Saturday, 11 March 2023

Guillermo's 1/48 Fine Molds Hayabusa III Ko

Another splendid Fine Molds 1/48 Ki-43-III Ko, this time Guillermo kindly sharing images of his build of the kit to represent a rather battered aircraft of Hiko Dai 204 Sentai  as photographed at Matsuyama airfield on the island of Formosa (now Taiwan) in August 1945. The tail number '01' has led to speculation that this aircraft was perhaps flown by 1st Chutai leader Lt Tatsukichi Nishimoto or even the Hikotai leader Capt Wataru Takahashi. Although no other obvious command markings are visible instructions were given during mid-1945 for formation leaders to avoid the display of garish identity markings which might lead to them being singled out in combat, instructions which were not always followed.

The 204th, which had been re-designated a Hiko Sentai from its previous Kyôdô (教導 - instructional) Hiko Sentai status in February 1944, lost all Ki-43-II aircraft sent to the Philippines campaign, with 17 pilots including all Chutai leaders being killed there. The surviving flying personnel returned to Mito, Japan, by transport plane in December 1944. At Mito the unit re-equipped with the III Ko before moving to Saigon, Indo-China in February 1945.  In April part of the unit moved to Formosa and was assigned to special attack duties as the Makoto (誠 - honesty or sincerity) 204 Sentai to participate in the Okinawa campaign and in July 1945 the main force of the unit joined it there. At the end of the war surviving  personnel of the unit still in Saigon were transferred into the 126th Airfield Battalion and Dai 64 Hiko Sentai. A 204th Hayabusa II in Burma displaying the previous form of unit insignia  is shown here.  It is now known that the white 'Chinzei Hachiro' arrow flight unit insignia on the fuselage, white painted fin tip, wingtips and possibly forward part of the spinner on that Ki-43-II aircraft denoted the 1st Chutai, with the 2nd and 3rd Chutai markings applied in red and yellow respectively.

After first painting the cockpit aotake Gulllermo re-painted it using Vallejo  Model Air 71.016 FS 34088 to represent the late war olive drab colour which was also applied to the exterior upper surfaces. The seat was finished aluminium and other details painted in accordance with the Aero Detail # 29 book on Hayabusa, For the under surface Guillermo used Vallejo Model Air 71.326 IJA Grey Green (which despite the name is a warm, slightly brownish grey not to be confused with 71.321 IJA Light Grey Green). Revell Lufthansa Yellow was used for the wing leading edge IFF strips and Vallejo 70.830  WWII German Green for the propeller. The drop tanks were painted with a mix of Medium Sea Grey and Medium Blue with their data markings hand-painted using Vallejo paints.

Guillermo carefully replicated the weathering and chipping indicated in the photographs of '01' by first applying two aluminium paints, Vallejo for the fuselage and Tamiya XF-16 enamel for the wings, together with some pre-shading of panel lines. Vallejo liquid masking was then applied with a sponge. Afterwards some areas of chipping were repaired and improved, painting some irregular spots and re-touching them with Vallejo aluminium. The hinomaru and other markings were applied by paint using Colourcoats RAF Roundel Red and Tamiya XF-2 Flat White, with only the decals for '01' and minor markings used. Weathering was achieved Winsor and Newton oil paints with some pigments for soil and dust effects on the tyres. Note how the fin leading edge marking extends a point along the fuselage spine and 'wings' onto the tailplanes, a detail not always captured in illustrations or decal sheets. In some depictions the red flash is shown with a narrow yellow border.  

Guillermo's primed model tellingly reveals how the basic Hayabusa airframe remained relatively unchanged throughout production. 

And compels a repeat reiteration against the use of Ko and Otsu designations applied to the Ki-43-II as they persist in the modelosphere and with kit and decal manufacturers. The Ko, Otsu, etc., suffix designations, sometimes rendered as a, b, c, etc., in English sources, were most usually used by IJAAF to denote armament variations in fighters which do not apply to the Ki-43. The detail differences in the II series were production changes to the airframe and engine/cowling and in Japanese references these sub-types are often divided by their features into early, mid and late production types with the II Kai as the final Nakajima-built type, all using the character ki (期) which means period but is sometimes given as 'production' in English. Thus:-

