YDH-90
| YDH-90 Mulchongsae-2 | |
|---|---|
 Variants of the YDH-90 and SY-90 | |
| Type | Anti-ship missile |
| Place of origin | Menghe |
| Service history | |
| In service | 2013-present |
| Used by | See "operators" |
| Wars | Innominadan Crisis One-Month War |
| Production history | |
| Unit cost | Buksŏng Industries Group |
| Variants | SY-90 |
| Specifications | |
| Weight | 570 kg (1,260 lb) (without booster) |
| Length | 3.45 m (11.3 ft) |
| Diameter | 35 cm |
| Warhead | HE fragmentation |
| Warhead weight | 100 kg (220 lb) |
| Engine | Donghae Gi-3-115 turbofan |
| Propellant | Kerosene |
Operational range | 280 km (150 nmi) |
| Speed | Mach 0.8 |
Guidance system | Inertial midcourse with terminal active radar homing and infrared homing |
The YDH-90 Mulchongsae-2 is a type of anti-ship missile developed in Menghe for the Menghean Navy. It was developed from the YDH-26 Mulchongsae and shares many components, even bearing the designation YDH-26D between 2011 and sometime before 2015. The main difference between the two missiles is that the YDH-90 uses a turbofan engine offset under the fuselage, enabling a longer range of 280 kilometers. In all other respects, including guidance and warhead design, the two missiles are identical.
Like the YDH-26, the YDH-90 comes in a number of variants, including the SY-90 land-attack cruise missile.
Design
The primary difference between the YDH-26 series and the YDH-90 series is a Donghae Gi-3-115 turbofan engine, which sits offset toward the bottom of the fuselage, with a larger intake and additional fuel tank space overhead. These changes extend the range of the missile to 280 kilometers, a target figure which the Menghean Navy requested in order to out-range MASURCA-V surface-to-air missiles in Sieuxerrian carrier battle groups. Aircraft armed with the "G" variant could operate from well outside the range of Aster missile coverage, but had to conduct risky below-horizon approaches to avoid engagement by long-range surface-to-air missiles.
Because of these changes, the YDH-26N is considerably larger in the vertical dimension, and also substantially heavier. As a result, it cannot be fired from standard YDH-26 surface launch boxes, which are derived from Mark 41 self-defense cells. Nor can it be fired from 533mm submarine torpedo tubes or submarine launch tubes. For the first few years after its introduction, it was only used by fixed-wing aircraft and helicopters. In 2018, however, the Menghean Navy began using a new angled launch box with the cross-section of an inverted pentagon to accommodate the YDH-90 and its booster. This box can be mounted on the same frame used for angled Mark 41 box installations, and can be stacked on top of itself.
All YDH-90 variants, starting with the YDH-90G, use an under-slung infrared imaging seeker, the same model carried on the later YDH-26D. This seeker cross-references the radar return with its infrared silhouette, making the missile more resistant to jamming, chaff, and decoys.
Variants
YDH-90
Anti-ship variants bear the prefix YDH, and are fitted with a 100kg warhead consisting of a high-explosive charge surrounded by a prefragmented outer sleeve. As on the YDH-26, this relatively light warhead is only enough to outright sink ships of frigate size and below, but can still damage larger ships and force them to expend missiles in self-defense.
- YDH-26D
- This designation was used at a 2011 defense expo, under a YDH-26 mockup with a turbofan engine in a redesigned rear fuselage. The Ministry of National Defense either discontinued this designation or never formally approved it.
- YDH-90G
- The baseline version of the YDH-90 anti-ship missile. This designation was formally confirmed in 2015, but may have been in use as early as 2013 when the missile is believed to have entered service.
- YDH-90N
- A 2023 guidance update incorporating many of the changes also applied to the YDH-26R, notably an AI function which can classify ships by their radar and infrared returns. This allows it to disengage from civilian, friendly, and neutral ships, as well as enemy ships not assigned as targets. It also reportedly has the ability to adopt an ideal approach path to engage hostile ships.
SY-90
The SY-90 series are land-attack cruise missiles derived from the YDH-90 body. All models use some form of electro-optical guidance to recognize a target's infrared profile, and carry a 100kg armor-piercing warhead to penetrate bunkers and other hardened targets.
- SY-90G
- The initial cruise missile variant introduced alongside the YDH-90G circa 2013. It is unknown if a SY-26 model designation was ever applied.
- SY-90N
- An upgraded variant introduced in 2019, the SY-90N features a tri-mode seeker with infrared and visual-band lenses and a passive radar receiver to home in on enemy radar emissions.
