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Wildnoob
09-22-2011, 01:47 PM
Being well flown do you think this Kawasaki fighter can be an effective machine against capable Allied pilots in their late war crates?

ps: I hope Gaston don't come here. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

JtD
09-22-2011, 02:19 PM
Yes, if the capable Allied pilot is not aware of your presence.

Also yes if the late war crate is an F6F or a bomber of some sort.

But other than that, the Ki-100 is pretty much two years behind. Could have been good if it had gotten to the front in early 1943...not so much in 1945.

To sum it up: No.

Bosskhyrkh
09-22-2011, 03:23 PM
It's too slow to be a serious threat in an energy fight. The ki-100 is actually slower than the ki61 levelflight and in a dive, it does climb and handle a bit better.

Some sources say it could compete because it could hold it's speed in a dive, but in Il-2 it doesn't dive very good...

VW-IceFire
09-22-2011, 03:26 PM
JtD is correct. From a raw performance standpoint the Ki-100 is not competitive with the latest Allied fighters. Contemporaries are the F6F-5, F4U-1D and F4U-4, P-51D and the P-47N. Of these it may be able to fight the Hellcat on somewhat even terms but aside from that it has less raw performance than any of them.

It is a good aircraft. The reason that the writings regard it so highly in my mind is due to other factors than raw performance. It reasonably easy to fly without any serious vices that I'm aware of, the engine worked most of the time, the armament was somewhat effective and it was sturdy enough to be able to dive with most American fighters.

No matter what it is an aircraft I really enjoy flying. It keeps speed from the dive fairly well and you can surprise opponents and hit them pretty hard with the 20mm. It also rolls quickly and has good control at almost any speed. It is quite fun to fly in my opinion... makes it worth the challenge of fighting against better American fighters. They can boom and zoom all day but if they make a mistake and you play your cards right... you can be all over them.

Luno13
09-22-2011, 04:03 PM
Indeed. Many online will not even pay attention to the Ki-100, and instead will worry about the J2M5 and Ki-84.

The careless become quick prey.

I find it interesting that the cannon are in the nose while the guns are in the wings. I wonder what the reasoning behind that was as it's different than anything except maybe the MC.202 (with .50s in the nose and .303s in the wing).

VW-IceFire
09-22-2011, 04:24 PM
Originally posted by Luno13:
Indeed. Many online will not even pay attention to the Ki-100, and instead will worry about the J2M5 and Ki-84.

The careless become quick prey.

I find it interesting that the cannon are in the nose while the guns are in the wings. I wonder what the reasoning behind that was as it's different than anything except maybe the MC.202 (with .50s in the nose and .303s in the wing).
Starting from the Ki-61-Tei (a model sorely missing from IL-2) the Ho-5 20mm cannons were installed in the nose. I'm not exactly sure what the installation requirements were but they managed to fit there with the slightly elongated Ki-61-Tei and they still fit even with the re-engined Ki-100.

I would have suspected that the weight and flex of the wings caused problems for wing installations but that is where they were forced to put the MG151/20s on the Ki-61-Hei. Of course these are two very different cannons...

Good question for sure!

Luno13
09-22-2011, 04:31 PM
Makes sense. I think the Ki-43 also had cannons installed at some point. A Ki-44 Shoki would also be nice to round out the fighters.

horseback
09-22-2011, 05:12 PM
If you have the space, packing in the cannon and its ammo closer to your CoG could make you more nimble and might impose fewer penalties in recoil, changes in CoG due to ammo expenditure, and there would be more structural strength already in place, unlike in a wing where the extra weight and recoil effects of a new and heavier gun would have to be more carefully accounted for.

The Ki-100 had more room in the nose area after all the extraneous equipment in the Ki-61's in line engine was eliminated. As I recall, putting heavier guns and ammo in the nose actually helped balance out the loss of the cooling and other systems that went away with the introduction of the radial power plant.

Most of the Japanese late-war fighters were at least partially rated on the basis of how easy they were to fly; in an air force where the majority of pilots were barely trained, just having confidence that you could take off and land your mount could make a critical difference in your confidence and ability to at least attempt your mission...

cheers

horseback

JtD
09-22-2011, 10:51 PM
As IceFire already pointed out, the 20mm cannon were already standard on most of the Ki-61's and had nothing to do with the change of the engine.

They put it in the same place they were on a La, it's not that unheard of.

DKoor
09-23-2011, 04:48 PM
The only prob with them is they have a hard time catching B-29s.

VW-IceFire
09-23-2011, 05:41 PM
Originally posted by DKoor:
The only prob with them is they have a hard time catching B-29s.
That is definitely an issue. An older campaign I did with the Ki-61 and Ki-100 had several B-29 interception missions but I always scaled the B-29 speed back a bit to help make the mission more interesting... those B-29s up high can really move.

There was a revised Ki-100-II with a turbo installation and revised cowling but I don't think they had time to build any.

TipsyTed
09-24-2011, 09:14 AM
Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further). According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84, winning something like 10 out of 10 mock dogfights between the two machines - with pilots being swapped inbetween. Which doesn't appear to be the case in IL-2. Also, many allied pilots regarded Ki-100 as the most potent Japanese fighter of the war while they at the same time considered Ki-61 meat on the plate. There is no substantional difference for me when I face these Kawasakis in late war US planes like P-51 or P-38 in IL-2 world. Clay pidgeons. Little sturdy tho, but nearly as slow as a Zero!

Wildnoob
09-24-2011, 11:25 AM
Originally posted by TipsyTed:
Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further).

Let's see...


According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84

172 kg/m² of wing loading for the Ki-84 and 174.76 kg/m² for the Ki-100. Pretty much pilot hability to decide a close in dogfigth.

But of course, when the Hayates (in real life) were suffering a lot from engine reliability problems, and the Ki-100 not, plus the fact already pointed out the Kawasaki fighter was easier to fly, no doubt he would be regarded superior.

According to my Kagero monograph about the Ki-84, the Hayates in front line service achived 580/590 km/h of top speed (against the official 624km/h Nakajima declared, and comparable to the Ki-100 speed). These speeds depended on the fuel, and of course, adequated maintence. The Japanese did efforts to provided 95 octane for the plane, but usually 87 that was in their tanks. More unfortunately for JAAF pilots is that such rather low top speeds had a tendency to become even lower as the time passed, due to the lack of capable mechanics, adequated maintence, spare parts (including their production quality) fuel, oils an so forth.

Our Ki-84 in IL2 don't suffer from any engine related problems, and is modelated as the one tested by the Americans in the post war with with 140 octane fuel the Japanese only could dream, and a well adjustable engine. Hence why you are complaining about it's performace - it's actually superior by a good margin. If I was a IJAAF pilot in those days, no doubt I would preffer a Ki-100 as the rest of the folks. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif


Also, many allied pilots regarded Ki-100 as the most potent Japanese fighter of the war while they at the same time considered Ki-61 meat on the plate.

Pilot reports are not the most reliable information you can use for performance evaluation of a plane.


There is no substantional difference for me when I face these Kawasakis in late war US planes like P-51 or P-38 in IL-2 world. Clay pidgeons. Little sturdy tho, but nearly as slow as a Zero!

Perhaps because there wasn't many difference really?

I created this tread more because tactical considerations that perhaps could make it more effective, specially as a defensive fighter, as it would be their role historically. As JtD pointed out, it's was not a plane for 1945, but perhaps early '43. And I will be more critic to say it would be a plane for early '42. The turbocharged model probably would offered a performance gain, but don't know if in satisfatory level.

Luno13
09-24-2011, 12:32 PM
Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further). According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84, winning something like 10 out of 10 mock dogfights between the two machines.

In my own tests, I personally find the Ki-100 to be much better in a close-in fight than the Ki-84. The Hayate has to be flown like a Mustang, and while it can turn, it loses a lot of speed doing so. The handling of the Ki-100 is noticeably better too.

Wildnoob
09-24-2011, 05:15 PM
Originally posted by Luno13:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further). According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84, winning something like 10 out of 10 mock dogfights between the two machines.

In my own tests, I personally find the Ki-100 to be much better in a close-in fight than the Ki-84. The Hayate has to be flown like a Mustang, and while it can turn, it loses a lot of speed doing so. The handling of the Ki-100 is noticeably better too. </div></BLOCKQUOTE>

Now I'm curious. My wing loading calculation wasn't correct? I missed something? The Ki-84 is similar in weight but with a considerably more powerful engine, and therefore power to weight ratio. And my calculation was based in the Nakajima factory data of 624 km/h top speed. Our Hayate is considerably more powerful. Or is IL2 that is really incorrect?

Luno13
09-24-2011, 06:56 PM
The numbers may be right, but they aren't the whole story.

VW-IceFire
09-24-2011, 09:36 PM
Both Ki-84 and Ki-100 turn fairly well. The Ki-84 has a huge speed advantage thanks to the modeling decisions made for it. But raw turning aside the Ki-100 is definitely better handling than the Ki-84... the turn is good, the controls work well at nearly all speeds, you can yank the Ki-100 into a turn extremely quickly. The Ki-84 doesn't handle nearly as well. It's good... just not quite as good.

If you did a mock horizontal fight between two experienced pilots that are used to flying Ki-61s they would probably out do Ki-84s all the time. It really depends on the test.

TipsyTed
09-25-2011, 03:25 AM
Originally posted by Wildnoob:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84

172 kg/m² of wing loading for the Ki-84 and 174.76 kg/m² for the Ki-100. Pretty much pilot hability to decide a close in dogfigth.
</div></BLOCKQUOTE>

It appears you've overlooked "according to Japanese sources"... This is not my own blabbering.


Originally posted by Wildnoob:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Luno13:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further). According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84, winning something like 10 out of 10 mock dogfights between the two machines.

In my own tests, I personally find the Ki-100 to be much better in a close-in fight than the Ki-84. The Hayate has to be flown like a Mustang, and while it can turn, it loses a lot of speed doing so. The handling of the Ki-100 is noticeably better too. </div></BLOCKQUOTE>

Now I'm curious. My wing loading calculation wasn't correct? I missed something? The Ki-84 is similar in weight but with a considerably more powerful engine, and therefore power to weight ratio. And my calculation was based in the Nakajima factory data of 624 km/h top speed. Our Hayate is considerably more powerful. Or is IL2 that is really incorrect? </div></BLOCKQUOTE>

Japanese speed tests were performed at military, not at war emergency power, like elsewhere in the world. That's the biggest reason for the discrepancy between ATAIU (680 kph) and Nakajima (624 kph) Type 4 speed data, and also the reason for much confusion about late war japanese aircraft performance.

The number 590 kph at 6+ km alt for Type 5 similarly comes from Japanese sources...

JtD
09-25-2011, 10:44 AM
624 km/h + 9% extra power do not equal 680 km/h. So the difference between military power and WEP is not the main reason.

It is, however, always important to remember it. The difference is much larger for the Ki-100 and I we do not have full WEP power available in game. It would close the gap considerably, even though not completely.

