How capable was the Ki-44?

[Irregualr23]

While the ki-84 suffers from the low production quality and de-rated Homare engine, the Ki-44II got Ha-109 which doesn't need to use ADI and can pull power with ease. It could climb up to 6000 meters in just 5min-36second at Military power. At least this thing is way more reliable than the Ki-84 and thus having better performance real combat. In comparison, the Ki-84 is the reduced-spec version of the Ki-44, it has heavier stick force than the Ki-44 and its combat flap was removed. The ki-44 is able to extend combat flaps at 450kph IAS, while Ki-84's flaps were restricted to take-off and landing only, with 270kph IAS limit.

The Japanese pilots were informed that the Ki-44II will out-run and out-climb the F6F-5 at low altitude, while the Ki-84 might be caught by the zoom climb of a lower Hellcat, and there was no mention on Ki-84's advantage over the Hellcat. The main disadvantage for this aircraft was its fire power, 4 x Ho-103 was not enough to deal with rugged F6F and F4U. There was an IJAAF recalled that he fired at a zooming Hellcat but saw only some puffs, Hellcats with 500m altitude disadvantage then caught him in the dive and punched him to a force landing. The exchange ratio of the Ki-44 against USN fighters was poor, despite its performance advantage over the Ki-61 and Ki-84.

It was common for American fighters to mistaken the scars punched by Ho-103 to be 7.7mm. The Ma-102 explosive round was powerful, but was handicapped due to its self-detonation problem. The Ma-103 was stable but less powerful, works like ordinary IAI. Those explosive bullets have to hit the cockpit to be lethal. If ki-44 was equipped with 20mm, it could be one of the best IJAAF fighter.

 

[andrewgeorge]

While the ki-84 suffers from the low production quality and de-rated Homare engine, the Ki-44II got Ha-109 which doesn't need to use ADI and can pull power with ease. It could climb up to 6000 meters in just 5min-36second at Military power. At least this thing is way more reliable than the Ki-84 and thus having better performance real combat. In comparison, the Ki-84 is the reduced-spec version of the Ki-44, it has heavier stick force than the Ki-44 and its combat flap was removed. The ki-44 is able to extend combat flaps at 450kph IAS, while Ki-84's flaps were restricted to take-off and landing only, with 270kph IAS limit.
View attachment 846597
The Japanese pilots were informed that the Ki-44II will out-run and out-climb the F6F-5 at low altitude, while the Ki-84 might be caught by the zoom climb of a lower Hellcat, and there was no mention on Ki-84's advantage over the Hellcat. The main disadvantage for this aircraft was its fire power, 4 x Ho-103 was not enough to deal with rugged F6F and F4U. There was an IJAAF recalled that he fired at a zooming Hellcat but saw only some puffs, Hellcats with 500m altitude disadvantage then caught him in the dive and punched him to a force landing. The exchange ratio of the Ki-44 against USN fighters was poor, despite its performance advantage over the Ki-61 and Ki-84.
View attachment 846598
It was common for American fighters to mistaken the scars punched by Ho-103 to be 7.7mm. The Ma-102 explosive round was powerful, but was handicapped due to its self-detonation problem. The Ma-103 was stable but less powerful, works like ordinary IAI. Those explosive bullets have to hit the cockpit to be lethal. If ki-44 was equipped with 20mm, it could be one of the best IJAAF fighter.

Interesting stuff!

Would a Ki-84 really be caught by an F6F in a climb though? Unless the Hellcat has a significant initial energy advantage, I'm thinking the Hayate simply has far too much power/weight to be reeled in by an F6F, especially in a climb. Even if the Hayate pilot isn't getting the most out of his Homare, the Hellcat is more than 60% heavier.

 

[Shortround6]

Would a Ki-84 really be caught by an F6F in a climb though? Unless the Hellcat has a significant initial energy advantage, I'm thinking the Hayate simply has far too much power/weight to be reeled in by an F6F, especially in a climb. Even if the Hayate pilot isn't getting the most out of his Homare, the Hellcat is more than 60% heavier.

A lot depends on the energy state (speed) of the two fighters and the actual weight at the point of engagement.
It also somewhat depends on the exact engine model of the Homare engine and when/if the F6F had water injection or if the water tank was full or nearly so.
Also may depend on altitude. at around 20,000ft the F6F had over 300hp more HP than the Ki-84/Homare 21
Time to about 5000 meters is not that far off between the two if the Hellcat is using water injection?

