Author Topic: Ki-61/Ki-100 discussion  (Read 12047 times)

Offline Perrine

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Re: Ki-61/Ki-100 discussion
« Reply #15 on: September 30, 2010, 10:19:01 PM »
check out this video never before seen in the western world until now :rock
http://www.youtube.com/watch?v=dcdbPh-uOVw

Offline Krusty

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Re: Ki-61/Ki-100 discussion
« Reply #16 on: September 30, 2010, 11:18:20 PM »
I never said they used the "A-5 nose".  They looked at the design of the engine mounts, and exhaust.  They obviously made tweaks.  Also, the 61 handles NOTHING like 205 or a 109, so you can pretend the He-100 that was sent to Japan, wasn't used as a platform. :)

First....

Frankly, everything in your post was blatantly wrong, but you're contradicting yourself here.

You said:

The 100 fuselage implemented the FW-190 A5's engine mounts in order to "narrow the already wider nose due to the radial". [...] They had to make due and basically modified the A-5's fuselage from the cockpit forward and even utilizing the 801D's exhaust, which were modified to fit as well.

That suggests explicitly they copied the 190A-5 airframe (despite the fact the airframes already were built and waiting engines in 1945).

The only thing they did was see what principles and what techniques were used, NOT copy the 190 setup.

Second, just... EVERYTHING you've said is wrong about this plane. It's no more a He-100 than the Ki-44 is a P-51.

Omigosh! The Ki-44 is based of a P-51!!! I mean, LOOK at it! The wing has a kinked root! It flies like no other Japanese plane before it! Speed and altitude performance! OMIGOSH!!!! </SARCASM>

It was not the equal of western fighters. It was not feared by the USAAF and the USN alike. It was not a He100 design (seriously, have you ever seen the He-100? Please check out the design). You seem to be spouting off every rabid Internet theory there is that has no historical fact or basis.

You may enjoy the Ki-61 in this game as it's modeled now, but you don't know beans about the real thing. I'm sorry if I offend, but it's clearly the case. I also have enjoyed the Ki-61 for many many years (before it seems to have gained some popularity in recent years). You're not the only one.

Offline Baumer

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Re: Ki-61/Ki-100 discussion
« Reply #17 on: October 01, 2010, 01:15:24 AM »
I've found this thread very interesting as I have been curious about the Ki-61's performance in AH. I have some information from a Japanese book that was translated and published in 1958 that's got some interesting info that's made me confused for what other books I've read.

Here are the pages for the translated version of the Ki-61 and Ki-100 descriptions.

http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/part1.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/part2.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/part3.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/part4.jpg

Here are the original pages,

http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/partA.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/partB.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/partC.jpg
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/partD.jpg

In the back it has this table,


page 2 of the table with the Ki-100 listed,
http://332nd.org/dogs/baumer/BBS%20Stuff/Ki61/AppxB.jpg

So the Ki-61 in AH is the same loaded weight as the Type 3 Model 1 (with the 12.7 x 2 and 20 x 2 guns) and climbs to 5000m (16,404 ft) in 7 minutes. However, the top speed in AH is between the speeds for the Model 1 (with the Ha-40 engine) and the Model 2 (with the Ha-140 engine). The Model 1's top speed is 348mph at 16,404 feet, the Model 2's top speed is 379mph at 19,685 feet and in AH the top speed is 372 mph at 15,000 feet. Also I'd like to point out that on the second page of the translated edition it states that shortly after the first Ki-61 was completed it was flown to a top speed of 368 mph. So there are many different numbers to look at in trying to ascertain what the performance should be.

Another area I was unclear on, the loaded weight for the Model 1 matches what we have, but the empty weight is very different. The table list's the empty weight as 2630 Kg (5,798lbs) but in AH the best empty weight is 6,440lbs so I'm not sure where that discrepancy comes from.

I hope this helps by providing a different source but it makes tracking the versions a bit more difficult.

<S> Baumer



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Offline nrshida

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Re: Ki-61/Ki-100 discussion
« Reply #18 on: October 01, 2010, 01:35:42 AM »
Thanks for the video Perrine. I did like to see the original footage even if the pseudo 1980s music was a little disturbing. Is that taken from a documentary do you know?

I am beginning to suspect that Krusty and Masherbrum have clashed before on these forums over these aircraft.   :noid

I think it's always difficult to separate the factual information from all the conjecture and subjectivity.

