Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: brady on June 10, 2004, 10:23:32 AM
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From another forum posted by Mike, does anyone care to comment on his findings:
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U.S. Far East Command. Mil Intell Sec. "Interrogations of Japanese Officials (English translations)." 2 vols. Typescripts, various dates. D811A2I3713.
_____. "Statements of Japanese Officials on World War II (English Translations)." 4 vols.
Typescripts, various dates. D811A2S7313.
Much of the rest of my research is Rene Francillon's work.
I believe that Gary uses Gustin as a source as the numbers seem to match.
Gustin actually does good research and provides much interesting info about aircraft but his summaries at the end of a section will usually just have one model listed. The problem is that he often does not list what model he is refrencing!
For example Gustin lists the Ki-84 as having a top speed of 392mph. That is it. One model.
Francillon on the other hand says the first prototype in November 1942 flew at 388mph, the fourth prototype flew at 392mph, and the pre-production arcraft added seperate exhaust stacks which gave another 9-10mph.
The problem with the speed for the actual production model is that the number did not seem to survive the war. No one has found a clear refrence.
However, I was able to put some info together. The most common engine in the Ki-84-1 was the type 21 engine. The engine chosen for the Ki-84-2 (part wooden) was also the type 21. The German & Japanese designers both stated numerous times during the war that making an aircraft part wooden would lose you 5-6mph. The Ki-84-2 flew at a speed of 415mph with a combat load. The engine on the pre-production Ki-84 developed 1800hp while the main production engine developed 1990hp on the same weight.
So, since the speed of the Ki-84-2 is a known value, and the engines were the same, i would guess the speed for the main production Ki-84-1 was about 420mph.
I would be willing to be talked down to 415mph for general lack of quality control.
However, that is a seperate issue in many ways as it ASSUMES that Japan is being bombed and that i have overdrafted my population. What idiot drafts his tool & die makers and heat treaters?
Well, Tojo. Moron. I probably will not.
I would be willing to make a change in my scenario that in return for my aircraft numbers i will slightly lower Japanese manpower.
Anyway, NARA is a great source for almost anything related to the war. especially since Clinton (who actually believed in Democracy) declassified virtually everything related to the -TINTS reports.
Mike
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Interesting.
I hope (kinda, thinking of my poor Mossie) you can get some more data.
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will be punting this one :)
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If the engine could put out 2000HP.....
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What octane fuel was the 415mph achieved at?
Also, didnt the U.S. test Ki-84s with 150 octane fuel at the end of the war?
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My memory may be playing tricks on me here, but I don't believe Japanese aviation fuel ever had an octane rating greater than 100, if it was THAT good.
Poor quality control exacted a bigger penalty in performance from the Ki-84 than many would admit. Top speeds for those aircraft that were actually flown in combat were considerably less than the 420mph quoted above. Late-war Japanese aircraft engines were notoriously unreliable and produced less power than the designers had intended.
On the other hand, a captured Ki-84 was brought to the U.S. and meticulously restored by the Army Air Corps. With high-octane American aviation fuel and a superbly tuned engine that Ki-84 did, indeed, approach that performance figure.
Regards, Shuckins/Leggern
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This guy I quoted above, says that the higher octane fuel would not of increased the Ki-84 preformance, since it was designed to operate on lower (well 87) Octane fuel. He also says that the test was run using 87 octaine fuel for the Ki-84. I will link the thread hear so you can read it in detail it is very interesting and their are more figures and referances:
A quote from the thread linked below:
"Just for reference about aviation gas, during WWII the US used 3 grades and they were classified as 80/87, 100/130, and 115/145. I'm also pretty sure that high performance American fighters only used the 115/145 grade. Also my 1972 Sanderson 'Private Pilot Manual' says it is ok to use a higher grade of the gasoline than your engine is rated for if your grade isn't available for a short period of time but it will not improve performance. "
See this thread all te good stuff is buried in the middle of it:
http://www.matrixgames.com/default.asp?URL=http%3A//www.matrixgames.com/forums/
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up
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The test was performed with 100 octane fuel. In a war condition (no ammo, but with guns) aircraft that was reconditioned here in the US.
