Kawasaki Ki-61 Hien / TONY

Hi. A comment about armament variants. I think your description of the variant names and armament is based on Francillon and widely spread in western aviation publications but is differenct from what is widely known in Japan. In Japan, the "standard" published information is as follows;

DESIGNATION Armament
Model 1 KO(Ki61Ia) 2 x HO103 12.7mm (Fuselage)
2 x Type 89 7.7mm (Wing)

Model 1 OTSU(Ki61Ib) 2 x HO 103 (Fuselage)
2 x HO 103 (Wing)

Model 1 HEI (Ki61Ic) 2 x HO 103 (Fuselage)
2 x MG151 /20 (Wing)
Model 1 TEI (Ki61Id) 2 x HO 5 20mm(Fuselage)
2 x HO 103 (Wing)

There are no official records nor designation for a 30mm cannon armed model. I am not even sure such existed.

Also, the Ki61I-kai designation was an initial name for the long fuselage models with the 20mm Ho5 guns in the nose. These were later redesignated as Ki61Id. I have never seen a Ki61I-kai-c or Ki61I-Kai-d designation in Japan, although I have seen a lot of it in Western studies.

reply

Wikipedia lists the Ki.61-II as one of the very few Japanese fighters able to reach the operational altitude of the B-29s raiding Japan with decent firepower. Subsequently, the majority of B-29s lost to Japanese fighters were shot down by the Ki.61-II.

reply

Ron,
Thank you and thanks for sharing all the great information that you have posted. Well, I'm sitting at home on a day off so I dug out the TAIC report 154A1-4. The performance figures of the Ki.61-1 on this report match exactly to the figures given on the confidential report COMPARATIVE PERFORMANCE AND CHARACTERISTICS REPRESENTATIVE ENEMY AND ALLIED AIRCRAFT Jap Fighters report that I have listed elsewhere on this sight. They are: Test Weight: 6,982 lbs. Engine: Kawasaki Type 2 /1,160hp /S.L. Range Clean: 1,520mls /156mph /1,500ft /199gallons. Max: 2,010mls /148mph /1,500ft /299gallons. Max.Speeds: 302mph /S.L. 322 /5Kft. 340 /10Kft. 358 /15Kft. 361mph /15,800ft. 352 /20Kft. 340 /25Kft. 318 /30Kft. Climb: 2,440fpm /SL. 2,520 /5k. 2,500 /10K. 2,300 /15K. 1,750 /20K. 1,200 /25K. 1,000 /27K. 500 /31,2K. 100 /35K. 5,000ft /1.9min. 10K /4.0. 15K /6. 20K /8.5. 25K /11.7. 30K /16.0.
In another report PROJECT TED NO. PTR-1115 Roll Rate at Low Speeds: Equal to FM-2, F6F-5 and F7F-3. Inferior to F4U-1D, F4U-4 and F8F-1. High Speeds: Slightly inferior to FM-2. Inferior to F4U-1D and F7F-3. And Greatly inferior to F6F-5, F4U-4 and F8F-1. The FM-2 was the only fighter in this comparison that could outturn the Ki.61-I at any speed. The Tony 1 gave up maneuverability to gain speed but by U.S. standard was still very maneuverable at lower speeds.

reply

Thanks Aaron.
Great find!

reply

Found a military document document marked RESTRICTED dated March 1945. The document(s)is numbered 154A-1 through 154B-4. It is titled TONY 1 and TONY 2. I only have time now to post one part of the document, so I'll start with the Ki.61-II first. Page 154B-2 states that the performance figures are based on fragmentary documentary evidence and resultant extrapolation of engine ratings. Engine: Kawasaki Ha-140 /1,440 hp at War Emergency power /5,700ft. Maximum Speed:
335mph /S.L. 423mph /28,000ft. Climb: 3,425fpm /S.L. 3,560fpm /6,000ft. 1,000fpm /37,400ft. 100fpm /43,000ft. 10,000ft /3.2min. 20,000ft /6.6min. Test Weight: 7,232lbs. Maximum Range: 2,120mls. /150mph. /1,500ft. /305gallons.
This is the only document I have ever seen that gave the Ki.61 (any variant) a speed of over 400mph.

reply

check the ki 100 site John.

