Menghean aircraft carrier Haebang

MH Haebang as commissioned, before refits.
History
Menghe
Name:	Haebang
Namesake:	Menghean War of Liberation
Builder:	Gyŏngsan Songsu-do Shipyard
Laid down:	3 February 1981
Launched:	19 August 1985
Commissioned:	3 June 1990
General characteristics
Class and type:	Haebang-class aircraft carrier
Displacement:	41,000 t (full) 36,000 t (standard)
Length:	250 m (821 ft) o/a 230 m (754 ft) w/l
Beam:	58.2 m (191 ft) o/a 31.3 m (103 ft) w/l
Draught:	10.4 m (34 ft) full
Propulsion:	4 shaft geared steam turbines, 180,000 shp
Speed:	30 knots
Endurance:	8,000 km at 18 knots
Armament:	2 × 8 YDG-36 surface-to-air missile (64 reloads) 8 × AK-630 CIWS
Aircraft carried:	28 DS-5HG fighters 11 Gyundoan-Han GH-28 helicopters

Haebang (Menghean: 해방 / 解放, "liberation") is an aircraft carrier in the Menghean Navy. She was laid down in 1980 and commissioned in 1990. A sister ship, Sŭngri, was planned, but never laid down, making Haebang the only ship in her class.

Haebang was the first Menghean aircraft carrier to be laid down after the end of the Pan-Septentrion War in 1945, and also the first Menghean aircraft carrier capable of launching and recovering jet aircraft. Due to a lack of design experience between 1945 and 1980, she featured a number of compromises and outright design flaws, particularly with regard to her flight deck layout, elevator placement, and propulsion system. Operational experience with the Haebang contributed to the design of the Sibiwŏl Hyŏgmyŏng class aircraft carriers, which corrected many of the Haebang's deficiencies.

Construction

During the 1970s, the Menghean Navy conducted a number of design studies for medium aircraft carriers. Sim Jin-hwan was a particularly strong supporter of major warship projects, believing that like the DS-5 fighter, they would demonstrate Menghe's ability to stand on an even technological ground with its rivals. As early as 1973, the Navy drew up a design sketch for an aircraft carrier which would use navalized versions of the Daesŭngri DS-2 fighter and Songrim SR-3 attack aircraft. Like other Menghean large-warship designs in the 1970s, however, this proposal remained on the drawing board due to budget constraints and technical challenges.

Work on aircraft carrier design concepts continued into the late 1970s. In the process, the Navy clarified the carrier's operational requirements, and improved upon the original layout. The final iteration of the design, designated Plan 115, was built around the fighter support role, and would provide a radius of air cover for groups of surface ships operating outside the range of land-based Navy fighters. Two carriers were planned, and both of them would be assigned to the South Sea Fleet.

The first of the two hulls was laid down on February 3rd, 1981 at the No.5 "battleship drydock" of the Songsu-do Naval Yard. Her hull was launched from the drydock on August 19th, 1985. While the original work schedule called for her successor, Sŭngri, to be laid down in the same drydock following her launch, economic instability and the urgent needs of the Second Emergency Shipbuilding Program meant that Sŭngri was cancelled.

The economic hardship of the Ryŏ Ho-jun era also interfered in Haebang's own fitting-out. Because Dayashina was seen as the most urgent threat, naval construction work prioritized surface combatants, such as the Chŏndong-class destroyers, and submarines. Work on the Haebang had all but stopped in 1987, and was slow to start up again after the Decembrist Revolution. Despite concerns from some moderates that an such an offensive weapon would undercut efforts to patch relations with Dayashina, Choe Sŭng-min insisted that Songsu-do complete work on the aicraft carrier. Haebang was finally commissioned on June 3rd, 1990, three years behind schedule and considerably over budget.

Name and classification

In the postwar era, the Menghean People's Navy did not originally have an official naming policy for aircraft carriers, as none had been built yet. Some internal documents refer to the early proposals as the Menggang or Ŭmgang class, naming them after Menghean rivers in compliance with prewar tradition, but these names were not official. Instead, the designs were officially labeled with Plan numbers, with the final iteration being Plan 115.

When the first Plan 115 carrier was laid down, the naval leadership decided to name her Haebang (Menghean: 해방 / 解放, "liberation"), in reference to the Communist victory in the Menghean War of Liberation. Her sister ship would be Sŭngri (승리 / 勝利, "victory"), also in reference to victory in that conflict. This started the postwar Menghean tradition of naming aircraft carriers after important events.

Design

Hull and flight deck

The hull design of the carrier Haebang uses an angled flight deck, with the landing area angled 7 degrees to port and the island on the starboard side. This allows for simultaneous takeoff, landing, and servicing operations, though with some limitations, as described below.

