Songrim SR-8

Songrim SR-8
Major variants of the SR-8 in service with the Menghean Navy
Role	Multirole combat aircraft
National origin	Menghe
Manufacturer	Songrim Aircraft Corporation
Introduction	2000
Primary users	Menghe Idacua Kolodoria
Produced	1999-2030 (planned)
Number built	406
Developed from	Glasic International Aircraft Eagle

The Songrim SR-8 (Formal designation: 송림 8호 전투기 / 松林八號戰鬪機, Songrim Pal-ho Jŏntugi, "Songrim No.8 Fighter;" Short designation 송림-8 Songrim-Pal "Songrim-8") is a twin-engine, all-weather multirole strike fighter based on the Glasic International Aircraft Eagle air superiority fighter. It is produced under license in Menghe by the Songrim Aircraft Corporation. In a nod to its original designation, its first variant was also known as the Jŏndoksuri, or "Martial Eagle," making it the first Menghean combat aircraft to bear an official nickname.

The most visible external difference between the SR-8 and the GIA Eagle is the presence of a foreign object damage deflection system in the engine intakes, a feature which the Menghean Army prioritized to allow rough-field operations. The hardpoints and pylons are also designed for Menghean munitions. Subsequent variants evolved broadly in tandem with Glasic variants, each time accumulating Menghe-specific changes, such as under-wing hardpoints rated for heavier payloads and domestic IRST and radar modules. All SR-8 variants also feature Menghean avionics and voice alerts.

Unlike the Daesŭngri DS-9 "Biho," which is one of Septentrion's most widely proliferated 4th-generation fighters, the SR-8 has only been exported to Kolodoria. Menghe's government was reluctant to permit exports during the 2000s in order to avoid competing with GIA's original model, and only approved the Kolodorian export deal after extensive negotiation with Tír Glas. Despite the small export numbers, the SR-8 has still been produced in large numbers for Menghe itself, with 288 operational airframes of all variants serving with the Menghean Navy alone. When including Army numbers, this makes Menghe the largest operator of GIA Eagle derivatives.

Licensing and development

Import competition

The Menghean Ministry of National Defense began examining candidates for a twin-engine heavyweight fighter in the early 1990s, seeking a platform that would fit between the DS-5's poor range and the SR-7's poor maneuverability. As sanctions on Menghe had been lifted following its regime change and the nuclear disarmament, foreign imports or license deals were once again on the table, and the MoND viewed them as a practical way to cut development costs and speed up availability.

Four foreign aircraft were selected for evaluation in 1993: the Letnian Or-27, the Glasic GIA Eagle, the Sieuxerrian Super-Mirage Export Model, and the Ostish Greif. The Greif, in competition with fighters well outside its weight class, was quickly ruled out, though not before Daesŭngri's engineers could thoroughly look it over. The Mirage was also eliminated, though Sieuxerrian engineers refused to hand over the airframe after trials, concerned about the risk of reverse-engineering. This left the Or-27 and Iolar, both outstanding in speed and maneuverability, as the finalists.

The decision between the two became a high-stakes one, not only because of the planes' capabilities, but because it could affect Menghe's geopolitical alignment for years to come. For much of 1994 the Or-27 seemed to be the preferred option, but the Letnian government pressured Orlov to export it with downgraded radar systems, angering the Menghean representatives. Tír Glas, hoping to exploit this break, offered the "Martial Eagle" model with its Al.85 Striga radar. As a further guarantee, GAC exported APR-70 kits for use on SR-7 upgrades, and held out the possibility of technology transfers for future domestic Iolar improvements. These promises won Menghe over, and in 1995 the MoD ordered 40 Martial Eagle airframes for training and evaluation, with a production license under negotiation. The OR-27 was still held out as an option if the Iolar did poorly, but the deal nevertheless marked a key milestone in Menghe's transition away from Letnian military equipment.

Iolar-M

The forty airframes delivered to Menghe in 1995 and 1996 were manufactured in Tír Glas under the designation "Menghean Eagle" (or Iolar-M). This custom variant combined the "Martial Eagle" airframe with the Al.85 Striga radar, as promised in the original international competition. The hardpoints were also modified to support Menghean bomb carriage units, which were produced locally in Menghe and fitted to the airframes after delivery.

Menghe's Iolar-Ms were assigned to the 56th Operational Testing Squadron, which compared their capabilities against those of the SR-7 and a single Or-27 purchased for testing. Pilots trained on the SR-7 roundly praised the new aircraft's thrust and agility, as well as its impressive radar suite. The Or-27 was found to have better agility, but the difference was deemed minor, and the Iolar's high thrust-to-weight ratio and full multirole capability easily counterbalanced it.