ROXunreal
09-25-2011, 02:31 PM
I agree that, in the game, the Ki-100 is much better at dogfighting than the Ki-84. The '84 is a boom and zoom plane, it can turn well but not for long without getting too slow, and unless over friendly territory and alone with the target, I avoid turning engagements. If booming and zooming, and being smart with the radiator (the huge cowl flaps grossly affect speed and zoom climb), the plane can really shine. Just have to watch the G's at high speed.

Wildnoob
09-25-2011, 02:52 PM
Originally posted by TipsyTed:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wildnoob:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84

172 kg/m² of wing loading for the Ki-84 and 174.76 kg/m² for the Ki-100. Pretty much pilot hability to decide a close in dogfigth.
</div></BLOCKQUOTE>

It appears you've overlooked "according to Japanese sources"... This is not my own blabbering.


Originally posted by Wildnoob:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Luno13:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further). According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84, winning something like 10 out of 10 mock dogfights between the two machines.

In my own tests, I personally find the Ki-100 to be much better in a close-in fight than the Ki-84. The Hayate has to be flown like a Mustang, and while it can turn, it loses a lot of speed doing so. The handling of the Ki-100 is noticeably better too. </div></BLOCKQUOTE>

Now I'm curious. My wing loading calculation wasn't correct? I missed something? The Ki-84 is similar in weight but with a considerably more powerful engine, and therefore power to weight ratio. And my calculation was based in the Nakajima factory data of 624 km/h top speed. Our Hayate is considerably more powerful. Or is IL2 that is really incorrect? </div></BLOCKQUOTE>

Japanese speed tests were performed at military, not at war emergency power, like elsewhere in the world. That's the biggest reason for the discrepancy between ATAIU (680 kph) and Nakajima (624 kph) Type 4 speed data, and also the reason for much confusion about late war japanese aircraft performance. </div></BLOCKQUOTE>

Uhmmm

So the 624 km/h Nakajima data is for military, not WEP?

If yes, where's the WEP then? The +9% of power JtD mentioned?

LEBillfish
09-25-2011, 09:09 PM
I'm really not sure why these Ki-100 discussions always slip to Ki-100 vs. Ki-84, and then naturally about the Ki-84 performance yet in brief a few things ALWAYS need to be remembered.

First off, if you want to understand the Ki-84 you need to put it in perspective.....Call it the "Super Hayabusa" if you wish, yet essentially it is Nakajima's war long accumulation of knowledge and experience. If you want an outstanding example of "continuous improvement" even when there was no demand it would be with Nakajima and the Ki-43. Folks really don't consider the Ki-43 fairly as here was an aircraft that was better armored, more maneuverable, climbed better, stronger control surfaces, 800 pounds lighter loaded, etc. etc. then the A6M Zero. Want to mention weapons, fair enough...However put it into perspective as Navy pilots rarely made use of the cannons except at very short range relying on their 7.7mm guns.....The Ki-43 having no cannons using their explosive 12.7mm machine cannon, and though the numbers don't make sense their are indeed reports of damage on allied aircraft that made folks assume the Ki-43 was using 20mm.

That said, we all know the Ki-43 had some basic design limitations. Well those were all rectified with what is really the next generation of Ki-43, that being the Ki-84.

Ultralight, well protected, heavily armed, cramming in a tremendously powerful engine....It really was "all that". So not only possessing incredible manueverability and firepower, but also had power up the ying yang.

In contrast however we have the Ki-100....Be clear on this....As much as the Ki-61-I was touted as being "close" to the maneuverability of a Ki-43, stronger and so on...The Ki-61-II was not...Compared to the Ki-61-I it was slower on the climb 1,500+# / 3/4 of a ton heavier and only eleven (11)-mph faster, no better armored, no better gunned, let alone could not turn near as well.

Then having no options not making deliveries....Were forced to make it worse adding more drag, losing speed over even the Ki-61-I and ultimately would turn no better if not worse then a Ki-61-II.

The Ki-100 was a "bandaid fix to the problem of deliveries and malfunctions", and it still didn't solve that issue.

Finally, do NOT take TAIU data as gospel. In most cases they were taking broke down, wore out and damaged aircraft that they knew nothing about, and trying to fly them in a manner the aircraft was not intended to be....More so not damage or destroy their only test model let alone kill the pilot who had not been trained on how to fly them.

It is excellent valuable data, yet is by no means the most exact.

K2

JtD
09-26-2011, 01:08 AM
LEBillfish, what are your sources for the numbers you're posting, such as weight and climb for the Ki-61 I/II? Which versions exactly are you comparing here? And at what power settings?

Personally, I by now consider the Ki-100 a considerable improvement over the Ki-61 I, performance wise. The increase in weight was acceptable, and it had an engine with an extra 300-400hp, a 30% increase, good enough to offset negative effects of the extra weight as far as climb and sustained manoeuvres are concerned. If you extrapolate the military power speed figure which seems to be around 580 km/h, you end up at around 600 km/h for WEP - which is faster than a Ki-61 I would go.

I know you've spend a lot more time researching all this than I did. I would appreciate if you could be a bit more specific about the figures you're posting, maybe even name their origin, so that I could look at the same sources and try to include new info into my image of these aircraft.

JtD
09-26-2011, 01:25 AM
Originally posted by Wildnoob:

So the 624 km/h Nakajima data is for military, not WEP?

If yes, where's the WEP then? The +9% of power JtD mentioned?

You can pretty much assume that all performance data of Japanese planes listed in literature is for military power. I've checked on several planes by now, and there was no exception. WEP settings probably weren't tested, like they typically weren't tested in Germany or the UK when testing climb performance early in the war.

The Homare 21 of the Ki-84 is rated at 1650 hp in 2nd charger gear for military and 1800 hp for WEP. Exact figures vary by source, I haven't found original data as of yet. This power increase will give you about 640 km/h top speed at the same altitude, but since it will be reached at a lower altitude, it will be even less. The US figures for the plane are 426 mph at 23000' at military power and 427 mph at 20000' at WEP. That data isn't completely conclusive either, as the altitude performance for WEP is worse than for military, which does not make sense at a first glance.

Luno13
09-26-2011, 01:30 AM
I'm not sure that I agree with the logic that if the Ki-43 was good, the Ki-84 was good, and that if the Ki-61 was mediocre, so was the Ki-100, and that thusly the Ki-84 must be better than the Ki-100...

To me, the Ki-84 was more of a development of the Ki-44 (which in turn was derived from the Ki-43). However, the Shoki wasn't well appreciated at all because it was designed as an interceptor and had high wing loading (by Japanese standards).

The Ki-84 has more in common with the Shoki than the Hayabusa in that it's an interceptor that's fast, has good climb, etc. It can turn in a pinch, but it's not the most favorable combat regime for that aircraft.

The Ki-100 is not maneuverable compared to a Ki-43, but for a late war fighter it does very well. It doesn't have the raw performance of the Ki-84, but the low speed handling is better and can sustain harder turns for longer duration.

In a turning contest, the Ki-100 wins. In a contest of speed and surprise, the Ki-84 has the upper hand. I get the impression from the aforementioned pilot accounts of the Ki-84 vs. Ki-100 fights that close-in turn fighting was evaluated. In the end, turning contests weren't that common in the late war, so the Japanese evaluation probably didn't reflect the reality of fighting against the allies.

JtD
09-26-2011, 03:45 AM
I don't know where from you and others get the idea that the Ki-84 was not a good turn fighter. It was. It is, in that regard, pretty similar to a Spitfire IX, which definitely is good at turning. With the engine up to specified power, the Ki-84 is as good as the Ki-100, if not better. You can see that in game, where the Ki-84 is as good or better than the Ki-100, except for maybe around 2000m using 110% power. However, if you fly both at 100% power only, the Ki-100 suddenly becomes a lot more competitive, I wouldn't think overall superior, but still noticeably better.

Eventually it all depends on which engine gives you which power. On the paper, the Homare 21 beats the Ha 112 and thus the Ki-84 the Ki-100. However, as we know that the Homare 21 had issues the Ha 112 did not have, and that might have been a deciding factor.

Wildnoob
09-26-2011, 07:29 AM
Originally posted by JtD:
I don't know where from you and others get the idea that the Ki-84 was not a good turn fighter. It was. It is, in that regard, pretty similar to a Spitfire IX, which definitely is good at turning. With the engine up to specified power, the Ki-84 is as good as the Ki-100, if not better. You can see that in game, where the Ki-84 is as good or better than the Ki-100, except for maybe around 2000m using 110% power. However, if you fly both at 100% power only, the Ki-100 suddenly becomes a lot more competitive, I wouldn't think overall superior, but still noticeably better.

Eventually it all depends on which engine gives you which power. On the paper, the Homare 21 beats the Ha 112 and thus the Ki-84 the Ki-100. However, as we know that the Homare 21 had issues the Ha 112 did not have, and that might have been a deciding factor.

That's what I said, JtD. The Ki-84 has a better wing loading, thanks to a little bigger wingspan, and considerable more power. And therefore power to weight ratio. The considerable engine problems were another thing, and I agreed this probably could have been the decisive factor for the Japanese found the Ki-100 a better machine.

This said, being able to match the Ki-100 in a turninfight, and possessing significantly more power, a completely working Ki-84 could dictate the fight. Otherwise, why loose so much time and resources with the Ki-84 when the Ki-61 was avaliable much earlier and consequentely the Ki-100 created? http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

Ah, and thanks for the info about the Japanese WEP data. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Bremspropeller
09-26-2011, 09:21 AM
The Ki-84 has a better wing loading,

2kg/m^2 is a non-issue, especially when other factors such as specific excess power, thrust/ drag and cL/cD-polars aren't known.

LEBillfish
09-26-2011, 11:16 AM
I'll "try" and assemble a minimal list of sources out of quite literally, 100's of books, papers and reports now, yet most of all the absolute end all authority on Japanese AIrcraft technical issues being Mr. Jim Long. The U.S. government and every writer on the planet trusts his work.....However know that many of those actually come from Mechanism of Military Aircraft which is the most detailed publication on any aircraft....Their numbers the same as posted except one, climb speed of the Ki-61-II.......However seeing the to 5k then to 8k compared for both the Ki-61-I then II you realize it was a typo at MoMA.

I'll post a longer explination when I have time tonight.....Oh and lastly....

Ki-84 based off of the Ki-44?.....Close this book and never open it again. Simply compare profiles of the three (Ki-43 as well), most make such assumptions based upon guns, then want to tell you about the Ki-44 40mm hehe.

K2

TipsyTed
09-26-2011, 11:19 AM
"Maneouverability" ? "Turning ability"

Fw 190 for example was considered more maneouverable than the Spitfire, despite having far higher wing loading and thus worse sustained turning ability. Another example is Yak-3, which was made a kind of "Fw 190-ish" by taking a Yak-1b and (among many other things) reducing its wing area and in turn increasing its dogfighting potential to the limit where it's considered by many to be the very best dogfighter of World War 2.