I have several magazine articles from the 70's that talk about this in depth. However, there is no known records from the flight tests, and I've checked with the Air Force Musuem on the issue.
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Originally posted by brady
This guy I quoted above, says that the higher octane fuel would not of increased the Ki-84 preformance, since it was designed to operate on lower (well 87) Octane fuel.
This didn't occur to me... sounds logical in a way but kinda contradicts what I read about Japanese pilots account of flying the N1K2s right after the war. They were ordered by the GHQ to fly the fighters to the location where they were impounded... on American fuel. They noted quite a difference...
On the other hand, I remember in the modelling of AirWarrior, the Bf109 did not take a knock down in performance when the fuel was hit on a base (fuel hit on a base was to lower octane on AW). The reason for that modelling was that the Bf109s were designed to operate at lower octanes. Is that true? This doesn't seem to match things talked about here or we just can't generalize things?
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My impression is that in the Wright field tests of the Ki-84 they used higher octane fuel to substitute water injection. Only way to check this out is to find a report which contains used MAP values. Anyway, it's very unlikely that the USAAF used somekind of higher ratings than were used by the Japananese with water injection.
gripen
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401mph
otherwise perk it
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Originally posted by Vermillion
The test was performed with 100 octane fuel. In a war condition (no ammo, but with guns) aircraft that was reconditioned here in the US.
I have several magazine articles from the 70's that talk about this in depth. However, there is no known records from the flight tests, and I've checked with the Air Force Musuem on the issue.
It seems that the Ki-84-II Japanese performance tests do exist, if brady is correct. Why would the Ki-84-II test out at 415mph on Japanese fuel when using the same engine but the Ki-84-I only 392mph? It seems likely,if the Ki-84-II data is real, that a common Ki-84-I in good working order would do 415-420mph.
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Mitsu... any comment? ;)
gonna go to the public library over the weekend...
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I cant see HTC modeling that AC with anything other than published top speeds..which is 392 MPH TAS. They didn't model anything else that way, with the eception of the G-10. However, it always good to dream.
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-ammo-,
The suggestion here would be to use the Ki-84-II data given that the only real difference was the wooden parts.
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While I love the Ki-84, a FM built on the 420mph data would make it an "uber plane".
Basically imagine an aircraft as manueverable as the N1K2-J, and that is faster than the P-51D from about 18k down to the deck.
Why would anyone fly anything else?
When the Ki-84 in question was tested head to head with a P-51D and a P-47D, it outperformed each aircraft in every way until you got above 20k.
Hell, I'd be happy to just find a detailed report on the aircraft and the testing that occurred. Its like a will-O-wisp trying to find that old data, and it was a hobby of mine for a couple of years.
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Why do u guys want everybody to fly the ki-84
Because that's what im gonna do when a 420mph uberturnclimbanddive plane is gonna be released in AH
since the 414 mph p38 is gonna be totaly worthless against it.
Yes i want that plane that is gonna get everything out of balance.
WTG go get it!!!!`
:rolleyes: :rolleyes: :rolleyes:
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Originally posted by brady
This guy I quoted above, says that the higher octane fuel would not of increased the Ki-84 preformance, since it was designed to operate on lower (well 87) Octane fuel. He also says that the test was run using 87 octaine fuel for the Ki-84. I will link the thread hear so you can read it in detail it is very interesting and their are more figures and referances:
A quote from the thread linked below:
"Just for reference about aviation gas, during WWII the US used 3 grades and they were classified as 80/87, 100/130, and 115/145. I'm also pretty sure that high performance American fighters only used the 115/145 grade. Also my 1972 Sanderson 'Private Pilot Manual' says it is ok to use a higher grade of the gasoline than your engine is rated for if your grade isn't available for a short period of time but it will not improve performance. "
See this thread all te good stuff is buried in the middle of it:
http://www.matrixgames.com/default.asp?URL=http%3A//www.matrixgames.com/forums/
You can use higher boost pressure without knocking when using higher octane fuel, and that improves performance. 1972 Sanderson is correct when it comes to normally aspirated engines.