After 18 months of flight testing, the commanders of the 56th Operational Testing Squadron formally approved the Iolar-M, but only on the condition that the design be fitted with FOD deflection gear and Menghean avionics. Because the Daesŭngri Aircraft Corporation was still working on what would become the DS-9, and because Daesŭngri's design team had more experience working on light fighters, the license for the Eagle variant was passed to the Songrim Aircraft Corporation, which had designed the Songrim SR-7 and licensed the Or-24 as the Songrim SR-6.

Domestic production changes

License production of the Menghean domestic variant began in 1999, with deliveries starting in 2000. In line with previous aircraft of foreign origin - like the DS-1 and SR-3 - it was given a domestic manufacturer designation, Songrim SR-8G.

Based on feedback from flight trials with the Iolar-M, the Songrim design team made a number of changes to the airframe, some of them based on features of the Or-27. Because the Menghean Army operated a number of unpaved airfields, Army evaluators requested the addition of variable-angle grated screens on the floors of the intake channels. During takeoff and landing operations, these screens fold up to the intake channel ceiling, diverting bleed air and debris through a set of gill-like vents in the intake channel floor.

These underside vents, in turn, prevented the installation of a ground targeting pod and terrain following pod in the positions under the intakes. On later variants with conformal fuel tanks, ground targeting and terrain following pods would be fitted to the CFT hardpoints instead. Airframes without conformal fuel tanks are unable to carry terrain following and ground targeting equipment.

The question of how to change the refueling system stirred greater debate. No other Menghean combat aircraft refueled through flying boom receptacles like those on the Eagle family, and the existing refueling point was relatively far back, making it impractable to fit a refueling probe there. A retractable refueling probe in the nose would also require shifting the placement of radar electronics. In the end, Glasic representatives convinced Menghe to transition to a flying boom refueling system, and secured export orders for KC-130M tankers. Accordingly, Daesŭngri modified its land-based DS-9 models to feature a refueling receptacle on the spine. As an interim measure, Menghean tankers were fitted with wingtip pods carrying paradrogues for legacy aircraft.

Design

Performance

Like the GIA Eagle, the Songrim SR-8 has excellent performance, with low wing loading and a high thrust-to-weight ratio. Compared with the DS-5 and SR-7, it bleeds less velocity in maneuvers, and it accelerates more quickly, even in a vertical climb. The squared-off engine nozzles contain 2D TV/TR units, a standard feature on the Martial Eagle and later Glasic models. In addition to adjusting the nozzle size for optimal performance, the thrust vectoring panels allow for greater maneuverability, and the thrust reversal panels allow the SR-8 to rapidly decelerate after touching down on a runway. Combined with the ability to perform a vertical climb on full fuel with a light air-to-air loadout, this qualifies the SR-8 as a STOL capable aircraft, allowing it to operate from short sections of runway between bomb craters or improvised runways in Menghe's road network.

The SR-8's high fuel capacity also gives it superior range, which can be extended further through the use of conformal fuel tanks. Though they cannot be jettisoned in midair, the SR-8's CFTs produce less drag than external drop tanks and impose fewer limits on maneuvering. Although the SR-8G was primarily oriented toward air-to-air combat, subsequent variants capitalized on this high range and performance by integrating better ground-attack capability.

Early-production SR-8s used the Glasic TF-530 turbojet. Under a memorandum of understanding signed in 1997, the first 120 engines were manufactured in Tír Glas by Morris Foley Aero Engines, and the next 120 were shipped in knock-down kits for local assembly. Subsequent engines would be built under license by Donghae Heavy Industries. Locally built engines bear the designation Donghae Type 74-124.

Armament

In its "clean" configuration, with no CFTs attached, the SR-8 has nine hardpoints:

• 3 under each wing, in a combined unit (center: 2050 kg; sides, 2 air-to-air missile rails)
• 2 under each lower fuselage corner (YGG-6/7 only)
• 1 centered under the fuselage (2050 kg)

With conformal fuel tanks attached, the four corner under-fuselage hardpoints are obstructed, but six new hardpoints become available. These can be fitted with bombs, bomb racks, or air-to-air missiles. In a divergence from Glasic practice, the forward inner and outer hardpoints on Menghean SR-8 CFTs are wired to support the mounting of targeting pods on adapter pylons. This change was necessary because of the lack of targeting pod mounting points under the fuselage, and it moderately reduces the space available for other payloads.

