Gyundoan-Han GH-36 Mulsuri

The Gyundoan-Han GH-36 "Mulsuri" (Osprey) is a twin-turbine-engine heavy compound utility helicopter designed in Menghe by the Gyundoan-Han design bureau. It is built in a number of variants, including the utility transport GH-36G, the ASW/ASuW-focused GH-36N, and the troop transport GH-36D. Its most distinctive feature is a push rotor in the tail boom, which, in conjunction with aerodynamic stub wings and a tandem rotor, allows the helicopter to cruise at speeds of 410 kilometers per hour.

Development

The GH-36 grew out of a Navy requirement for an anti-submarine-focused helicopter which could cover a wider area of ocean than the existing Gyundoan-Han GH-28 Ppulsoeori. The designers focused on increasing the helicopter's cruise speed, which would allow it to deploy a larger sonobuoy field in the same span of time. Increased speed also conferred other advantages. Arriving more quickly at a transient sonar contact reduces the area of uncertainty around the submarine's possible location, as it cannot travel as far before the helicopter arrives. Once on site, a faster helicopter can also lay rows of sonobuoys more quickly, increasing the chance of detecting a submarine in a V-type search pattern.

To better exploit this increased speed, the helicopter would require more sonobuoys; to better exploit a larger sonobuoy payload, it would require greater endurance; and to better exploit greater endurance, it would require a heavier weapon load. All of these requirements resulted in increasingly large sizes for the competition entries. Because the Navy planned to use the new type on the Hasŏ-class cruisers, still in development, this was deemed to be an acceptable constraint.

Variants

GH-36G

The GH-36G is the baseline utility model which grew out of Gyundoan-Han's concept-demonstration prototype. It has no armament or hardpoints, and no sensors apart from basic navigation equipment. Crew and passengers can enter through vertically-opening clamshell doors on the right side of the cockpit, and there is a cargo ramp under the tail boom. There are also emergency exit windows to the left of the cockpit and on both sides of the fuselage aft. On the military version of the GH-36G, the cargo bay is left empty, and can be either loaded with light vehicles and supplies, or fitted with stretchers or canvas seats. This variant is mainly used for supply transport and personnel transport missions within friendly lines, including vertical replenishment of certain ship classes. The GH-36D specializes in air assault against hostile areas.

GH-36N

The GH-36N is a specially designed variant for naval operations, and the original objective of the project. It was first introduced on the Hasŏ-class cruisers and Insŏng-class destroyers. It can carry a total of 42 sonobuoys, with 30 in a reserve storage rack and 12 in two revolver assemblies ready for ejection. These are typically a mix of active and passive sonobuoys, as well as a few special-purpose sonobuoys for measuring water temperature and currents and communicating with submarines. Within the four-man crew, the assistant sonar operator is tasked with manually loading sonobuoys from the reserve rack to the ready revolvers; once back at his seat, he remotely controls the revolvers, selecting the desired sonobuoy type and ejecting it through a small hatch in the bottom of the fuselage. Because of this ejection system, the cabin is not pressurized, which limits the GH-36N's maximum safe altitude.

Unlike the GH-36G and GH-36D, which have large sponsons on either side of the fuselage, the GH-36N has two stub wings, each supporting two hardpoints. It is able to carry torpedoes, anti-ship missiles, and air-to-air missiles, as well as rocket pods and bombs. These diverse payload options allow the GH-36N to engage in anti-surface missions, attacking isolated corvettes, auxiliary ships, and small craft. The YGG-7 air-to-air missiles also provide a small measure of self-defense capability when operating in contested airspace. Owing to the GH-36N's slow speed, low ceiling, and poor agility, it is unlikely that it would be able to engage fighter aircraft such as the Dassault Rafale on anything close to equal terms, but air-to-air armament could complicate interception, and would allow the GH-36N to pick off enemy anti-submarine helicopters.

Because the sponsons were removed to make space for these stub wings, extra fuel tanks are carried inside the cargo compartment, which is also occupied by sonobuoy storage, sonar-processing computer equipment, and the sonar operator stations. An extendable boom probe on the lower right corner of the fuselage allows for in-flight refueling from slow-flying fixed-wing aircraft, though GH-36Ns seldom exploit this capability as there are no tankers in the air wings of Menghean carrier battle groups and anti-submarine battle groups.

Sensors consist of a deployable magnetic anomaly detector over the right side sponson, a surface-search radar under the fuselage for detecting periscopes and snorkels, and an electro-optical sensor under the nose. Chaff/flare ejectors are installed on either side of the tail, and four jammers are spread around the airframe.

The main rotors can fold to allow easier hangar storage. The tail, however, does not fold, in part because of its thickness with twin stabilizers included and in part because of the heavy driveshaft to the psuher propeller.

GH-36D

The GH-36D was specially developed in 2017 to test the feasibility of carrying out heliborne air assaults across the Strait of Portcullia. It has a refueling probe like the GH-36N, but retains the hull sponsons and rear cargo door of the GH-36G. It also adds a winch on either side of the airframe above the forward doors, allowing transported troops to fast-rope to the ground. The GH-36D lacks the range to make a round trip across the strait on its own internal fuel, but could top off its tanks en route and during the return. Such an operation would be extremely risky, however, and some reports suggest that Menghe's GH-36Ds will be assigned to the new class of landing helicopter dock ships upon their completion.

Ship classes using the GH-36

• Hasŏ-class cruiser
• Insŏng-class destroyer

Users

• Menghe

Specifications (GH-36N)

General characteristics

• Crew: 4 (pilot, copilot, 2 sonar operators)
• Length: 16.93 m (55 ft 7 in) fuselage only, probe retracted
• Wingspan: 4.93 m (16 ft 2 in)
• Height: 5.16 m (16 ft 11 in)
• Empty weight: 9,702 kg (21,389 lb)
• Max takeoff weight: 16,500 kg (36,376 lb)
• Powerplant: 2 × Taesan T508-1 Turboshaft, 2,400 kW (3,200 hp) each
• Main rotor diameter: 2× 14.98 m (49 ft 2 in)
• Main rotor area: 1,409.9 m² (15,176 sq ft)
• Propellers: single blade, 3.39 m (11 ft 1 in) diameter

Performance

• Maximum speed: 450 km/h (280 mph; 243 kn)
• Cruise speed: 410 km/h (255 mph; 221 kn)
• Never exceed speed: 460 km/h (286 mph; 248 kn)
• Range: 1,200 km (746 mi; 648 nmi)
• Service ceiling: 4,850 m (15,910 ft)

Armament

• Hardpoints: 4 with a capacity of 500 kg,with provisions to carry combinations of:
  • Rockets: HB-8/20 rocket pod (20 × H-8 rocket)
  • Missiles: YGG-5 Dando, YDH-26, YDH-45
  • Bombs: GYGP-500 (electro-optical)
  • Other: YŎ-35/2 torpedo, 30mm gunpod

See also

• Gyundoan-Han GH-28 Ppulsoeori