YDG-36

YDG-36
Type	Surface-to-air missile
Place of origin	Menghe
Service history
In service	1983-2010
Specifications
Weight	182 kg
Length	3.95 m
Diameter	223mm (seeker head) 200 mm (body)
Warhead	18 kg
Detonation mechanism	radio proximity fuse
Engine	solid fuel rocket motor
Operational range	14 km
Flight ceiling	12,000 m
Speed	1050 m/s
Guidance system	Semi-active radar homing (36G, 36D) Infrared homing (36N, 36R)

The YDG-36 (Formal designation: 36식 대공 유도탄 / 三六式對空誘導彈, sam-ryuk-sik daegong yudotan, "Type 36 anti-air missile;" Short designation 유대공-36 Yudaegong-samryuk "YDG-36") is a type of surface-to-air missile developed in Menghe during the 1970s and early 1980s. As Menghe's first domestically-designed surface-to-air missile, it had a long and troubled development history. Intended for land and naval service, it was generally considered unsatisfactory in both roles, and by the end of the 2000s it had been retired from all active warships.

Development

During the early 1970s, the Democratic People's Republic of Menghe began design work on a new, short-ranged surface-to-air missile. The development program was initially promoted by the Menghean People's Navy, which lacked an intermediate SAM between the bulky YDG-32 and the short-ranged YDG-31. It was planned for implementation on a successor class to the Nunbora-class destroyers, which ended up not materializing on schedule. Early prototypes of the missile used radio command guidance, but even with this simpler guidance method, the designers encountered great difficulties in miniaturizing the necessary components. Menghe's electronic industrial base, still reeling from the Menghean War of Liberation, lagged well behind that of the other great powers.

The situation changed in 1978, when Menghe gained a license to produce the Letnian R-23 missile as part of the Daesŭngri DS-5 fighter project. A land-launched, booster-equipped R-23 was briefly considered, but it would have been just as long and bulky as the YDG-32, negating the aims of the project. Instead, the design team decided to accelerate the design process by using the R-23's seeker head on a modified version of the prototype missile body, which was similar in diameter. This involved shifting the missile's main guidance system from command guidance to semi-active radar homing, and developing a new illuminator antenna to support its guidance.

Accelerated development during the project's late stages brought its own share of problems. In 1983, the MoND formally approved the missile for service, giving it the designation YDG-36, and it entered production the following year, to arm the Chŏndong-class destroyers. But trials to fine-tune the guidance system were not yet complete. In combination with poor quality control, this caused the first batch of missiles to perform very poorly in tests. It was only in the early 1990s, with the development of the YDG-36D and -R variants, that the missile's reliability improved, though even then its overall characteristics were poor compared to contemporary point-defense missiles then entering service.

Design

The YDG-36 is a short-range, point-defense missile, capable of engaging helicopters and anti-ship missiles but with insufficient range to provide fleet air defense. It is propelled by a solid-fuel motor, and has a range of 14 kilometers. Early variants have a distinct nose bulge, as the seeker head is 223mm in diameter while the missile body is 200mm in diameter. On the D and R variants, the seeker is smaller and there is no nose bulge.

The missile comes in two main variants. Variants G and D use semi-active radar homing, relying on an illuminator attached to the warship (or, abortively, the launch vehicle). Variants N and R use an infrared homing system, autonomously homing in on the target's heat signature. All launcher types are designed to carry a combination of radar-guided and infrared homing missiles, and may fire these missiles in a mixed salvo, for greater redundancy against jamming and countermeasures. The infrared homing variant, however, has a much shorter range - just 6 kilometers, according to some sources - because it must acquire the target before launch.

Naval launch system

Mugunghwa-class corvette Juksun was completed with a YDG-36 launcher and magazine for sea trials of the weapon.

The naval launch system for the YDG-36 consists of a swiveling, trainable launcher with a total of eight reusable launch boxes. These launch boxes are reloadable, and reload by elevating to the vertical position, like a twin-arm launcher. New missiles are then rammed in from below, in groups of four. The magazine contains 24 missiles, plus 8 in the launcher, for a total of 32. The missiles on the left side (facing in the same direction as the launcher) are radar-guided, while the missiles on the right side are infrared-homing; each half of the launcher is specifically wired to support that missile type. The magazine has a depth of 4.8 meters, which on most Menghean ships translates into two decks; it is 6.7 meters long and 5.7 meters wide.

While cruising, the front and rear ends of the missile boxes are usually covered by thin metal panels, to protect the missiles inside from the elements. When switching to a battle-ready state, crew members manually remove these panels, which on some arrangements requires traversing the mount to access the front ones. Sources disagree on whether the radar-guided missiles can be fired with the panels still mounted, though in any case this would leave the remaining missiles permanently exposed. The infrared-guided missiles must acquire the target before launch and can only be fired with the panels removed.

On all warships carrying the naval YDG-36 system, each mount is paired with two radar illuminators. This was even the case on the trials ship Juksun, suggesting that the mount is wired to require it. Menghean sources claim that each illuminator can guide two missiles toward one target at maximum.

Variants

YDG-36G

Initial radar-homing variant, using a seeker head derived from the R-23R.

YDG-36N

Initial infrared-homing variant, using a seeker head derived from the R-23T.

YDG-36D

Upgraded radar-homing variant unveiled in 1995. Some sources speculate that it uses a seeker derived from that of the Skybolt, which Menghe licensed in 1992 as the YGG-6.

YDG-36R

Upgraded infrared-homing variant unveiled in 1996. Appears to use the same seeker as the abortive YGG-6N infrared-guided AAM.

Launch platforms

• Chŏndong-class destroyer
• Menghean aircraft carrier Haebang
• Mugunghwa-class corvette (Juksun, a trials ship)

See also

• List of Menghean missiles