YDH-26
| YDH-26 | |
|---|---|
 Major variants of the YDH-26 | |
| Type | Anti-ship missile |
| Place of origin | Menghe |
| Service history | |
| In service | 2002-present |
| Production history | |
| Manufacturer | Buksŏng Industries Group |
| Specifications | |
| Weight | 540 kg (YDH-26GJS) 450 kg (YDH-26G) |
| Length | 401 cm (YDH-26GJS) 332 cm (YDH-26G) |
| Diameter | 35 cm |
| Warhead | 130 kg warhead |
Detonation mechanism | Contact fuse |
| Propellant | kerosene |
Operational range | 110 km |
| Flight altitude | sea skimming (3 m) |
| Speed | Mach 0.8 |
Guidance system | inertial guidance, terminal active radar homing |
The YDH-26 Mulchongsae (Formal designation: 26식 대함 유도탄 / 二六式對艦誘導彈, i-ryuk-sik daeham yudotan, "Type 26 anti-ship missile;" Short designation 유대함-26 Yudaeham-iryuk "YDH-26") is a type of subsonic anti-ship missile developed in Menghe during the late 1990s and early 2000s. With a mass of 450 kilograms and a 100-kilogram warhead, it is relatively lightweight and compact. It serves as a smaller, cheaper complement to heavier Menghean anti-ship missiles like the YDH-23 and YDH-28.
Development
The YDH-26 was developed by the Buksŏng Industries Group, formerly Institute 92, Menghe's main manufacturer of medium-range subsonic missiles. It was conceived as a lighter replacement for the YDH-24, able to be carried by helicopters and carrier-borne fighters. In this role, it would complement the larger YDH-28, which offered a longer range and heavier warhead at the cost of greater size and weight. Designers also emphasized minimizing production costs, to aid in mass-production and make the missile more attractive on the export market.
At-sea test firings of the YDH-26 took place in 2000, using a modified Plan 261 missile boat as the launch platform. The missile was found to perform well, and in 2002 it was introduced to service on the Sŏwicho-class corvette Hwŏncho, the second in her class.
Design
The subsonic YDH-26 follows a conventional cruciform wing design, with fixed stabilizers mounted halfway down the missile's length and similarly shaped steering fins mounted at the rear. An intake for the turbojet is slung underneath the missile's body. Prior to launch, these fins are folded against the missile's body, allowing it to be stored in more compact launch containers; these fins automatically spring open shortly after launch.
The YDH-28 is relatively compact, even when compared with other subsonic anti-ship missiles. Its smallest air-launched variant has a mass of only 450 kilograms, while its heaviest variant has a mass of 540 kilograms. Tradeoffs of this small size include a short range of 110 kilometers and a small 130-kilogram warhead. Buksŏng's sales manual states that the missile is recommended for use against warships displacing between 4,000 and 400 tons, i.e. frigates and corvettes, though it can also be used to damage larger ships and impair their effectiveness against a follow-up strike.
By default, the YDH-26 uses inertial navigation to travel to an attack point designated upon launch. It makes its initial approach at an altitude of 15 meters to avoid striking friendly warships and rogue waves. Once it is 25 kilometers from the target position, the missile climbs in altitude, activates its radar seeker, and begins searching for targets. When a target in the designated area is detected, the missile updates its course and drops to a sea skimming altitude of 3 meters, where it makes its final approach. At a range of one kilometer, the missile performs a pop-up maneuver and descends on a quasi-ballistic arched trajectory, increasing the probability of a hit against a low-freeboard target.
Due to its small size and relative simplicity, the YDH-26 is considered one of the most cost-efficient missiles in service in Septentrion. This is especially true of the basic "G" variants, which reportedly cost under $400,000 to manufacture. The missile is also designed for easy storage and maintenance, and can be stored fully-fueled for a period of up to 15 years.
Variants
The YDH-26 has a large family tree, with air-launched, surface-launched, helicopter-launched, and submarine-launched variants. The missile body itself has also undergone change over time, with spinoff variants such as the SY-26. This section will organize variants by each area, then list combinations in a table below.
By missile variant
YDH-26G
This is the standard baseline variant of the YDH-26. It has a simple active radar seeker and radio altimeter, and uses a low-cost turbojet engine to reach a range of 110 kilometers.
YDH-26G1
This is the designation used for YDH-26G missiles which have undergone an incrmental software upgrade. The G1 variant possesses home-on-jam capability, slightly improved resistance to countermeasures, and terrain-following capability when cruising over land. It also performs pseudo-random maneuvers during its final 5-kilometer approach, to reduce the probability of interception by point-defense SAM systems and close-in weapon systems.
YDH-26N
This is a major variant of the YDH-26 which entered service in 2011. It has a more efficient Donghae Gi-3-115 turbojet 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 260 kilometers, a target figure which the Menghean Navy selected 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. Only air-launched versions (YDH-26BiN) exist.
SY-26
The SY-26 is a land-attack cruise missile derived from the YDH-26, akin to the AGM-84E SLAM. It has a large electro-optical seeker in the nose and CSNS guidance for attacking stationary targets. The electro-optical seeker allows the missile to engage moving vehicles and targets with unknown exact coordinates, and provides resistance against CSNS jamming. Despite its cruise missile designation (SY, sunyang yudotan), the SY-26 can also engage surface ships using its electro-optical seeker.
Some sources indicate that the SY-26 is only used by the Menghean Navy, whereas Menghean Army aviation units have adopted the SY-55 Kkamagwi. In terms of overall characteristics, the two missiles are redundant.
