Hasegawa Ki-61 Hei

[Alain Gadbois]

Hi!

After seeing the beautiful Ki-61 by Greif8 (Ernest), I decided to jump in with the Ki-61.

Got this when it came out a long time ago...

Guess it is time to build it and finally land on the shelf!

 

 

The contents are typical Hasegawa, fine engraved line with restrained rivets is some areas.

 

 

The bonus parts include a standing pilot, but mostly nice new guns and pitot tube!

 

The decal sheet looks usable ...

 

For those curious ones, here are the deco options in the kit, number 2 being the same as the one built by Ernest, as mentioned above:

 

 

 

Here is the only work done to date on it, the spar and bottom fuselage glued together!

 

Still thinking of the markings I will use, from the box or other. Doing some research online for the correct type (Hei), that will appeal to me. Could by an all green one, as we don't see them very often in models.

 

By for now!

Alain

[j ferguson]

Hi Alain,

Watch out for the chance that kobuyashi's was the only plane with the venturi.  Some years ago someone found photos of kobuyashi and a couple of comrades adding a venturi to a ki-61.  He had been been flying twin-engine planes earlier in his career and may have wanted an artificial horizon which he'd come to like in the twins and which may not have been standard with the ki-61 at the time. Assuming that the ki-61 either didn't have any vacuum instruments, turn and bank or gyro compass, it wouldn't have had a suction pump either and so the need for a venturi.  It's also possible that he was installing a gyro driven gunsight which would also have needed a suction source.  You may be able to find  a discussion of this along with the photos at j-aircraft.com.  

 

It looked like the installation photos were taken of just his plane, but of course that doesn't mean that his colleagues didn't copy what he'd done.  Of course it could have been an official field modification and to more than just his aircraft.

good luck with what is sure to be an interesting build.

 

If this doesn't make any sense to you, ask and I'll expand on it a bit.

[Greif8]

Glad I could inspire you to enter the GP Alain!  I'll follow your build with interest.  My kit did not have the metal barrels which would have obviated my having to scratchbuild them, so the end result would have looked better.  Have fun with the build!

 

Ernest

[Alain Gadbois]

13 hours ago, j ferguson said:

Hi Alain,

Watch out for the chance that kobuyashi's was the only plane with the venturi.  Some years ago someone found photos of kobuyashi and a couple of comrades adding a venturi to a ki-61.  He had been been flying twin-engine planes earlier in his career and may have wanted an artificial horizon which he'd come to like in the twins and which may not have been standard with the ki-61 at the time. Assuming that the ki-61 either didn't have any vacuum instruments, turn and bank or gyro compass, it wouldn't have had a suction pump either and so the need for a venturi.  It's also possible that he was installing a gyro driven gunsight which would also have needed a suction source.  You may be able to find  a discussion of this along with the photos at j-aircraft.com.  

 

It looked like the installation photos were taken of just his plane, but of course that doesn't mean that his colleagues didn't copy what he'd done.  Of course it could have been an official field modification and to more than just his aircraft.

good luck with what is sure to be an interesting build.

 

If this doesn't make any sense to you, ask and I'll expand on it a bit.

Thanks for the very useful input! One of the options I'm considering has the ventury tube. It does look different than the usual model. perhaps you can shed some light on this?

 

 

 

On the top left, the other, green, option.

9 hours ago, Greif8 said:

Glad I could inspire you to enter the GP Alain!  I'll follow your build with interest.  My kit did not have the metal barrels which would have obviated my having to scratchbuild them, so the end result would have looked better.  Have fun with the build!

 

Ernest

Thank you! I think the guns were missing from the box you got second hand.

 

Alain

[Greif8]

That is quite possible Alain.  I made do the best I could by scratch building them instead of using the platic ones that were not the best to be honest.

 

It looks like you have some really cool markings to choose from!

