Senkaku Sentinels - Air War over the East China Sea

[apophenia]

Senkaku Sentinels - Part 1: Ramping up in a Crisis-Ridden Region

Analysts are still divided about why the Senkaku Incident turned 'hot' in May 2023. The increasingly aggressive stance adopted by China and its People's Liberation Army played a part. Mixed messaging from politicians in both Beijing and Tokyo added to the confusion. But the conflict may simply have been the inevitable outcome of Xi Jinping's escalating, expansionist rhetoric. To get to grips with the Senkaku Incident, it is necessary to review regional events and tensions immediately prior to the outbreak of active hostilities.

"You say you’ll change the constitution. Well, you know ..."

In March 2018, the Party Constitution of the Communist Party of China (CPC) and the 'un-written' State Constitution of the People’s Republic of China (PRC) were revised to eliminate presidential term limits. [1] This effectively made Xi Jinping 'President-for-Life' - as well as CPC Party General Secretary and Chair of the Central Military Commission. World opinion of China had been cooled by the militarization of the South China Sea and perceived 'debt traps' laid by Beijing's Belt and Road Initiative. International attitudes towards China became positively chilly when the July 2021 'Black Sheep' crack-down by the People's Armed Police (PAP) and People's Liberation Army (PLA) in Hong Kong further damaged the PRC's human rights reputation. [2]

Perhaps surprisingly, Beijing did little to halt the exodus of Hong Kong residents lucky enough to have foreign passports. Nor did the social-control meltdown in Hong Kong interfere with the PLA's probings of Taiwan's security arrangements.

Even in the 21st Century, Japanese relations with Taiwan have been intentionally 'opaque' in hopes of maintaining stable (and profitable) Japan-PRC relations. A modest improvement came with the 2021 establishment of the Japan-Taiwan Maritime Cooperation Dialogue (JT-MCD). Outwardly, little changed with the JT-MCD. Japan did not recognize the Republic of China as a sovereign state, only Taiwan as a maritime neighbour. As before, in the event of war between the ROC and PRC, Japan promised little more than humanitarian aid. And Taiwan upheld its territorial claims to 'Tiaoyutai' ... although Japan's 'stewardship' of the Senkaku Islands was acknowledged by Taipei. More positively, the JT-MCD allowed for intelligence sharing between Japan and Taiwan along with the coordination of their respective coast guard activities. [3] Surreptitiously, the coast guards acted as information-sharing intermediaries. 'Sanitized' Japanese Self-Defence Force intelligence was automatically supplied to the Japan Coast Guard (JCG). Intel on Chinese military activities, especially those near Japan's southern archipelago, was then shared with the ROC Coast Guard which, in turn, passed on this information directly to the Taiwanese military.

JT-MCD coordination of coast guards also helped address some fisheries issues through bipartisan research exercises. And there matters may have come to rest. A sea-change (no pun intended) came with the appointment of retired Vice-Admiral Yoji Koda - former Commander-in-Chief, JMSDF Fleet - as head of the Japanese delegation to the JT-MCD. As VAdm Koda had been an advisor to the Japan National Security Secretariat, the Government of Japan took seriously any concerns and warnings he might relay about about Chinese naval strategy. So too did Koda-san's Taiwanese opposites. That was the key motivator for arranging for the covert exchange of military intelligence. It was also a major instigator of a more forward positioning of Japan Coast Guard assets in the aftermath of repeated incursions by the Chinese Haijing [4] around the Senkaku Islands in February 2021.

Haijing High Jinks - 'Little Blue Men' and 'White Hulls'

As it turned out, the Japan Coast Guard's redeployment of assets south to the Ryukyu Islands chain came not a moment too soon. Incursions by Chinese vessels into the Japanese-controlled waters around the Senkakus had begun again in earnest. Towards the end of March 2023, JASDF Kawasaki P-1 aircraft on routine patrols began noting odd formations of Chinese fishing boats skirting the edges of Japanese territorial waters off the Senkaku Islands. By April, a regular cat-and-mouse game had begun between patrolling Japan Coast Guard ships and Chinese small craft pushing closer to the Senkakus. The pattern was worryingly similar to August 2020 when more than 100 small Chinese vessels were used to harass the Senkakus. Once again, Chinese 'fishing boats' transited the region without fishing and, most revealingly, without transmitting the Automatic Identification System (AIS) data, as such vessels are legally required to do.

Encounters became increasingly tense in the waters off the Senkakus during April 2023. As Japan Coast Guard vessels tried to escort interloping 'fishing boats' out of these territorial waters, packs of Chinese boats swarmed and circled the JCG craft. On 17 April, Chinese tactics began to ramp up. After a mock ramming attack by a Chinese boat on a 35-metre JCG Patrol Craft, guardsmen from PC-15 Kurinami [5] prepared to board their erstwhile attacker. That boarding plan was thwarted by the sudden appearance on deck of uniformed Chinese personnel armed with assault rifles. This appearance by the 'Little Blue Men' confirmed that these 'fishing boats' were actually operated by what the US DOD calls the People's Armed Forces Maritime Militia (PAFMM). Sensibly, the commander of the PC-15 withdrew to a safe distance and monitored the Chinese flotilla.
   
After this encounter, relations between the two nations quickly heated. As the Japan Coast Guard deployed more capable vessels around the Senkakus, Chinese Haijing cutters replaced Maritime Militia units. A special delegation of the Government of Japan flew to Beijing in an attempt to cool things down. The diplomatic mission seems to have had the opposite effect. In 'post-game analysis', it has been suggested that Tokyo's failure to invoke Article V of Anpo/Ampo (the 1960 Japan/United States Security Treaty) emboldened the Chinese leadership. However, such maritime clashes had occurred previously without being regarded as "armed attacks by a third party". Clearly, for reasons of internal politics, key members of the Suga Cabinet thought it essential that Japan be seen to be defending itself. [6]

At sea, several attempts were made by Haijing cutters to ram JCG patrol boats. The first incident, on 10 May 2023, involved Haijian 3184, an 1,800 tonne Shuwu class patrol cutter which ran at the 26 tonne Shiraume class patrol boat CL-06 Maya Sakura. [7] With its manoeuvrability and 29 knot top speed, the Maya Sakura was able to evade Haijian 3184. Another JCG patrol boat - the Hayagiku class CL-09 Tobiume was less fortunate. Slightly slower than Shiraume class boats, CL-09 was caught out by a 1,700 tonne Zhaotim class patrol cutter - the Yuzheng 45013. Rammed in its stern, the Tobiume quickly foundered and sunk. The JCG crew was picked up by the Haijing cutter and interned at Wenzhou until their release was negotiated six months after the Senkaku Incident had ended.

The next victim was the 10 metre Orion class surveillance boat, SS-76 Muribushi. [8] Although very fast, these fibreglass 'SS' boats proved vulnerable to the high-pressure water cannons mounted on Haijing cutters. That was the fate of SS-76. With its wheelhouse smashed by water cannons, the disabled 5 tonne craft was run down by Haijian 301, a ship with 100 times the displacement of the JCG boat. Rammed at high speed, the Muribushi didn't so much sink as disintegrate. Its task accomplished, the Haijing's Kaobo class simply sailed away, leaving the survivors from SS-76 to fend for themselves in the water. With that callous act, the Chinese had drawn first blood.

(To be continued ...)

_________________________________________

[1] Under the 1978 Party Constitution, Xi would have had to leave office at the end of his second term in 2023.
 
[2] The 13 July 2021 student protests in Kowloon's Hung Hom district marked the anniversary of the passing of Hong Kong's 'New Security Law'. Xia Baolong, the Director of the Hong Kong and Macau Affairs Office was sacked in the aftermath of the protest suppression. However, it seems that most of the civilian casualties were at the hands of the Hong Kong Police Force (and some PLA reservists), not People's Armed Police personnel.

[3] There were also tentative plans within the JT-MCD to permit exchanges of Japanese and ROC military liaison officers. However, a definitive decision on such exchanges was passed over to the 2024 JT-MCD sessions.

[4] This was reinforced by a reorganization of JCG assets - resulting in a considerable increase in the number of hulls assigned to 11th Regional Coast Guard Headquarters, Okinawa. We have avoided the PRC term 'Chinese Coast Guard'. Despite its use of 'white hulls', the Haijing is a component of the People's Armed Police (PAP).
   
[5] PC-15 Kurinami (ex-Takamatsu) was one of two Hayanami class Patrol Craft transferred south from the 6th Regional Coast Guard. The other hull was PC-12 Setogiri (ex-Imabari).