reply

WHAT!? NO MENTION OF THE KI 100? IT HAD BETTER NUMBERS THAN THE KI 61. THE JAP COPY OF THE DB 601 ENGINES HAD A LOT OF PROBLEMS WITH MAIN BERINGS SO THEY HUNG A GOOD RADIAL ENGINE ON THE KI 61 AIRFRAME AND CALLED IT THE KI 100. LIGHTER,FASTER AND A BETTER RATE OF CLIMB.WOULD LOVE TO HAVE ONE TO PLAY WITH.

reply

I'm amazed how people cling to WW 2 propaganda that was discarded by 1943. This is 2011.
Some still won't admit the Ki 61 is a Japanese fighter design.
It's as absurd as calling the P-51 with the 'Malcom hood' an American copy of the Spitfire because it has the canopy and engine shared. Heck even the guns in some versions.
The Mustang name was British too.
These folks keep repeating that Japan bought examples of German Heinkel and Messerschmitt fighters, well so did Russia. Does that make the Soviet LaGG-3 a copy of the He 100 just because it was influenced by some of it's features?
They won't say that but they'll say it for the Ki 61.
Pure ignorance! Voght and Doi had nothing to do with Heinkel or Messerschmitt!
Unfounded propaganda should be exposed for what it is.

reply

Background of the Kawasaki Hien fighter:
Takeo Doi graduated from Yamagata University in 1924, and Department of Aeronautics, Faculty of Engineering, Tokyo Imperial University.
In 1927, he started his career in Aircraft Department of Kawasaki Dockyard Company Limited, Kobe.
(1923 - 1933). The company invited Dr Richard Vogt from Germany as a technical advisor to teach its engineers in the construction techniques of Dornier Flugzeugwerke on
aircraft which Kawasaki was building under license. As a chief designer, Vogt trained new-face engineer Doi to be his successor. They worked jointly on several aircraft projects, including the (KDA-5 Army Type 92 biplane fighter, KDA-2 Army Type 88 reconnaissance
Surveillance biplane, KDA-3 single-seat fighter, and KDA-5 Army Type 92-I biplane fighter).
During this period, Doi was dispatched to Europe, where he worked for one and a half years.
In Europe, he studied the art of aircraft engineering in the field of airplane industry.
When Doi was in the United Kingdom, he paid attention to the technology of George Dowty, founder of Dowty Aviation
Dowty Rotol, a British manufacturing company based in Cheltenham manufacturing propellers..
As Dowty's technology in aviation hydraulic systems was state-of-the-art and met the requirement of the Japanese military, Doi chose his product as the landing gear of Type 92-I biplane fighter.
This decision helped Dowty to develop his company, Dowty Aviation, and became a milestone for the expansion of the Dowty Equipment group thereafter.
After Vogt returned to Germany, Doi became the key person in the design bureau of Kawasaki Aircraft until the company ceased operations at the end of World War II. His most important and outstanding work was the design of Army Type 3 Fighter Kawasaki Ki-61.
The Kawasaki Ki-61 Hien was a Japanese World War II fighter aircraft used by the Imperial Japanese Army Air Force. The first encounter reports claimed Ki-61s were Messerschmitt Bf 109s, then an Italian design, which lead to Allied code name "Tony", assigned by the United States War Department.
The Ki-61 Hien demonstrated surprising performance that surpassed the famous Mitsubishi A6M Zero.
(- Online astronomy & history site.)
The myth that the Ki 61 was an He 100 copy is not borne out here.

reply

the reason why the Tony was chosen over the tojo is a simple one

the pilots prefered the easier to fly and more stable Tony.
The Tojo was a beast to fly and required the pilot be experienced in order to handle
also, dispite its great statistics it was not very stable in the air which made aiming the guns and keeping a bead on the target very difficult
in short, it was a great hot rod but a mediocre war plane.

The Tony, on the other hand was easier to fly and very stable in flight, meaning it was more ideal plane for the inexperienced rookie pilots that filled the ranks of the Japanese air force.

reply

I WOULD LIKE TO SEE THAT REPORT AS WELL.
My opinion is that the build and armor of the Tony is more battle worthy than the Tojo's but the reliable, less vulnerable radial engine of the Tojo compensates.
I also agree that the manueverability or the early Tony doesn't come with all the safety restricted moves of the Tojo (no snap roll, no stall, no inverted flight, no flick moves ...etc). The Tojo had the climb rate especially vs later model Tonys.
I say early and later Tony because the Tony was so much heavier with each model.
That's not so true of the Tojo. It gained less than 500 lbs loaded. The last inline Tony gained about a ton since the mock dogfight in August, 1942.