Originally, design studies for Menghe's aircraft carrier called for steam catapults on the bow, in order to boost aircraft to the necessary takeoff speeds. Designs as late as Plan 113 used this configuration, which left more flat space forward for parking aircraft and allowed for the launch of heavier aircraft types. During late development, however, the Navy encountered problems with land-based catapult tests, and determined that the technical challenges were still too great. As a result, the final Plan 115 design was built with a ski jump forward. The angle of this ski jump is relatively gradual, reaching 4 degrees at the far end and averaging 2 degrees overall.

The ski jump has two takeoff positions, "G" and "N" arranged in an echelon formation. Of these two, only the first (G) can be used during landing operations; the second (N) is on top of the landing area. Additionally, because the N position requires the jet to pass over the G position, jets using it can only take off after the other jet has done so (or when the other position is not in use). Thus, any delay in launching from the G position will also delay launches from the N position. Launch position G is also relatively close to the forward hangar elevator and munitions elevator, and while a jet blast deflector redirects the exhaust upward, any accidents involving the jet exhaust could spread flames into the hangar or munitions elevator shaft. For this reason, the Menghean Navy typically keeps both elevators in the "up" position during takeoffs, a measure which limits the potential damage but further hampers the carrier's low sortie rate and inconvenient elevator arrangement.

In addition to its fixed-wing takeoff and landing facilities, the flight deck has six clearly marked takeoff and landing positions for helicopters. All six of them are arranged along the angled landing deck, meaning that helicopter launch and recovery operations cannot be conducted simultaneously with fixed-wing landing operations. The on-deck helicopter fueling and re-arming area is also relatively small, at the back of the flight deck.

Hangar

The internal hangar is 123 meters long, 22.3 meters wide, and 6.7 meters tall (405 × 73 × 22 feet). A retractable fireproof barrier, 63 meters from the aft end, can divide the hangar into two halves if the carrier is damaged.

The hangar and flight deck are linked by two aircraft elevators. The aft elevator is a standard outboard type. Though 13 meters wide at its inward end, its projecting outward end is 17 meters wide, and aircraft can park on it with their rear sections hanging over the water. In this way, the aft elevator can lift two jets or two helicopters at once, though they must be moved onto the elevator one at a time. The forward aircraft elevator is an older inboard type, and is 18 by 8.8 meters. It can lift one jet or one helicopter at a time. It is much closer to the takeoff and landing points, but as described above, safety guidelines discourage the use of the forward elevator during takeoff operations.

In addition to the large aircraft elevators, there are a total of three mid-size elevators which can be used to lift munitions, drop tanks, and other supplies from inside the ship. All three have dimensions of 6.5 × 2 meters. To reduce the risk of fire spreading to the magazines, each elevator has two sections: one running from the flight deck to the hangar deck, and one running from the hangar deck to the munitions magazine deeper in the hull. Munitions are transferred horizontally between the two elevators at the hangar deck level, where they overlap. This transfer point is blocked by a fireproof and blast-proof barrier when not in use, as is the door between the magazine elevator and the hangar. Like the forward aircraft elevator, the forward munitions elevator is closest to the launch point, but this position also renders it unsafe during takeoff operations.

Air wing

As designed, the Haebang can carry a maximum complement of 28 jet aircraft and 11 helicopters. Organizationally, this air wing is divided into operational aircraft, which are part of the ship's squadrons, and spare aircraft, which are used as replacements for lost airframes and as sources of spare parts.

• 24 air superiority fighters (2 squadrons) plus 4 spares
• 8 anti-submarine helicopters (2 flights) plus 2 spares
• 1 search-and-rescue helicopter

In practice, it was found that this "full capacity" air wing limited sortie rates, as the hangar was cramped near the aft elevator and the aft elevator itself was used for jet aircraft parking. To improve sortie rates, the Haebang transitioned to a "reduced capacity" air wing of 24 fighter aircraft and 10 helicopters in the mid-1990s. This was done by deleting the spare airframes, which were found to be less useful than planned.

• 24 air superiority fighters (2 squadrons)
• 8 anti-submarine helicopters (2 flights)
• 2 search-and-resuce helicopters

Both air wing makeups reflect the narrow role of the Plan 115 carrier: an air defense escort ship for surface action groups. The fixed-wing complement is entirely comprised of air-superiority aircraft - originally, DS-5HGs, which have no anti-ship missile launching capability. Instead, Menghean People's Navy doctrine called for anti-ship missile strikes to be provided by surface ships, such as the Nunbora-class and Chŏndong-class destroyers. The anti-submarine helicopters (originally GH-28Ns) also augmented the fleet's protection against undersea threats, as the Yobu-class destroyers had no helicopter facilities and the Nunbora and Chŏndong classes had only minimal anti-submarine armament. At the time Haebang entered service, Menghe had no fixed-wing carrier-based utility aircraft, and this was not a design consideration during development. As such, due to the lack of catapults and adequately sized elevators, Haebang was unable to operate the Demirkan-Yŏng'an DY-11 family of aircraft even after their introduction in 2008. This severely constrains its effectiveness when compared to later Menghean carrier classes, as it is unable to conduct fixed-wing airborne early warning patrols.