LEBillfish
09-26-2011, 11:49 AM
Originally posted by TipsyTed:
"Maneouverability" ? "Turning ability"

Fw 190 for example was considered more maneouverable than the Spitfire, despite having far higher wing loading and thus worse sustained turning ability. Another example is Yak-3, which was made a kind of "Fw 190-ish" by taking a Yak-1b and (among many other things) reducing its wing area and in turn increasing its dogfighting potential to the limit where it's considered by many to be the very best dogfighter of World War 2.

"Instability" is the word you're looking for...The more unstable a platform, the quicker it can change position YET becoming a more difficult aircraft to keep in control.

K2

Luno13
09-26-2011, 12:50 PM
Ki-84 based off of the Ki-44?.....Close this book and never open it again. Simply compare profiles of the three (Ki-43 as well), most make such assumptions based upon guns, then want to tell you about the Ki-44 40mm hehe.

As requested, some profiles. And no, I generally don't use armament or powerplant as the first line of comparison. I'm talking airframe and design.

http://www.aviastar.org/pictures/japan/nakajima_ki-43.gif

http://www.aviastar.org/pictures/japan/nakajima_ki-44.gif

http://www.aviastar.org/pictures/japan/nakajima_ki-84.gif

To me, the Ki-84 is directly related to the Shoki. It has a similar intended purpose as well (interceptor vs. fighter).

JtD
09-26-2011, 01:42 PM
Also check the Ki-43 II. Allied pilots commonly misidentified Ki-84 and Ki-43, but not Ki-44.

Anyway, I don't think the Ki-84 is closer to the Ki-43 than the Hawker Typhoon is to the Hurricane or the Hellcat to the Wildcat. Technically they had very little in common.

Wildnoob
09-26-2011, 02:19 PM
According to my Kagero monograph about the Ki-84, the IJAAF specifications for it were for a universal fighter combining the best features of the Ki-43 (agility) and the Ki-44 (good performance, firepower).

LEBillfish
09-26-2011, 03:36 PM
Originally posted by Luno13:
As requested, some profiles. And no, I generally don't use armament or powerplant as the first line of comparison. I'm talking airframe and design. To me, the Ki-84 is directly related to the Shoki. It has a similar intended purpose as well (interceptor vs. fighter).

Haha...nice try....now use a Ki-43-II or better III.

K2

Luno13
09-26-2011, 05:54 PM
Haha...nice try....now use a Ki-43-II or better III

Before accusing me of having ulterior motives, please recall that you failed to specify which Ki-43 variant.

http://en.valka.cz/files/ki-43-iiib_507.jpg

http://www.hikotai.net/images/ki44.gif

http://www.aviastar.org/pictures/japan/nakajima_ki-84.gif

I still don't agree that the Ki-84 is directly related to the Ki-43. While it shares some elements, it at least equally shares elements with the Shoki.

Also remember that the Ki-43-III first flew in 1944...The Ki-84 first flew in 1943... So who's the development of who? (just a joke http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif )

The profile comparing is going on a tangent anyway. Even if the Ki-84 looked just like a bolt-for-bolt copy of the Ki-43 you can't make the argument that it was better than the Hayabusa while at the same time arguing that because the Ki-100 looked like that Ki-61 it must have been just as mediocre. It's like saying that because the Seversky P-35 was slow, so was the P-47.

LEBillfish
09-26-2011, 07:59 PM
Originally posted by Luno13:
I still don't agree that the Ki-84 is directly related to the Ki-43. While it shares some elements, it at least equally shares elements with the Shoki.

Also remember that the Ki-43-III first flew in 1944...The Ki-84 first flew in 1943... So who's the development of who? (just a joke http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif )

The profile comparing is going on a tangent anyway. Even if the Ki-84 looked just like a bolt-for-bolt copy of the Ki-43 you can't make the argument that it was better than the Hayabusa while at the same time arguing that because the Ki-100 looked like that Ki-61 it must have been just as mediocre. It's like saying that because the Seversky P-35 was slow, so was the P-47.


Well, this aspect of the discussion wearing me out, so I'll leave you with this tidbit....

Nakajima's Ota Ki-43 production lines were retooled/converted to Ki-84 production lines. Call me goofy, yet if I want to make Hien-II's I don't convert a Ki-45 line, I retool a Ki-61 line......and don't forget, when Nakajima stopped making Hayabusas to make Hayates, Tachikawa began making them (or more finally bumping production).

However, do with it what you may....There's no doubt that experience with all the aircraft they manufactured was applied, however the Ki-44 is too vast of a departure from the end result.

K2

....p.s. a Ki-100 did not just look like a Ki-61-II......they were Ki-61-II's with the nose chopped off and different engine added on losing all of the Hien aerodynamics.

LEBillfish
09-26-2011, 08:43 PM
Originally posted by JtD:
LEBillfish, what are your sources for the numbers you're posting, such as weight and climb for the Ki-61 I/II? Which versions exactly are you comparing here? ........

Okay, first off there are 'really' only 2 versions of the Ki-61-I, not 4, one version of the Ki-61-II, and in the end only really 1 of the Ki-100 as though the canopy and subsequent fuselage change was an "intended" improvement most of the aircraft remained the same with only minor changes such as insturment layout and so on.

Of those you would have the Type 3 Fighter Model I wherein the Ko-Hei (1a-1c) are exactly the same aircraft with constantly evolving armor resulting in fuel capacity reductions that you can find a posting I made regarding such here:
http://www.j-aircraft.org/smf/index.php?topic=11282.0
Range Here: http://www.j-aircraft.org/smf/index.php?topic=11056.0

....and the Type 3 Fighter Model 1 Tei (1d) which was a substancial change ultimately costing the aircraft speed and weight, yet the improvements outweighed the loss......That dramatic change is why so many have had trouble classing it as a Ki-61-I. Never the less still utilizing the Ha-40 fell into the same grouping.

What you will discover is, most Ki-61-I statistics pertain to the Ki-61-I Otsu. Armor, subsequent fuel reductions, armament and so on was middle of the road for this version. More so the Ko and Hei were really nothing more then stepping stone versions (just like the Ki-43-Ia-Ic, there was really only the "Ki-43" eventually called the model 1 when the II came out yet was always in the 1c configuration).

So, 99% of the time when you see a general Ki-61-I spec for all (Ko-Tei), it is an Otsu.

The Ki-61-II though there are photos of the prototype bubble canopy version (intended to be the III) really only had one version before the end of the contract.....This aircraft should really not even be counted as a combat aircraft as the 99 delivered were for the most part out of service, the balance 275 chopped up to make the Ki-100.

So in a sense statistically, you only have 2 versions of the Ki-61-I of which the Otsu is always used, Ki-61-II data being more on paper, YET the Ki-100 which is a Ki-61-II from the firewall back essentially, Ki-100-Ib versions only saw 12 built so do not count, and of the Ki-100-Ia version, 272 of 378 were chopped up Ki-61-II, the remaining 106 only differing in they were built as intended from scratch.

That said, Mechanism of Military Aircraft data is as follows....I post this in that most other publications simply copy it. There is an error however. That error being in the Ki-61-II climb rate to 5km which is listed as 5 minutes yet in actuality was 6 minutes.

http://78sentai.org/78V/albums/recon/10001/Ki-61spec.jpg

That said, if you look over a number of publications you'll find speed, climb, weight and so on varies slightly....Yet oddly there are always associated statistics to those that remain the same...Why?...Well my guess would be in some cases it was a bit of literary license, others errors...who knows.

In any case that then takes us to TAIU testing where we find a VAST difference between the Ki-61-I and the Ki-61-II regarding performance.....Fact of the matter is testing of the Ki-61-I was performed on the Cape Gloucester 68th Sentai Hien S/N 263 (uncoded 163) and the engine had to be refit, and once it had is my understanding it only lasted 3 runs before failure.

Lastly For the Ki-61 experimental airplanes, I'm adding some documented figures from an official handling manual published 5 March 1942 by the Army Flight Test Department, which I'm marking with *. This manual was a blueprinted document carrying the Japanese-equivalent title "KI 61 Handling Reference" on its cover. It was captured on 2 May 1944 at Hollandia.

Also see the note below about the figures from the handling manual.

I'm using the current project designations for the various models, which were not necessarily used by WWII Japanese pilots and ground crews in these complete forms seen here.

Ki-61 Experimental Planes - maximum speed = 591km/hr at 6000 meters

Ki-61 Experimental Planes - weights: 2238 empty; 2950 loaded

Ki-61 Experimental Plane w/2 x 13mm and 2 X 7.5mm MGs** - maximum speed = 585 (altitude not stated)*

Ki-61 Experimental Plane w/2 x 13mm and 2 X 7.5mm MGs - cruising speed = 450 (altitude not stated)*

Ki-61 Experimental Plane w/2 x 13mm and 2 X 7.5mm MGs- climbing speed = 250 (altitude not stated)*

Ki-61 Experimental Plane w/2 x 13mm and 2 X 7.5mm MGs - rate of climb [sic] = 5000 meters in 5 minutes*

Ki-61-I Otsu Production Planes - maximum speed = 592 at 4860

Ki-61-I Otsu Production Planes - Cruising speed = 400 at 4000

Ki-61-I Otsu Production Planes - climb performance = 5000 meters in 5'31"

Ki-61-I Otsu Production Planes - weights: 2210 empty; 2950~3250 loaded

Ki-61-I Hei Production Planes - maximum speed = (not given)

Ki-61-I Tei Production Planes - maximum speed = 580 at 5000

Ki-61-I Tei Production Planes - climb performance = 5000 meters in 7 minutes

Ki-61-I Tei Production Planes - weights: 2630 empty; 3470 loaded

Ki-61-II Kai Production Planes - maximum speed = 610 at 6000

Ki-61-II Kai Production Planes - climb performance = 5000 meters in 6 minutes

Ki-61-II Kai Production Planes - weights: 2855 empty; 3825 loaded

*NOTE: The other figures given in the official handling manual for the Ki-61s are as listed below. Be aware that the manual was a preliminary document, issued early in the Ki-61 program as a reference for use by the flight testing personnel at the Army Flight Test Department, for on the date that the manual was issued there were only about four experimental Ki-61s in existence.

Overall length = 8.765 m
Overall span = 12.000 m
Overall height = 3.700 m
Weight empty = 2210 kg
Weight expended = 2390 kg
Standard weight = 2790 kg
Overload weight = 2950 kg
Wing loading = 139.5 kg/m2
Wing span loading = 19.4 kg/m2
Power loading = 2.54 kg/HP
Wing area power = 55.0 HP/m2
Wing area = 20 m2 (including ailerons)
Mean aerodynamic Chord length = 1.820 meters
A text note from page 2 of the translated document: "This manual is based on the Experimental Ki-61. A certain amount of variations from the further experimental and service types must be expected."

