chinese engineers initially proposed to use an air-drop bomb for China’s first nuclear test, but this was regarded as too ambitious and the first nuclear device adopted a less radical tower-mounted arrangement. However, the design of the first air-droppable nuclear bomb continued at Beijing Nuclear Weapon Research Institute (9th Bureau). The ignition system for the air-drop nuclear bomb was tested on a Soviet-made Tu-4 Bull bomber flown by the PLA Air Force (PLAAF) 4th Independent Regiment. In Spring 1965 a dummy nuclear bomb and a real nuclear bomb were delivered to the Lop Nor nuclear test site for China’s second nuclear test scheduled in 1965.
On 14 May 1965, a PLAAF 4th Independent Regiment Tu-4 bomber dropped a 35kt yield nuclear bomb at Lop Nor, indicating that China was ready to deploy an operational aircraft-delivered atomic bomb. China conducted five air-drop tests, four of which are thermonuclear, from PLAAF H-6 (Tu-16 Badger) bombers between June 1967 and October 1970. These tests provided the PLAAF with valuable experience in the use of aircraft-delivered nuclear weapons. On 7 January 1972, a PLAAF Q-5 attacker dropped a KuangBiao-1 (KB-1) hydrogen (thermonuclear) bomb at Lop Nor. The success of the test suggested that China had deployed an fully operational thermal nuclear weapon.
Following the introduction of China’s nuclear missile delivery systems in the late 1970s, China gradually phased out most of its air-dropped nuclear bombs from active service, with only a small number (100~200) retained in its inventory.
China's first air-dropped atomic bomb dropped by a Tu-4 bomber (Source: Chinese Internet)
Kuang Biao 1 air-dropped hydrogen bomb carried by the Q-5 attacker (Source: Chinese Internet)
The air-dropped hydrogen bomb carried by the H-6 bomber (Source: Chinese Internet)