 

Ernest

[j ferguson]

Hi Alain,

The photos I saw of the installation of the larger venturi did not start with one of what was there before the project began.  If the plane started out with only the turn and bank indicator vacuum (suction) powered, a smaller venturi would have been adequate.  My Cessna 120 was so equipped.  I had to install the larger venturi to develop sufficient suction to drive the artificial horizon and heading indicator.  Kobuyashi and company may have been doing what I did, except in my case I bought an electric turn and bank because at the 100 mph cruise speed on my plane the bigger venturi was only sufficient for the two instruments referred to above.  

 

If the Japanese artificial horizon and heading indicators were similar to ours from that period, less vacuum was required and they might have been able to run all three instruments with the one you typically see on ki-61s.

 

You sometimes see these venturi's on the noses of pre-war DC-3's.  When you do there are usually two of them - the better to get the instruments operating at lower air-speeds.

 

I'll look around and see if I can find a good photo of the smaller venuturi.  IIRC they were about an inch in diameter and maybe 7 to 8 inches long with the mounting point about an inch behind the forward part and a shallow horn extending aft.

 

I suppose it's not surprising that these are sometimes installed backwards by modelers who hadn't looked closely at the instructions.

[j ferguson]

OK guys, the small ones are called 2 inch venturi's because they draw 2 inches of mercury (suction)  the bigger one which was on Kobuyashi's plane is probably a 4 inch one.  Remember the larger cone goes aft.

 

google 2 inch venturi to see if this was the alternative.

[Alain Gadbois]

Hi! I did a bit of research on 2 inch venturi tubes. Be sure to add aviation in your key words because there are many different uses for venturis!

What I found is that usually the vacuum tube goes in the aircraft through the mount. This one has a tube going back and looks more like the one in the photograph.

Many of the small venturis don’t have the cone on the forward extremity.

In other news, I started gluing the cockpit parts, and fitting the various optional gun panels in the wings, and just general clean-up of parts. No boring photos for that!

Alain

 

[j ferguson]

the 2 inch venturis i'm  familiar with don't have the cone in front and the tube is contained in the mount.

[Juggernut]

On 12/30/2022 at 11:46 AM, Alain Gadbois said:

 

 

 

Take care if you're using these profiles for markings.  At least one of the aircraft in these profiles is identified incorrectly.  Chuichi Ichikawa's aircraft in the lower left corner is identified and drawn incorrectly.  The actual aircraft was a Ki-61-1 Tei (d) and not a Kai-Hei (modified c) as described.  I still haven't been able to determine what exactly a Kai (short for Kaizo) Hei actually is.  The meaning of the term is "modified C" but what that exactly means I do not know.  There's a big difference between the Hei and the Tei airframes, the latter being longer due to the Ho-5 20mm cannon being installed in the cowl.  The alleged Katabami (and not a shamrock as stated but it's impossible to tell from the angle of the extant photograph) is done well but the fuselage band and the yellow lightning bolt are subject to interpretation.  There's only one known photo of this aircraft which is why the coloring is subject to interpetation.  It is my opinion that the lightning bolt is actually red with a white outline based on study of the extant photograph.  The observer who took said photo described the aircraft as being "Chocolate Bar brown" (see image  below).  The image is from pg. 26 of Meatballs and Dead Birds, A Photo Gallery of Destroyed Japanese Aircraft in World War II, by James P. Gallagher.

 

The other one from the 244th that you've got the arrow on (2nd from bottom right) is a Hei and you shouldn't have any issues if you're doing that one.  If you've got the 244th Sentai book by Takahasi Sakurai, you'll most likely find it in there in addition to the two photographs you've shown above.

 

Sorry for the hijack, just wanted to set the record straight (as much as I can based on my knowledge, information, and belief) on that one profile.  EDIT:  After reviewing the information in my 244th Sentail book, there are some more discrepancies between those profiles and what's in the book but it's not anything worth getting into.

 

 

 

Edited January 5, 2023 by Juggernut

[Alain Gadbois]

3 hours ago, j ferguson said:

the 2 inch venturis i'm  familiar with don't have the cone in front and the tube is contained in the mount.