The famous Hellcat / Ki-100 combat report is a classic example, of course there is motivation to make exagerated claims. The particular aircraft I uploaded the photos for was delivered to French Indochina in 1945, the pilot who flew it there explained that it was intended as a morale booster (most other Ki-100s being reserved for the defense of the Japanese mainland). Presumably to give hope showing 'new' aircraft being produced even at this stage of the conflict.

As Wmaker has observed in the confines of the virtual environment that is Aces High the realities of an actual war are less pressing as people often choose to dogfight to the end and test their skill etc.

I try to look at the aircraft from an engineering standpoint, especially in the unique case of the Ki-61 / Ki-100, since they have so much in common.

This is probably also because I want to understand what this change or that would do to the performance of an aircraft. I find it really worthwhile to try and understand some of the more advanced dynamics discussed by Stoney, WMlute and HiTech etc.

I think an AH simulation is about as close as anyone can hope for in evaluating the comparative qualities of the real aircraft at this stage. I think that's what keeps us asking for new models to be added.

Here are a few diagrams of interest. Some comparing the cowling modification to accommodate the radial engine. These have been kindly shared from JHerne's personal library.


















This last scan for your perusal Wmaker. The first six rows seem to be about dimensions. Seventh row engine information including weights. Eighth row propeller data I imagine. Ninth row wing loading and power to weight ratios? Tenth perhaps fuel tanks & capacities? Eleventh looks like Unloaded Weight, fuel capacity in kgs and finally fully loaded weights. Shows an apparent internal fuel increase from the Ki-61-I onwards.

So again it is showing the Ki-100-I to be 105 kgs lighter than the Ki-61-I. I'm afraid I can't decipher the exact subtype of the Ki-61-I in the top of the first column.



Excellent data Baumer, thanks for posting that. Going to take a look at it now...

« Last Edit: October 01, 2010, 01:38:41 AM by nrshida »
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Offline Perrine

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Re: Ki-61/Ki-100 discussion
« Reply #19 on: October 01, 2010, 03:49:45 AM »
Thanks for the video Perrine. I did like to see the original footage even if the pseudo 1980s music was a little disturbing. Is that taken from a documentary do you know?

I guess it's a Japanese documentary released to DVD only



Get ready for more elevator/lobby music + engrish dub :x
It's got generic title Japanese Army Aircraft of WW2
Split in 4 parts
http://www.youtube.com/watch?v=R3CauO3NOBE&fmt=18

« Last Edit: October 01, 2010, 04:40:28 AM by Perrine »

Offline Wmaker

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Re: Ki-61/Ki-100 discussion
« Reply #20 on: October 01, 2010, 05:36:56 AM »
However the specification (including weights and measures) at the bottom of the Wikipedia article is for the Ki-100-1a/b Goshikisen. Which would correspond to the data in the first column of the third and forth scans you kindly uploaded. Assuming that the Ki-100-1a/b Goshikisen is the same model or similar to the Ki-100-I?

That gives the empty weight at 2,525 kgs, which all seems consistant so far.

If the Aces High Ki-61 is the KI-61-I-Tei, and that is the same actual model as the Ki-61-I-KAIc, as you stated, then the empty weight is listed at in the middle column of the second scan as 2,630 kgs.

So it is actually true then, that the Ki-100-1a/b Goshikisen was indeed lighter than the version of the Ki-61 we currently have in Aces High?

105 kilos or 231 pounds lighter, as well as the additional power?

Help me out Wmaker, I know you have an eye for data & I am now confused about the model types so I even suspect I am reading the data wrong?

Yes, that is how it looks regarding empty weight. But when I talk about aircraft weights I always talk about normal takeoff weights as that gives a better comparison due to many reasons like the power and wing loading comparisons. The when looking at the normal take off weight the Ki-100 would be 25kg heavier than the Ki-61 we have in AH. And yes, the 3D-model is AH1 vintage. I have a hunch that when Ki-61 gets updated the flight model might be redone aswell just like the Mosquito's FM was. We'll have to wait and see but I think there's a good change that might happen.


Here are a few diagrams of interest. Some comparing the cowling modification to accommodate the radial engine. These have been kindly shared from JHerne's personal library.

----------------


This last scan for your perusal Wmaker. The first six rows seem to be about dimensions. Seventh row engine information including weights. Eighth row propeller data I imagine. Ninth row wing loading and power to weight ratios? Tenth perhaps fuel tanks & capacities? Eleventh looks like Unloaded Weight, fuel capacity in kgs and finally fully loaded weights. Shows an apparent internal fuel increase from the Ki-61-I onwards.