**NOTE: The manual used 13mm and 7.5mm to identify the guns. Other references may use 12.7mm and 7.7mm.


I'll add a list of sources later tonight if I can make time editing this post..

K2

Welp, 1/4 of the way done, will try and update tomorrow.....Didn't break it all down to Ki-61/100 specifics though.

J.I.Long's Airtell Research Report #99-3 Ki-61/100 Serial Numbers, Dates of Assembly & Characteristics
J.I.Long's Airtell Field Notes Japanese Army Fighter "Tony"
J.I.Long's Airtell Research Report #86-1 Estimated Assembly Date For A WWII Japanese Aircraft/A Relic of the Air War over New Guinea/Type 3 Fighter Tony # 640
J.I.Long's A PacFront Extra, Cockpit Layout- Type 3 Fighter Model 1
J.I.Long's Airtell Letter Report Correspondence w/ R.E.Cowley (Japanese inline engine comparisons)
J.I.Long's Airtell Letter Report Correspondence w/K.Weeks (Type 3 Fighter Reference Drawings)

1939-45 Fighters & Bombers of the Japanese Air Force Part 1, Fraus... Czechoslovakian
1939-45 Fighters & Bombers of the Japanese Air Force Part 2, Fraus.... Czechoslovakian
Aero Detail #24, Nakajima Ki-84 Frank “Hayate”
Aero Detail #29, Nakajima Ki-43 Oscar “Hayabusa”
Aeroplane November 2005, Ki-100 Article
Aircraft Profile #118, The Kawasaki Ki-61 Hien, Rene J. Francillon
Avions #119, Ki-44 Shoki...French
Avions #122, Tateo Kato...French
Bf-109-B-E Selected Views, Author Unknown
Design Details of the Mitsubishi Kensei Engine, W.G.Owens
Emblems of the Rising Sun (IJAAF Markings), Peter Scott
F.A.O.W. # 16 Army Type 2 Fighter "Shoki" Ki-44...Japanese
F.A.O.W. # 17 Army Type 3 Fighter "Hien" Ki-61...Japanese
F.A.O.W. # 19 Army Type 4 Fighter "Hayate" Ki-84...Japanese
F.A.O.W. # 21 Army Type 2 Fighter "Toryu" Ki-45...Japanese
F.A.O.W. # 23 Army Type 5 fighter Kawasaki Ki-100…Japanese
F.A.O.W. # 27 Type 96 Carrier Fighter A5M...Japanese
F.A.O.W. # 29 Type 97 Army Type 97 Fighter Ki-27... Japanese
F.A.O.W. # 32 Type 97 Carrier Torpedo Bomber, B5n, Kate...Japanese
F.A.O.W. # 33 Type 99 Carrier Dive Bomber, D3A, Val...Japanese
F.A.O.W. # 38 Type 100 Command Recon. Plane, Ki-46…..Japanese
F.A.O.W. # 53 Kyofu, Shinden, Shidenkai...Japanese
F.A.O.W. # 59 G4M Mitsubishi Betty Type 1 Attack Bomber….Japanese
F.A.O.W. # 61 Navy Interceptor J2M "Raiden"...Japanese
F.A.O.W. # 65 Type 1 Fighter, Hayabusa...Japanese
F.A.O.W. # 69 Navy Carrier Dive Bomber Suisei D4Y……Japanese
“F” Gunnery Play, Variants, Crews & Details (Numerous IJA-IJN plane stats)…..
He-100 Select Views, author unknown
JAAF Camouflage & Markings WWII, D.W. Thorpe
Japanese Aircraft Equipment 1940-1945, Robert C. Mikesh, Schiffer Publishing
Japanese Bomber Performance Charts, Author unknown
Japanese Military Aircraft Illustrated, Unknown (Japanese),...Japanese
Kawasaki Ki-61Hein in Japanese Army Air Force Service, R.M.Bueschell
Koku Fan, 1974-3
Maru Mechanic #43 J2M & N1K....Japanese
Maru Mechanic #46, P1Y & G4M…..Japanese
Mechanism of Military Aircraft #2, Ki-61 & Ki-48...Japanese
Mechanism of Military Aircraft #6, Ki-45 & Ki-51...Japanese
Mechanism of Military Aircraft #?, E13A1, Jake...Japanese "Partial"
Mechanism of Military Aircraft #?, D3A1...Japanese "Partial"
ModelArt 272, Camouflage & Markings of IJN Fighters .......Japanese
ModelArt 493, Ki-84 Hayate……Japanese
ModelArt 533, Camouflage & Markings of the IJA Bombers ....Japanese
Modelling Manual #?. Kawasaki Ki-61 Type 3 Fighter Hein……Japanese
Monografie Lotnicze #5 Hien...Polish
Monografie Lotnicze #48 Ki-43...Polish
Monografie Lotnicze #78, North American B-25 Mitchell, K. Janowicz...Polish
Mushroom Model #6103 Yellow Series, Mitsubishi A6m Zero, Artur Juszcak
Mushroom Model #6107 Yellow Series, Mitsubishi A5M Claude, T. Januszewski
Nakajima Ki-43 Hayabusa in Japanese Army Air Force/RTAF/CAF/IPSF Service, R.M.Bueschell
Profile Publications #160, The Mitsubishi, G3M “Nell”
Romance of Engines, Chapters 36-38 (DB-601 vs. Ha-40)….. Takashi Suzuki
Squadron Signal #34, B-25 Mitchell in Action
Squadron Signal #97, TBD Devastator in Action
Squadron Signal #122, SB2U Vindicator in Action
Squadron Signal #6059, Golden Wings 1941-1945 (USN-USMC Aircraft of WWII), J. Sullivan & D.Lucabaugh
Squadron Signal #6079, Thunderbolt, the Republic P47 Thunderbolt in the Pacific Theater, E.R.McDowell
T.A.I.U. Datasheets # 154A-1 thru 4 & 154A-1 thru 4, Ki-61-I & II
Zentrale fur wissenschaftliches Berichtswesen uber Luftfahrtforschung, Forschungsbericht FB505, 151/20 Mauser Cannon……German

3/202 Kokutai, Waldemar Pajdosz & Andre Zbiegniewski's/Kagero
64 Sentai, K. Janowicz's/Kagero
68 Sentai, K. Janowicz's/Kagero
7 December 1941, The Air Force Story, L.R.Arakaki & J.R.Kuborn
A War of their Own, Bombers Over the Southwest Pacific, Capt. M.K.Rodman
Aces of the Rising Sun, H. Sakaida
Air Force (US) Combat Units of WWII, Department of the Air Force, Maurer
Air Power & Warfare, United States Air Force Academy, Col. A.F.Hurley & Maj. R.C. Ehrhart
Air-to-Air Claims and Credits for Navy and Marine Corps Patrol Type Aircraft During World War II (Appendix 4), Mr. James C. Sawruk
Airlift & Airborne Operations in WWII, R.E.Bilstein
Airpower and Maneuver Warfare, M. van Creveld
Airpower in Three Wars, Gen. W.W.Momyer
Airpower Myths and Facts, Col.P.S.Meilinger
Airwar 004 Japanese Aces, Army Aviation 1937-1945, ????????? ??????? (russian)
Aerial Interdiction, Air Power and the Land Battle in Three American Wars, E. Mark
Aeronotes 3, Deployments & OOBs
Aeronotes 4, New Guinea Area Operations
Airpower Employment of the 5th Air Force in the WWII SouthWest Pacific Theatre, Major James A. Barr
Archie to Sam, a Short Operational History of Ground Based Air Defense, K.P.Werrell
American Airpower Comes of Age Vol. 1, General Henry H. “Hap” Arnold’s World War II Diaries, Maj.Gen. J.W.Huston
American Airpower Comes of Age Vol. 2, General Henry H. “Hap” Arnold’s World War II Diaries, Maj.Gen. J.W.Huston
Capt. Nelson Flack: The rediscovery of a Black Sheep (Article), Master Sgt. Greg Henneman
Case Studies in the Achievement of Air Superiority, B.F.Cooling
Case Studies in the Development of Close Air Support, B.F.Cooling
Case Studies in Strategic Bombardment, R.C.Hall
China-Burma-India, AirForce Magazine, March, 2005 (Article)
Combat Chronology 1941-1945 (U.S. Army Air Forces in WWII), K.C.Carter & R.Mueller
Combat Sorties Flown by Fighters in Theatres vs. Japan, by Theatre & by Sortie, Jan.1943-Aug.1945 table
Combat Squadrons of the Air Force in WWII, Department of the Air Force, Maurer
Combat Tactics in the SouthWest Pacific, Capt. T.M. McGuire Jr.
Completing the Circle Around Rabaul, The Siezure of the Admiralties, Feb.- May 1944, David Osborn Scott
Enemy Aircraft Destroyed in European Theatre of Operations by Type of AAF Airplane, Aug.1942-May1945
Fifth Air Force Light & Medium Bomber Operations During 1942 & 1943: Building Doctrine & Forces That Triumphed In the Battle of the Bismark Sea & the Wewak Raid, Maj. T.D.Gann
General Kenny Reports, A Personal History of the Pacific War, G.C.Kenny
Hitting Home, The Air Offensive Against Japan, Daniel L. Haulman
How SouthWest Pacific Area Operations Influenced the Royal Austrailian Air Force, Major Jonathan B. Wills
I'm in the Army Now (New Guinea info), Roy S. Weaver Jr.
Imperial Japanese Army Air Units Battlefield Photograph Collection, Dainippon Kaiga Publ.
Introduction to the United States Air Force, Capt. B. Chance Saltzman & T.R. Searle
Japan in the Pacific War & New Guinea,
Japanese Air Operations in New Guinea, Shindo Hiriyuki
Japanese Army Air Force Fighter Units and Their Aces 1931 – 1945, Hata, Izawa, Shores
Kenneth N. Walker, Airpowers Untempered Crusader, M. Byrd
Kogun, The Japanese Army in the Pacific War, Saburo Hayashi & Alvin D Coox
MacArthur's Eagles: The U. S. Air War over New Guinea, 1943-1944, Lex McAulay
Mission Type Orders in Joint Air Operations (Command and control, New Guinea highlighted), Maj. Michael E. Fischer
Naval Aviation in the Pacific, United States Navy
Osprey Aviation Elite #5, B29 Hunters of the JAAF, K.Takaki & H.Sakaida
Osprey Aircraft of the Aces #13, Japanese Army Air Force Aces 1937-1945, H. Sakaida
Osprey Aircraft of the Aces #22, Imperial Japanese Navy Aces 1937-1945, H. Sakaida
Performance of B25 Aircraft of 38th Bomb Group During 18 Months of Combat in New Guinea, W.J. English
Piercing the Fog, Intelligence and Army Air Forces Operations in World War II, J.F.Kreis
Preemptive Defense, Allied Air Power Versus Hitler’s V-Weapons, 1943–1945, Adam L. Gruen
Principles of War, Gen. Carl von Clausewitz
Strategic Air Warfare, An Interview with Generals C.E.LeMay, L.W.Johnson, D.A.Burchinal, & J.J. Catton, R.H.Kohn and J.P.Harahan
Strategy for Defeat, The Luftwaffe, 1933-1945, W.MURRAY
The Army Air Forces In World War II, Vol. 1, Plans and Early Operations, January 1939 to August 1942
The Army Air Forces In World War II, Vol. 2, Europe-Torch to Pointblank, August 1942 to December 1943
The Army Air Forces In World War II, Vol. 3, Europe-Argument to VE Day, January 1944 to May 1945
The Army Air Forces In World War II, Vol. 4, The Pacific-Guadalcanal to Saipan, August 1942 to July 1944
The Army Air Forces In World War II, Vol. 5, The Pacific-Matterhorn to Nagasaki, June 1944 to August 1945
The Army Air Forces In World War II, Vol. 6, Men & Planes
The Army Air Forces In World War II, Vol. 7, Services Around the World
The Enlisted Experience, Conversations with Chief Master Sergeants of the Air Force, J.R.Bednarek
The Quest, Haywood Hansell and American Strategic Bombing in World War II, C.Griffith
The Strategic Air War Against Germany & Japan, a Memoir, Maj.Gen. H.S.Hansell Jr.
The United States Strategic Bombing Surveys (European & Pacific War),
They Fought With What They Had, W.D.Edmonds
U.S.A.F. Historical Study #113, The 5th Air Force in the Huon Peninsula Campaign, January to October 1943
U.S.A.F. Historical Study #116, The 5th Air Force in the Huon Peninsula Campaign, Oct. 1943 to Feb. 1944
United States Air Force and its Antecedents Published and Printed Unit Histories, a Bibliography, J.T.Controvich
U.S. Naval Aviation in the Pacific, The Office of the Chief of Naval Operations, United States Navy
United States Naval Aviation 1910-1995, Part 5 WWII
Warpath Across the Pacific, 345th Bomb Group, "Air Apaches", L.J.Hickey
Weapon of Denial, Air Power & the Battle for New Guinea, Gary Null
With Courage, the U.S. Army Air Forces in WWII, Nalty, Shiner, Watson