[6] This position was most strongly supported by then-Minister of Defence Nobuo Kishi - brother of former PM Shinzo Abe. (In the Feb 2024 Suga Cabinet shuffle, Kishi was moved to the Ministries of Administrative Reform and Civil Service Reform. In the Defence portfolio, Kishi was replaced by his predecessor - Taro Kōno. In that shuffle, Kōno also retained his position as Minister of State for Okinawa and Northern Territories Affairs.) Was Kishi 'shuffled' for advocating that Japan 'go it alone"? Many believe that it was Kishi's off-the-cuff remarks on the desirability of nuclear weapons for Japan which ultimately cost him the Defence portfolio.

[7] 'CL' is for 'Craft, Large' which refers to a variety of JCG general purpose patrol boats with nominal 20 metre lengths.

[8] Somewhat awkwardly, 'SS' is for 'Surveillance boat, Small'. In 2021, the JCG's 11th Regional District had four 'SS' boats - SS-62 Antaresu, SS-75, SS-76 Muribushi, and SS-77. These were later joined by two transfers from the 6th Regional District - SS-63 Bega (ex-Iwakuni) and SS-71 Kentaurusu (ex-Uwajima).

[apophenia]

Senkaku Sentinels - Part 2: Jumping from the Kiyomizu Stage [1]

With the loss of the unfortunate helmsman from SS-76 Muribushi, it was obvious to all that China was quite prepared to use deadly force. Less clear was what Beijing's immediate motives were in and around the Senkaku Islands. However, it was apparent that the People's Liberation Army Air Force (PLAAF) was also increasing its routine proddings and testing of Taiwan's air defences and readiness. Were the April 2023 Chinese probings in the Senkakus a feint intended to draw attention away from some imminent PLA move against Taiwan? No one knew.

"You can’t see the whole sky through a bamboo pole" - Over-Flights and ADIZs

The Air Defence Identification Zones (ADIZs) of Japan and the People's Republic of China overlap (see attached map). This was intentional since the PRC claims the Senkaku Islands as its own 'Diaoyu' Islands. On station off remote Taisho Island - the easternmost of the Senkakus - the JCG patrol vessel PLH-06 Okinawa detected overflights by Chinese aircraft enroute for the Taiwanese ADIZ. [2] Since the research vessel JS Asuka (ASE-6102) was then performing trials with an AESA air defence radar system, this Japanese Maritime Self-Defence Force (JMSDF) ship was redirected to the Senkakus to track Chinese incursions into Japanese air space.

It did not take PLAAF aircraft long to detect radar emissions from the JS Asuka. On 06 May 2023, ASE-6102 found herself being targeted by the locked-on radar of an overflying Chinese Xian H-6M 'Ubazame' medium bomber. [3] This cruise missile carrier did not deviate from its flightpath towards Taiwanese air space but the PLAAF crew kept their targeting radar locked on the JS Asuka as the bomber overflew Uotsuri Island. The implied threat was clear enough - another H-6 variant is a dedicated anti-ship missile carrier. On 09 May, JS Asuka was replaced in its 'radar picket' role by the Kongō class  guided missile destroyer, JS Kirishima (DDG-174). In theory, the JS Asuka was capable of defending itself against air attack - its 8-cell Mk41 VLS being armed with RIM-162 ESSM. However, JS Kirishima has a 90-cell Mk 41 VLS loaded with a preponderance of RIM-66 SM-2MR surface-to-air missiles. Should PLAAF aggression extend beyond radar 'lock-ons', JS Kirishima could respond in kind.

"A single arrow is easily broken, but not ten in a bundle ..."

Chinese landings on the Senkakus took Tokyo off guard. It shouldn't have surprised anyone - Chinese activists had landed there in the past. For the most part, the 'Little Blue Men' landed only long enough to plant Chinese flags before leaving again. Still, these were clear breaches of Japanese sovereignty and the Government of Japan felt obliged to respond in force. Actually, a Japanese 'response in force' had already begun with the deployment of Tokkei-tai personnel aboard JCG craft in the disputed zone. Most of this 'Special Security Team' were armed to prevent Chinese boardings. But Tokkei-tai marksmen were also armed with a mix of 7.62 mm Howa M1500 sniper rifles and 12.7 mm McMillan Tac-50 anti-material rifles. If ramming by a Haijing vessel was imminent, JCG marksmen were under orders to target the Chinese ship's bridge with no warning shots.

Similarly, Japan's Self-Defense Force's Tokubetsu-Keibitai was embarked upon deployed JMSDF ships. This Special Boarding Unit (SBU) was made responsible for disarming any 'Little Blue Men' the JMSDF were able to close with at sea. Boarding parties preferred compact MP5A5 SMGs but Type 20-F carbines were also used. 'Overwatch' of boarding parties was provided with designated marksmen using Heckler & Koch MSG90 sniper rifles and Howa Minimi 5.56mm light machine guns. A pattern was quickly established in boarding operations. Chinese deck crews - especially 'Maritime Milita' - succumbed quickly. Firefights were far more likely to break out below-decks. The revised boarding drill became 'sweep' the decks, then drop smoke grenades down hatches and into vents. Only on a few, rare occasions were follow-up fragmentation grenades required.

Ashore on the Senkakus were members of the Suiriku kido-dan or Amphibious Rapid Deployment Brigade - with dramatic footage released of the ARDB coming up beaches in their own AAV-7A1 light armoured vehicles. [4] More dramatic still was the deployment of another element of the JSDF's Tokushusakusengun (Special Forces Group) -  the 1st Airborne Brigade (1AB) which was shown parachuting on the islands from 401st Tactical Airlift Squadron (TAS) C-130H Hercules. Equipment drops followed from Kawasaki C-1s of the 403rd TAS. As impressive as all this imagery was, in reality, Japan was less capable than it appeared from such comprehensive and rapid deployments of its troops and equipment. The truth of the matter didn't match the rhetoric of independent action coming from the Government of Japan.

"Stand Back and Stand By" - The Government of Japan Adopts a More Independent Stance

What Tokyo didn't want was a focus on the crucial aid by US forces in Japan. There had been concerns about how the United States would respond to Chinese threats to the Senkakus. Reassurances came within days of President Biden's inauguration - for the new Administration, the Senkakus fell under Article V of the Japan/United States Security Treaty. As reassuring as that was, the Suga Administration was determined to emphasize Japanese resolve and capabilities. That stance primarily reflected the preferences of Suga's hawkish then-Minister of Defence, Nobuo Kishi. This decision not to invoke Article V of the so-called Anpo/Ampo treaty would come back to haunt all post-mortums of the Senkaku Incident. [5]

Behind the scenes, the 1960 Japan/United States Security Treaty remained essential. As noted, the insertion onto the Senkakus of the JSDF's Amphibious Rapid Deployment Brigade and 1st Airborne Brigade (1AB) made for good media events. Supporting those units once deployed onto these remote islands was another matter. Much of the literal 'heavy lifting' was done on the quiet by the USMC's new 3rd Marine Littoral Regiment based in Okinawa. [6] Officially, these US activities were part of a US Expeditionary Advanced Based Operations (EABO) exercise. In reality, the Marine Corps was adding much-needed logistics support to the JSDF in a conflict zone. Without such back-up, it is unlikely that Japan could have sustained its Senkaku operations in 2023. [7]

USMC assistance had already made another of Japan's material advantages possible. The JMSDF's Izumo class 'helicopter destroyers' were designed from the outset to accommodate STOVL fighters like the Lockheed-Martin F-35B Lightning II (although that was not publicly admitted until 2018). Still, Japan's rapid deployment of shipboard F-35Bs took PLA intelligence off guard. Three factors had contributed to this speedy deployment. First was JASDF access to the F-35B expertise of Marine Fighter Attack Squadron 121 based at MCAS Iwakuni as well as JASDF secondments aboard the USS America (LHA 6) for operational training of Japanese pilots. The second was the willingness of the Marine Corps to defer delivery of a dozen F-35B Lightning IIs in favour of Japan. [8] The third was the JMSDF's decision to not install 'ski slope' decks on its two Izumo class STOVL carriers. That last choice sped up Izumo refits but limited take-off weights for the JASDF F-35Bs. As a result, Lightning IIs operated strictly in the crucially-needed air superiority role throughout the Senkakus Incident.

"Jaku niku kyo shoku" - The weak are meat; the strong eat

With no runways on the Senkaku Islands, the immediate in-theatre air-defence fighter became the JASDF F-35B Lightning IIs embarked aboard the JMSDF's Izumo class 'mini carriers'. Each vessel carried a half-dozen F-35Bs (alongside SH-60K helicopters and V-22 Osprey tilt-rotor craft). JS Kaga was first on station due west of the Senkakus on 28/29 April 2023. She was relieved on 10 May by JS Izumo which was positioned further east, between Taisho Island and the main grouping of the Senkakus. Although the decks of the modest Izumo class carriers were crowded, the ship-launched F-35Bs had a huge advantage over PLAAF opponents flying near the limits of their range and load-carrying abilities.