Gun armament consists of a six-barreled rotary autocannon in the right wing root, carrying 400 rounds of 23×133mm ammunition. As Menghe already operates 23×115mm ammunition in some fighters - notably the DS-5 and SR-7 - standard Army and Navy practice is to designate the SR-8's gun as 23mm "new," in order to avoid errors in supply shipments and the arming of planes.

Sensors and electronics

The SR-8G and SR-8N use the Al.85 Striga radar, which has both air search and ground search modes. On the SR-8N, this radar has a built-in terrain-following mode, eliminating the need for a separate terrain-following navigation pod.

Later SR-8 variants would also introduce IRST sensors, mounted above the nose and offset to the left. Though Glasic Eagle models from the "Steppe Eagle" onward carried IRST sensors as well, the SR-8N and SR-8D use Menghean indigenous IRST designs.

Variants

Iolar-M

This is the designation given to the initial batch of forty custom Eagle models delivered to Menghe between 1995 and 1996. Originally placed in one of the Army's operational testing and evaluation squadrons, these airframes were transferred to the Menghean Navy in 2003 and currently serve with the 36th and 37th Heavy Fighter Squadrons in Yŏnpo-gu airbase.

SR-8G Jŏndoksuri

This designation was given to the first batch of SR-8 airframes domestically manufactured in Menghe between 1999 and 2005. The SR-8G can be easily identified by its lack of outboard under-wing hardpoints and its lack of an IRST sensor over the nose. It is very similar to the Glasic "Martial Eagle," leading to its official nickname "Jŏndoksuri," or "War Eagle." It does, however, differ from the Martial Eagle model in several respects, most notably in the addition of FOD deflection grills and the use of the Al.85 Striga radar in place of the Al.75 Striga on earlier models.

SR-8G1

The G1 designation is given to SR-8 airframes which were upgraded and overhauled in the late 2010s and early 2020s. In addition to replacing worn-out airframe components, these upgrades added the F110-GE-129++ turbojet engine, which can generate 89 kN of thrust dry and 160 kN in afterburner. G1 modifications also included radar and targeting system upgrades to permit the use of air-to-ground munitions, though the fly-by-light system and outboard underwing hardpoints were deemed too intensive to install as a refit.

SR-8N Chowŏnsuri

This variant was rushed into production in 2005 in response to the breakdown of relations with Maverica, Innominada, and the Entente Cordiale. It incorporates a broad swath of changes from the Glasic "Steppe Eagle" model, referenced in its "Chŏwonsuri" name. These include a dedicated air-to-ground targeting suite, an improved electronic warfare suite, an extra set of outboard under-wing hardpoints, and an IRST module forward of the cockpit. Despite its broad similarities, the SR-8N is not a Steppe Eagle copy: the IRST module is the same indigenous type used on the Daesŭngri DS-9G and N models, and the extra under-wing hardpoints are rated for payloads of 750 kilograms each, nearly double that of the Steppe Eagle outboard hardpoints. Similarly, while the SR-8N can carry conformal fuel tanks with six hardpoints each, these are Menghean-model hardpoints with bomb carriage points spaced at 250 and 480 millimeters. Beyond these changes, the SR-8N's engines are the same F110-GE-100 type used on the SR-8G.

SR-8D Gŏmdoksuri

The SR-8D was ordered in 2015 and introduced in 2016 as a generational improvement on the SR-8 design. Externally, it is very similar to the SR-8N, with the same hardpoint arrangement and sensor placement. The main visible change is the addition of an infrared missile approach warning system with apertures on the tail extensions and on either side of the fuselage. On close examination, the IRST module is slightly different, and houses an entirely new electro-optical sensor suite with greatly improved range and sensitivity. The canopy is identical in shape, but uses tinted glass, likely a radar-absorbent polymer related to the SR-12 program. Interestingly, the tinted canopy upgrade appears to be absent on the first batch of airframes delivered in 2016, only to be added in refits from 2018 onward.

Inside its nose, the SR-8D also carries an entirely new active electronically scanned array radar, domestically developed by the Samsan Defense Group. Though its exact capabilities are classified, this AESA system is claimed to have increased range, increased sensitivity against low-RCS targets, and reduced maintenance requirements. The air-to-air and air-to-ground electronics suite was also updated, adding compatibility with a wide range of new and upcoming Menghean munitions. Both the pilot and the copilot have large multifunction LCD screens, also developed by Samsan, and both can use the Keikō helmet-mounted display.