So again it is showing the Ki-100-I to be 105 kgs lighter than the Ki-61-I. I'm afraid I can't decipher the exact subtype of the Ki-61-I in the top of the first column.

Thanks for the images! That third image is particularly interesting showing the fairings that were incorporated to the original Ki-61 fuselage in the Ki-100 to prevent flow separation after the cowling. I think I have these in the depths of my HD aswell. :)

The Ki-61-I- subvariant based on the weight and ammo load etc. seems to be the the one we have in AH, KI-61-Tei/KAIc. Again, it is best to compare the take off weights instead of empty weights. ;)

And Baumer, thanks for the scans! :)
« Last Edit: October 01, 2010, 05:44:18 AM by Wmaker »
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Offline Masherbrum

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Re: Ki-61/Ki-100 discussion
« Reply #21 on: October 01, 2010, 12:35:24 PM »
See Rule #4
« Last Edit: October 06, 2010, 09:24:38 AM by Skuzzy »
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Offline nrshida

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Re: Ki-61/Ki-100 discussion
« Reply #22 on: October 01, 2010, 05:02:02 PM »
I think this has been a very productive and interesting thread so far. Not only have we finally found useful data regarding the weight savings of (at least one model of) the Ki-100 conversion, but I believe Baumer is right, the unloaded weight of the current AH Ki-61 is 292 kilos too high? That's quite a lot. Also a sort of hidden error, as the excess weight only announces itself slowly as you burn down from 100% fuel. Could this explain the other discrepancies in performance?

If the data is correct doesn't this make it a bug?  :rofl  :bolt:










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Offline Masherbrum

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Re: Ki-61/Ki-100 discussion
« Reply #23 on: October 01, 2010, 05:25:13 PM »
I think this has been a very productive and interesting thread so far. Not only have we finally found useful data regarding the weight savings of (at least one model of) the Ki-100 conversion, but I believe Baumer is right, the unloaded weight of the current AH Ki-61 is 292 kilos too high? That's quite a lot. Also a sort of hidden error, as the excess weight only announces itself slowly as you burn down from 100% fuel. Could this explain the other discrepancies in performance?

If the data is correct doesn't this make it a bug?  :rofl  :bolt:


It is 292 kilos too heavy.   Also, in the MA's you RARELY need more 50% fuel. 
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Offline Wmaker

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Re: Ki-61/Ki-100 discussion
« Reply #24 on: October 03, 2010, 08:48:04 AM »
Another area I was unclear on, the loaded weight for the Model 1 matches what we have, but the empty weight is very different. The table list's the empty weight as 2630 Kg (5,798lbs) but in AH the best empty weight is 6,440lbs so I'm not sure where that discrepancy comes from.

One thing missing from a normally given empty weight but still included in "AH empty weight" is the pilot. ;) That explains roughly 200lbs. I have to say that the difference between empty and normal take-off weight found in the literature is suprisingly high. The internal fuel load of 595liters shouldn't weigh much more than 950lbs. I guess drop tanks could explain it but why would they be listed in the "normal" take-off weight? But I guess that's plausible.

Would love to see a detailed load table for the aircraft!
« Last Edit: October 03, 2010, 09:09:11 AM by Wmaker »
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Offline EagleDNY

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Re: Ki-61/Ki-100 discussion
« Reply #25 on: October 03, 2010, 01:16:15 PM »
I've enjoyed coming back to AH and reading the forums again.  It does not seem that much has changed though.

I would like to see the Ki-100 make it into AH - by all accounts it was a significant improvement on the Ki-61 and was used operationally. HTC did a beautiful job on the Ki-84, and I have no doubt that if they put some effort into a Ki-100 that it would see a lot of use in the MA. 

Offline Krusty

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Re: Ki-61/Ki-100 discussion
« Reply #26 on: October 03, 2010, 02:14:02 PM »
As WMaker and I have mentioned, empty weight is not always so accurate (what is "empty?") but fully loaded usually is awlays the same.

You can't just say "it's too heavy" all by itself. What version is it? Does it have the steel plates all over? Does "empty" include the oil reservior, the liquid coolant, the guns themselves or just the ammo for the guns?


One thing to consider is that the Ki-61 apparently varied widely in configuration of fuel tanks.