To back up the ground forces, Japanese Air Self-Defence Force (JASDF) F-15JSI (Japanese Super Interceptor) fighters were deployed to a Forward Operating Location at Shimoji Air Base (a part of Miyako Shimojishima Airport) on Shimoji-shima in the Ryukyus. With their cruising speed of 1,000 km/h, newly-upgraded F-15JSIs on active alert could be scambled from Shimoji and, in less than half an hour, would be intercepting PLAAF H-6 'Ubazame' bombers intruding over the Senkakus. Since it was a flying distance of only 170 km from the southern Ryukyus to the Senkakus, the intercept role could also be performed by the JASDF's single-engined Mitsubishi F-2 fighters. But the latter aircraft were more normally employed in an anti-shipping role.

(To be continued ...)

_________________________________________

[1] The Kiyomizu stage is a lofty observation deck at Kyoto's Kiyomizu Temple. Legend says that all wishes will come true if one jumps off this stage but remains uninjured. However, any jumper who dies, goes directly to Nirvana. In other words, commit fully to an endeavor and you cannot lose.

[2] The Okinawa is a 4,000 tonne Tsugaru class 'Patrol vessel, Large, Helicopter'. In the 11th Regional District, PLH-06 has two sister ships - PLH-04 Uruma and PLH-09 Ryukyu. All of the 11th's PLHs are home-ported at Naha.

[3] 'Ubazame' ('Basking Shark') is the slightly derisive JASDF code-name for maritime-role Xian H-6s. In a conventional bomber role, the H-6 is code-named 'Tanuki' - 'Raccoon Dog' being the closest Japanese approximation to the old NATO reporting name 'Badger'.

[4] To address the Chinese overflight challenge, the ARDB were accompanied by air defence missiles (Type 03 Chu-SAM medium-range and Type 11 short-range SAMs) along with their associated truck-based radar. These air defence systems were delivered by the Osumi class LST 4002 Shimokita and put ashore on Uotsuri-shima by the Shimokita's LCAC hovercraft.

[5] In one assessment, Kishi's strong ties with Taiwan are seen as a negative influence. The argument goes, that there would have been deterrence value in an earlier basing of defensive weapons on the Senkakus. Instead, Kishi had emphasized the deployment of radar systems to track Chinese overflights headed for the Taiwanese ADIZ. Another argument places blame with Suga himself. Had Taro Kōno remained Minister of Defence, better advantage might have been taken of Nobuo Kishi's personal connections to Taiwan's leadership - in particular, with President Tsai Ing-wen.

[6] The 3rd MLR was actually the very first Marine Littoral Regiment stood up in 2022. The Regiment's seemingly out-of-sequence numbering results from this unit having evolved from the the 3rd Marine Regiment) ... Expeditionary Advanced Based Operations (EABO)

[7] An example was the delivery in-theatre of Type 88 ground-based coastal defence systems and their SSM-1A missiles. Normally truck-mounted, these missile launchers were quickly palletized to allow their sling-loaded delivery to Uotsuri-shima by USMC MV-22 Osprey tilt-rotor transports. Such flight freed up the JASDF's half-dozen operational Ospreys to focus on other tasks.

[8] This deferment was possible because of an earlier decision to reduce the number of aircraft per VMFA squadron.

[Old Wombat]

Interesting reading.

[apophenia]

Senkaku Sentinels - Part 3: Opening Act for the Advantage of Air Power

A lone Japanese strike aircraft was inbound and air-search radars began to light up aboard PLA-Navy East Sea Fleet ships. Multiple PLA-N calls went out for PLAAF top cover and were responded to by two 172nd Brigade J-16 Flanker fighters. Overhead, WSO Kong Jun Shàowèi (Air Force 2nd Lt) Zhang Honglei quickly found the Japanese interloper on radar.  Meanwhile, the PLA-N's anti-aircraft defences got lucky - the first incoming Japanese ASM-2 Kai anti-shipping missile was hit by a Chinese HQ-10 point-defense missile. The second Japanese ASM-2M impacted amidships on a Type 056 Jiangdao class corvette - Quanzhou (588). Lead pilot, Kong Jun Shàngwèi (AF Major) Bian Xuan and his wingman, Kong Jun Zhongwèi (AF 1st Lt) Jin Huihui punched off their drop tanks and dove to intercept. With their Shenyang J-16 Flankers [1] in full afterburner, the Chinese pilots quickly closed the distance.

The second volley of missiles from the Japanese strike aircraft had been launched. The first ASM-2 Kai narrowly missed the 4,000 tonne Type 054A Jiangkai II class frigate Yangzhou (578). The second missile flew high and took out the Yangzhou's Type 382 search radar antenna. With missiles fired, the launch aircraft had turned away to the east to evade the Yangzhou's HQ-16 surface-to-air missiles [2] and anti-aircraft gun fire. Almost at once, the Japanese aircraft reversed its direction and applied afterburner - obviously the fast-diving Chinese fighters had been detected. Easing his throttles, Major Bian fired the first of his PL-10 missiles ... but this 'Pen Lung' [3] homed on the Japanese aircraft's towed RF decoy.

The Japanese aircraft dropped to wavetop height ... while continuing on its odd, westward course. Suddenly, it became apparent that this aircraft was not trying to evade its Chinese pursuers - it was heading straight for the Zibo, a Type 052D Luyang III class destroyer. This had turned into a Kamikaze mission! Bian hit his afterburners again and fired off two more PL-10s. The first 'Pen Lung' struck a wavetop and detonated but the second missile took the tail off of the Japanese fighter. The crippled aircraft hit the surface inverted as the water all around it erupted with exploding shells from the Zibo's AA guns. There was no sign of the Japanese pilot ejecting. As the two J-16s climbed out over the Zibo, Jin's WSO, Kong Jun Shàowèi Liu Jiaji, called 'Bingo Fuel' and the two fighters headed towards Zhangzhou airfield - their temporary home base. [4]

"Seiten no heki-reki" - A Thunderclap From a Clear Sky

Almost immediately, a second Japanese strike aircraft appeared. PLA-N calls resumed for top cover ... but, low on fuel, Bian and Jin could not respond. Evidently, the first JASDF pilot had sacrificed himself to distract from his companion. The second aircraft loosed an ASM-2 Kai missile at the Binzhou - a Type 054A Jiangkai II class frigate - to no effect. With his mount apparently struck by anti-aircraft fire, the Japanese pilot ripple-fired his remaining three missiles at the blinded Zibo. This time, two of those missiles struck with deadly effect. The crippled Japanese aircraft augered in close enough to the Rongcheng - a Type 082 Wozang class mine countermeasures vessel - that this MCM was lightly damaged (although this was unlikley to have been intentional - the aircraft clearly being out of control by that stage). Once again, no pilot was seen to eject from the stricken Japanese aircraft.

In this first major air-to-surface encounter of the Senkaku Incident, results seemed to be mixed. The Japanese had committed their strike aircraft in a rather piecemeal fashion and both aircraft were lost. No East Sea Fleet ships had been sunk. But that was not to say that the PLA-Navy had suffered no losses. The corvette Quanzhou had been holed through her living quarters decks; the Rongcheng MCM had damage to its wheelhouse; and the frigate Yangzhou was a shambles - with fires burning below decks and battle damage to multiple systems. All three vessels had to withdraw and limp back to Wenzhou along with the older Type 053H3 Jiangwei II frigate Putian which had taken the Yangzhou under tow.

As for the lost Japanese aircraft, multiple PLA-N gun crews made claims for the second aircraft downed. For the first, Kong Jun Shàngwèi Bian Xuan claimed the first Mitsubishi F-2 strike fighter 'kill' of the Senkaku Incident. Understandably, Maj. Bian had misidentified the Japanese aircraft he had shot down. That was no F-2. It was the previously unannounced Lockheed Martin/Mitsubishi A-16AJ - a UCAV (Unmanned Combat Aerial Vehicle) conversion of F-16A fighters. In the confusion of conflict, it would take the Chinese military some time to realize that they were now up against unmanned strike aircraft.

The JASDF's maritime strike capability would eventually turn the tide during the Senkaku Incident. However, in this brief air war over the Senkakus, the dramatic events which followed this opening air-sea battle are well-known. It is not our intention to retell those stories here. Rather, we will focus of the development of the aircraft which played those starring roles - the LM/Mitsubishi A-16AJ and the manned Mitsubishi F-2A.

Image The mounts of KJ Shàngwèi Bian Xuan/KJ Shàowèi Zhang Honglei and KJ Zhongwèi Jin Huihui/KJ Shàowèi Liu Jiaji. Both Shenyang J-16Cs lack individual aircraft numbers. Jin's aircraft has a replacement fin tip but features no distinguishing markings. Bian's fighter carries the PLAAF's FTTB crest on its fins and two victory stars below the cockpit on the portside. [5]

(To be continued ...)