During design work on the DS-9 Biho, the Ministry of National Defense required that the new fighter be able to operate from carriers as well as land bases. Because reverse compatibility with the Haebang class was part of that requirement, Daesŭngri had to design the DS-9 for both STOBAR and CATOBAR operations. Fortunately, the Army's requirement for good operations on short and damaged airstrips overlapped with the former requirement, and the DS-9's good handling at low speeds and high angles of attack made it easy to adapt for ski-jump takeoffs. Additionally, the DS-9's folding-wing joints gave it similar external dimensions to the DS-5 at 25-degree wing sweep, allowing DS-9s to be parked in deck positions originally spaced for DS-5s. Thus, the DS-9 air wing has the same organization as the "reduced capacity" air wing above, and during Menghe's involvement in the Ummayan Civil War Haebang carried a mix of both aircraft types. Notably, although the DS-9HG and HN are multirole aircraft, the low-angle ski jump of the Haebang limits their maximum takeoff weight, preventing the usage of heavy anti-ship strike loadouts.

Armament

For an aircraft carrier, the Haebang was built with an unusually strong defensive armament. She sported no fewer than eight AK-630 close-in weapon system mounts, arranged in four pairs at each corner. Each pair was directed by a single fire-control radar. This arrangement allowed full 360-degree gun coverage, with a 90-degree starboard arc and a 60-degree port arc where two pairs overlap. While most other Menghean warships sporting AK-630 mounts also had manual fire director posts as backup, these appear to be absent on the original Haebang.

In addition to the gun-based CIWS system, Haebang was also built with a point-defense surface-to-air missile armament. This consisted of two eight-box YDG-36 launchers, one forward and one aft of the island, elevated two decks above the flight deck. Each launcher carried 32 internal reloads. As with other YDG-26 launchers, typical doctrine called for loading one side of the launcher with SARH-type missiles and the other half with infrared-guided missiles, providing greater redundancy against aircraft or missile countermeasures. Each launcher was paired with two radar directors on the superstructure, for full 360-degree coverage with 90 degrees of two-launcher overlap on each side of the ship.

For additional defense against anti-ship missiles, Haebang carried four smoke and chaff rocket projectors, two on each side of the ship.

As part of major refits conducted in the early 2010s, Haebang received a total overhaul of her defensive armament. All AK-630 mounts were removed and replaced with rocket launchers for hardkill and softkill anti-torpedo defense projectiles. Previously, the ship had carried no anti-submarine or anti-torpedo weaponry. The YDG-36 box launchers were also removed. In their place, the Navy installed combined gun-and-missile CIWS mounts. Like the YDG-36 mounts, these included surface-to-air missile reloads inside the ends of the island. Although the number of guns was reduced, this new arrangement featured slightly improved gun coverage, as each mount could cover a full 270-degree arc.

Powerplant

Haebang relies on conventional steam turbine propulsion, with oil-fired boilers connected to turbines driving four propeller shafts. Her machinery is split between two compartments, one forward and one aft, for better redundancy in the event of missile or torpedo damage. Exhaust from the boilers is trunked through a single large funnel on the island.

Though the DPRM gained extensive experience with high-pressure gas-fired steam powerplants when building destroyer-size warships, the power plant on the Haebang was still larger in size and power than anything on a previous postwar ship. Consequently, reliability problems with the powerplant plagued the ship in service. During at-sea maneuvers in 1996, Haebang was observed to slow down with a large plume of dark smoke issuing from the funnel, likely due to an engine room fire. Tugboats later brought her back to Songsu-do, where she remained in drydock for over a year. She suffered engine problems again in 2005, during Menghe's withdrawal from Ummayah, but was able to complete the voyage on reduced power.

Menghean state media claim that the Navy fully resolved Haebang's engine hazard problems during her mid-life refits in the early 2010s, installing a modified boiler design with improved efficiency and reliability. Since her refits, Haebang has not been observed with heavy smoke indicative of engine problems, though occasional leaked reports suggest that her crew remains dissatisfed with the boilers' reliability.

Service

Even after her long delays in construction and fitting-out, Haebang saw continued problems. Her first few years of service amounted to an extended sea trial period, as the Navy trained pilots in carrier operations and air crew in at-sea servicing. The ship also had a number of maintenance issues during its breaking-in, including problems with the electronic flight command system.