Trying to Obtain:
L.J.Hickey, Taylor, Tagaya, Revenge of the Red Raiders, 22nd Bomb Group, "Red Raiders"
L.J.Hickey, Taylor, Tagaya, Kens Men Against the Empire, 43rd Bomb Group, "Kens Men"
L.J.Hickey, Claringbould, Rampage of the Roarin 20's, 312th Bomb Group, "Roarin 20's"
L.J.Hickey, Tagaya, Saga of the Sun Setters, 38th Bomb Group, "Sun Setters"
Model Art 263 & 428, Ki-61 & Ki-61/Ki-100
Maru Mechanic 2 & 37 Ki-61 & Ki-61/Ki-100
F.A.O.W. "Blue Series" #98
Watanabe Yohji's, Hien: the Struggle of the Type 3 Fighter
Jiro Kimata's Rikugun Koku Senshi
Nihon Kokuki Soshyu, Vol. 4 Kawasaki
Nihon Kokuki Soshyu, Vol. 5 Nakajima
Gakken Series, No.???? - Ki-61
Gakken Series, No.7 - RABAUL AIR WAR
Gakken Series, No.28 - IJN/IJA/American Bases
Gakken Series, No.52 - Nakajima Type 1 Fighter, Hayabusa
Airview #???? Ki-61
MILITARY AIRCRAFT #16, Imperial Japanese Army Aircraft of the Pacific War

megalopsuche
09-26-2011, 10:03 PM
Originally posted by Wildnoob:
ps: I hope Gaston don't come here. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

http://forums.ubi.com/images/smilies/34.gif

LEBillfish
09-26-2011, 10:44 PM
BTW as to armament....

First off, no Ki-43 with cannons...

Secondly, the Japanese in New Guinea realized they needed heavier weapons in their aircraft. The Ki-43 rather set in stone, yet with the delivery of some 800 Mauser 151/20 cannon allowed Kawasaki to fit roughly 388 aircraft with them (at the factory, there was NEVER field upgrades) by turning them on their sides and altering the inner wing framework some also 'increasing' (as all hien had them) the wing bulges.

The combination worked well, oddly the Japanese never impressed with multiple single type gun set-ups feeling 2 was enough so usually in pairs (like the Germans).......Once out of Mausers they finally finished the Ho-5, essentially a Browning M2 Machine Gun upscaled from their Ho-103 12.7mm/.50cal to 20mm.

However, the Ho-5 was a large gun...Think of how a Browning .30cal upscales to a .50cal, and you can imagine how much bigger a 20mm/.79cal gun becomes......So, instead of messing with the wings they decided to place them in the fuselage. The lower rate of fire worked better with syncronization, and since an easier removable tail for service was in the works, lengthened out the fuselage to accomodate the much longer 20mm round vs. the 12.7.....Those changes made in the Tei, or 1d.

The Ki-61-II simply carried on with it.....and naturally since Ki-100 were Ki-61-II's, they were the same as well.

K2

VW-IceFire
09-26-2011, 10:58 PM
Some great info up there. I didn't realize the Ho-5 was so closely related to the Browning. Interesting.

So how on earth did they fit the Ho-5 inside the Ki-84 wing. Sounds like it was quite the cannon.

Regarding the design debate... I had done some reading and I guess Nakajima designers consulted quite a bit of their previous development work on three aircraft for producing the Ki-84. The Ki-43, the Ki-44 and the little known Ki-62 which was Nakajima's entry into the DB601/Ha50 engine program. As the Ki-61 was the successful bid, Nakajima moved on to the next project and... from what I've read incorporated much of the work on the Ki-62 into their Ki-84 project... although they bear no superficial resemblance to my eye. I guess the details are the key part here... it's little surprise that each successor aircraft bore at least a superficial resemblance to the last.

Japanese aircraft have very interesting histories that are often much more obscure than other types. Really interesting topic.

JtD
09-26-2011, 11:56 PM
Thanks for these long and detailed posts. One question remaining for me: Are these performance figures for clean aircraft, or is it for instance possible that the wing pylons were not fitted with the early Ki-61, but later became so standard that on the II and the Ki-100 they were fitted during testing?

Afaik, the TAIU data for the II is simply an extrapolation of Ki-61 I performance based on the change in engine power.

I would also like to remind everyone again that the data is for military power, and that the Ha-40 generated about 10% extra power at WEP, while the Ha-112 generated about 20% extra. That will shift the relative performances considerably.

I assume that the praise for the Ki-61s manoeuvrability comes from the very early aircraft, which apparently were quite a bit more lightweight than the later ones. I doubt that the Ki-100 had any practical disadvantage vs. a I Tei.

LEBillfish
09-27-2011, 07:36 AM
Originally posted by JtD:
Are these performance figures for clean aircraft, or is it for instance possible that the wing pylons were not fitted with the early Ki-61, but later became so standard that on the II and the Ki-100 they were fitted during testing?........

......I assume that the praise for the Ki-61s manoeuvrability comes from the very early aircraft, which apparently were quite a bit more lightweight than the later ones. I doubt that the Ki-100 had any practical disadvantage vs. a I Tei.

Testing would of been performed at optimum conditions (clean, no drop tanks, bombs, ammo, minimal fuel) and also fully loaded I'd think (w/DTs full fuel, ammo)....However, would be matching in the numbers so I'd assume all three were clean.

As a side note I also just noticed that the Ki-61-I weight is wrong, the data sheet shows for the experimental model, so drop that down to 2,210Kg Empty.

Well remember, bigger doesn't always equal better....In the case of the Ki-61-I vs. II, standard H.P. of 1,100 & 1,350 respectively gives us a power to "empty" weight of .50hp/Kg for the I, .47hp/Kg for the II.....Take off power of 1,175 & 1,450 gives us .53hp/Kg I, .50hp/Kg II. In kind though I've not checked I doubt there was a prop or gearing change between the Ha-40 and Ha-140...Meaning the combination would not of been optimized.

That said, the Ki-100s primary disadvantage was the loss of aerodynamics....That was the whole point of the Ki-61 series. In fact I've read where struggling with that due to the cowling was the most difficult problem to solve as the Ki-61 fuselage is a scant 33" wide, the Ha-112-II engine and cowling 50" wide.....Naturally as well cooling on the radial causing more drag then the classic radiator as it is a massive area.

Aerodynamics carry with the aircraft throughout...So it is very possible though top speeds were the same, acceleration may not have been.

K2

JtD
09-27-2011, 09:30 AM
I think you're getting the wrong impressions when comparing powerloading of an early I with the II. It appears that the added weight was worth the resulting performance loss, otherwise the I Tei models would still be flying around with less armour, less fuel tank protection and worse firepower. If you check the powerloading of a I Tei and compare it with a II, the II looks better. In terms of performance the II was definitely an improvement over the late I, only that it did not work...

Regarding propeller, your sheet (and other sources) say a 3m prop for the I and a 3.1m prop for the II. Reduction ratio for the Ha 40 was 0.643 according to TAIC, and I'd assume that it was changed with the prop and the engine. If not - well I guess we just found the reason for the Ha-140's failure. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Drag of a radial engine is not necessarily bigger than that of a V12, the bulky radiator under the fuselage is a big problem, too. I think the engine mount was the big setback of the Ki-100 in terms of aerodynamics, and even with that the engineers did a splendid job, all things considered.

And thanks for posting that list of various books, which wasn't there last time I looked at that post.

Edit: Reduction ratio according to Famous Airplanes of the World (Bunrin-do): Ha-40: 0.646, Ha-140: 0.594

TipsyTed
09-27-2011, 09:46 AM
Power to weight ratio is cruical with acceleration, climb and maneouverability.

Power output alone - for top speed.

I believe they were pushing after speed (especially at high altitudes) more than anything else with Ki-61-II.

VW-IceFire
09-27-2011, 05:17 PM
Side question.. did the Ki-61-II see combat? I've read up to the point where it was issued to the frontline but not sure if it actually came into contact with enemy aircraft or not.

LEBillfish
09-27-2011, 09:42 PM
Originally posted by JtD:
And thanks for posting that list of various books, which wasn't there last time I looked at that post.

That's roughly a 1/4 of them, need to get the rest added to the list simply for my own organization.



Originally posted by VW-IceFire:
Side question.. did the Ki-61-II see combat? I've read up to the point where it was issued to the frontline but not sure if it actually came into contact with enemy aircraft or not.

Well, we are already WAY out of the realm of my studies (focussing on the Ki-61-I and air combat in New Guinea), yet of the 99 produced I'd suspect that some had mechanical failures (more then likely most in that the Japanese INTENDED on sorting out the issues as they came up...YET...with production over probably did not). Some would of been destroyed on the ground, some given to training schools, maintenece schools...SO of the few left that flew, some given to the 55th & 56th in April 1945 as well as other Hien units...if...