_________________________________________

[1] Many Japanese pilots found the NATO reporting name 'Flanker' difficult to say. To the JSDF, the PLAAF's Shenyang J-16 was a 'Fuka' (Shark). 'Fuka' was derived from the Chinese nickname 'Feisha' (Flying Shark).

[2] The HQ-16 surface-to-air missiles were also known as FL-3000N (for Naval) Flying Leopards. To the JSDF, the HQ-16 was code-named 'Nutaunagi' (or Hagfish).

[3] In Chinese, Pen Lung means 'Air Dragon' (the PL-10 also being known as the 'Pili' or 'Thunderbolt'). No JSDF code name was applied but the PL-10 was sometimes referred to as Chu-Suzume ('Chinese Sparrow') ... and acknowledgement of its ultimate US origins.

[4] In peacetime, the 172nd Combat Aircraft Air Brigade is home-based at Cangzhou, Hebei. Normally operating as the PLAAF's 'Blue  Force' OpFor unit, the 172nd Bde's two J-16 flight groups were forward-based at Zhangzhou for operations over the East China Sea.

[5] For propaganda purposes, Bian and Zhang were awarded 'kills' for both Japanese aircraft. No doubt this was to the chagrin of PLA-N gunners and the embarassment of the over-rewarded aircrew. The display of the FTTB crest reveals KJ Shàngwèi Bian's part-time association with that 171st Bde test unit (also home-based at Cangzhou).

[apophenia]

Senkaku Sentinels - Part 4: "Review past, know future" [1]

The notion of an unmanned F-16 wasn't new. In the 1990s, Lockheed (and later, Lockheed Martin Tactical Aircraft Systems or LMTAS) [2] proposed or undertook a whole range of improvement programmes for the F-16 Fighting Falcon airframe. The most extreme conversion proposal was the late '90s F-16A Long Range Defender UCAV - involving replacing existing wing panels with thicker, longer, low-aspect ratio wings of 18.29 m span. To suit the pilotless UCAV missions, the F-16 cockpit was to be gutted and replaced with an additional 1,300 litre fuel tank. The F-16's fixed gun armament would also to be removed.

Other F-16 improvement programmes were of a more incremental nature. Two were developed (at least in part) for export F-16As. The first was a tail-mounted braking parachute thought necessary for landing on wet or icy runways. The second were a pair of Conformal Fuel Tanks (CFTs). The latter were tested as 'shapes' in 1994 (although LM did not commence full CFT flight-testing - on an F-16C - until Sept 2001). Use of CFTs more than made up for the lack of a centreline tank - usually replaced on USAF operational missions by an AN/ALQ-131 Electronic Countermeasures (ECM) pod [3] in any case. Pod-carrying USAF F-16As carried twin underwing drop tanks - usually of the smaller 1,400 litre variety [4] - to make up for the absence of a centreline tank. However, on the F-16A, use of an ECM pod and twin drop tanks meant that only two underwing pylons were free for carrying weapons. CFTs freed-up underwing pylon space. And, unlike drop tanks, those CFTs produced very little additional drag.

Both UCAV conversion and Conformal Fuel Tanks played a major part in the design of the Lockheed Martin/Mitsubishi A-16AJ. This joint-venture conversion program made use of old F-16As stored by AMARC at Davis Monthan AFB in Arizona. Removed from storage and with their wings removed, F-16A airframes were trucked the 190 km to a previously under-utilized LM facility in Gilbert, AZ, for a more complete stripdown. From there, airframes were air-shipped to Mitsubishi at Nagoya (either by contracted USAF C-17As or by leased An-124 cargo aircraft from Ukraine's Antonov Airlines). To put it mildly, these procedures were unusual for US Foreign Military Sales (FMS) of surplus equipment. Generally, such sales demand that all upgrade work be performed in the US by American contractors. However, the surplus F-16As were provided under an 'Other Transaction Authority' procedure – effectively meaning that the modified airframes remained the property of the US Government.

"Fishing sea bream with shrimp as bait" - Transforming the Fighting Falcon [5]

At Mitsubishi's Komaki South facility at Nagoya, a full stripdown and rebuild line was established for the F-16As. [6] Many of the systems were refurbished but otherwise unchanged - including the Pratt & Whitney F100-PW-220E turbofan engines. The most dramatic visual change introduced was the removal of the cockpit, complete with the F-16A's distinctive canopy. The fly-by-wire F-16A controls lent themselves to UCAV conversion - all control inputs being fully digital to begin with. The forward section of the former cockpit area was occupied by YDK Technologies UCAV control systems and a Subaru RPVC (Remote-Pilot Vision Centre) - revealed by its Fujitsu E/O turret protruding above the revised fuselage profile. Aft of the YDK control systems bay was a new 995 litre 'F4T' (Far-Forward Fuselage Fuel Tank). This F4T fed fuel into the existing forward-fuselage internal tank while the adopted Conformal Fuel Tanks fed the main fuselage tank. [7]

Another upgrade being applied was the LM-supplied Diverterless Supersonic Inlet (DSI) with its large, hump-like structure blended with the lower fuselage. This inlet was designed to slow entering air at supersonic speeds while deflecting boundary layer air. More importantly for the Mitsubishi project, the DSI eliminates the 'corner reflectors' of the F-16A's boundary layer splitter plate while also blocking radar 'views' of the engine's compressor face from low angles. While the base F-16A airframe is in no way 'stealthy', its wing-body blending does reflect incident radar energy away from potential receivers. This unintentional effect, combined with the DSI and removal of the canopy, does serve to reduce the F-16A airframe's radar signature.

While the LM/Mitsubishi modifications could not be considered a 'least-mod' conversion, work progressed quite speedily. The first public sign of progress was a manned analogue completed almost entirely by Lockheed Martin at Gilbert. Final assembly of this 'Proof-of-Concept' aircraft was undertaken by Mitsubishi at Komaki South with its maiden flight being made at Nagoya. The Japan Defence Agency re-designated this POC as their XA-16FTB - for Experimental Attack model 16, Flying Test Bed. This Fighting Falcon was no longer a 'fighter', it was now regarded as a dedicated attack aircraft.

Image The XA-16FTB (Flying Test Bed) manned prototype/POC demonstrator, '019'. Beyond its cockpit, '019' reveals other differences from both the unmanned XA-16AJ prototype which followed and operational A-16AJ UCAV conversions. Note that at this stage, '019' retains its wingtip missile rails while lacking the drag-chute tail-housing of the F-2A. [8] This aircraft was never fitted with Conformal Fuel Tanks - the CFTs being proved on the follow-on XA-16AJ prototype. Another distinct feature of the XA-16FTB was the mocked-up undernose AN/AAQ-40 EOTS housing (this Electro-Optical Targeting System housing being later removed). [9]

Painted in the red-and-white colours of the Air Development & Test Wing, '019' is an ex-USAF block 15 F-16A. The insignia of the ADTW is worn on the tailfin (along with the logo-signature of its parent organization, ATLA). [10] Note that, as a result of Japan's unusual F-16A 'purchase' agreement, the XA-16FTB retains its original USAF serial - 82-1019. (A similar stricture applied to the unmanned prototype XA-16AJ UCAV '738' which also wore its original USAF serial - 81-0738.) Now retired from active JASDF use, the XA-16FTB airframe is currently on loan to the Gifu-Kakamigahara Air and Space Museum.

(To be continued ...)

_________________________________________

[1] On ko chi shin is akin to the Chinese wengù-zhixin - meaning: gain new insights through restudying old material.

[2] The Fort Worth division of General Dynamics which built the F-16A was sold to Lockheed in March 1993. Lockheed and Martin Marietta then merged in March 1995 to form Lockheed Martin.

[3] The F-16A's 1,135 litre centreline tank was normally used exclusively for ferry missions.

[4] These 370 US gallon/1,400 litre drop tanks were preferred over the optional 600 US gallons/2,270 litres. The latter imposed severe performance limitations upon F-16As - both due to their greater drag penalty and higher weight (each loaded 2,270 litre tanks carrying 1,815 kg of fuel versus only 1,135 kg of fuel for each 1,400 litre drop tank).

[5] Ebi to tai no tsuri means gaining great profit at small cost. Although both are quality ingredients, the lower-value shrimp bait is used to catch the higher-value sea bream for dinner.

[6] This work allowed Mitsubishi to call back workers laid off due to Covid-19 and the resulting 'pause' on the Mitsubishi SpaceJet regional airliner program.

[7] Internal fuel capacity - combining all three fuselage tanks with the wing tanks - now reached close to 5,000 litres (weighing almost 3,950 kg). The set of CFTs carry an additional 1,705 litres (450 US gallons) of fuel (weighing 1,360 kg) for a total fuel load around 6,700 litres (5,310 kg). For ferry purposes, twin 1,400 litre drop tanks (2,800 litres/4,760 kg) could be added for a maximum fuel load of 9,500 litres (10,070 kg).

