Kawasaki Ki-78 Kai-Otsu of 52nd Sentai, 3rd Chutai; Philippines, Sep. 1944

Dizzyfugu · February 14, 2015, 06:39:56 AM

Here's #1 that's been waiting for a week for the photo shooting... The Ki-78 Kai Otsu. Looks familiar, but it's probably only 50% of the original, tiny research aircraft left...

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

Some background:
The Kawasaki Ki-78 started its life as KEN III (Kensan III - research III) at the Aeronautical Research Institute and built at Kawasaki Kokuki Kogyo K.K. (川崎航空工機業株式会社 - Kawasaki Aircraft Industries).The plane was originally planned as a high speed research aircraft and designed to investigate laminar profile wings with high wing loadings.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

The KEN III was a very small and compact aircraft, reduced to a minimum. It featured a streamlined, minimum cross-section fuselage, together with a cockpit canopy that was more deicated to speed than good pilot sight. An all-metal construction was used in combination with a small thin wing with a laminar flow profile and a sharp leading edge. The aircraft was fitted with a licence-built Daimler-Benz DB 601A engine. For short duration power boost methanol/water injection was used, and cooling was improved by a 45 kW (60 hp) turbine driven cooling fan for the radiators, which were placed on both fuselage flanks, right behind the cockpit.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

Early in 1938 a high-speed research program was started at the Aeronautical Research Institute of the University of Tokyo, with the attempt to break the World Absolute speed record.
By the outbreak of the war, the whole KEN III project was taken over by the Imperial Japanese Army who gave it the military type designation Ki-78. Kawasaki received the order to build two prototypes of the Ki-78, construction of which was started in September 1941.
The first was completed more than a year later and was flown for the first time on 26 December 1942, but it did not live up to the high expectations concerning top speed - instead of the projected 850km/h the Ki-78 never exceeded 700 km/h (435 mph) under ideal circumstances. Handling was also hazardous. The second Ki-78 was therefore never completed.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

A feasibility study to improve the KI-78 flight performance and make it suitable as a high speed fighter showed that extensive airframe modifications were needed. Consequently the World Absolute speed record project was officially terminated and the unfinished second prototype as well as a third airframe modified into what would soon become the Ki-78 Kai.

The Ki-78 Kai was an almost new design. While it kept the KEN III's sleek lines, including the DB 601 and the fan-augmented radiator arrangement, the wings had been considerably enlarged (by ~4m²/171ft²) and the fuselage stretched - primarily in order to improve agility at medium altitude: true to IJA tradition.

As a consequence, armor and other protective measures were reduced to a minimum, while armament consisted of a single 20mm cannon, firing through the propeller hub, plus two 12.7mm machine guns in the wings, outside of the propeller disc. Still, the Ki-78 Kai was about 200kg heavier than the KEN III.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

This machine was quickly ushered into production and reached front line units in late 1943, though. Upon the first clashes with Allied fighters the poor survivability became obvious, despite the type's speed and climbing rate potential. This led, after only 50 machines, to the Ki-78 Kai-Otsu (or Kai-II/Improved, Type 2), which received additional armor for cockpit and engine, and a revised armament of two 20mm Ho-5 cannons in the wing. The engine-mounted gun was deleted in order to save weight again, but the modified aircraft weighed again about net 50kg more, but still achieved a staggering 675 km/h in level flight.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

This revised version arrived in the Pacific theatre around May 1944, where it replaced the obsolete (but still popular) Ki-27. While the type's performance was on par with the modern Alied fighters of the time, many aircraft were lost due to poor tactics and unexperienced pilots. Furthermore, the Ki-78 Kai was not designed to take much damage, so that it was unpopular, even though in the hands of experienced pilots it was a serious opponent.

Neverthless, until April 1945 only 320 Ki-78 Kai were produced and production was stopped in order to concentrate on radial-powered engines and fighters with a better high altitude performance.

General characteristics:
Crew: 1
Length: 8.17 m (26 ft 7 1/2 in)
Wingspan: 9,65m (31 ft 7 1/4 in)
Height: 3.74 m (12 ft 4 in)
Wing area: 16,05 m² (173.3 ft²)
Empty weight: 2.247 kg (5.893 lb)
Loaded weight: 3.148 kg (6.940 lb)
Max. takeoff weight: 3.400 kg (7.495 lb)

Powerplant:
1× Daimler-Benz DB 601A V-12 inverted liquid-cooled piston engine,
rated at 1,160 kW (1,550 hp) with Water/Methanol injection for short durations

Performance:
Maximum speed: 675 km/h (420 mph; 364 kn) at 3,500 m (11,500 ft)
Range: 850 km (528 mi)
Service ceiling: 12,000 m (39,370 ft)
Rate of climb: 17.0 m/s (3,345 ft/min)
Wing loading: 196 kg/m² (40 lb/ft²)
Power/mass: 344 W/kg (0.21 hp/lb)

Armament:
2x 20mm Ho-5 cannon with 250 RPG in the outer wings
Provisions for two hardpoints, able to carry a 150kg (330lb) bomb each, but rarely used

The kit and its assembly:
This is a conversion of AZ Model's Ki-78, which is available in two double sets – the aircraft is so tiny that they put two kits into the box! There had been plans to convert the record breaker into a fast fighter – and my whif is more or less an interpretation of this idea.