From the link I made in my original response, here's a breakdown of some of the differences (please note, they are talking about IL2's modeling of the planes, and how it's wrong -- not related to AH's modeling)

Quote
Each of the three models we have in the simulation (Ko, Otsu, Hei) had varied fuel tanks and capacities as the aircraft evolved. The Ki-61 Ko (1a) thru Hei (1c) had various "internal" fuel tanks during it's production run. These varied from 750 liters to 500 liters placed about wings and fuselage....Exact numbers are per serial number (source Jim Long)

* Type 3 Fighter, Ki-61-I Ko, coded s/n's 113-500
Fuel Tanks: 2/190l. outer wing tanks, 1/170l. center wing tank, 1/200l. fuselage tank = 750l. + 2x200l. drop tanks = 1,150l..

* Type 3 Fighter, Ki-61-I Otsu, coded s/n's 501-1092
Fuel Tanks s/n 501-513: 2/190l. outer wing tanks, 1/170l. center wing tank, 1/200l. fuselage tank = 750l. + 2x200l. drop tanks = 1,150l..
Fuel Tanks s/n 514-649: 2/190l. outer wing tanks, 1/170l. center wing tank = 550l. + 2x200l. drop tanks = 950l..
Fuel Tanks s/n 650-1092: 2/170l. outer wing tanks, 1/160l. center wing tank = 500l. + 2x200l. drop tanks = 900l..

* Type 3 Fighter, Ki-61-I Hei, coded s/n's 3001-3400
Fuel Tanks: 2/170l. outer wing tanks, 1/160l. center wing tank = 500l. + 2x200l. drop tanks = 900l..

Now what we're seeing there are a couple of changes. First off the removal of the 200l. fuselage tank, secondly a reduction in size of internal tanks forced by improvements in bullet-proofing (armor) about the fuel tanks in that you can't make the wings thicker in practicallity, so the tanks get smaller.

To correctly address this issue (and coupled with armor), the simulation's 3 versions should have the following maximum internal fuel capacities (including drop tanks as optional loadouts):
Ki-61-I Ko: 750l. internal = 750l.
Ki-61-I Ko: 750l. internal + 1x200l. drop tank = 950l.
Ki-61-I Ko: 750l. internal + 2x200l. drop tanks = 1,150l.

Ki-61-I Otsu: 750l. internal = 750l.
Ki-61-I Otsu: 750l. internal + 1x200l. drop tank = 950l.
Ki-61-I Otsu: 750l. internal + 2x200l. drop tanks = 1,150l.
Ki-61-I Otsu: 550l. internal = 550l.
Ki-61-I Otsu: 550l. internal + 1x200l. drop tank = 750l.
Ki-61-I Otsu: 550l. internal + 2x200l. drop tanks = 950l.
Ki-61-I Otsu: 500l. internal = 500l.
Ki-61-I Otsu: 500l. internal + 1x200l. drop tank = 700l.
Ki-61-I Otsu: 500l. internal + 2x200l. drop tanks = 900l.

Ki-61-I Hei: 500l. internal = 500l.
Ki-61-I Hei: 500l. internal + 1x200l. drop tank = 700l.
Ki-61-I Hei: 500l. internal + 2x200l. drop tanks = 900l.

That could also affect empty weight (the weight of the tank, the anti-leak lining or bullet resistant plating around it would still be there even if the tank was empty).

Offline nrshida

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Re: Ki-61/Ki-100 discussion
« Reply #27 on: October 04, 2010, 05:29:36 AM »
Krusty, Wmaker did not say empty weights are often inaccurate. He said he prefers personally to talk about normal takeoff weights. YOU said 'empty weight is not always so accurate'.

Are you suggesting that the term 'empty weight' for one particular model has a different meaning to the term 'empty weight' for another version? Surely an author, an authority on the subject, would attempt to present comparable data? In other words it would be consistently measured for this one and then for that one. Otherwise what use is it? He'd make himself look rather silly and inexpertly would he not?

Wmaker also agreed the data tells a different story to what seems to have become generally accepted, on these forums at least, regarding the performance of the Ki-100. I think we had established therefore the value and importance of first finding quantifiable data, then verifying that data from at least one other source, then comparing the data to the models we have in Aces High. All this RATHER than painting with a wide brush and bringing opinion and feeling to the discussion. All of which is subjective.

I thought one positive thing about this thread was that we had together managed to find data from three separate sources in literature and presented it, and that those sources all seemed to agree, especially on weights (amongst other things).