The SR-8D's airframe substitutes composite materials for aluminium in many places. This reduces the airframe's empty weight, improving performance. It also reduces the SR-8D's radar cross section: though far from stealthy, especially with extrernal armament, the SR-8D does generate a smaller radar return, reducing the range at which enemy radars can detect and lock it. Combined with the new AESA radar set, this upgrade gives the SR-8D a range advantage in air-to-air engagements, allowing it to exploit long-range missiles like the YGG-110 Chŏn Chang.

In keeping with the tradition of parallel designations, the SR-8D is also publicized under the nickname "Gŏmdoksuri," or "Golden Eagle."

SR-8R Bam

This variant was first unveiled as a small-scale model at a Menghean defense expo in 2015. At that time, it was already labeled SR-8R, even though the SR-8D had not yet been delivered to operational squadrons. It was also given the nickname "Bam," or "Night," in contrast to all other SR-8 variants, which had been named for eagles in tandem with Glasic variants.

Compared to the SR-8D, which is externally very similar to the SR-8N, the SR-8R has an entirely new wing design with jagged trailing edges. These changes reportedly increase internal fuel capacity and improve planform alignment with no negative impact on performance. The sides of the nose are also more angled, with some resemblance to the SR-12, and the fuselage angles outward under the wings, further improving planform alignment and adding space for small internal weapons bays. On the basis of these changes, the original plaque advertised the SR-8R as a "true" fifth-generation stealth aircraft.

Though a buzz of interest followed the introduction of the SR-8R model, there were no reports that the Menghean Ministry of National Defense has authorized procurement of the type. This would mean that the SR-8R designation is unofficial, as variant letters are allocated by the MoND rather than the designer. It seems likely that the MoND has prioritized the "safer" SR-8D, while focusing new fifth-generation development effort on the Songrim SR-12 and Daesŭngri's New Carrier Fighter. Because Songrim's fifth-generation design team is also preoccupied with the SR-12, there has been little subsequent news about the SR-8R, and as of 2021 no full-scale working prototype has been built. Scale models and marketing images have occasionally trickled to the press, some of them fake, possibly in an effort to deceive foreign intelligence.

Operational service

Ummayan Civil War

Menghe deployed two squadrons of SR-8Gs, or 24 aircraft in total, to its intervention in the Ummayan Civil War, where they supported land operations by intervening Menghean forces and the rebel Taleyan People's Front. Menghean commanders mainly used them as bomb trucks, making low-level attacks with unguided munitions while DS-5s provided air cover. A subsequent internal review by the Ministry of National Defense criticized this approach, which put both types at greater risk.

Menghean records show that a total of four SR-8s were lost during the deployment in Ummayah. Menghean sources claim that both combat losses were a result of surface-to-air missiles, while the remaining losses were accidental crashes. Sources in Tyran claim that one of the accidents was in fact a Typhoon pilot's air-to-air kill, and claim another probable kill from air-to-air fire. The latter may have been an SR-6 engaged at long range, also reported in Menghean records as an accident.

Innominadan Crisis

SR-8s saw combat again during the Innominadan Crisis, when Menghe launched a ground invasion of Innominada during its civil war. Employment of SR-8s in this conflict initially focused on delivery of standoff munitions from safe ranges, but after Maverica mobilized forces to prepare its own intervention from the north, the Menghean Army stepped up its tempo of operations in an effort to occupy Innominada's southern provinces before Maverican forces could arrive. This resulted in riskier attacks, often without proper SEAD support or preliminary reconnaissance. Non-combat accidents also became more common, with a mid-air collision between an SR-8 and a BAC 1-11 AWACS plane on February 5th, 2015 killing all aircrew involved. Subsequent reviews of the fighting also indicated that Menghean planners had underestimated the capability of Tyrannian- and Sieuxerrian-designed surface-to-air missile systems exported to Innominada.

Total combat losses from the Innominadan Crisis came out to 14 aircraft, of which eleven were lost to surface-to-air missiles and two were lost to ground fire, one of them nearly returning to base but losing power after its remaining engine shut down. The fourteenth was lost in air-to-air combat with an Innominadan Rafale fighter. As in Ummayah, some sources speculate that Menghean sources attributed one or possibly two further air-to-air kills to surface-to-air missiles in an effort to improve the SR-8's air-to-air kill-to-loss ratio, but the total figures for airframes written off appear to be valid. Five additional airframes were lost in accidents, including one in an air-to-air collision.