Starting point was that the whole aircraft had to be enlarged, in order to put a decent fuel amount and some armament somewhere. First step was increased span/wing area – I found a pair of outer P-38 wings that had a very good size and shape for the task, and the lower side was still "clean" so that I could cut out new openings for the landing gear, using the original parts.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

Once the wings were in place, I added a 5mm plug in front of the fin, so that span/length ratio could be kept – the only place due to the flanks-mounted radiators. I kept the fin OOB, because it was big enough, but I implanted bigger horizontal stabilizers - these come from a Matchbox Brewster Buffalo but were considerably reduced in depth, trying to match the main wings's shape.

Scratched air scoops for the oil cooler were added under the front fuselage, a styrene tube in the nose holds the propeller which was mounted on a longer axis, and steel needles were implanted as wing cannons.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

Painting and markings:
This one is based on a real aircraft, a Ki-84 I found in literature. It was painted in a rather light khaki drab tone from above, with greenish-grey undersides, plus white markings on wing and fin tips.

The upper basic tone is FS 34087 from Modelmaster, applied over a basic coat of acrylic Aluminum (Revell), so that the metal would shine though and even appear chipped in some areas – some wet sanding enhanced the effect, and dry painting with lighter colors like Humbrol 83 (Ochre) emphasized the worn look. An area behind the cockpit received only very little green cover, the propeller spinner was painted in a mix of Olive Drab and Humbrol 95 (Concrete).

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) - WiP by dizzyfugu, on Flickr

For the underside I used Humbrol 90, actually Sky Type 'S', but it comes very close to IJA grey and makes a nice contrast to the brownish upper side. Here, too, the paint was applied over an Aluminum primer coat.

The white markings were painted with very light grey; the cockpit interior was painted in a IJA "Cockpit Green", a tome very similar to RLM02. I used Modelmaster's "Faded Olive Drab" as basic tone, plus some dry painting with light grey. The landing gear was kept in aluminum.
Decals were puzzled together from various sources and sheets, e. g. from a Ki-27 aftermarket sheet and a squadron markings set.

1:72 Kawasaki Ki-78 Kai-Otsu (US Code "Mandy"); aircraft "4" of 52nd Sentai, 3rd Chutai; Sarabia Airfield, Negros Island, Philippines; September 1944 (Whif/AZ Model kit conversion) by dizzyfugu, on Flickr

Captain Canada · February 14, 2015, 06:57:09 AM

That's a neat looking little beast ! Like you said, looks familiar...glad we have the build pics to see everything you did to make it.

perttime · February 14, 2015, 10:28:27 AM

Yep: a neat little beast.

It reminds me of the Finnish VL Pyörremyrsky and Puuska projects, to produce a domestic alternative to the Bf 109 - or preferably something a little better. A few different configurations were proposed and a prototype was built of one of the larger proposals, named Pyörremyrsky (Tornado). The much smaller Puuska remained a paper project but it was to be the smallest and fastest they could build around a DB 605 A-1 and a MG 151 20 mm Motorkanone with 200 rounds of ammunition.

sandiego89 · February 14, 2015, 11:24:53 AM

Really great paint/weathering. Looks nice and grimy.

Radiators give it a great look.

su27rules · February 14, 2015, 01:24:24 PM

Very cool!! Very nice!!

zenrat · February 14, 2015, 03:49:48 PM

It's got a US code name! It must be real!

Very good. I was having real problems with perspective on the picture of the fuselage half/cockpit and then I turned the laptop upside-down...

Dizzyfugu · February 15, 2015, 12:07:38 AM

Quote from: zenrat on February 14, 2015, 03:49:48 PM
It's got a US code name! It must be real!

LOL! Certaimly, who'd doubt it? Funny thing is, BTW, that the Ki-78's early project code "KEN" is frequentloy mistaken as a US code name - which is not the fact at all.

Quote from: zenrat on February 14, 2015, 03:49:48 PM
Very good. I was having real problems with perspective on the picture of the fuselage half/cockpit and then I turned the laptop upside-down...

I know what you mean, was the same for me. Actually, the original pic has been turned 180°, I hoped that the perspective issue would become better, but it still seems to be puzzling...

Anyway, thanks a lot for the feedback. This one is very subtle, many will say "Oh, I know that aircraft and AZ models does a whif boxing, so what?". But this conversion was pretty thorough - even though the whol thing was built in just 3 or 4 days!

Cheers!

NARSES2 · February 17, 2015, 03:47:37 AM

That is nice. I've built the kit (s) out of the box with WIF markings and thoroughly enjoyed them