初期 - (hatsu ki) = first period (Ki-43-II with annular oil cooler and long Ki-43-I wingspan)
中期 - (naka ki) = middle period (Ki-43-II with enlarged under cowling cooler and shortened wingspan)
後期 - (nachi ki) = later period (Ki-43-II with rearwards thrust exhaust stacks and landing light in port wing leading edge)
末期 - (matsu ki) = end or final period (this is the Ki-43-II Kai with individual thrust exhaust stacks but note that a further refinement was the provision of water-methanol boost to the Kai)

Only the main features of each sub-type are noted above but not all the additional detail changes, especially of armament, armour and other protective equipment/enhancements. The official IJAAF table of aircraft designations ('Table of Aircraft Desgnations and Armament, Army Air Headquarters Secret' # 16979 of 9 December 1943) makes no such distinctions as it does for other fighter types, whilst the official report 'Study of Increase of Armor, Bullet-Proofing, Fire Extinguishing Equipment and Armament on Various Aircraft; Aircraft Section; Supply Depot (Luzon)' of 22 March 1944  lists various upgrades to the II as production changes, detailing dates and first change serial numbers but no Ko or Otsu suffix are tabled. The incremental improvements in Hayabusa fuel and armour protection also counter that other persistent belief in the aircraft's inherent vulnerability. In a report on combat in Burma on 20 January 1944 the Japanese command expressed satisfaction with the improvement in fuel and armour protection for the Type 1 fighter (Hayabusa) from serial # 5800, noting that one aircraft had returned safely with 39 hits and no doubt that was one of the 23 Oscars of 50 and 204 Sentai's  47 sortied that were claimed as destroyed, probable or damaged on that day. The two Spitfire squadrons involved, 136 and 607, claimed 7 Oscars destroyed, 8 probables and 8 damaged. The Japanese reported one 'self destroyed' and two failed to return for a total of three lost. They also claimed 9 Spitfires (or 'P-40s') destroyed and 6 uncertain, whereas only two were lost. Three Spitfires returned damaged, one from a head-on attack by another Spitfire which was admitted, with two of their pilots wounded. After that digression onwards with Guillermo's excellent interior details.

With special thanks to Guillermo for sharing these images and details of his build. 

Image credit: All model photos © 2023 Guillermo; Photo via Guillermo


Michael Thurow said...

Modelo muy estupendo Guillermo! With great interior detail and finish.
Thanks Nick for the clarification of Ki-43-II sub-types. I wasn't aware of the rather free interpretation as Ko, Otsu... A distinction has been made in literature between the two exhaust versions on the 'middle period' production (sideways vs. rewards) but obviously there was none.

Straggler 脱走兵 said...

Hi Michael

In Jim Long's seminal and thorough study of Ki-43 production and serials ('Japanese Army Type 1 Fighter (Ki-43) Models, Record of Production and Serial Numbers' 1995/1998) he used the 'a' and 'b' suffix with the II for convenience but divides each into 'early' and 'late' designations. That effectively proposed four rather than three main sub-types before the final Ki-43-II Kai by splitting naka ki mid-production Hayabusa into two categories. And one example of the complexity is that some 'late' Ki-43-IIa (sic) aircraft had large armoured headrests which he identified as Tachikawa-built examples with the # 15000 base number. Many of the incremental improvements in the March 1944 report were undoubtedly retro-fitted to earlier variants by Japanese Army Depots engaged in repair or major overhaul maintenance.


Straggler 脱走兵 said...

PS The armour provision introduced for Ki-43-II was 16mm (0.33 in) surface hardened steel plates for the head (in the headrest/turnover pylon) and for the back behind the seat to a combined weight of 40 kg. Officially from # 5866 for Nakajima (August 1943) and # 15351 for Tachikawa (February 1944). Those were tested to resist armour piercing bullets up to a velocity of 710 m/s for 13mm and 520 m/s for 20mm, and for explosive shells impenetrable to 20mm and 30mm and resistant up to 730 m/s for 37mm. The Japanese did not pursue dural armour.

12mm bullet proofing of fuel tanks was introduced for the Ki-43- II with Nakajima-built # 5666 (July 1943) and Tachikawa-built # 15031 (August 1943).


Alex said...

A very nice well-worn Ki-43. The detailing of the cockpit
is just fine. Thanks Guillermo and Nick for sharing.
It's very interesting and useful information about Hayabusa's modifications. I used to think that "Ko", "Otsu" etc were official modifications. thanks.

Baronvonrob said...