[8] Some export 'Vipers' featured drag chutes but USAF aircraft did not - hence the 'short' F-16A style tail-housing.

[9] It was found that this Electro-Optical Target System housing caused some undesirable air flow around the engine intake. However, that became a moot point. Despite the AN/AAQ-40 being a standard fitment on JASDF F-35s, the US Congress refused to grant export permission for this EOTS as 'unattached' equipment to Japan.

[10] Better known by its former name, Test Research Development Institute (TRDI), the Ministry of Defense's Acquisition Technology and Logistics Agency (ATLA) now covers both procurement management and acceptance testing of aircraft.

[apophenia]

Senkaku Sentinels - Part 5: "Snakes follow the way of serpents" [1]

In Japanese Air Self-Defence Force (JASDF) planning, both the manned Mitsubishi F-2A fighter and the LM/Mitsubishi A-16AJ were to be armed with domestically-produced ASM-3 Kai anti-shipping missiles. The Mitsubishi ASM-3 Kai has a hybrid rocket motor/ramjet engine - the missile reaching high speed on its rocket before the burned-out rocket chamber was transformed into a combustion chamber for the sustaining, air-breathing ramjet. That hybrid engine allows the ASM-3 Kai to reach speeds over Mach 3. Details of the ASM-3 Kai warhead remain classified but, at the speeds reached, the impact of the missile body alone would impart considerable kinetic energy.

The operational concept for the ASM-3 Kai was straightforward but had two variations. In the first, a low-flying launch aircraft would loose its missile just outside the opposing force's radar detection range. The ASM-3 Kai would then hug the waves until reaching its target ship. In the second, a launch aircraft at either low- or medium-altitude would launch its ASM-3 Kai which would immediate pop up to higher altitude using its rocket motor. Upon reaching the opposing SAM defence range perimeter, the missile would then dive steeply. Pulling up at the last moment, the ASM-3 Kai would skim the surface to its intended target.

Unfortunately, production of the original ASM-3 had to be cancelled in order to rework the design. But the results were worthwhile. The ASM-3 Kai's range was almost doubled, allowing manned Mitsubishi F-2A fighters to launch these missiles from safer distances. However, the delayed deployment meant that there were insufficient ASM-3 Kai missiles to equip the A-16AJ UCAVs during the Senkaku Incident. Instead, the A-16AJ Baipa had to be armed with the older, slower, much-shorter-range ASM-2 (Type 93) missile which the ASM-3 Kai had been meant to replace. [2]

"A serpent is a serpent, and none the less a viper"

The A-16AJ Baipa was intended to be a high-risk partner to the manned Mitsubishi F-2A fighter. During the Senkaku Incident, those risks were pushed even higher. The unmanned aircraft needed to go in closer to launch the slower, shorter-range ASM-2s. For obvious reasons, the manned F-2As were assigned the faster, longer-range ASM-3 Kai missiles. As a result, losses of A-16AJs were disproportionately large - but far better to lose matériel than pilots!

There was an unexpected benefit to this mix of anti-ship missile types. Operational experience revealed that joint missions greatly increased the success rate of the missile strikes. The most successful missile impacts were recorded with ASM-3 Kai missiles. In some cases, however, ASM-2s struck targets when the supersonic ASM-3 Kai missiles (loosed at the same time) had succumbed to Chinese anti-air defences. JASDF planners concluded that success was increased when both ASM-3 Kai and ASM-2 missiles were launched during the same attack. Apparently, forcing the East Sea Fleet to counter two disparate threats simultaneously, meant that one or the other of the two missile types could get through. In other words, two different incoming missile types would often overwhelm PLA-Navy close-in weapon system defences.

"There were many beautiful vipers in those days ..."

The LM/Mitsubishi A-16AJ conversions did everything that was asked of them - and more - during the Senkakus Incident. Lessons were also learned in the process. In some mission profiles, emphasis on automatic versus remotely-piloted control was the reverse of that expected. This required rapidly-introduced changes to operating program files. In many cases, changing options was built into the core program. In others, thousands of lines of new code were needed. Fortunately, no major bugs were introduced. Programming errors may account for some A-16AJ combat losses. But the Baipa conversions were based on fairly elderly airframes so simple mechanical failures are a more probable explanation of unaccounted for A-16AJ losses.

The overall A-16AJ Baipa loss rate approached 50% of the available fleet (if three training and orientation losses are included in the count). A number of minor tweaks were made to control systems - both onboard and in the Mitsubishi Electric CKK-16-01 (Chijo kanseikyoku 16-01) Ground Control Stations. Other improvements had to wait until the Senkakus conflict was over - for example, improved data link communications infrastructure plus updated INS and SATCOM equipment. There was also a call for an optional separation between visual inputs for piloting and targeting but this was not realized (since it demanded fairly major changes to the Subaru Remote-Pilot Vision Centre and probable replacement of the Fujitsu electro-optical turret).

"He that has been bitten by a snake is afraid of a rope" - Chinese proverb

The effectiveness of the A-16AJ Baipa in combat was now proven. More difficult for Japanese strategists to assess was the degree to which surprise played a part in that success. PLA-Navy air defence crews and PLAAF fighter pilots all tackled the Baipa assuming that it was a manned fighter-bomber. That worked in the JASDF's favour. But, now the Chinese were aware of the true nature of the A-16AJ. Would the Baipa UCAV [3] be viable in the next conflict when its unmanned nature was known from the outset? The A-16AJ loss rate had increased noticably towards the end of the Senkakus Incident. Had the Chinese got the measure of the Baipa? Or were the A-16AJs simply being employed more aggressively?

In the aftermath of the Senkakus Incident, the future of the A-16AJ - or potential UCAV follow-ons - was anything but secure. But no-one could question the Baipa's combat record over the Senkaku Islands. The reputation of the A-16AJ Baipa was secure.

Image: '608' is an LM/Mitsubishi A-16AJ Baipa (Viper) of 207 Hiko-tai, Kokujieitai. [4] The 2-tone blue scheme is identical to that on manned Mitsubishi F-2A fighters. On the vertical tail is the 207 HT unit marking - the Shachihoko (Fish-Tiger), a mythical sea monster. [5] Note belly-mounted LM Sniper Extended Range (XR) targetting pod.

Inset: ASM-2 (Type 93) missile on outboard under-wing pylon (left). Larger view of 207 HT's Shachihoko emblem (right).

(To be continued ...)

_________________________________________


[1] The expression ja no michi wa hebi is actually intended to mean something akin to 'it takes one to know a one'.

[2] Likewise, Kawasaki P-1 patrol aircraft had to make do with ASM-1C and AGM-84 Harpoon anti-ship missiles during the conflict. P-1 missile strikes were responsible for sinking three minor Haijing vessels (and a North Korean 'spy ship' thought to be penetrating Japanese territorial waters on behalf of Beijing). Of necessity, however, most P-1 operations were focused on PLA-N submarine detection. Fortunately for Japan, most East Sea Fleet submarines had been redirected into the Taiwan Strait or South China Sea.

[3] The JASDF preferred the term UTA (Unmanned Tactical Aircraft) over Unmanned Combat Aerial Vehicle. In English, the Baipa would routinely be described as a UCAV. But in Japanese usage, the A-16AJ was always a Mujin Senjutsu Kokuki (MSK)

[4] The 207 HT is part of the JASDF's 9th Air Wing. The original 207th Tactical Fighter Squadron was disbanded - appropriate to the A-16AJ home base - at Naha in March 1986. The revived 207 HT is never referred to by role - only as a 'Squadron'.

[5] Considered appropriate to the A-16AJ's maritime strike role, this emblem was actually inherited from the 102nd Tactical Fighter Squadron. The disbanded 207 TFS featured a plum blossom motive but this was associated with that squadron's original founding base of Hyakuri (Ibaraki Prefecture).

All operational A-16AJs were assigned to the 207 Hiko-tai, home-based at Naha Air Base on Okinawa. However, a major 207 HT detachment was deployed to a Forward Operating Location at Ishigaki Air Base further south in the Ryukus. A JASDF Type-3 airfield (shared with F-15EXJ interceptors in troubled times) is 170 km flying distance from the Senkakus. A second A-16AJ detachment rotated through Shimoji Air Base (a part of Miyako Shimojishima Airport, SHI) on Shimoji-shima, 115 km ENE. Both airfields have long runways but, for safety, Shimoji must be closed to commercial traffic when A-16AJs were being operated. In both cases, direct mission control was secluded 'off base'.

