YDCh-71
| YDCh-71 | |
|---|---|
 YDCh-71 missile and cross-section, with 125mm APFSDS round for comparison. | |
| Type | anti-tank guided missile |
| Place of origin |  Menghe |
| Service history | |
| In service | 2011-present |
| Used by | Menghe |
| Production history | |
| Designer | Hanbyŏl Design Bureau |
| Produced | 2010-present |
| Specifications | |
| Length | 62.4 cm |
| Diameter | 125 mm |
| Wingspan | 37 cm (fins extended) |
| Propellant | solid fuel rocket |
Operational range | 3 kilometers |
Guidance system | SACLOS |
Steering system | aerodynamic surfaces |
The YDCh-71 (Formal designation: 71식 대전차 유도탄 / 七一式對戰車誘導彈, chil-il-sik daejŏncha yudotan, "Type 71 anti-tank missile;" Short designation 유대차-71 Yudaecha-chilil "YDCh-71") is a Menghean 125mm gun-launched anti-tank missile developed for the JCh-5 and JCh-6 main battle tanks. Like the YDCh-70 before it, it uses beam-riding SACLOS guidance with an overflight attack mode, firing a downward-facing shaped charge as it passes above the target. Though inferior to the YDCh-73 in range, accuracy, and flexibility, it is less expensive to produce, and backwards-compatible with the two-piece carousel autoloader of the JCh-5.
Design and Development
Work on the YDCh-71 proceeded in tandem with work on the YDCh-70, and was motivated by the same concerns. The Menghean Army increasingly regarded direct-impact shaped charges as inadequate against the composite armor schemes of the latest enemy tanks, and when working with the fixed charge diameter available for a 125mm gun-launched projectile, they had little room for improving penetration. These concerns, which intensified after Menghean contact with Tyrannian forces during the Ummayan Civil War. The YDCh-19, introduced in 2002, was already regarded as obsolete in some design circles, a doubly severe concern given the JCh-5's inability to use full-length APFSDS ammunition.
The Hanbyŏl Design Bureau, which was responsible for the YDCh-18 and YDCh-19, was the first to begin work on their replacements. Given a tight set of deadlines and unforgiving cost ceilings, the designers opted for a unique "overflight" attack mode, with a downward-facing warhead that would attack the target's thinner roof armor. The YDCh-70, apparently an adaptation of an existing prototype missile body, entered service in 2008, but with a diameter of 152mm it could only be used in external launch tubes. The gun-launched version would require more intensive work, as it needed an all-new missile body: the YDCh-19 was spin-stabilized and could not consistently point a warhead downward.
The result was a rather innovative missile, with long cruciform fins and a short, stubby body. The sustainer rockets fire through four side apertures, as on the YDCh-19, but are not angled to impart spin, and the missile relies on a gyroscope to right itself after firing (the round can rotate within the autoloader) and remain upright on course to the target. The rear booster section is identical to that on the YDCh-19, firing propellant through a spring-governed vent to throw the missile clear of the gun before its sustainer rockets activate. The internal components of the overflight fusing system were borrowed directly from the YDCh-70, also a Hanbyŏl design, but the rest of the missile was unique in execution, and had no clear counterpart anywhere in Septentrion.
Guidance of the YDCh-71 is beam-riding, semi-active command to line-of-sight, and requires no modification of the rangefinder/guidance module which supports the YDCh-19, allowing any individual tank to be compatible with both. As on the YDCh-19, the missile flies 5 meters above line-of-sight for the first portion of the approach to avoid colliding with ground obstacles or obscuring its rear sensor in the dust. At 800 meters from the target it descends to 2 meters above line of sight. At this point, fusing and firing are identical to the YDCh-70, with a laser profiler activating the downward-facing shaped charge when the missile passes over the target. Like any SACLOS system, it does require constant line-of-sight between the two tanks, and requires the firing tank to remain stationary, unlike the non-line-of-sight YDCH-73.
One advantage of the YDCh-71 is that like the YDCh-19, it can be handled as a two-piece tank round, with a booster section in place of the propellant charge and the entire missile in place of the projectile section. This makes it fully compatible with the carousel autoloader of the JCh-5, in which rounds are broken down into two pieces for storage around the turret walls and floor. By contrast, the full-length "Type 03 special" APFSDS round and the diving NLOS YDCh-73 missile cannot be broken down into two pieces, restricting them to the JCh-6 and JCh-8 main battle tanks. As such, the YDCh-71 is the only ammunition option for the JCh-5 which can reliably defeat an advanced AVA-model tank from the forward 60-degree arc. For this reason, it remains in production as of 2019, to keep reserve JCh-5 units relevant until the type has been fully replaced by the JCh-6 and JCh-8.
Like the YDCh-70, the YDCh-71 was shrouded in secrecy throughout its development and early deployment, in an effort to prevent Maverican intelligence sources from learning about the Menghean Army's improved anti-tank capabilities and devising countermeasures. No announcement about its entry to service was made, and no model missiles were displayed at arms exhibitions. When the YDCh-72 was unveiled in 2012, the skipped -71 designator led to professional and armchair speculation about whether an unknown ATGM existed; the Menghean Army's official explanation was that a cancelled prototype had borne the number, but this was without precedent in the Menghean armed forces, where formal designations are only applied after a weapon is approved for service. Official publications on the YDCh-71's characteristics were only released after the Innominadan Crisis, when both the YDCh-70 and YDCh-71 were used on a large scale against Innominadan government forces.
Service history
The YDCh-71 made its first combat debut in the Innominadan Crisis, where it was used against Innominadan armored forces in the early stages of the conflict. Tank crews reportedly gave favorable reports of its effectiveness, though there were some complaints about the reliability of its fusing system. Its line-of-sight restriction also avoided friendly-fire problems which had plagued the YDCh-72 and -73. As of 2019, the missile remains in production, and has been delivered to JCh-6 units awaiting deliveries of the more expensive YDCh-73.
Following the Innominadan Crisis, Menghe lifted export restrictions on the now-declassified YDCh-71, allowing it to be exported to Menghean allies. Dzhungestan, Polvokia, Argentstan, and Ummayah have already placed orders, the latter agreeing to take the missile in place of the more advanced YDCh-72.