Thanks and you are correct. However in the photograph above there is definitely some kind of tubing going back so distance along the fuselage.

 

Alain

[Alain Gadbois]

2 hours ago, Juggernut said:

 

Take care if you're using these profiles for markings.  At least one of the aircraft in these profiles is identified incorrectly.  Chuichi Ichikawa's aircraft in the lower left corner is identified and drawn incorrectly.  The actual aircraft was a Ki-61-1 Tei (d) and not a Kai-Hei (modified c) as described.  I still haven't been able to determine what exactly a Kai (short for Kaizo) Hei actually is.  The meaning of the term is "modified C" but what that exactly means I do not know.  There's a big difference between the Hei and the Tei airframes, the latter being longer due to the Ho-5 20mm cannon being installed in the cowl.  The alleged Katabami (and not a shamrock as stated but it's impossible to tell from the angle of the extant photograph) is done well but the fuselage band and the yellow lightning bolt are subject to interpretation.  There's only one known photo of this aircraft which is why the coloring is subject to interpetation.  It is my opinion that the lightning bolt is actually red with a white outline based on study of the extant photograph.  The observer who took said photo described the aircraft as being "Chocolate Bar brown" (see image  below).  The image is from pg. 26 of Meatballs and Dead Birds, A Photo Gallery of Destroyed Japanese Aircraft in World War II, by James P. Gallagher.

 

The other one from the 244th that you've got the arrow on (2nd from bottom right) is a Hei and you shouldn't have any issues if you're doing that one.  If you've got the 244th Sentai book by Takahasi Sakurai, you'll most likely find it in there in addition to the two photographs you've shown above.

 

Sorry for the hijack, just wanted to set the record straight (as much as I can based on my knowledge, information, and belief) on that one profile.  EDIT:  After reviewing the information in my 244th Sentail book, there are some more discrepancies between those profiles and what's in the book but it's not anything worth getting into.

 

 

 

Thanks for all the info, it is much appreciated. I also have many reservations on any profiles, so I try to cross check with other info. I used this image as it has both options I am considering. 
I don’t have the book you mentioned but the photos I found give a good idea of this aircraft.

 

Alain

[Greif8]

I blow hot and cold when it comes to building a model to be as close to accurate as possible.  Sometimes I want to do that and sometimes it is not such a big deal to me.  I certainly took a lot of "artistic license" with my Ki-61 build.  The goal of that build was more about trying to spray a decent NMF for the first time than it was getting the depicted aircraft 100% historically accurate.  There is certainly room for both views - even within the same modeller. 

 

Ernest

Edited January 6, 2023 by Greif8

[Skyraider3D]

Alain, if you need any help on your build and want to get it accurate, please let me know and I am happy to help. I've spent (wasted? ) 100s of hours of my life researching Ki-61s when illustrating the Osprey book on Ki-61 and Ki-100 Aces by Nicholas Millman. Most profile art of Ki-61s out there is inaccurate and this applies to the samples above as well as to most scale model kit instructions and decals sheets. I myself made a number of mistakes with the Osprey art (deadline pressure).

 

The identifying feature of the Ki-61 Hei (which was a short-nose model) is of course the 20 Mauser cannon, which makes it easy to recognise in pictures. On the wing and a small circular inspection hatch will need to be scribed in as this is missed in all artwork and drawings:

 

 

 

The standard interior colour for the Ki-61-I Hei is grey-green (not RLM 79 Sandgelb or anything like that), although some early production models may have had blue-grey or even a mix of both. AK RC328 is a good match for the grey-green and MRP 417 for the blue-grey. Please note that all Ki-61-I Heis were delivered in bare metal, so any camouflage will be field applied and most likely dark green. From memory I can't think of any Ki-61-I Heis with solid camouflage, but it's quite likely they did exist but I'll need to check my references.