[apophenia]

Senkaku Sentinels - Part 6: The Mitsubishi F-2A Update Program

The Mitsubishi F-2A fighter had evolved from the F-16 - being, in effect, the Japanese take on General Dynamics' proposed US F-16 Agile Falcon with its 25% larger wing. [1] Whereas the F-16 has four underwing pylons, the 'big wing' F-2A has six. By comparison with the F-16 - or, indeed, the A-16AJ - an F-2A also had larger horizontal tailplanes and a larger engine air intake. As one of the 'stars' of the Senkaku Incident, there were no complaints about F-2A performance. However, even before the outbreak of fighting, the Japanese Air Self-Defence Force had been finalizing its plans for an F-2A Mid-Life-Upgrade (MLU). Service and industry reviews of the A-16AJ program caused some rethinking of this F-2A MLU. With a modicum of extra effort, this MLU would be able to incorporate the best features of the A-16AJ onto an updated F-2A fleet.

From the outset, it had been intended that the Mitsubishi F-2A fighter be the primary carrier of the supersonic ASM-3 anti-ship missile. As previously recounted, the Mitsubishi fighter was an outstanding success in that role. That success would also colour the planners' view of other JASDF fighter aircraft and their potential as anti-shipping missile launch platforms.

Improving the Breed - "Every great story seems to begin with a snake"

The revised F-2A MLU adopted the A-16AJ's Conformal Fuel Tanks (CFTs) along with the Diverterless Supersonic Inlet (DSI). With its six underwing pylons, the F-2A did not really require the extra carrying space allowed by the CFTs. Rather the conformal tanks were adopted primarily for their weight savings while loaded and their drag reduction. The DSI was adopted primarily for its marginally-reduced radar signature. The DSI actually reduced top speed slightly but, with a new emphasis on the attack role for the F-2A, this was deemed acceptable. As modified and refurbished, the upgraded F-2A was redesignated by the JASDF as the Mitsubishi F-2M Kai.

The A-16AJ's wingtip ECM pods were also briefly considered for the mid-lifed F-2 but objections to this plan eventually won out in favour of load-out flexibility. A typical load-out for the upgraded F-2M Kai was (from inboard): 2 x ASM-3 Kai anti-ship missiles; 2 x AAM-4 (Type 99) medium-range missiles (or AGM-88E HARM anti-radiation missiles); 2 x ASM-3 Kai anti-ship missiles, and 2 x wingtip AAM-5 (Type 04) short-range missiles. For ultra-long-range missions, 2 x 2,270 litre drop tanks could be substituted for the pair of inboard ASM-3 Kai missiles. More commonly, longer-range was made possible by inflight refuelling - which was simplified by the arrival of the first Mitsubishi KC-3A Tanchō medium-range tankers. [2]

"It was like looking for a needle in a haystack full of vipers" - Samuel Beckett

At the start of the Senkaku Incident, the Japanese Air Self-Defence Forces had three on-going air-launched anti-shipping missile programmes. Two were subsonic US missiles - the Joint Strike Missile (JSM, US AGM-184A) [3] and Long Range Anti-Ship Missile (LRASM, US AGM-158C). [4] Neither JSM or LRASM played much of a role in the Senkaku Incident - primarily because their carrier aircraft were assigned other roles as priorities. In both cases, the F-35 and F-15 fighters (JASDF carriers of the JSM and LRASM, respectively) were employed almost exclusively in interceptor roles during the conflict.

By contrast with the US missiles, [3] the hybrid-powerplant ASM-3 Kai could exceed Mach 3. To employ an old cliché, the only problem with the ASM-3 Kai was that there just weren't enough of them. In a few cases, the F-2As carried four ASM-3 Kais but the commonest load during the conflict was twin drop tanks (2,270 or 1,400 litre) and a pair of ASM-3 Kai missiles (along with the usual self-defence missiles). Towards the end of the Senkaku Incident, consideration was given to F-2As carrying JSMs as ASM-3 Kai stocks ran low. Fortunately, that substitution never became necessary. However, stocks of the ASM-2s fired by the A-16AJs were now entirely depleted. In any future conflict, a new 'mix' of anti-shipping missile would be needed.

Image: Post-MLU Mitsubishi F-2M Kai strike fighter carrying ASM-3 Kai anti-shipping missiles and 600 US gallon underwing tanks. For self-defence, '563' carries AAM-5 (Type 04) short-range IR missiles on its wingtip rails.

Inset: Mitsubishi F-2M Kai carrying four AGM-184A Joint Strike Missiles on its underwing racks. For self-defence, '539' carries the older AAM-3 (Type 90) IR missiles on its wingtip rails. Here, the centre underwing pylons are empty but these pylons could be loaded twin self-defence AAM-4 (Type 99) missiles or AGM-88E HARMs.

(To be continued ...)

_________________________________________

[1] For the Japanese FS-X contest (which led to the F-2A), Mitsubishi was partnered with General Dynamics. Two of GD's concept submissions - SX-2 and SX-3 - featured the larger Agile Falcon wing but few construction details were provided. As a result, an entirely new wing of mainly composite construction was designed for the F-2A by Mitsubishi engineers.

[2] With AAR demand increasing, the JASDF's six KC-46A Pegasus tankers were overstretched. The shoot-down of a new PLAAF Xian Y-20 tanker during the Senkaku Incident also showed the vulnerability of larger tanker aircraft in the regional airspace of the East China Sea (Higashi shina kai). As a result, it was decided to complete three Mitsubishi SpaceJet prototype airframes as KC-3A inflight refuelling tankers.

[3] The Joint Strike Missiles (JSM) were integrated into the F-35 (Block 4 software fit) in 2022. A Lightning II can carry one JSM within each of the fighter's internal bays - which restricts the missile's size. Despite this, the JSM has a respectable maximum range of 565 km (although this would be much reduced if operated at low level). The JSM's carries a relatively modest 125 kg warhead.

[4] The externally-carried LRASM has a more substantial 450 kg warhead. Maximum range is 480 km - although ~370 km is more realistic on low-level missions. Had they been available in larger numbers and the F-15s not otherwise engaged, the LRASM would have been valuable assets during the Senkaku Incident.

[elmayerle]

Going to be interesting to see if this prompts Japan to order some F-15EJ aircraft to carry both ASM-3-Kai and LRASM.

[apophenia]

Thanks Evan. All will be revealed in the post after this one
_______________________________________________________

Senkaku Sentinels - Part 7: The Future and Further UCAVs?

In the aftermath of the Senkaku Incident, JASDF planning attention turned to replenishment and upgrades. The first conclusion was that, if fighter-sized UCAVs were to be restocked, these unmanned aircraft would have to be new, stealthier designs. A request for Expressions of Interest (EOI) issued to industry received three proposals in reply. The first was from Lockheed-Martin for an 'optionally-piloted strike fighter' derivative of the F-35A. [1] The other two EOI submissions came from Japan's traditional keiretsu conglomerates - Mitsubishi, Kawasaki, and Subaru.

The proposal from Mitsubishi Heavy Industries was fairly straightforward. While waiting for the sixth-generation Mitsubishi F-X (aka F-3) stealth fighter to deploy in 2030, MHI would develop an interim UCAV. The airframe design would be relatively conservative, allowing a proof-of-concept demonstrator to be created from Mitsubishi's X-2 stealth prototype. As proposed, the X-2 would remain piloted - with a YDK Technologies UCAV control system mounted in the former rear cockpit. The major change would be the replacement of the existing tailplane group with new V-configured 'tailerons'. This rearrangement was intended to further reduce radar signature and the resulting reduction in manoeuvrability was considered acceptable for a strike UCAV.

The fully-developed UCAV concept was dubbed the Mitsubishi XA-2 Mizuchi (Watersnake). [2] MHI intended that Mitsubishi Electric would create replacements for the A-16AJ's YDK Technologies UCAV control system and Subaru Remote-Pilot Vision Centre. Primary armament would be four pylon-mounted ASM-3ER missiles - an extended-range derivative of the advanced ASM-3C anti-ship missiles then in development. For self-defence, the XA-2 Mizuchi would carry two AAM-5 IR missiles (one each in enclosed, fuselage-side bays). All fuel was to be carried internally.

Image, bottom Mitsubishi X-2FTB (Flying Test Bed) proof-of-concept modification proposal for the Mitsubishi XA-2 Mizuchi (Watersnake) UCAV. Note: this image illustrates the earliest proposed stage of X-2FTB testing (hence the exhaust nozzle manoeuvring 'paddles' not being fitted here).

The third proposal was a joint submission by Subaru Aerospace and Kawasaki Heavy Industries. This approach was not the norm in Japanese practice, but it allowed each firm to focus on one major aspect of their joint submission. Subaru Aerospace was to focus on developing the UCAV airframe (largely because of Subaru predecessor Fuji's experience with composite construction). The airframe layout was clearly influenced by the Northrop/MDC YF-23 prototype fighter design - although the Subaru FXS UCAV would be considerably smaller than that US fighter). The offensive armament was to be a single, hypersonic anti-shipping missile which, unusually, would be mounted on the UCAV's back. As such, the two airframes - UCAV and missile - had to be highly integrated.