By launch method
Fixed-wing air-launched variants
Variants of the YDH-26 fired from fixed-wing aircraft have designations starting with "Bi," which denotes bihaenggi or airplane. These variants retain the folding wings of the land-based models, allowing them to be packed closer together and carried closer to the aircraft's fuselage. They omit the solid-launch booster, which is unnecessary if the missile is launched with sufficient speed and altitude for the sustainer engine to operate.
The YDH-26Bi family has two standard bomb suspension lugs, which are spaced 250mm apart. This allows direct carriage on bomb racks and pylons compatible with Menghean 500-kilogram guided bombs, without the need for a launch rail or adapter pylon. Once released, the missile briefly enters free fall to clear the launch plane, then its fins snap open and its engine activates. Menghean training documents recommend a launch altitude of at least 100 meters above ground level so that the missile can gain lift before impacting the ground.
Helicopter-launched variants
Helicopter-launched variants have designations with the suffix "Jik," denoting jiksŭnggi or helicopter. Like the "Bi" variants, they have two overhead bomb suspension lugs at a 250mm interval, but they retain the solid-fuel booster, to allow launches from low speed and hover positions. When released, the missile first drops in free fall with its fins closed, then snaps open its fins and fires the solid-fuel booster, climbing and accelerating forward. After the booster is exhausted, it drops off, and the sustainer motor kicks in.
Submarine-launched variants
A submarine-launched variant was unveiled in 2006, though it was rumored to have been in development several years earlier. Submarine-launched missiles are derived from the booster-equipped land-launched variants, but are stored inside a watertight, pressure-resistant cylinder with the dimensions of a 533mm torpedo. This cylinder can be ejected from a submarine's torpedo tube at a depth shallower than 50 meters, at which point it tilts nose-up and rises to the surface. When it reaches the surface, its cap ejects, and the missile flies out under solid-fuel power.
Variant table
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Coastal defense system
In 2005, as part of the country's pivot to defensive warfare, the Coastal Defense Forces of the Menghean Army placed a request for a self-propelled, land-based launcher for the YDH-26 missile. The resulting system, which was publicly displayed in 2008 and bears the designation JYDH-26 (Jaju-Yudotan Dae-Ham, Self-Propelled Missile, Anti-Ship), consists of eight vehicles:
- 1x JYDH-26JS (Jungdae Salyŏngcha), Company/battery command vehicle with radio and wire connections. Crew of five.
- 1x JYDH-26SR (Susaek Reida), search radar vehicle with an elevating mast to detect ships within horizon range. Crew of three.
- 3x JYDH-26BG (Balsagi), launcher vehicle with eight missiles. Crew of four.
- 3x JYDH-26JCh (Jaejangjŏn-Cha), reload vehicle with eight missile boxes and a crane. Crew of two.
The original JYDH-26 system was designed around the Taekchŏn T512 heavy utility truck. It was later supplemented by a lighter system on the Samsan S915, which carries fewer missiles per truck (4 instead of 8) and has a shorter-range acquisition radar, but is cheaper to produce and maintain.
Byŏk container battery
The "Byŏk" ("wall") system is a version of the YDH-26 launch battery in which all components are installed in 20-foot ISO containers. A full-size battery is made up of fifteen 20' containers: three for the command post, two each for the radar and drone posts, and two for each of the four launch platoons. Other combinations are also possible, including a minimum battery with three command modules and one launch platoon. The modules can be linked with VHF radio, SHF radio (a modified MChGJ-0800), or cables running over the ground. The manned modules contain not only control equipment, but also basic living amenities: bunks, lockers, food and water storage, and an electric stovetop. Thus, once the unit is emplaced, the crew does not require separate accommodations.
The Byŏk battery can be arranged as a tightly packed installation, but it is also possible to disperse the individual platoons over an area as much as 20 kilometers in diameter. The modules within each platoon must be closer together - one brochure provides a figure of 50 meters - but otherwise there are no restrictions on their arrangement. They can also be painted in the liveries of private shipping companies, and shuttled between positions on civilian trucks. This allows a commander to disperse the modules across parking lots, construction sites, and shipping centers, making it virtually impossible for an adversary to distinguish battery elements from civilian containers using satellite and aerial imagery.
- Byŏkdul B1: Launch unit with four YDH-26 boxes and a rolling steel door on the roof. This module is uncrewed, and controlled by a B2 module.
- Byŏkdul B2: Launch control unit with control stations, radio antennas, and a generator, as well as bunks and basic amenities for two crew members.
- Byŏkdul S1: First half of the battery command post.
- Byŏkdul S2: Second half of the battery command post.
- Byŏkdul S3: Living spaces for the battery command crew.
- Byŏkdul J1: Long-range surface ducting radar and generator.
- Byŏkdul J2: Control and communications unit for the surface search radar, with four crew, bunks, and basic amenities.
- Byŏkdul M1: Contains two helicopter-type unmanned aerial vehicles with visual and IR cameras, which can visually identify radar contacts and assess post-strike damage.
- Byŏkdul M2: Control and communications unit for the unmanned aerial vehicle, with three crew, bunks, and basic amenities.
Variants
Variants without boosters
- YDH-26G: baseline model with radar guidance only
- YDH-26N: model with backup infrared seeker
- YDH-26D: model with backup infrared seeker and pseudorandom evasive maneuver profile
Variants with boosters
- YDH-26GH: baseline model with radar guidance only
- YDH-26NH: model with backup infrared seeker
- YDH-26DH: model with backup infrared seeker and pseudorandom evasive maneuver profile
Submarine launch variants
- YDH-26GJ: baseline model with radar guidance only
- YDH-26NJ: model with backup infrared seeker
- YDH-26DJ: model with backup infrared seeker and pseudorandom evasive maneuver profile