John Haas' 1/48 53rd Hiko Sentai Heaven Shaking Dragon Killer

John Haas has kindly shared these images of another of his Nichimo Ki-45 builds in 1/48th scale, representing a modified late production Tei aircraft of the 53rd Hiko Sentai's air-to-air ramming flight. The Toryu (屠龍) officially the Type 2 Two Seat Fighter - Ni-shiki Fuku-za Sentoh-ki  (二式複座戦闘機) usually abbreviated to Ni-shiki Fuku Sen (二式複戦 ) remains a popular modelling subject and like the Luftwaffe's Messerschmitt 110 its genesis as a heavy escort fighter and disappointing performance in that role led to a more successful secondary career as an air defence bomber interceptor. A career in which it has become iconic. Even so, and although Toryu features so strongly in the imagery of combat against the B-29, it was actually rated by the IJAAF as having the worst high altitude performance of the fighters available for air defence duties, with even the Hayabusa considered superior in that respect. And at an early stage it was envisaged to provide a predominantly night interception role which has been largely unappreciated.

John built this model shortly after the kit was first issued and used Bunrin-do's FAOW # 26 for reference, removing and fairing over the oblique armament, adding a fairing over the rear canopy aperture and cutting down the aerial mast to represent a ramming aircraft. As far as he can remember he used Polly-S acrylic light grey RLM 76 for the overall base colour and JAAF Dark Green for the intricate mottle. He found the Nichimo model excellent to build,  going together like the proverbial "piece of cake".

The 53rd Hiko Sentai was established at Tokorozawa in May 1944 ostensibly as a night  fighter unit with the Ki-45 as original equipment and responsibility for the air defence of the Kanto area. It was part of the newly re-organised 10th Air Division, expanded from the original 17th Air Brigade in March of that year. The 53rd was organised with a HQ, three Hikotai, and a Seibitai maintenance unit. By July 1944 the 10th Air Division held under command six air regiments including the 53rd. This Toryu unit is well known from a series of rare colour photographs of its aircraft taken by IJAAF photographer Kikuchi Shunkichi at Matsudo in late November 1944 and it was also the subject of both the Nichimo kit and the earlier 1972 Revell 1/72 kit (anyone remember Battledec of England who must have been one of the first to offer an aftermarket decal sheet for the Revell Ki-45?). An excellent article on the 53rd Hiko Sentai which reproduces those colour photos may be found in Issue 11 of Arawasi magazine (Summer 2009). It also includes a fascinating first hand pilot's perspective by Sgt Negishi Nobuji.

The unit insignia was a stylised and enjoined '5' and '3' painted in blue for the HQ, white for the 1st, red outlined white for the 2nd and yellow outlined white for the 3rd Hikotai. The aircraft of the ramming flight were further distinguished by a large representation of a Karimata arrow painted on the fuselage side. This has frequently been described as a Kaburaya or signal arrow but in fact represents the bifurcated or twin pointed arrow used for hunting big game as well as in war so the connotations are evident. Karimata arrows often had a whistling or shrieking bulb attached to them behind the tip as shown on the 53rd's marking but were not the 'turnip head' signal arrows per se. The purpose and meaning of the distinctive coloured bands sported on the propeller spinners of the unit are unknown.

In August 1944 the 53rd moved to Matsudo to replace the 1st Hiko Sentai (Ki-84) which had been transferred to Gannosu in the Western air defence district under 12th Air Division command. It was to remain at Matsudo almost to the end of the war. By October 1944 the unit was still officially rated as "Newly organised. Combat ability below required standard".

On 6 November 1944 the 10th Air Division instructed that shinten seikutai (heaven shaking air superiority unit) air-to-air ramming flights of four aircraft were to be formed within all fighter units under command with the exception of the 18th Sentai and 17th Dokuritsu Hiko Chutai. The original concept of 'special attack' suicide units to dive against ships - tokubetsu kôgeki tai (abbreviated to tokko or to-go tai) - was extended to 'crash dive' aircraft with bombs onto formations of B-29s, but the technique proved impractical beyond theory and instead air-to-air ramming was developed with more freedom as to the tactics used (bitterly opposed by some unit commanders and the subject of controversy within the IJAAF as to its effectiveness).  Aircraft which were not part of the designated shinten seikutai also sometimes made impromptu air-to-air ramming attacks and often accidental collisions were reported as deliberate ramming attacks for propaganda purposes.

In January 1945 the 53rd was designated as a permanent night fighter unit restricted to nocturnal operations only and a period of advanced night flying training began which was so intensive that it led to a serious decline in morale. Aircrew were supposed to occupy darkened rooms and to wear dark tinted glasses in daylight. In late January the unit was provided with some Type B radar systems, the 'Tachi' ground units at Matsudo scanning a 90 sector with a radius of 125-150 miles. The ground scanner was combined with 'Taki' 15 air-to-air radar and height finder equipment by which in co-ordination with the ground units the course and altitude of enemy aircraft could be plotted and intercepted. The system was developed under the auspices of the 10th Air Division through the formation of the 1st Radar Guide Unit which drew on the fruits of the Tama Army Technical Research Station to disseminate and improve radar techniques. The project was highly secret and it was absolutely forbidden to photograph the ground equipment and those aircraft fitted with the air-to-air radar systems although a radar equipped Ki-45 Bo type can just about be made out in a distant shot of aircraft at Matsudo. The Bo was reportedly equipped with a single Ho-301 40mm cannon in the ventral position due to the weight of the radar equipment and the successful use of the short ranged but potent weapon at night. Another little known Toryu variant equipped with the long barrelled 37mm Ho-204 in the nose and a single oblique firing 20mm Ho-5 as special equipment was designated Ki.  Every night, between 1900 hrs and 0500 hrs a quarter of the unit were required to remain on the intensive Alert-A status, meaning that pilots stood by their aircraft which were kept ready for immediate take-off, whilst in addition from 0100 to  0500 hours a single flight of aircraft were required to maintain a patrol orbit at 16,500 ft over Tokyo.

The IJAAF aspiration to achieve successful nocturnal radar guided interceptions was overtaken by events and the perceived impending threat of invasion. With the carrier raids in February 1945 and the appearance of US fighters over Japan the Class A pilots of the unit (the most experienced) were designated to alert status during daylight hours for B-29 interceptions (to free up single seater aircraft for fighter vs fighter combat) and following a change of 10th Air Division policy in March the night interception duties were henceforth restricted to just a single flight of four aircraft whilst two flights were required on daylight alert status, one of them the ramming flight. The remainder of the unit were to continue with intensive training. By May 1945 because of dissatisfaction with the night flying training regime and the loss of aircrew through nervous breakdowns the exclusive night flying role of the unit was finally rescinded. Nevertheless at the end of the war the 53rd was still officially designated as a night fighter unit. In July 1945 the 53rd had 34 Ki-45 on strength but only a small number of those were deployed in actual air defence sorties.

The 1972 Revell kit in the smaller scale featured aircraft '25' of the 53rd Hiko Sentai's 3rd Hikotai leader

Nichimo chose the same subject as Revell for their 1970s box art

Image credits: Model photographs all © 2015 John Haas; Revell box art © Revell 1972 via Ken Glass; Nichimo box art © Nichimo from author's collection.