YDG-67

The YDG-67 is a type of very-long-range surface-to-air missile developed in Menghe. Unlike the preceding YDG-39, YDG-60, and YDG-62, all of which were licensed copies of foreign long-range missiles, the YDG-67 is a domestic Menghean design. It is fired from a strike-length Mark 41 VLS canister, and can be launched from surface ships using the Mark 41 VLS or from land vehicles with Mark 41 VLS canister adapters. The family of launch vehicles, radar vehicles, and command posts for the YDG-67 is collectively known as Masul Chang ("Magic Spear"), though this name is sometimes applied to the missile itself.

Development

The YDG-67 was likely ordered in response to the rumored development of long-range active-radar-homing missiles in other countries in Septentrion, particularly the S-400 missile system, given Letnia's history of exporting surface-to-air missile systems to Maverica. Rather than pursuing a license agreement, as had been done with the YDG-62, the Menghean government pushed for a domestic design program, reasoning that Menghe's electronics and aerospace sectors were sophisticated enough to produce a high-quality weapon.

Development began at some point in the late 2000s, but experienced repeated delays, apparently due to problems meeting the MoND's demanding range requirements. The missile entered service in 2018.

The seeker on the YDG-67 is derived from the seeker on the YDG-64N, scaled up to fit the larger nose cone and increase acquisition range. The YDG-64N's seeker was reportedly optimized to distinguish small airborne targets, even low-flying or notching ones, from background terrain, although the details of the seeker's capabilities are unclear.

In 2021, it was rumored that an upgraded seeker was in development. This new seeker will have a wider search angle and a longer search range, expanding the size of the target acquisition basket and making it harder for a target to evade the missile on its terminal track. It is expected that the upgraded missile variant will be designated YDG-67N.

Description

The YDG-67 is a relatively large surface-to-air missile, with a diameter of 480 millimeters and a length of 6.48 meters. It has a solid-fuel booster stage which propels it into the air and brings it to altitude, and a solid-fuel cruse stage which brings it the rest of the way to the target after the booster falls away.

Official Menghean sources claim that the YDG-67 has a range of 360 kilometers, though unofficial estimates range from 300 to 450 kilometers. Even the lower estimate would place it among the longest-ranged surface-to-air missile systems in Septentrion. It achieves this range by using an optimized flight trajectory, first climbing to high altitude and then cruising in the much thinner upper stratosphere. This trajectory also allows the missile to descend on its target in the terminal approach, increasing its speed and making evasion more difficult.

Like the YDG-60, YDG-62, YDG-64, YDG-65, and YDG-66, the YDG-67 has a two-stage guidance system. Before launch, predicted intercept coordinates are programmed into the missile, and an inertial guidance system controls the missile in its ascent, pitching it in the correct direction as it emerges from the vertical launch cell and bringing it toward those coordinates. During the cruise phase, the missile receives continuous course mid-course guidance updates, which adjust the location of the planned intercept point if the target changes its speed or course. Without mid-course updates, the missile continues on its last known course to the target. If radar contact with the target is lost and there are multiple missiles approaching it, the launch platform can send a command update signal to spread the missile formation and increase the probability of an active radar lock.

In its mid-course phase, the YDG-67 has full cooperative engagement capability, meaning that it can also receive mid-course updates from a separate radar site or an airborne early warning platform. Separate radar sites and AEW platforms can also transmit target information to a launch platform operating under restrictive EMCON states, allowing the launch platform to launch a missile on an intercept course even if it lacks line-of-sight to the target or has its radar arrays switched off.

On terminal approach, the YDG-67 is guided by an active radar seeker which illuminates the target and processes the reflected signal. Combined with the missile's descending trajectory, this allows the YDG-67 to acquire and lock onto targets which have broken line of sight with the launch site by flying low or flying behind mountains. It also eliminates the need for the launch site to emit radar guidance signals at the target, and allows the YDG-67 to be fired at targets beyond the launch site's line-of-sight or outside the range of its target illumination radars.

The YDG-67 is able to engage a wide range of airborne targets, including fixed-wing aircraft, helicopters, cruise missiles, anti-ship missiles, and unmanned aerial vehicles. It has some anti-ballistic missile capability, though it is not as effective in this role as the YDG-65 or YDG-68. It also has a secondary anti-ship capability, again using its active radar seeker to acquire the target. The missile's high speed makes it challenging to intercept in the anti-ship role, but because of its small warhead, high trajectory, and high cost, it is not typically used as an anti-ship weapon.

Masul Chang air defense system

Masul Chang ("Magic Spear") refers to the full system of vehicles and radars associated with the land-launched YDG-67, though the term is sometimes incorrectly applied to the missile itself. All heavy vehicles in the system are based on the Taekchŏn T512 8×8 heavy utility lorry, balancing offroad mobility with on-road speed.

To fully exploit the missile's long range and active radar terminal guidance, the Masul Chang system places a great emphasis on the networked transmission of targeting information between distant radar sites and launch batteries. Each launch battery is provided with a radar antenna for sector search, but this is normally switched off to avoid revealing the launch battery's location. It also lacks the necessary detection distance to exploit the YDG-67 missile's maximum range.

The Masul Chang air defense system is used by both the Menghean Army and the Menghean Navy, in the latter case serving with coastal defense formations.

Role

While the tracked Chŏlgung air defense system is a corps-level asset which follows the advance and retreat of Army formations, the Masul Chang air defense system is an Army-level asset which is normally stationed in the rear areas of an Army's zone of jurisdiction. This provides a broad zone of coverage over friendly rear-area targets, and can fill gaps between front-line SAM defenses.

Battalion structure

• Battalion headquarters
  • YR-423 E/F-band radar
  • YR-452 D-band radar
  • YR-374 A-band radar
• 3× Masul Chang battery
  • YG-60JS command post
  • 4× YG-60B1 TEL (4× YDG-67 each)
  • 2× YBR-66/64 Pyobŏm TELAR (8× YDG-64 and 8× YDG-66 each)
• Missile technical battery
  • 12× Taekchŏn T512 with crane (4× YDG-67 each)
  • 6× Samsan S915 with crane (8× YDG-64 and 8× YDG-66 each)
• Logistics company