...If they did see combat it would of been against B-29's and various fighters over homeland Japan. However my information slows quickly at that point as my books begin discussing units issued the Ki-100 (59th & 244th as example) and older aircraft pressed back into combat....Best bets if you'd like to find out would be May 1945 onward, naturally only looking at existing Hien Homeland Defense units.

That said...if I had to "guess"...IF any Ki-61-II saw combat i'd suspect it would be less then 20 yet that is just a guess.

K2

VW-IceFire
09-28-2011, 10:12 PM
Interesting information. Thanks for sharing!

Gaston444
10-04-2011, 03:01 PM
Originally posted by Wildnoob:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TipsyTed:
Perhaps Ki-100 is just one of those areas, where IL-2 and reality depart a bit (further).

Let's see...


According to Japanese sources, Ki-100 was overhelmingly superior in a close in dogfighting to Ki-84

172 kg/m² of wing loading for the Ki-84 and 174.76 kg/m² for the Ki-100. Pretty much pilot hability to decide a close in dogfigth.
---------------

According to my Kagero monograph about the Ki-84, the Hayates in front line service achieved 580/590 km/h of top speed (against the official 624km/h Nakajima declared, and comparable to the Ki-100 speed). These speeds depended on the fuel, and of course, adequated maintence. The Japanese did efforts to provided 95 octane for the plane, but usually 87 that was in their tanks. More unfortunately for JAAF pilots is that such rather low top speeds had a tendency to become even lower as the time passed, due to the lack of capable mechanics, adequated maintence, spare parts (including their production quality) fuel, oils an so forth.

Our Ki-84 in IL2 don't suffer from any engine related problems, and is modelated as the one tested by the Americans in the post war with with 140 octane fuel the Japanese only could dream, and a well adjustable engine. Hence why you are complaining about it's performace - it's actually superior by a good margin. If I was a IJAAF pilot in those days, no doubt I would preffer a Ki-100 as the rest of the folks. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif


Also, many allied pilots regarded Ki-100 as the most potent Japanese fighter of the war while they at the same time considered Ki-61 meat on the plate.

Pilot reports are not the most reliable information you can use for performance evaluation of a plane.


There is no substantional difference for me when I face these Kawasakis in late war US planes like P-51 or P-38 in IL-2 world. Clay pidgeons. Little sturdy tho, but nearly as slow as a Zero!

Perhaps because there wasn't many difference really?

I created this tread more because tactical considerations that perhaps could make it more effective, specially as a defensive fighter, as it would be their role historically. As JtD pointed out, it's was not a plane for 1945, but perhaps early '43. And I will be more critic to say it would be a plane for early '42. The turbocharged model probably would offered a performance gain, but don't know if in satisfatory level. </div></BLOCKQUOTE>

If you had any serious knowledge on the issue, you would know it's been established for a decade now that Japanese speed charts are all without WEP, which WEP had a long endurance of over ten minutes on these things. Even the Zero A6M5 was probably 590 km/h + by engine bench output, and was reportedly only modestly slower than early Corsairs in combat. (The Ki-43 was slower due to inferior fuels used by the Army, yet has vastly outscored the Zero and all other Japanese types in the number of kills apparently).

Even the Ki-44 was 650 km/h in the Japanese's own tactical evaluation documents of the defence of Tokyo against B-29s. It was by far the most effective interceptor there during the evaluation, but the Ki-84 was not present... It does seem the Ki-61-1Koh/Otsu/Hei really were no better than 590 km/h in that same evaluation. If you look at all the Ki-61 pictures of the 244th Sentai in 1945, or any operational Ki-61-I, you will only see the short-nose Ki-61-I-Koh/Otsu/hei being used because they were so much better than the longer-nosed Tei, which was 600 lbs heavier for some reason.

The longer-nosed Tei variant was massively used as a Kamikaze aircraft (large number of such schemes and units, all using the Tei exclusively, as that was the only combat use it was good for), and almost all the pictures I have seen of it at a various bases shows a cannibalized wreck being stripped for spare parts to keep the earlier short-nosed Koh-Otsu-Heis flying...

I have never actually seen a picture of a Ki-61-I-Tei in flight out of thousands of Ki-61 pictures... Would love to see one though...

It has been settled long ago that the top speed of the Ki-84, with Japanese fuels, was around 690-700 km/h. So it was around 90-100 km/h faster than the Ki-100...

How about a little dose of reality about the Ki-100 in this fantasy-churning site, this from experienced people who trained to fight on the actual aircrafts? What do you say?:

"Aeroplane" November 2005, "Ki-100 fighter Database" p. 61-77. (16 full pages on nothing but the Ki-100, with remarkable details, including on the development of the projected high-altitude turbo-charged variant)

Textual quote : P. 76:

"At these schools, the cream of the IJAAF's instructors, all very experienced combat pilots, would give their opinion on the new fighter (Ki-100). Almost all the Akeno instructors were graduates of the 54th Class of the Army Air Academy and also highly-qualified sentai commanders in their own right.

During March and April they would fly the Ki-100 in comparison tests against the most capable Japanese fighter then in service, the Ki-84 "Frank". After extensive testing the conclusion drawn by the Akeno pilots left little to the imagination.

In short, it stated that given equally skilled pilots, the Ki-100 would ALWAYS win a fight with the Ki-84 in any one-to-one combat. They further added that in a combat situation with up to three Ki-84s, the Ki-100 pilot could still develop the battle to his advantage.

The results of the evaluations at the Hitachi school were just as clear-cut. Captain Yasuro Mazaki and captain Toyoshia Komatso,also both graduates of the 54th class, developed the combat evaluation situations for the new fighter, and in order to give an unbiaised opinion of the aircraft, they swapped aircraft after each engagements and attempted combat from the opposite standpoint.

In the first combat the Ki-100 was flown against a single Ki-84 with the Ki-100 winning outright.

Mazaki stated: "When we entered combat with the Ki-100 taking the height advantage, the Ki-100 won every time. Even with an altitude disadvantage the Ki-100 could hold down the Ki-84 in two or three climbs during the exercise"

He added that the Ki-84 was "only superior to the Ki-100 in diving speed. The Ki-100 was much better in the turn and while climbing."


Against the P-51: "Aeroplane" p.77: "I learned how to take my fighter out of the firing line of the P-51 when being chased. I might never be able to shoot it down, but I was sure I would never be downed!"

P. 77. "The Ki-100 could fight equally against the P-51D"

P. 77. "The maneuverability of the Ki-100 was the best of the Army's frontline fighters with the exception of the Ki-43... And it had a strong advantage in that even less experienced pilots could fly it easily and fight with it."

But after all, these were just the guys who were there... What do they know compared to 2011 simmers? http://forums.ubi.com/images/smilies/88.gif

Gosh, these real-life pilots, they don't even know their maths. Crunching numbers on a computer, that's where it's really at....

Gaston

P.S. The real math about all this is coming your way soon... By the way, I've just read around 300 Spitfire Mk IX-XII-XIV combat reports, and practically the ONLY thing they ever do is boom and zoom like I've never seen any other type do... Not one sustained turn in the bunch, and almost no turning at all...(P-47D drivers, on the other hand, are totally obsessed with sustained horizontal turn-fighting). Gosh, simmers would just have made mincemeat of these guys, wouldn't they? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

G.

DrHerb
10-04-2011, 03:33 PM
Aaaaaand.......

http://i214.photobucket.com/albums/cc80/VMF-214_Prop/popcorn4qt.gif

Luno13
10-04-2011, 04:47 PM
The Ki-100 may win out against the Ki-84 nine out of ten times, but I'd like to see how those tests were conducted.

I mentioned in my tests in this game that the Ki-100 certainly could outmaneuver the Ki-84. Personally, I find the Ki-100 more maneuverable because it is easier to take it to the edge of its turn performance due to its docile handling characteristics. If the Ki-84 played it smart though and flew carefully like a Mustang pilot would, then the favor would easily be 9/10 towards the Hayate.

So, a few words on a page aren't conclusive, and can go either way. I brought up my personal experience because it contradicts the common wisdom that the Ki-84 is hands down better...it depends on how each aircraft is flown.


If you look at all the Ki-61 pictures of the 244th Sentai in 1945, or any operational Ki-61-I, you will only see the short-nose Ki-61-I-Koh/Otsu/hei being used because they were so much better than the longer-nosed Tei, which was 600 lbs heavier for some reason.

The longer-nosed Tei variant was massively used as a Kamikaze aircraft (large number of such schemes and units, all using the Tei exclusively, as that was the only combat use it was good for), and almost all the pictures I have seen of it at a various bases shows a cannibalized wreck being stripped for spare parts to keep the earlier short-nosed Koh-Otsu-Heis flying...

I have never actually seen a picture of a Ki-61-I-Tei in flight out of thousands of Ki-61 pictures... Would love to see one though...


It seems to me that you're suggesting that the Tei variant was hardly flown in combat. Considering that it was first produced in 1944, there might be something to do with the production quality of the engine that it used. I imagine that other Ki-61 variants produced at the same time would have suffered similarly. This is why the engine was replaced.

The Tei models were used as home defense fighters and weren't all simply cannibalized or used as kamikazes.

If the caption is correct, this photo shows a Tei put to good use, circa 1945:

http://www.asisbiz.com/il2/Ki-100/Ki-100-244Sentai-R24-Kobayashi/images/1-Ki-61-I-Tei-244-Sentai-Tembico-Kobayashi-4424-Japan-1945-01.jpg

JtD
10-06-2011, 04:41 AM
Originally posted by Gaston444:

Even the Zero A6M5 was probably 590 km/h + by engine bench output, and was reportedly only modestly slower than early Corsairs in combat.
...
Even the Ki-44 was 650 km/h in the Japanese's own tactical evaluation documents of the defence of Tokyo against B-29s.

Please provide the sources and/or basis for these three statements.

mauld
10-12-2011, 04:07 PM
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Gaston444
10-31-2011, 12:33 PM
Originally posted by Luno13:
The Ki-100 may win out against the Ki-84 nine out of ten times, but I'd like to see how those tests were conducted.

I mentioned in my tests in this game that the Ki-100 certainly could outmaneuver the Ki-84. Personally, I find the Ki-100 more maneuverable because it is easier to take it to the edge of its turn performance due to its docile handling characteristics. If the Ki-84 played it smart though and flew carefully like a Mustang pilot would, then the favor would easily be 9/10 towards the Hayate.

So, a few words on a page aren't conclusive, and can go either way. I brought up my personal experience because it contradicts the common wisdom that the Ki-84 is hands down better...it depends on how each aircraft is flown.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> If you look at all the Ki-61 pictures of the 244th Sentai in 1945, or any operational Ki-61-I, you will only see the short-nose Ki-61-I-Koh/Otsu/hei being used because they were so much better than the longer-nosed Tei, which was 600 lbs heavier for some reason.