But the question is if the Ki-84 can break the engagement (get out of gun range) against the Hellcat which more like tens of seconds rather than several minutes of climb.
An F6F at higher speed than the Ki-84, for what ever reason, has a lot of energy to turn into zoom climb for a short period of time.

 

[TM06]

For what it's worth, there were some prototypes of an improved Ki-44 designated Ki-44-III. It's obscure as hell but I was given some excellent sources on the War Thunder forum a while ago when making a suggestion for the aircraft to be added.
The main changes were the replacement of the Ha 109 with the Ha 45-21 (Homare) and a redesigned wing - the first two prototypes had a 19m2​ wing while the next few prototypes had a 21m2 ​wing. The new wing allowed for it to carry two 20 mm Ho-5 cannons alongside the two 20 mm Ho-5's in the cowling.
They tested it alongside the Ki-84 in 1943 but it was found to be inferior, so no production orders were given.

 

[Irregualr23]

Interesting stuff!

Would a Ki-84 really be caught by an F6F in a climb though? Unless the Hellcat has a significant initial energy advantage, I'm thinking the Hayate simply has far too much power/weight to be reeled in by an F6F, especially in a climb. Even if the Hayate pilot isn't getting the most out of his Homare, the Hellcat is more than 60% heavier.

A Ki-84 running at +250mm military rating has no advantage in speed and climb than the Hellcat, if not worse. The British compared one captured Ki-84 with the Seafire LF.III using +250mm setting and the plane was inferior to the Seafire in almost every aspect. A Ki-84 running at +350mm rating may obtain a slight climb advantage and match the Hellcat in speed, but it was questionable whether the low manufacturing quality and less skilled IJAAF pilots allowed this slight advantage to be developed. A Ki-84 using +450mm/+500mm TO power will definitely out-climb the Hellcat, but that power setting was restricted to 1-minute use and was rarely saw in combat, there was no confirmation on successful utilization of the TO power( 1-min usage) of the Homare engine to be WEP (5-10 min usage).

Both Ki-44 and Ki-84 would be out-turned by the Hellcat, as mentioned by the Japanese pilots. Thus it was hard for both Ki-44 and Ki-84 to develop their potential marginal advantage over the Hellcat and Corsair, when fighting in numerical disadvantage situation.

 

[Irregualr23]

When against the USN raids on Tokyo in Feb 1945, the IJAAF gave the following suggestion on combating the F6F-5:
1.二式単戦
イ旋回性は敌に比し劣る。敌はその长所を巧みに利用し、射弾回避及び反撃を実施するをもって、少なくも小队以上を终结し速度を利して一撃必坠の攻撃を指向するを要す。
ロ速度及び上升性能は中空以下に于いては我が方有利にして、上升离隔成功せる例あり。
ハ低位戦においては相互支援可能なるも、速度により一挙に高度获得后、高位より戦闘を开始するを有利とす。
2.三式戦
イ旋回性能我と概ね同等若しくは敌やや优る。我が高度差１５００ｍ付近より突进せば、敌の旋回回避により射距离内に入りたるときは追随困难なること多し。
ロ急降下速度は、我よりやや大なり。
ハ半奇袭以上においては撃坠は容易なるも、防火装置良好にして一撃炎上せしむるはやや困难なり。
3.四式戦
イ高位戦は有利なる戦闘を実施し得るも、我が离脱不彻底なるときは低位より急上升反撃す。
ロ低位戦は相当の苦戦を免れず。敌は旋回性の优れるを利し、相当执拗なる追蹑攻撃を実施す。速やかに戦闘圏を脱し、高度获得后戦闘を実施するを要す。
1. Type 2 fighter (ki-44)

• i. Its turning performance is inferior compared to the enemy. The enemy skillfully exploits this advantage to evade gunfire and counterattack. It is necessary to conduct attacks aiming for a decisive blow using speed, ideally with at least a flight (three or more aircraft).
• ii. In terms of speed and climb rate below medium altitude, our side holds an advantage, and there are cases where successful separation by climbing was achieved.
• iii. In low-altitude combat, mutual support is possible, but it is more advantageous to rapidly gain altitude through speed and commence the engagement from a higher position.