SR-8 losses over Innominada led Menghean Army Aviation to re-evaluate some of its strategies, as well as the quality and vulnerability of its equipment. Work on the Keikō HMD was restarted in an effort to improve pilots' situational awareness, and the MoND's procurement board began an investigation into the effectiveness of the SR-8's then-current ECM suite, which is also fitted to the DS-9. Three years after the Menghean intervention, Songrim unveiled the SR-8R, which incorporates additional passive sensors and makes use of radar-absorbent materials. Experience from SR-8 losses may also have pushed the MoND to accelerate work on the Songrim SR-12, though further issues with the latter plane would delay its production approval to 2019.

Total losses

As of December 2019, a total of 42 SR-8 and Iolar-M fighters of all variants have been lost in Menghean service. A loss is defined here as any damage so serious that the plane had to be written off from the national stockpile. Accidents in training and peacetime flights are included, and crashes during military operations which were not plausibly due to enemy action are counted under "non-combat losses" below.

Notably, the Iolar-M, Iolar-M2, and SR-8R have not seen combat, and the SR-8D was only introduced in 2013. Therefore, their low loss figures mainly indicate less active service in and out of combat.

Variant	Non-combat losses	Losses due to enemy action
Iolar M	2	0
Iolar M2	1	0
SR-8G	11	7
SR-8N	10	8
SR-8D	2	1
SR-8R	0	0
Total	26	16

Current status

As of December 2019, Songrim Aircraft Corporation reports that its factory in Insŏng has completed 406 SR-8 airframes of all types, not including Iolar-Ms built in Tír Glas. Subtracting 42 lost airframes and adding 50 surviving Iolar-Ms, this brings the total currently in service to 414, of which 156 (12 squadrons) are in Naval Land-Based Aviation and 258 (21 squadrons) are in Army Aviation, with 6 spares in reserve. These numbers are reported on the website of the Menghean Ministry of National Defense.

Declassified MoND documents state that the Army requires 288 airframes and the Navy 180 in order for all Advanced Multirole squadrons to be fully equipped; with 32 spares, the total procurement goal comes out to 500 aircraft. A central government press release states that mass production of the SR-8R will continue until at least 2025, by which time the production goal will have been met. Production may also be renewed for additional years to replace Iolar-Ms, which the MoND does not consider front-line units, and possibly to replace early-model SR-8Gs.

The appearance of the fifth-generation Songrim SR-12 has also led to speculation about the future of the SR-8 program. Though the Menghean government has not published firm cost figures on either airframe, the SR-12 is believed to be considerably more expensive in both procurement and maintenance, and will not be able to replace the SR-8 on a 1:1 basis. Notably, while both aircraft are reportedly produced at Songrim's Rogang Aircraft Factory, the 2025 deadline suggests that SR-8 production is continuing at 3/4 of its peak level. Some analysts speculate that production of both aircraft will continue into the foreseeable future, with full retirement of the SR-8 occurring as late as 2075.

Operators

• Idacua: Idacua operates 60 SR-8Ns as of 2021.
• Template:Country data Kolodoria: Kolodoria placed an order for 90 SR-8Ns in 2019. The first batch of airframes were delivered later that year, all of them secondhand airframes transferred from Menghean front-line squadrons equipped with SR-8Ds.
• Menghe:

Specifications (SR-8G, no CFTs)

General characteristics

• Crew: 2 (pilot, WSO)
• Length: 19.43 m (63 ft 9 in)
• Wingspan: 12.77 (41 ft 11 in)
• Height: 5.81 m (19 ft 1 in)
• Wing area: 55.66 m² (599 ft²)
• Empty weight: 12,830 kg (28,290 lb)
• Loaded weight: 21,960 kg (48,410 lb)
• Max. takeoff weight: 38,000 kg (84,000 lb)
• Powerplant: 2 × Donghae 74/124 afterburning turbojet
  • Dry thrust: 74 kN (16,630 lbf) each
  • Thrust with afterburner: 124 kN (27,876 lbf) each

Performance

• Maximum speed:
  
• At sea level: Mach 1.2 (1465 km/h; 792 kts)
• At altitude: Mach 2.5 (2,655 km/h; 1433 kts)
• Combat radius: 950 km (590 miles) (6,000kg payload, hi-lo-hi mission)
• Ferry range: 5,500 km (3,400 miles) with CFTs and three external tanks
• Service ceiling: 20,000 m (66,000 ft)
• Wing loading: 394 kg/m² (80.8 lb/ft²)
• Thrust/weight: 1.15 (full internal fuel)

Armament

• Guns: 1× GP-24/6 revolver cannon, 475 rounds (23x133mm)
• Hardpoints: 13 (4 per wing, 4 under fuselage, 1 centerline) without CFTs with a capacity of 10,400 kg