The longer-nosed Tei variant was massively used as a Kamikaze aircraft (large number of such schemes and units, all using the Tei exclusively, as that was the only combat use it was good for), and almost all the pictures I have seen of it at a various bases shows a cannibalized wreck being stripped for spare parts to keep the earlier short-nosed Koh-Otsu-Heis flying...

I have never actually seen a picture of a Ki-61-I-Tei in flight out of thousands of Ki-61 pictures... Would love to see one though...


It seems to me that you're suggesting that the Tei variant was hardly flown in combat. Considering that it was first produced in 1944, there might be something to do with the production quality of the engine that it used. I imagine that other Ki-61 variants produced at the same time would have suffered similarly. This is why the engine was replaced.

The Tei models were used as home defense fighters and weren't all simply cannibalized or used as kamikazes.

If the caption is correct, this photo shows a Tei put to good use, circa 1945:

http://www.asisbiz.com/il2/Ki-100/Ki-100-244Sentai-R24-Kobayashi/images/1-Ki-61-I-Tei-244-Sentai-Tembico-Kobayashi-4424-Japan-1945-01.jpg </div></BLOCKQUOTE>

First the Ki-100 issue:

Your tests in-game show a relatively minor difference in turn maneuverability, based plausibly on the relatively small difference in wing loading, while in real life, from co-altitude, the Ki-100 could take on 3 Ki-84 and have a reasonable chance of winning... The difference shows that the wingloading alone, or in combination with power loading, is not predictive of actual turn performance at all... The Japanese were not some foreign evaluators, and the switching around of pilots indicates they went out of their way to eliminate a false perception.

They were also objective enough to recognize the Ki-84's superiority in dive and zoom fighting.

Furthermore, in a real-life late war low-altitude turning combat over the sea that was very prolonged (suggesting lower speeds at least from the middle to the end) with roughly equal numbers of about 12 P-47Ns, showed a result of 11 to 0 against the Ki-84. This indicates to me the Ki-84 likely could not out-turn the P-47D in low speed low altitude sustained turns as well (at which the P-47 excelled, despite a wider initial radius of turn, and contrary to popular belief).

That is not surprising to me at all, as even the standard P-47D was likely one of the best Allied turnfighter in low speed sustained turns available in Europe, save maybe for the P-38... Yes, many types like the Spitfire could carve a much tighter unsustained high G turn, but likely could not sustain speed so well comparatively when the turning was prolonged... My analysis of several hundred Spitfire combat reports, of several Marks, on Mike William's "WWII aircraft performance" site, shows convincingly an aircraft that used dive and climb tactics almost exclusively, never sustaining turns beyond one circle, while the 600 P-47Ds combat reports on the same site show the heavier US aircraft to be used almost obsessively (and successfully except vs the FW-190A)as a sustained turn fighter, this against the very same German types... It's all there for anyone to see...

As for the Ki-61-I-Kai-Tei being used in combat as a normal fighter, I agree with you that probably did happen on some scale (given the 1300 produced!), but consider the following: If you have the exact same power engine and a similar airframe, with one weighting 600 pounds more than the other, would you not try to fly all your missions on the lighter aircraft, which even then was hardly successful already?

I did see two other pictures of Ki-61-1-Kai Teis with kill markings: One was supposedly a Kobayashi mount, but the order of the kill markings on it was completely wrong, which was not the case on any of Kobayashi's operational short-nose Ki-61s... This suggest they were applied all at one time for publicity purposes, and that he may have never flown it (according to the extensive and well-researched Japanese decal sheet by Life-Like decals).

If it was used in combat, it was likely used for the ramming attack tactic with guns removed, as that would lighten it somewhat. You have to remember the pilot was a lot more valuable than the airframe, so wasting an experienced pilot if faster and better short nose Ki-61s were around (595 km/h short nose vs 570 km/h for the long nose Tei) was not as likely as one would think...

Another brown-green Tei I saw with kill markings had them in yellow on the nose, and it was estimated by Japanese marking experts that the kill markings were probably spurious there as well... The Teis were probably used extensively as training aircrafts, or for novice pilots...

The fact that not a single photo of a flying Ki-61-Kai-Tei has ever surfaced (and only one I have seen with the engine running on the ground!) speaks volumes compared to the litterally hundreds of flying short-nose Ki-61 photos I have seen... I have also seen dozens, or even more, photos of cannibalized Ki-61-I-Kai-Teis, suggesting they were used to harvest parts in large numbers: In fact such cannibalized photos represent the majority of Tei photos I have seen in total...

Note also that the majority of decal markings for Ki-61-I-Kai-Teis I have found were for Kamikaze aircrafts within Kamikaze-specific Sentais...

But you are quite correct that it could not have helped but to be used in normal combat as well... I do not exclude that: I am just pointing out what was the seemingly prevailing useage of these at the time. This notion is confirmed in a Kagero book by Krzysztof Janowicz (Miniatury Lotnicze #23) dedicated to the 68th Sentai, where I got the slower 570 km/h figure for the Tei as well.

Gaston

Gaston444
10-31-2011, 12:48 PM
Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gaston444:

Even the Zero A6M5 was probably 590 km/h + by engine bench output, and was reportedly only modestly slower than early Corsairs in combat.
...
Even the Ki-44 was 650 km/h in the Japanese's own tactical evaluation documents of the defence of Tokyo against B-29s.

Please provide the sources and/or basis for these three statements. </div></BLOCKQUOTE>

The engine Bench test Zero model 52 speed estimation was just that: An estimation for true WEP. From the accepted 570 km/h figure to 590 km/h at the uncertain WEP value I don't see any great mystery here... Japanese pilots routinely speak of the Model 52's somewhat greater engine combat boost option...

The Tokyo area defense Japanese evaluation was disseminated online a few years ago, and is now surprisingly hard to find (probably because the title of the AH(?) thread was different and made no reference to it): I will keep looking... It was dated, with detailed administrative origins, and I have no doubt it was authentic. The 650 km/h speed of the Ki-44 Tojo seems perfectly reasonable given the 595 km/h speed of the Ki-61 in the same report, and the known 690 km/h + of the Ki-84...

I don't see where you see a problem, but please assume I made it all up if it makes you feel better... In the meantime I'll keep looking...

Gaston

Wildnoob
10-31-2011, 02:56 PM
Originally posted by Gaston444:

Even the Zero A6M5 was probably 590 km/h + by engine bench output, and was reportedly only modestly slower than early Corsairs in combat.

Gaston, the trolling "boost" already achived its limit, I suggest to back to military power.http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Gaston444
10-31-2011, 06:21 PM
Correction: The Ki-61-I-Kai-Tei's speed was not reduced to 570 km/h from 590 km/h on the earlier shorter-nosed models, but indeed to 550 km/h..........

This is the full quote from above-mentionned Janowicz's book on page 18 (the model is wrongly described as a "hei" (c) but the modifications are clearly those of a "Tei" (d):

"The rear of the fuselage was detachable for easy access to several mechanisms and devices... The wing construction was stronger to enable the suspension of extra fuel tanks or bombs... All these changes resulted in the top speed being reduced to 550 km/h." P.18


I'll leave it to your imagination how widely used in combat the "Tei" was with a 550 km/h top speed...

No wonder in the later stage of war, in mid-1945, all you see flying against the B-29s are the earlier short-nose versions of the Ki-61... Check all the numerous 244 Sentai photo records and tell me if you see a SINGLE long nose Tei being prepared for battle, over the entire field...

Wildnoob (appropriate name), go do some research and you will find the extra drag of radial engines amounts to 1% over inlines...

Now consider this: The A6M5 Zero weighted around 6000 lbs at most, the Ki-61-I around 7000 lbs at least, had 1% less drag and exactly the same power... So you can believe 590 km/h for a Ki-61, but not for an A6M5?

It was a big surprise ten years ago to find that no Japanese speed chart ever included WEP performance. It's about time it sank in... There's nothing surprising about a 650 km/h Ki-44 Tojo either...

Gaston

Erkki_M
11-01-2011, 02:23 AM
LMAO Gaston, heavier plane with same engine power must be slower? Go check your physics again!

BTW its F=ma what happens when a is zero? http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

KIMURA
11-01-2011, 02:48 AM
Same shape and thrust but more more lift needed cause more drag, Erkki. http://forums.ubi.com/images/smilies/winky.gif

Erkki_M
11-01-2011, 05:37 AM
Originally posted by KIMURA:
Same shape and thrust but more more lift needed cause more drag, Erkki. http://forums.ubi.com/images/smilies/winky.gif

Read my post again: "heavier plane with same engine power must be slower?" It most certainly does not need to be.

Erkki_M
11-01-2011, 06:33 AM
Originally posted by KIMURA:
Same shape and thrust but more more lift needed cause more drag, Erkki. http://forums.ubi.com/images/smilies/winky.gif

Whats your point? What are you trying to prove? Where did I say the shape remains constant, unchanged? I was commenting Gaston's Ki-61 vs. Zero logic. As usually, hes wrong...

Wildnoob
11-01-2011, 06:56 AM
Think I never head about A6M5's outruning Hellcats in any power regime. The contrary, a lot. But according to Gaston's logic with the Corsair citation, this was surely a fact.

Thank you Gaston, now I understand why the Japanese kept the Zero in production until 1945. And the A6M8 would have thrashed the P-51H and the F8F had the war continued. Damn Allied propaganda! http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

KIMURA
11-01-2011, 08:06 AM
Originally posted by Erkki_M:
LMAO Gaston, heavier plane with same engine power must be slower? Go check your physics again!


My point was that phrase above. Increase of weight has the same effect on speed drop than any other introduced change on the airframe.

JtD
11-01-2011, 11:55 AM
Originally posted by Gaston444:

The engine Bench test Zero model 52 speed estimation was just that: An estimation for true WEP. From the accepted 570 km/h figure to 590 km/h at the uncertain WEP value I don't see any great mystery here... Japanese pilots routinely speak of the Model 52's somewhat greater engine combat boost option...

No, an increase in engine boost alone does not increase a plane's top speed considerably. For instance, the WEP on the Fw 190 increased the top speed by a mere 8 km/h, even though the change in power output was considerable. What increases significantly is the speed below full throttle altitude, in case of the Fw about by 24 km/h. In order to increase top speed, you'd need a considerable increase in engine rpm to have the supercharger do more work, which was not the case for the A6M5 (2700 rpm military, 2750 rpm WEP).

Also your reply did not address how the A6M was only moderately slower that the early F4U.

A new question arising from you post: The 570 km/h are accepted as what by whom?


The Tokyo area defense Japanese evaluation was disseminated online a few years ago, and is now surprisingly hard to find (probably because the title of the AH(?) thread was different and made no reference to it): I will keep looking... It was dated, with detailed administrative origins, and I have no doubt it was authentic. The 650 km/h speed of the Ki-44 Tojo seems perfectly reasonable given the 595 km/h speed of the Ki-61 in the same report, and the known 690 km/h + of the Ki-84...