 

About the venturi tube, only a select few aircraft of leading pilots of the 244th Sentai were equipped with this. Indeed Kobayashi's #295 and Kuroe's #88 had them (although the latter had it removed together with the field camo in the winter of 1944/45). It's said they were installed for use with an experimental gyro gunsight, but I've found no evidence of the latter and a standard Type 100 Army reflector sight appears to be installed in both. The venturi itself is a license-built copy of the USAAC AN5807-1 (Type B-4A), which was also produced by Sperry amongst others. An accurate 3D-printed resin version of this was recently released by Luminaero (product U003x032).

 

About the shamrock-adorned Tony... it's a bit of a red herring (as well as a Ki-61-I Tei if it even existed at all), so best leave well alone. The 56th Sentai machine you pointed at in the profiles is also invalid. It was also a Ki-61-I Tei and the number was 751 (Osprey profile 28). Kuroe's #88 is definitely one of the more exiting valid schemes and I also have photos of it with camouflage. Remember that if showing it without camo (winter 1944/45), the ailerons will still have the summer 1944 field camo as these fabric-covered items could not be paint-stripped like the metal skin. You can clearly see their dark appearance in the photos you posted.

Edited January 5, 2023 by Skyraider3D

[Alain Gadbois]

10 hours ago, Skyraider3D said:

Alain, if you need any help on your build and want to get it accurate, please let me know and I am happy to help. I've spent (wasted? ) 100s of hours of my life researching Ki-61s when illustrating the Osprey book on Ki-61 and Ki-100 Aces by Nicholas Millman. Most profile art of Ki-61s out there is inaccurate and this applies to the samples above as well as to most scale model kit instructions and decals sheets. I myself made a number of mistakes with the Osprey art (deadline pressure).

 

The identifying feature of the Ki-61 Hei (which was a short-nose model) is of course the 20 Mauser cannon, which makes it easy to recognise in pictures. On the wing and a small circular inspection hatch will need to be scribed in as this is missed in all artwork and drawings:

 

 

 

The standard interior colour for the Ki-61-I Hei is grey-green (not RLM 79 Sandgelb or anything like that), although some early production models may have had blue-grey or even a mix of both. AK RC328 is a good match for the grey-green and MRP 417 for the blue-grey. Please note that all Ki-61-I Heis were delivered in bare metal, so any camouflage will be field applied and most likely dark green. From memory I can't think of any Ki-61-I Heis with solid camouflage, but it's quite likely they did exist but I'll need to check my references.

 

About the venturi tube, only a select few aircraft of leading pilots of the 244th Sentai were equipped with this. Indeed Kobayashi's #295 and Kuroe's #88 had them (although the latter had it removed together with the field camo in the winter of 1944/45). It's said they were installed for use with an experimental gyro gunsight, but I've found no evidence of the latter and a standard Type 100 Army reflector sight appears to be installed in both. The venturi itself is a license-built copy of the USAAC AN5807-1 (Type B-4A), which was also produced by Sperry amongst others. An accurate 3D-printed resin version of this was recently released by Luminaero (product U003x032).

 

About the shamrock-adorned Tony... it's a bit of a red herring (as well as a Ki-61-I Tei if it even existed at all), so best leave well alone. The 56th Sentai machine you pointed at in the profiles is also invalid. It was also a Ki-61-I Tei and the number was 751 (Osprey profile 28). Kuroe's #88 is definitely one of the more exiting valid schemes and I also have photos of it with camouflage. Remember that if showing it without camo (winter 1944/45), the ailerons will still have the summer 1944 field camo as these fabric-covered items could not be paint-stripped like the metal skin. You can clearly see their dark appearance in the photos you posted.

Thanks already for the info provided!

I would not mind getting more help!

The camo on the fabric surfaces I had not noticed yet, and it explains why the white wing bands have their edges strangely darkened. It is the remains of the hastily applied green paint that oversprayed on the white.

I will scribe the round panel very soon.

Under the wing, there is a part that represents the opening for the spend casings. It is very shallow. I wonder if it should be drilled out?

Also about the venturi, the photos show one in place. Do you have a better photo of it? It is different from the others it seems.

 

Many thanks,

Alain

Edited January 6, 2023 by Alain Gadbois