reply

Ron,
I would love to see the actual report on the Ki.61-I vs Ki.43-II, Ki.44-I, Bf.109E and P-40E. It would be very interesting to see how the Ki.61-I bested its foes. It is obvious to see the Hien's ascendency over all but the Ki.44-I. I have not seen any actual test reports of the Tojo so all I have to go on is articles and commonly published figures. From what I have read to date, the Ki.44 has the maximum speed, roll rate and climb advantage. IMO dive, acceleration and ruggedness are similar. The Tony's only clear advantage is a tighter sustained turn. But as I said, this is just my opinion.

reply

Aaron,
I saw that website before but I'm still unsuccessful in spotting some of the info you found there.
There are some similar that I saw in the past but can't seem to find again.
Sometimes Aviation History or Flight Journal magazines ..etc, have some good stuff.

Debtman,
You must have your tongue in cheek.
Otherwise, a book I want to recommend to you is Japanese Aircraft of the Pacific War by Rene J Francillon.

While it's true that the Ki 61-I emerged victorious outright in mock dogfights between the standard Ki 43-II, a Ki 44-I, a Bf 109E and a captured P-40E in the summer of 1942, something is lost in the translation on the way to your comment, Debtman.
The 30-mm cannons were not the low velocity short range MK 108s. The Ho-155(105) wing mounted 30s on the Ki 61-I KAId had a decent range of 900 m. The cowl guns were 12.7-mm machine guns.

reply

The Ki-61 was an hybrid between a leased Me-109 and a captured P-40.During the last stages of WW2,a few number of Tonys was used in kamikaze missions.The standard variants was the Ki-61Ko (4xRu 12.7mm machine-guns),Ki-61 Otsu (2xRu 12.7mm machine-guns and 2xHo-5 20mm cannons) and Ki-61KAIc (4xMK-108 30mm cannons)

reply

Ron,
Thank you for the complement. I am just an anthusiast like yourself. I have been fortunate to come across so many military and manufacturers document only through the computer (internet, which my wife Diana said I had to get years ago, bless her heart). Yes, I totaly agree that the Ki.61 was superior to the P-40E in 1943, but the contemporary P-40 would be the N-1. This curtiss fighter would outclimb and outturn the Hien. But you are correct that the E model was still in great numbers in the Pacific and probobly the model the Tony would most likely apose. However, apples to apples the P-40E was a full year old by that time. The Tony had a very good roll rate at slower speeds. I have not found any posted exact figures at this time. You are exactly right though about the comparison being later US fighters. It is a navy report dated Jan. 26,1943. Controlled sercumstances, I am sure. I would really like to see the Ki.61-1 compared to its actual contemporarys like the P-39N. Especially if the Allison is pushed to the limits.

Ron,
I am really starting to wonder. Did you get my e-mail about the sight that has a lot of the info that I have been sharing? If not, please let me know. There are a lot of great sights out there. I would be very interested in all the sights /books that you have found the great information that you have been sharing with the rest of us. Please do not hesitate to e-mail me at Yahoo. No, I'm not going to try to sell you insurance. I work at a hospital in the maintenance department. I am a stationary steam engineer and CPO (pool boy) among other things. My college degree is in accounting....go figure. We'll talk about my kids later if you promise to take one or two....three or four.

reply

I appreciate the comment on dive speed.
On comparing this fighter to the Zero, my answer would be that the A6M2 ruled in 1942 till it was demystified and the Ki 61 followed by taking back air superiority on it's debut.
Allied tactics were updated to dive against Zeros and that played right into the strength of the Tony. Of course it could still dogfight too (perhaps better than it's European counterparts). With the -II version it had improved altitude performance and range, gaining it's reputation against B-29 raids. Unfortunately, it was still dogged by engine trouble. Enter the Ki 100 surprise!

reply

What could have been if in the spring of 1943 the Luftwaffe got their hands on a specimen of the Ki 61 Hien and installed a real DB 601A power plant, and 3 MG 151s all in the nose. The cowl mounted pair with reliable electric synchronization (none of the Browning derived slow rate synchronization suffered by Japanese pilots) with a 20-mm motor hub cannon and no wing guns to compensate for the heavier engine. Voila! You have a much more aerobatic ninja fighter than the Bf 109. The Hien was the first tough Jap fighter. Now it's drawbacks would be gone early on. The best of both fighters in one should result.

reply