Interestingly, the top speed listed for the Ki-44 in Japanese documents is 605 km/h. I don't see where the 45 km/h increase should suddenly come from, the engine data does not support performance like that. A much more reasonable explanation is a simple typo, but that could only be checked against the original document and even there only against the context.

JtD
11-01-2011, 11:58 AM
Originally posted by Gaston444:
Correction: The Ki-61-I-Kai-Tei's speed was not reduced to 570 km/h from 590 km/h on the earlier shorter-nosed models, but indeed to 550 km/h..........

Japanese sources state 580 km/h top speed for the Ki-61 Tei.

Gaston444
11-06-2011, 08:34 PM
This book review makes a reference to the same Japanese self-evaluation document where the Ki-44 was listed at 650 km/h:

http://www.aeroscale.co.uk/mod...=showcontent&id=6999 (http://www.aeroscale.co.uk/modules.php?op=modload&name=Reviews&file=index&req=showcontent&id=6999)

Quote:"Mr. Millman does a good job of keeping us up with the unit histories and giving the little understood Shoki units their dues. Some Shoki units were moved about, in whole or in part, as ‘fire brigades.’ As a result the unit history of some sentai, such as the 246th, can be confusing. It is mentioned that Japanese evaluations rated the 47th Sentai as ‘…the best in Division…’ while the famous 244th Sentai, with their popular elaborately marked Ki-61 Heins, was rated as ‘adequate.’ By the end of the war the Ki-44 made up 18% of Homeland Defense units, even though Shoki was only 9% of Japanese fighter production."

Find the reference in this Osprey book for this passage, and you will find the Japanese document in question, though the wording I saw was "adequate" for the Ki-44 unit and "unsatisfactory" for the 244th Sentai, but obviously the wording and the subjects are too close to be coincidences...

The Ki-61 was listed as 590 km/h for 1190 HP, the Ki-44, very light, sleek at 650 km/h for 1520 HP, which is plenty enough power(!), as were many other Japanese types: J2M3 "Jack" was estimated at 650 km/h by the TAIC, as was N1K1 "George"... Jesus Christ: With 1900 hp what do you expect? Do you still think the Ki-84 "Frank" was plodding along at the often quoted 625 km/h?

It is true the Spitfire Mk IX was surprisingly crappy at 655 km/h regardless of if it was boosted to +18 lbs or +25 lbs: The speed was much increased in the lower altitudes with the extra boost, but the actual top speed remained unchanged despite the power going from 1700 to 2000 HP (sort of the same story for P-47Ds boosted to 72": No increase in maximum speed above 25 000 ft, but a considerable increase below that: Kind of makes you wonder about Robert Johnson's claims of 470 + MPH at 30 000 ft http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif)... On the Spitfire Mk IX this was a problem with radiator design I think, which was solved in the Mk XIV which could do 720 km/h on roughly the same power...

But why someone would assume a lightweight 6000 lbs Japanese radial engined fighter would be stuck well below 400 MPH with 1520 HP, or even 1900 HP, is quite beyond me... The day of William Green as a master source of information are a bit behind us I would think...

As for the A6M5 not being able to do 590 km/h, who knows? That was still 50 km/h slower than early Corsairs, and already a bit of a stretch to be just "slightly" slower as Corsair pilots can be seen to say on film during wartime (on the record if it ever is)... The Hellcat -3 did 609 km/h (convert from 379 MPH): http://www.wwiiaircraftperformance.org/f6f/f6f.html

That is still 20 km/h faster than the calculated top speed of the Model A6M5 and A6M5a Zero, bearing in mind that later models of the A6M5 were ALL slower due to much heavier weights, so at best 575-580 kmh for an A6M5b and 565-570 km/h for an A6M5c.

So just where is the problem? If you don't even believe 570 km/h for the A6M5, I would suggest the problem lies with you...

Gaston

Luno13
11-06-2011, 08:57 PM
But why someone would assume a lightweight 6000 lbs Japanese radial engined fighter would be stuck well below 400 MPH with 1520 HP, or even 1900 HP, is quite beyond me...

There's more behind performance than horsepower...

Wildnoob
11-07-2011, 06:07 PM
Someone has data or estimatives about the maximum speed of the Ki-43 variants with boost? I was impressed that Oleg's Ki-27 has a boosted speed of 520 km/h, while his Ki-43 Model 1 has only 495.

JtD
11-08-2011, 12:24 AM
In terms of speed, the Ki-43 I is modelled about correctly for military power. Figures I found are 440km/h at 1000m and 490km/h at 5000m. Speed gains for WEP settings (~ +100hp) would be in the region of 15-20 km/h, but that mostly below full throttle altitude.

The Ki-27 on the other hand is shown too fast, but you will be unable to fly 520 km/h in game because the engine will overrev. The real planes full throttle altitude was at about 3500m and up to that altitude, performance in game is about correct. It is a case where Il-2 compare is not accurate, unless you switch engine overheat off (which prevent engine damage from over-revving).

ImpStarDuece
11-09-2011, 04:00 PM
Originally posted by Gaston444:


It is true the Spitfire Mk IX was surprisingly crappy at 655 km/h regardless of if it was boosted to +18 lbs or +25 lbs: The speed was much increased in the lower altitudes with the extra boost, but the actual top speed remained unchanged despite the power going from 1700 to 2000 HP... [SNIP]

On the Spitfire Mk IX this was a problem with radiator design I think, which was solved in the Mk XIV which could do 720 km/h on roughly the same power...



http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif http://forums.ubi.com/groupee_common/emoticons/icon_confused.gif

Are you aware, at all, of how a supercharged aircraft engine works? Or what a Merlin power curve looks like, or a Griffon power curve?

Power at altitude, not outright horsepower, determines speed. Boosting the Merlin only increased power below critical altitude.

Yes, the Mk XIV was slightly more slippery than the Mk IX, BUT, the Griffon not only produced MORE power than the Merlin 60 family, but it did so AT A HIGHER ALTITUDE.


Merlin 66 power curves
http://www.spitfireperformance.../merlin66hpchart.jpg (http://www.spitfireperformance.com/merlin66hpchart.jpg)

Griffon 65 power curves
http://www.spitfireperformance.com/griffonhp_b.jpg

Spitfire F Mk IX had 1565 hp and made 408 mph but a critical power altitude of around 25,000 ft, where the air was thinner.

Spitfire LF Mk IX had 1720 hp and made around 404 mph, but its critical altitude was around 21,000 ft. More power overall, but produced at a lower altitude, pushing heavier air.

Spitfire HF Mk IX had 1710 hp and made about 416 mph, but its critical altitude was about 27,500 ft. Less power than the LF, but produced at a higher altitude, pushing less dense air.

The Spitfire XIV had 2000 hp and could do 448 mph, but at 26,000 ft. At this altitude, its producing about 1700 hp, around 400 hp more than a Merlin 60 series engine at the same altitude.

Gaston444
11-27-2011, 12:13 AM
You are right the Spitfire Mk XIV was just as crappy as the Mk IX if +18 lbs in the Mk XIV is compared to + 25 lbs in the Mk IX: They both did around 380 MPH at 4000 ft., compared with the P-51B with less power which did 400 MPH at that height with only around +21 lbs (around 72 or 75" hg) on a Merlin...

http://www.spitfireperformance.com/merlin66_18_25.jpg

I overestimated in my mind the aerodynamics of the Mk XIV, and you are correct in pointing this out...

It is worth mentionning however that the Spitfire Mk IX at +25 lbs outclimbs below 20k any other major WWII fighter, including any Me-109K-4s AND the Spitfire Mk XIV at +18 lbs...

The top piston-engined climber of WWII below 20 000 ft was the +25 lbs boost Spitfire Mk IX: Barring the time figures of what the +21 lbs Mk XIV did, that bears repeating for a barely 410 MPH (655 km/h) fighter...

With such a superior world-beating climb rate performance, it is rather odd that its top speed is still around that of a Me-109G-6, especially given that the same two-stage Merlin is known as such a great high-altitude engine in the P-51...

Much slower climbing Me-109Gs were by then zipping along at 680-720 km/h...

The main point I was making is that 650 km/h is well below the lowest top speed you can expect for that kind of power in the 2000 hp range, and you probably should get much higher, the Spitfire being peculiar in that respect given its unbeatable overall sustained climb rate performance...

So the idea that the sleek and lightweight Ki-44 cannot do 650 km/h on 1500 hp, or that the Ki-84 didn't do 690 km/h on 1800 hp, seems dubious DESPITE that particular example: ie: The point I was making...

For the Ki-44 at least, original Japanese sources do say 650...

Gaston

P.S. And Robert Johnson was still full of it with his 470 MPH claim at 30k... http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

JtD
11-27-2011, 09:21 AM
The Ki-44 did not have 1500 hp available at altitude and did not do 650 km/h at sea level. Try finding a matching pair of numbers in order to make sense.

A P-47 might need about 2800hp to attain the speed at the altitude mentioned. This was clearly within the abilities of the engine. In fact, later, larger P-47 models did attain the speed at the altitude at that power.

ImpStarDuece
12-05-2011, 11:06 PM
Originally posted by Gaston444:
You are right the Spitfire Mk XIV was just as crappy as the Mk IX if +18 lbs in the Mk XIV is compared to + 25 lbs in the Mk IX: They both did around 380 MPH at 4000 ft., compared with the P-51B with less power which did 400 MPH at that height with only around +21 lbs (around 72 or 75" hg) on a Merlin...

http://www.spitfireperformance.com/merlin66_18_25.jpg

I overestimated in my mind the aerodynamics of the Mk XIV, and you are correct in pointing this out...

It is worth mentionning however that the Spitfire Mk IX at +25 lbs outclimbs below 20k any other major WWII fighter, including any Me-109K-4s AND the Spitfire Mk XIV at +18 lbs...

The top piston-engined climber of WWII below 20 000 ft was the +25 lbs boost Spitfire Mk IX: Barring the time figures of what the +21 lbs Mk XIV did, that bears repeating for a barely 410 MPH (655 km/h) fighter...

With such a superior world-beating climb rate performance, it is rather odd that its top speed is still around that of a Me-109G-6, especially given that the same two-stage Merlin is known as such a great high-altitude engine in the P-51...

Much slower climbing Me-109Gs were by then zipping along at 680-720 km/h...

The main point I was making is that 650 km/h is well below the lowest top speed you can expect for that kind of power in the 2000 hp range, and you probably should get much higher, the Spitfire being peculiar in that respect given its unbeatable overall sustained climb rate performance...


Gaston, divorce the notion of climb performance being related to speed performance in your mind.

Please.

Just do it.

Climb is related to specific excess power.

Top speed is related to drag vs thrust at a specific altitude.

The P-51 and Bf-109 were faster than the Spitfire because they had fundamentally less drag or (in the case of the 109s with DB605AS, ASM engines) more power at altitude.



With such a superior world-beating climb rate performance, it is rather odd that its top speed is still around that of a Me-109G-6,

If you understood even the basics of aircraft performance, then you'd realise that there is nothing odd about that at all.