2. Type 3 fighter(ki-61)

• i. Its turning performance is roughly equal to or slightly inferior to the enemy. If attacking from an altitude advantage of around 1,500 meters, the enemy often manages to evade by turning, making it difficult to stay within firing range.
• ii. The enemy has a slightly superior dive speed compared to ours.
• iii. While shooting down the enemy is relatively easy when achieving a partial surprise attack or better, their fire suppression systems are effective, and causing them to burst into flames with a single hit is somewhat difficult.

3. Type 4 fighter(ki-84):

• i. It is capable of conducting favorable engagements in high-altitude combat. However, if our withdrawal is incomplete, the enemy may launch a steep climbing counterattack from lower altitude.
• ii. In low-altitude combat, we cannot avoid considerable difficulty. The enemy leverages superior turning performance to execute persistent pursuit attacks. It is necessary to quickly exit the combat zone and re-engage after regaining altitude.

 

[beers]

The main changes were the replacement of the Ha 109 with the Ha 45-21 (Homare) and a redesigned wing - the first two prototypes had a 19m2 wing while the next few prototypes had a 21m2 wing. The new wing allowed for it to carry two 20 mm Ho-5 cannons alongside the two 20 mm Ho-5's in the cowling.
They tested it alongside the Ki-84 in 1943 but it was found to be inferior, so no production orders were given.

The tail was also changed a fair bit in the pursuit of better takeoff and landing characteristics. Mostly enlarged.

 

[Airborne2001]

Here is an artists interpretation of the Ki-44-III:

This drawing was posted by blackkite on secretprojects.co.uk. (Not sure who exactly drew it.)

Nakajma Ki-44-III?

Something i put together quickly but i assume this is how it would have looked

www.secretprojects.co.uk

 

[Steamed_Banana]

In Shores Bloody Shambles, the Ki-44 is largely dismissed because it rarely got into the fight due to it's limited range. It was basically used almost as point defense. When it did get into action, though it may have had impressive performance, it didn't seem to have much more effect than the Ki-43s they were already using.

 

[Shortround6]

The Bloody Shambles books may not be a good source for the Ki-44 unless you are including Air War for Burma (vol III) ?
Perhaps you are.

From Dec 1941 through April 1942 the Japanese never had more than nine K-44s in operation in South East Asia. Some times as few as 2-3. Yes they were short ranged, but such a small number of aircraft are note going to make much difference. 3-4 Ki-44s tagging along with 12-30 other Japanese aircraft and not going to make a big impression.
These were also the Ki-44 Is with two 7.7mm machine guns in the cowl and two 12.7mm guns in the wings. They also had the single speed supercharger engine that offered 1250hp at 4000 meters.
They were withdrawn for home defense of Japan after the Doolittle raid and didn't go back to China/South Eat Asian until Oct. 1943. These would be the Ki-44 II but again, in very low numbers for a number of months.

 

[taly01]

They were withdrawn for home defense of Japan after the Doolittle raid and didn't go back to China/South Eat Asian until Oct. 1943.

I often wonder where the Ki-44 served, cause they are rarely mentioned, even though they made some 1,220 over 3+ years. My conclusion is also the monthly production rate was was so low they were attritioned through normal service losses.

 

[GregP]

Here's a Ki-44 from me:

 

[Steamed_Banana]

The Bloody Shambles books may not be a good source for the Ki-44 unless you are including Air War for Burma (vol III) ?
Perhaps you are.

yes that is actually the one I'm referring to, though they didn't have a huge number of Ki-44 even later in the game, and they came into action only when Allied strikes approached the vicinity of their bases.

What I've yet to see however is a comprehensive 'both sides' operational history of the air war in China. Bloody Shambles III only covers this tangentally, where it overlaps with British operations.

If such a thing exists, I'd love to see it. I'm ready to buy it!

 

[andrewgeorge]

In Shores Bloody Shambles, the Ki-44 is largely dismissed because it rarely got into the fight due to its limited range. It was basically used almost as point defense. When it did get into action, though it may have had impressive performance, it didn't seem to have much more effect than the Ki-43s they were already using.

yes that is actually the one I'm referring to, though they didn't have a huge number of Ki-44 even later in the game, and they came into action only when Allied strikes approached the vicinity of their bases.