KHI designers took great pains to ensure that their missile design would not unduly compromise the low-observable features of the Subaru UCAV. The anti-shipping missile's propulsion was very similar to that of the ASM-3 Kai - in other words, it was a rocket motor booster which turned itself into a sustaining ramjet engine. But there the similarity with the in-service missile ended. The Kawasaki XASM-5 Kobanzame (Remora) missile body was effectively a scaled-down and tailless version of the UCAV itself. However, the approach to flight stability and attitude control was quite different. On launch, attitude control was handled by drooping wingtips (which could act asymmetrically for yaw/roll control). As the air-breathing ramjet took over, the wingtips 'straightened' to reduce radar signature. At this point, all flight control was handled by asymmetrical operation of vectoring jet nozzles.

Image, top The Subaru Aerospace AXS UCAV concept along with the operating phases of the Kawasaki Heavy Industries XASM-5 Kobanzame (Remora) anti-shipping missile. The AXS shows the Kobanzame missile in its stowed position atop the AXS fuselage. Top right shows the XASM-5 launching and igniting its hybrid rocket booster motor. Top left shows the Kobanzame with air-breathing ramjet propulsion (note the missile's wingtip position and vectoring nozzles).

(To be continued ...)
_________________________________________

[1] This optionally-manned 'F-35 OPSF' was an updated version of LM's original 2006 optionally-manned F-35 concept. Experience with the jointly-developed A-16AJ Baipā helped firm up the 'F-35 OPSF' design.

[2] The Mizuchi is actually a legendary Japanese serpent-like creature or dragon. The mythical Mizuchi was to be found in aquatic habitats, which made it a suitable namesake for a maritime strike UCAV.

[elmayerle]

Be interesting if Japan used this incident to persuade the US government to let them purchase all IP rights to the AGM-137A/BGM-137B TSSAM and recruite NGC personnel to continue development.  Combining aspects of the two versions would give you, among other things, a ship- or ground-launched all-aspects stealthy ASM in addition to the main air-launched variants.  Yeah, it's subsonic but they won't see it coming until way too late.

[apophenia]

Evan: Interesting idea. That would give the JSDF a mix of cruise missiles - hypersonic gliders and surface-hugging subsonics. The trip-up would be that "persuade the US government" part 

My non-whif sense is that the Japanese are quite determined to free themselves from FMS constraints where possible. I'm not clear on the exact history but US refusal to sell the F-22 to Japan was one of the straws. There is also a sense that the JSDF knows what capabilities it requires in the East China Sea and, increasingly, the US is unable to provide such missile types. Hence the current emphasis on supersonics with a future push for hypersonics, whereas US imports such as the JSM and LRASM were as seen more as 'needs must' purchases. (Had the F-35 been capable of accommodating the ASM-3 Kai, I wonder if Japan would have ever considered buying the JSM?)

Since the '70s, Japan has pretty much followed its own course on developing air- and surface-launched missiles. Within the JSDF, the conclusion appears to be that this has given them a technological lead - eg: SSM-1B (Type 88) and ASM-1C (Type 90). The Japanese consider both of their domestic products superior to the US Harpoons which they replaced ... while the US is just now beginning to replace the Harpoons themselves.

[apophenia]

Senkaku Sentinels - Part 8: Lessons Learned from the Senkakus Incident

In light of Japanese Self-Defence Force reviews, it was decided that there would be no direct replacement of the spent A-16AJ Baipā (Pit Viper) force. One conclusion was that much of the Baipās' success was attributable to Chinese opponents confusing these aircraft with manned F-2A fighters. As soon as it became clear to the PLAAF and PLA-Navy that they were facing unmanned strike aircraft, Chinese counter tactics improved to the detriment of the A-16AJ fleet. It was judged unlikely that this element of surprise could be recaptured. Future JASDF UCAVs remained undetermined but, in all likelihood, they would need to be both smaller and stealthier - the favoured approach being the US 'Loyal Wingman' concept. [1]

By the end of 2023, the leading candidate for a 'Loyal Wingman'-type A-16AJ replacement was Boeing Australia's new Airpower Teaming System (ATS). [2] To control these smaller UCAVs in flight, two manned aircraft types were considered. These 'Aniki' ('Big Brother') control aircraft were the 2-seat Mitsubishi F-2B and the multi-seat Kawasaki EP-1. The first option would give the Mitsubishi trainers a fully operational role - with the F-2B's 'back-seater' controlling a pair of UCAVs. The second option used the new, 7-seat AEW&C variant of Kawasaki's P-1 patrol aircraft. Each Kawasaki EP-1 would be able to control up to eight 'Loyal Wingman' simultaneously. The two control aircraft options were not considered mutually exclusive.

In the meantime, all efforts would be made to speed up the development and deployment of a domestic stealth fighter - the Mitsubishi F-3 (aka F-X). These future fighters are generally viewed as air-superiority types - and they will act in that role. However, the F-3 has also been designed for the stealthy, internal carriage of anti-shipping missiles. That internal bay has been scaled for the ASM-3 Kai but, doubtless, future missile developments will also be tailored to the interior space available in the stealthy F-3.

Performance reviews also whittled down the range of Japanese anti-shipping missiles somewhat. Many successful anti-shipping missiles types were eliminated by attrition during the Senkakus Incident - including the ASM-1, ASM-1C, and ASM-2. Production of the ASM-3 Kai was to be completed before continuing with the improved ASM-3C variant and its extended-range derivative, the ASM-3ER. Further orders were also placed for the subsonic AGM-158C Long Range Anti-Ship Missile (which became the de facto replacement for the ASM-2). The less utile AGM-184A Joint Strike Missile was retained primarily to arm any future 'Loyal Wingman' type drone but also for its potential use by JASDF F-35s. Future emphasis was now on the domestic Hypersonic Cruise Missile (HCM, to ultimately replace the AGM-158C) and Hyper-Velocity Gliding Projectile (HVGP, as replacement for the ASM-3 Kai and ASM-3C). [3]

Analysing Beijing's Motives - Strategic Strike or Supply-Chain Upsets

In the aftermath of battle in the East China Sea, it was still not entirely clear what Beijing's motivations had been. Less than half of the PLA-Navy's East Sea Fleet was committed against the Senkakus - the rest of that Chinese fleet had gone south. Losses were taken on both sides in the fighting around and above the Senkakus but, by most measures, the Japanese Self-Defence Force had prevailed. Japan still held the Senkakus and were now better-prepared to defend these islands. By contrast, Chinese losses seemed to gain Beijing very little. Rather than focusing their full might on taking the Senkaku Islands, Beijing seemed to be distracted by other ambitions.

Some analysts thought that Xi Jinping was simply sabre-rattling to distract his own population from a slump in the PRC economy. There had been a post-Covid 'bounce' in China's domestic economy - indeed, exports to the US actually grew at first (despite US trade sanctions). But supply-chain concerns had prompted efforts to 'decouple' the US economy from that of the PRC. Ironically, it was US supplier countries like Taiwan which led the way in 'decoupling'. Japan followed suit for its own economic reasons. However, as Chinese growth and productivity slowed, it became increasingly obvious to the Chinese population that PRC debt was growing rapidly. The Chinese economy was actually performing well compared to many other countries. But Xi's government could paper over that growing debt for only so long. Inflation had begun to eat into the savings of the aging Chinese citizenry.

Others analysts believed that the Senkaku Incident and related activities further south were simply Beijing's opening moves against Taiwan. In this argument, previously successful PRC 'cabbage tactics' from their South China Sea expansion were now being applied against Taiwan. This interpretation challenged previous models which suggested that the PRC would be content with causing chaos on Taiwan until its beleaguered citizens demanded their island's 'reunification' with the mainland. But that earlier model could not account for Beijing risking direct military actions in the Spring of 2023.

If China's gains in the Spring of 2023 were modest territorially, they were certainly in line with 'salami slicing' techniques employed in the past. So, what were Xi's gains in his 2023 'Zaochun' (Early Spring) campaign? In the Senkakus, the Chinese gained little more than harsh experience. Beijing had tested Japanese mettle and discovered that the Suga Government was more that willing to fight to curb any major PRC encroachments. Moreover, the Japanese Self-Defence Force had acquitted itself well in combat. With more focus, the PLA was more than capable of taking the Senkaku Islands ... but Beijing now knew that it must be prepared to take serious losses to gain whatever value the Senkakus represented to China. So, was the Senkaku Incident simply a feint to draw attention away from PLA moves against Taiwan?

Tackling Taiwan - Feints, Strategems, and Deadly Force

It is worth reviewing the PRC's Spring 2023 actions against Taiwan. Increasingly bellicose language from Beijing included direct threats of war if Taiwan was not 'brought back into the fold'. Such threats were in line with Xi's objective of causing chaos on Taiwan until the populace succumbs. But Xi Jinping had also set himself a timeline ... and a faltering PRC economy had established a timeframe of its own. Did Xi now see a limited war as a welcome distraction for his own population? The scale of the Spring 2023 operations suggest that China was simply testing the waters - at least to begin with.