What are you talking about 'steel plates all over', 'anti-leak lining' and 'bullet resistant plating'? Even if these things did vary between the versions of the Ki-61 and also the versions of the Ki-100, any structural component like armour plating and self-sealing fuel tanks that would obviously be covered in the unloaded weight figure of the aircraft. We also named the exact versions.

Why I think that fully loaded weights is not a useful metric for performance comparison is because if you take off with 50 litres of fuel in a Ki-61 and 50 litres of fuel in a Ki-100 the Ki-100 is still going to be lighter. We've already discovered in this thread that the MAXIMUM internal fuel capacity of the Ki-100-I was higher than the KI-61-I-Tei / Ki-61-I-KAIc. So as I mentioned previously you would not be comparing like with like.

You know, one could almost be forgiven for thinking that some players do not wish to have certain aircraft modelled as accurately as possible. Or otherwise have some other motivation to keep things exactly as they currently are.

The most interesting item that's been uncovered in this thread so far doesn't even pertain to the Ki-100. It's Baumer's observation that Aces High's current Ki-61, the KI-61-I-Tei / Ki-61-I-KAIc model (we are told this is the AH model), seems to be too heavy when empty of fuel and ammunition.

I repeated his experiment. The weight for a Ki-61 in Aces High with 100% internal fuel, full ammo load (and one pilot) is 7650 lbs (3477 kg).

We've got 3470 kg listed on two of our sources. So that's close enough (although they seem to have forgotten about the pilot) and further we can infer that HTC has decided the given data to be internal fuel only, no drop tanks.

With no fuel, no ammunition (and one pilot) the weight was 6440 lbs (2927 kg), as Baumer reported. In the literature however we have a figure of 2630 kg listed as empty weights (from two different sources).

So there is a discrepancy of 297 between the weight of the actual aircraft with the Aces High version of the Ki-61 and the data given in the literature.





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Offline Wmaker

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Re: Ki-61/Ki-100 discussion
« Reply #28 on: October 04, 2010, 06:25:23 AM »
Generally agreed nrshida,

No use of talking other Ki-61 variants and their fuel capasities or differences in equipment weights that are normally included in the empty weight. If we are trying to take a detailed look into the weight of the particular variant we have in AH.

I tried to construct a rough estimate of the a real life weight table of the Ki-61 that we have in AH:

 2630kg  : Empty weight (can be found from several sources, Francillon, etc.)
~36,4kg  : Oil (40liters of oil, 0.91kg/l)
~67,4kg  : Coolant (65 liters, 70% water, 30% Glysantin, taken from 109E --> should be close enough for this purpose.)
~ 100kg  : Pilot(+parachute?)
~ 431kg  : Full internal fuel (595liters of fuel, source ML#5, 0.725kg/l density used)
~ 121kg  : Ammunition (Weight taken straight from AHII)
-----------------------
3385,8kg : Total

3470kg    :Aces High take-off weight/Weight mentioned in literature
As you can see, coolant, oil and pilot can add quite a bit of weight to the normal "dry" empty weight of the aircraft and they off course have to be included in the "empty weight" of an Aces High aircraft as we can't remove the pilot or drain the plane from coolant/oil. The internal fuel in AH weighs 428kg, which is very close to my estimate of 431kg. So based on this the difference in the weight isn't 292kg anymore but closer to 84,2 - 87,2kg. There could be a slight difference in the weight of the coolant between 109E and Ki-61 but it isn't going to be hundreds of kilos... ;) Another thing is the ammunition, I haven't compared real life ammo weights to AH, but again, we aren't talking about significant differences here.

EDIT/Just checked the ammo weight from Mike William's excellent site (http://www.quarry.nildram.co.uk/WW2guneffect.htm). The rounds alone can weigh 101kg. If we count 20kg for the disintegrating belt components, we are there. ;)/EDIT
« Last Edit: October 04, 2010, 06:43:34 AM by Wmaker »
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Offline Baumer

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Re: Ki-61/Ki-100 discussion
« Reply #29 on: October 04, 2010, 07:48:29 AM »
Wmaker the only point I'd like to add is that sometimes (depending on the source documentation) I have seen items like coolant and oil included in the empty weight.

I don't have enough documentation to firmly state that there is an issue with the Ki-61 we have. However, what I do have, leads me to think it might be slightly over weight (642lbs subtracting 200lbs for the pilot = 442lbs overweight), and as Krusty pointed out it may be a little to fast.

 
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