Excellent Ki43!.. and finally a perfect explanation of the "Otsu" and "Ko" designations now even I understand :))

Gratitude to both Guillermo and Nick

Anonymous said...

Another very nice build - excellent job on the markings, and duplication of wear, Guillermo - again combined with some useful and still little-known history. For myself, I always had it wrong. Great stuff, thanks to you both.

Kevin Bade said...

Pardon me but 16mm is .63 inches or about 5/8ths of an inch and that sounds like rather thick armor plate. 12mm is just under a half inch. Just trying to get the math straight. Otherwise I love the Hayabusa & the explanation of kai & otsu. From now on for me it'll be Mk.I, Mk.IIs & MkIII. Happy modelling folks!

Straggler 脱走兵 said...

The dimensions are as recorded in the Japanese document referenced in the blog post and in the British Intelligence Objectives Sub-Committee Report 'Armour of Japanese Airplanes' of October 1945 which presents the ATIG (Air Technical Intelligence Group) report of Cdr Sheldon W Brown of the USN. Cdr Sheldon's report is based on an interview with Maj Taneo Koinumaru (sic?) who graduated from the Metallurgical Department of Tokyo University in 1940 and was engaged in the research of special steels at the Army Air Technical Research Labaoratory at Tachikawa. The table contained therein specifies a thickness of 16mm or 0.63 inches for the Ki-43 head and back armour which matches the Japanese data. Aero Detail 29 mentions only 12mm for both the head/back armour and fuel tank protection but I think that arises from a misreading of the Japanese documents where the term 'bullet proofing' is used for fuel tank protection only and not for cockpit armour..


Straggler 脱走兵 said...

PS My 0.33 ins in the previous comment above is a typo. It should read 0.63 ins!

Guillermo said...

Thanks to all, I really enjoy building this FineMold's Ki-43-III Ko Hayabusa. Specially to Nick, he gave me the whole information about colors, so I spent time checking any detail of what to do in my model.

Best regards,


Jose Luis Flores Cota said...

Memituuuuuusss!!!! Siempre lo he dicho!!! Eres el mejor!!! Muchísimas felicidades!!! Abrazote de oso mi hermanito!!!!

WK said...

Beautiful model, skillfully built and painted. I have yet to get my hands on a FM Oscar, but they certainly are in my sights.


Kevin Bade said...

Nick sir I was in no way doubting your research as far as the Hayabusa armor plate thickness goes. Just surprised to learn that the Oscar III had thicker pilot head armor than a P-51 or a FW-190A which by what I can find were about 11mm & 12mm respectively. So much for the"lightly" armored Japanes a/c. Possibly metallurgical differences in the quality?

Straggler 脱走兵 said...

Hi Kevin, I didn't take your comment that way but made the mistake of not realising that I had included a typo in my previous comment - 0.33 ins instead of 0.63 ins - before replying - doh! The composition of the steels used by the Japanese for armour varied throughout the war, beginning with Ni-Cr-Mo (Nickel, Chromium and Molybdenum) and due to a shortage of Nickel ending with Si-Mn-Cr (Silicon, Manganese and Chromium). Surface hardening was used for plates greater than 7mm. The Japanese Army pilot armour initiative commenced in 1939 with the discovery of armour plate in Russian aircraft but did not got under way seriously until the B-17 was examined and systematic development was then undertaken.

Aero Detail 29 mentions that the armour was added to 'both sides' of the roll bar on late production II which is puzzling as it is difficult to see how armour each side would protect the pilot's head. Perhaps they meant front and back but that would mean a combined thickness of 32mm. Unfortunately the drawings in the ATIG report are crude and do not throw light on how the head armour was actually fitted in the Ki-43. I'm guessing it was either a plate recessed in the forward face of the roll bar but behind the head rest or attached to the sloping rear face but it doesn't appear visible in photos. The extant II gives no indication and the roll bar is suspect being of the earlier type in a late production airframe. Maybe there are intel or crash reports out there which provide details but I've not so far encountered any.


Yves Marino said...