Warning signs appeared in mid-April 2023 when mainland services were cut off to Taiwan's Kinmen Island. [4] That was followed by a reaffirmation of China's intention to enforce its February 2021 'Maritime Police Law'. Under that law, PRC jurisdiction was extended to the 'First Island Chain' - including both the Senkakus, Taiwan, and the islands of the South China Sea. Under Article 21 of the 'Maritime Police Law', the Haijing was enjoined to act against foreign military or government vessels operating in waters under the PRC's jurisdiction - that is, any waters claimed by Beijing. Article 47 entitles the Haijing to use deadly force against foreign vessels without warning. Much of this violated the UN Convention on the Law of the Sea - to which the People's Republic is a signatory - but Article 47 was also a recipe for disaster. With so many conflicting territorial claims in the region, violence became a near certainty. It didn't take long.

On 27 April, armed clashes occurred in the Taiwan Strait between Haijing ships and a flotilla of Taiwan Coast Guard patrol cutters. [5] Exchanges between PLA-N and Taiwan Navy vessels followed but, for the most part, PLAAF aircraft stayed outside of Taiwan's immediate airspace. The major exception came without warning. Escorted by Shenyang J-11 Flankers, PLAAF Xian JH-7A 'Flying Leopard' struck at Taiwan's Taiping Dao (aka Itu Aba) - the largest of the Spratly Islands in the South China Sea. Several helicopters and at least one ROCAF C-130 were destroyed on the apron at Taiping Island Airport (RCSP). Obviously, the ROC Marines' FIM-92 Stinger MANPADS were a wholly inadequate air defence for the island.

As the landing craft of the People's Liberation Army Marine Corps (PLAMC) raced for shore, Taiping Dao's defences were pummeled with ship-to-shore missiles. [6] Despite this, the Taiwanese Marine Corps defenders were able to inflict heavy casualties on the PLAMC as they came ashore. However, the outcome was a foregone conclusion and the fighting comparatively brief. Before sunset, Taiping Dao (and nearby Zhongzhou Reef) were completely under PRC control. And that was Beijing's total territorial gain for the Spring 2023 fighting - 46 hectares of dry land and some submerged rocks. Yet Xi Jinping seemed pleased with the outcome and Beijing insisted that the PLA had prevailed in the conflict.

'The Future is Unwritten' - 'Reunification' with Taiwan by Other Means?

It remains unclear what Xi's ultimate goal was in the Spring of 2023. Perhaps Beijing's objective was simply to test the resolve of the United States and its regional allies. Or was the PRC Politburo simply pursuing   'reunification' with Taiwan by causing chaos? Certainly the people of Taiwan were now living in more fear than ever. It is possible that the West will never know the true intentions behind the 2023 'Zaochun' (Early Spring) campaign.

The real question for the immediate future is: How will the United States and its allies prepare for further armed aggression from the People's Republic of China? 'Unwritten' or not, the future is now upon us.

( Fin )

_________________________________________

[1] In one fell swoop, those conclusions eliminated all existing domestic UCAV proposals from further consideration. The Mitsubishi XA-2 Mizuchi and Subaru AXS (along with its Kawasaki XASM-5 Kobanzame missile) withered on the vine.

[2] The 'attritable' nature of ATS fit very well within Japanese operational experience. In JASDF planning, 'Loyal Wingman' was viewed primarily as a mini-UCAV. However, there still was an option to procure reconnaissance packages as well. No details have been released about exactly how the Japanese intend to arm such unmanned strike aircraft.

[3] The Hypersonic Cruise Missile (HCM) was to be powered by a high-speed scramjet engine. However, as the 'cruise missile' in the name suggest, the HCM will also have a longer range than is normal with scramjet-powered missiles. By contrast, the Hyper-Velocity Gliding Projectile (HVGP) will have a solid-fuel rocket engine. Somewhat similar to one of the ASM-3 Kai modes, the HVGP will pop up to high altitude outside an opponent's air defence zone. Then, instead of diving and hugging the surface, the HVGP's warhead payload will separate from the booster body. The warhead section would then glide in a high-velocity dive to its intended target.

[4] Kinmen Island is only 2 km off the Chinese coast. In past 'heat ups', Kinmen has been heavily shelled from the mainland. However, with the 'normalization' of Taiwan-PRC relations in the early 21st Century, Kinmen came to rely upon mainland Fujian province for services - Jinjiang City for fresh water and Xiamen for telecommunication links. Prior to Xi's rise, there was even hope for developing a Free Economic Zone on Kinmen Island, in order to smooth trade dealings with the PRC. That fantasy has now evaporated as Kinmen Island waits for the PRC's next move.

[5] The first Penghu encounter between the Haijing and the Taiwan Coast Guard occurred just west of Qimei Island late on 27 April. By chance, the two flotilla's were led by the largest ships of the Haijing and the Taiwan Coast Guard - the Haixun 06 and Chiayi (CG5001), respectively. Fortunately, neither vessel was particularly heavily-armed. Haixun 06 fired on Chiayi ... but far beyond the effective range of its 37 mm gun.

[6] Details are sketchy regarding which missile types were used. One confirmed type is a previously-unseen land attack variant of the YJ-62A subsonic cruise missiles fired from Type 052C destroyers. These 'YJ-62G' missiles have a range of at least 280 km (the US Navy's Office of Naval Intelligence assessing its potential range being as great as 400 km).

[elmayerle]

Evan: Interesting idea. That would give the JSDF a mix of cruise missiles - hypersonic gliders and surface-hugging subsonics. The trip-up would be that "persuade the US government" part 

My non-whif sense is that the Japanese are quite determined to free themselves from FMS constraints where possible. I'm not clear on the exact history but US refusal to sell the F-22 to Japan was one of the straws. There is also a sense that the JSDF knows what capabilities it requires in the East China Sea and, increasingly, the US is unable to provide such missile types. Hence the current emphasis on supersonics with a future push for hypersonics, whereas US imports such as the JSM and LRASM were as seen more as 'needs must' purchases. (Had the F-35 been capable of accommodating the ASM-3 Kai, I wonder if Japan would have ever considered buying the JSM?)

Since the '70s, Japan has pretty much followed its own course on developing air- and surface-launched missiles. Within the JSDF, the conclusion appears to be that this has given them a technological lead - eg: SSM-1B (Type 88) and ASM-1C (Type 90). The Japanese consider both of their domestic products superior to the US Harpoons which they replaced ... while the US is just now beginning to replace the Harpoons themselves.

OTOH, a lot of concepts developed by Northrop and its partners in the course of TSSAM development could be applied to indigenous japanese developments.  Too, if the purchase price was decent enough, it would at least let the USG getsome value for unused assets.  Considering that JASSM/AGM-158 was started only after TSSAM wsa killed and only has frontal aspect LO, I could see some definite interest in incorporating aspects of TSSAM into a new design.  Besides, if I understand what I"ve read correctl, JASSM-ER and LRASM use the same engine that TSSAM did but without the LO exhaust nzzole TSSAM used.

[apophenia]

That makes sense - and I do like this 'missile mix' notion. The big question would be US willingness to release technology and FMS.

I note that both the AGM-137 and AGM-158A are roughly the same length - ie: too long to fit into the F-35 weapon bays. Would it be feasible to 'shave' about two feet off the TSSAM's total length without unduly compromising the design?

[elmayerle]

I note that both the AGM-137 and AGM-158A are roughly the same length - ie: too long to fit into the F-35 weapon bays. Would it be feasible to 'shave' about two feet off the TSSAM's total length without unduly compromising the design?

Well, considering that BGM-137B was, IIRC, a foot shorter than AGM-137A, I'd say it was possible to shorten the bird that much though you would have to be careful where you did the shortening.  OTOH, air-launched TSSAM was intended to be LO even as an externally carried store (which did complicate matters a bit) so that might not be as much of a problem as other missiles might be.

[apophenia]

Right. So, maybe, the TSSAM (or derivative) makes more sense as an external store for the F-35s once the F-2M Kais begin to phase out of service.

[GTX_Admin]

I would say that the AGM-158 has largely taken over the role the AGM-137 was envisioned for.  You also have the Kongsberg NSM/JSM coming in the future and it is definitely able to fit inside an F-35:

[elmayerle]

Yeah, AGM-158 has taken over the role envisioned for AGM-137A, it was started very shortly after AGM-137A was cancelled.  I do believe, though, that the AGM-137A/BGM-137B family was more modular and would better adapt itself to ship-launched or ground-launched LO anti-ship missiles.  Too, unlike AGM-158, it was designed for all-aspect stealth, even in carriage.