AT-4 Spigot

9K111 Fagot
Polish anti-armor team with the 9K111 Fagot.
Type	Anti-tank weapon
Place of origin	Soviet Union
Service history
In service	1970–present
Used by	See Users
Wars	2008 South Ossetia war,War in Donbass, Syrian civil war, Iraq War (2014–present)
Production history
Designer	Tula Machinery Design Bureau (Tula KBP)
Designed	1962
Produced	1970
Variants	See Models
Specifications
Weight	12.5 kg (28 lb)
Length	1,100 mm (3 ft 7 in)
Diameter	120 mm (4.7 in)
Action	400 mm versus RHA or 200 mm towards armour inclined at 60°
Rate of fire	3 rds / min
Muzzle velocity	80 m/s (180 mph; 290 km/h) at launch 186 m/s (420 mph; 670 km/h) in flight speed
Effective firing range	70–2,500 m (230–8,200 ft)
Warhead	High Explosive Anti-Tank (HEAT) warhead
Warhead weight	1.7 kg (3.7 lb)
Guidance system	SACLOS wire-guided missile

The 9K111 Fagot (Russian: Фагот; "bassoon") is a second-generation tube-launched SACLOS wire-guided anti-tank missile system of the Soviet Union for use from ground or vehicle mounts. The 9K111 Fagot missile system was developed by the Tula KBP Design Bureau for Instrument Building. "9M111" is the GRAU designation of the missile. Its NATO reporting name is AT-4 Spigot.

The 9K111 Fagot was developed by the Tula Machinery Design Bureau (Tula KBP). Development began in 1962 with the aim of producing the next generation of SACLOS ATGMs for use in both the man portable role and the tank destroyer role. The 9K111 Fagot was developed alongside the 9M113 Konkurs; both missiles use similar technology, only differing in size, and can use the same launchers. The missile entered service in 1970.

The anti-tank platoon of a Soviet BTR equipped motor rifle battalion had two (sometimes three)ATGM squads, each with two 9K111 Fagot teams. The team consisted of three men; the gunner carries the 9P135 launcher and tripod as a back pack, and the other two men each carry two launch tubes. The men also carry assault rifles, but do not carry an RPG, because unlike the earlier missiles there is only a small deadzone within which the missile cannot engage the target. Besides the four missiles carried by each team, each squad would normally have an extra eight missiles carried in their transport, usually a BTR. It can also be deployed from the BMP-1P, BMD-1P, BTR-D and UAZ-469.

North Korea was said to have acquired a number of the systems during the late 1980s until the 2000s from the USSR. These were subsequently reverse-engineered under the designation Bulsae-2. A further upgrade called the Bulsae-3 was introduced in 2016 that replaced the wire-guidance with laser guidance, which gives greater range while being less susceptible to jamming like wireless radio-guidance and enables the designator to be separate from the launcher.