Hi Guillermo!
Your model is amazing and a great inspiration for every modeller!
I just want to comment on Ki.43-II variants and designations. I believe the 4 types you mention should not include the KAI -final version of Ki.43-II.
In FAOTW #65 on page 13 there are cowlings of all Ki.43 variants and for Ki.43-II we can find 5 different sub-types. I believe there is a typology very similar to the one you are quoting but with different descriptions as follows:
1. Zenki zen-gata (early-early production) or pre-production type of Ki.43-II - the one with the annular radiator, small additional oil cooler and big wingspan
2. Zenki ko-gata (early-late production) - bigger oil cooler under the chin, smaller wingspan, cowling is the same as above with bigger opening
3. Koki zen-gata (late-early production) - reshaped cowling with smaller opening, straight short exhaust pipe, longer covers of the machine gun muzzles etc.
4. Koki ko-gata (late-late production) - aft pointing exhaust pipe, wider roll bar behind the pilot, fuel cooler under the fuselage, landing light on port wing leading edge etc.
5.Kai (final production) - upgraded engine with 14 separate exhaust stacks etc.

I believe production type 2 from the above list is missing in the periods as described in your article. In FAOTW #65 on page 27 there are photos of this sub-type - note the size of the cowling opening compared with the next type in the same book.
Best regards!
Yves Marino

Straggler 脱走兵 said...

Thank you for your input Yves. I agree that there can be four preliminary variants before Kai if the cowling intake difference between 2 and 3 is considered, but Aero Detail 29 lists only three (including the cowling changes)and uses the terminology as shown in the blog. Jim Long in his seminal 'Japanese Army Type 1 Fighter (Ki-43) Models, Record of Production and Serial Numbers (1995-1998) also sub-divides II production into four variants but uses the 'a', 'b' suffixes thus:- IIa 'Early', IIa 'Late', IIb 'Early' and IIb 'Late' but does not describe the cowling differences. I notice that in their latest release of the 1/72 Ki-43-II kit Special Hobby also use those suffix.

As for the terminology it is unofficial and a matter of semantics rather than fact. 'Hatsu ki' is 'first period' and 'zenki' is 'early period'; 'gata' 型 means 'type' not 'production'. The second variant you list is 前期後型 - 'early later type' but not sure about your reading of those characters or inclined to FAOW's choice of them!

Also please bear in mind that I wrote 'Only the main features of each sub-type are noted above but not all the additional detail changes' and did not dive into the cowlings issue, Aero Detail lists 10, 11 and 3 detail changes respectively for each of the three production variants and 5, 2 and 4 for the three cowlings. I may dive into those details later but the above is not an 'article' as such more an observation on the use of 'ko', 'otsu', etc., which you do not address. Finally the official JAAF table of aircraft designations lists only Ki-43-II and not the production changes which were not treated as aircraft type variants.


Yves Marino said...

Hi Nick!
Thank you for your reply and additional notes.
What I wrote is my understanding for a relatively simple classification of Ki.43-II sub-types. I do not speak Japanese and can only recognize simple characters (like for Ki, Koh, Otsu, Hei, Tei etc.). The names I gave to the 4 sub-types are my interpretations, not translations. I believe that most of the sources using the Koh and Otsu resp. a and b variants and adding early and late sub-types (as you mentioned it above), try the same: 2 groups with 2 sub-types each. But they mostly include the Kai as a late Otsu/b type. IMHO Kai does not belong to the former 4.
Honestly even if the classification suggested in FAOTW and my interpretation of it is slightly incorrect, it helped me greatly to understand most of the visual differences between the above mentioned sub-types. Of course, not all of them have been listed here.
Best Regards!

Straggler 脱走兵 said...

Thank you Yves. It was not clear from your comment that the designations were your own interpretations and not the designations used in FAOW. If you look at the plan profiles on pages 78 and 79 of the FAOW you will see that there is little difference depicted between the 2nd and 3rd II sub-types (the cowling intakes are not visible but it seems that the muzzle openings are differenced - although not very clearly) and that all the drawings show the same headrest. FAOW 65 was published in 1997 and Aero Detail 29 in 2000. The latter publication draws on some well respected authorities including Jim Long which is the reason I defer to its presentation in the blog. I think the cowling schematics in AD 29 are also clearer than those in FAOW.

I wouldn't suggest that the FAOW designations are incorrect as such but that interpretation of the sub-types is varied. As mentioned before there was undoubtedly crossover of modifications in production batches. Since they were not official the classification of those changes is open to discussion. My main point was that the 'ko', 'otsu'/'a','b' etc., often applied and conveyed as official designations are inappropriate other than as a kind of shorthand; but the danger there is that they have been widely accepted as official designations.

Thanks for the good discussion.