What I've yet to see however is a comprehensive 'both sides' operational history of the air war in China. Bloody Shambles III only covers this tangentally, where it overlaps with British operations.

If such a thing exists, I'd love to see it. I'm ready to buy it!

I suspect the larger point about the Ki-44 not having a huge effect on the air war is true, even in China. IJAAF air forces were going to be on the losing end of a prolonged air war against the British, Americans, and Chinese regardless of what types they were flying.

 

[Shortround6]

Real problem with trying to figure out the effectiveness of the Ki-44 is that it made up about 9% of total fighter production.
They made about 40% of the number of Ki-61s built.
The "sample size" for many combats may be to small to get a good assessment.
Ki-44s were used at the front/s in small numbers at the mid/end of 1943 and production peaked during the winter of 1943/44. Production per month in the last 1/2 of 1944 was about 1/2 of what is was in the first 1/2 of the year and production stopped totally in Jan 1945 (2 aircraft) and yet on July 1st 1945 Ki-44s made up 31% of permanently stationed air defense fighters and 18% of the combined permanently stationed and Mobile Air Defense Forces (Ki-84s and Ki-100s).
The Japanese built about 35% the number of Ki-44s that they did Ki-84s and many of them never left Japan.

 

[Steamed_Banana]

Real problem with trying to figure out the effectiveness of the Ki-44 is that it made up about 9% of total fighter production.
They made about 40% of the number of Ki-61s built.
The "sample size" for many combats may be to small to get a good assessment.
Ki-44s were used at the front/s in small numbers at the mid/end of 1943 and production peaked during the winter of 1943/44. Production per month in the last 1/2 of 1944 was about 1/2 of what is was in the first 1/2 of the year and production stopped totally in Jan 1945 (2 aircraft) and yet on July 1st 1945 Ki-44s made up 31% of permanently stationed air defense fighters and 18% of the combined permanently stationed and Mobile Air Defense Forces (Ki-84s and Ki-100s).
The Japanese built about 35% the number of Ki-44s that they did Ki-84s and many of them never left Japan.

I think production numbers can be misleading, since even when only a few hundred aircraft are built, if they are active at the front line during key battles, they can still have an important role.

The issue with the Ki-44 was that in most Theaters where the Japanese were operating, combat often required long flights over dense mountainous forests (especially in China and South Asia, as well as New Guinea) and / or vast expanses of water before the enemy could be engaged. Ki-44 just didn't have the legs for any of that. The only way it's going to come into significance is it's based somewhere that the Allies are trying repeatedly to destroy or bomb and it can function as an interceptor.

It also looks like Ki-44 was a bit more optimized for attacking bombers than fighters, though that is debatable. From the wing-loading, which I know doesn't tell the whole story, it will not necessarily out-turn some Allied fighters like Spitfire, P-40, Wildcat, Corsair etc., and it's not quite fast enough overall to necessarily outrun them sufficiently for BnZ. It does have an excellent climb rate, and apparently dived fast too, as well as good low altitude speed. I think the reputation it earned in some Allied circles is due to it being immune to the usual energy fighting tactics that Allied pilots used with some success against Ki-43 and A6M. This of course came as a shock. Same for Ki-61, I think it was good but it's advantages get overstated just because it was different, i.e. had different strengths and weaknesses that weren't fully known right out of the gate.

Being better at attacking bombers could be significant though, seeing as well into 1943 the Allies were often sending planes like Beaufighters, B-24s, and B-17s in small unescorted groups or solo recon flights over or near Japanese bases. Especially if they were flying at relatively high altitude, they could often escape or evade Ki-43 or A6M without being shot down, (though not without risks). The sudden appearance of a better performing fighter may change that calculus.

One factor in air combat that I think is often overlooked is that fighter designs which were in use for a very long time, like the Ki-43, A6M, Bf 109, P-40, Spitfire, Hurricane etc., became somewhat known quantities, and standard tactics would be developed against them. New fighters are always somewhat of an extra problem until these parameters are known. Major upgrades or improvement can be game changers because the standard tactics against type may no longer work or not work as well.

I think this was one of the advantages of the Ki-43-II and A6M3 with their better altitude performance. It was clearly a big advantage for the Spitfire Mk VIII and IX compared to the Mk V. The P-40F and L were enough of a shock to the Germans and Italians in North Africa that they designated them as a different plane, often referring to them as P-46. The DB 605 versions of the Bf 109 and MC 205 etc. also introduced significant new problems, as did the improved faster-rolling, tighter-turning P-38J and L, and the new paddle bladed P-47s that could climb all the sudden. The La-5FN which suddenly had so much power down low. The fast-climbing FM-2, so much better in this trait than an F4F. And so on.

I'll see if I can find some examples of Ki-44 in action in Bloody Shambles Vol III and post them.

 

[Shortround6]

I think production numbers can be misleading, since even when only a few hundred aircraft are built, if they are active at the front line during key battles, they can still have an important role.

The Ki-44 was not sent to the front line in any numbers (not more than 9-20) until late 1943 and not at all for much of 1942 and early 1943.

The Ki-44 held about 485 liters of fuel but that is not much for the size of it's engine. But it is within 10-15% of the P-39/P-40/F4F all without drop tanks. A little more fuel than Hurricanes or Spitfires. There were two different drop tank sets ups but I don't know when they showed up. A pair of 130 liter tanks is certainly not great but equal to the P-39s and P-40s with normal drop tanks?
Ki-61 only had about 10% more fuel but it had less drag so range was better?

It took a while for the Japanese to even figure out what to do with it. In part because they tried to give it to some squadrons to replace Ki-27s and we can imagine how that went over with the pilots
Some accounts claim (western false statements?) that at first the Japanese thought that pilot needed 1000 hours to handle the Ki-44. Later they found that pilots that were not indoctrinated in the high "G" form of combat could actually handle them fairly easily (land/take-off) without high accident rates. Using boom and zoom they could be pretty effective.

It also looks like Ki-44 was a bit more optimized for attacking bombers than fighters, though that is debatable

I don't know what they were thinking but the Ki-44 was later than the Ki-43 and just about everybody was trying to put more guns or larger guns in their fighters.
Japanese Navy had already put 20mm guns in the wings of the Zero (small ones). The Requirement for the Ki-44 (1939,very early 1940) was around 2 years later than the Ki-43 requirement and the Ki-44 was, at least to start, a contemporary of the Ki-60 and Ki-61.
The Ki-44 II was several years later and the whole 40mm rocket gun was not part of the initial design.

 

[beers]

From the wing-loading, which I know doesn't tell the whole story, it will not necessarily out-turn some Allied fighters like Spitfire, P-40, Wildcat, Corsair etc.

Spitfires, very unlikely. Wildcat and Hellcat, also unlikely for as long as they have speed to burn. But P-40, Corsair, and the other types? I don't think they stood a chance in a turnfight thanks to both the maneuver flaps and the much higher excess power of the Ki-44. That last part would even give it a chance against the first three aircraft mentioned in some situations.

Remember that while its handling was said to be bad/dangerous by some japanese pilots, these are the same ones that came off the Ki-27 and Ki-43 shortly before - anything flying in 1940 or later would have handled worse than these two, especially in the dogfights that japanese pilots loved doing.

 

[Steamed_Banana]

Spitfires, very unlikely. Wildcat and Hellcat, also unlikely for as long as they have speed to burn. But P-40, Corsair, and the other types? I don't think they stood a chance in a turnfight thanks to both the maneuver flaps and the much higher excess power of the Ki-44. That last part would even give it a chance against the first three aircraft mentioned in some situations.

Remember that while its handling was said to be bad/dangerous by some japanese pilots, these are the same ones that came off the Ki-27 and Ki-43 shortly before - anything flying in 1940 or later would have handled worse than these two, especially in the dogfights that japanese pilots loved doing.

Well maybe that's a discussion for another thread, but I don't necessarily agree that a Hellcat is going to out-turn a P-40, P-40s also had flaps which could be used at maneuver settings (manually) and I think Corsairs are fairly close to a Hellcat in turning circle though I haven't looked at it in a while. I'm not too concerned about it either way.

 

[Admiral Beez]

I like the Ki-44. It's the first Japanese fighter that was robust and armoured, trading light weight and fragility for survivability. It just needs a better engine.