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"You can use higher boost pressure without knocking when using higher octane fuel, and that improves performance. 1972 Sanderson is correct when it comes to normally aspirated engines."
So your saying that since the Ki-84 was not normaly aspirated that the suposidely higher octane fuel burned in it during the test provided a better preformance?
The guy also mentions that they DiD Not use 100 octane fuel, as normaly beleaved in the test with the Ki-84 post war but the 80/87 octaine fuel.
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(http://www.allaboutwarfare.com//files/pictures/tmp/ki84-perfdata1.jpg)
(http://www.allaboutwarfare.com//files/pictures/tmp/ki84-perfdata2.jpg)
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I have (hopefully, that's not a "had" because I can't find it) a translated Ki-84 manual. IIRC, the performance listed in there was quite a bit less than the TAIC estimates.
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Frankely I was a bit shocked at the preformance figures this Lemurs fellow was sugecting, howeaver he presented a good case for his sugestion of 415-420 mph for the Ki-84, so I enquired hear to see just what everyone thought. I have E mailed him and provided a link to see if we can get him to come hear a debate the issue.
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Pyro i suppose they are more on par with the first two columns shown below ;)
(http://www.allaboutwarfare.com//files/pictures/tmp/ki84-perfdata3.jpg)
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Originally posted by brady
"You can use higher boost pressure without knocking when using higher octane fuel, and that improves performance. 1972 Sanderson is correct when it comes to normally aspirated engines."
So your saying that since the Ki-84 was not normaly aspirated that the suposidely higher octane fuel burned in it during the test provided a better preformance?
The guy also mentions that they DiD Not use 100 octane fuel, as normaly beleaved in the test with the Ki-84 post war but the 80/87 octaine fuel.
I'm not saying anything about that particular KI-84, but I just noted that with a little or no adjustments you can get higher power from a super/turbocharged engine with higher octane fuel.
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I am not an aircraft mechanic so take this with a grain of slat please. I do however build high performance engines on a side job.
Whenever you have an engine that is super/ turbo charged, nitroused or with a very high compression ratio ( normally above 10.5/1) a higher octane fuel is required to help prevent detonation inside the combustion chamber. A higher octane fuel is not easier to burn and requires more heat to start the flame front inside the cylinder. A colder spark plug and a closer gap helps in this aspect also.
I don't know how this is affected with altitudes higher than what you would find at a race track. We do carry a small weather center with us when we go to read air density, temp and humidity so we can have an idea of how to tune the car that day.
I don't know if this will help or even contribute to the conversation just throwing the ole .02 in.
Have a great weekend.
Robert
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Hi all,
Brady, i am Lemurs from Matrix.
Quote:
The test was performed with 100 octane fuel. In a war condition (no ammo, but with guns) aircraft that was reconditioned here in the US.
I have several magazine articles from the 70's that talk about this in depth. However, there is no known records from the flight tests, and I've checked with the Air Force Musuem on the issue.
End.
Actually, I did not know what fuel was used. Thanks for the info on the test... the data at NARA seems to have been lost as i could not find it!
Like i said at Matrix this is just a logic chain that i am working on.
I have a feeling that 'bad quality & control' on late war Japanese engines is more complicated than we know.
I have found some data on Jap engines since i origionally posted and it seems the HA45 was built for 93-94 octane fuel. 100 octane fuel would probably boost you by 2-3mph. Thats it.
Higher octane fuel does not burn as easy so with a lower compression engine you will eventually have a dirty intake and it won't help your performance much. Anything higher than 100 octane would not help at all and would degrade your performance quicker.
HOWEVER, by '44 Japan was using pine nuts, coal, shale, etc to make aviation fuel and i have heard that much of the late war fuel was in the range of 85-87 octane which is just not enough.
That is why Jap pilots at the end of the war reported performance gains using allied fuel.
And i suspect much of the 'bad engines from the factory' was low octane fuel prematurely detonating.
I realize Japan had many troubles building things to spec at the end of the war, this was a project to see what the Ki-84 was capable of as built in Japan when the engine worked.
Michael
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Ring Ring!!....It's time to bring Ki-84? ;)
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Hi all,
As i said in my post on Matrix this is all putting together pieces for me.
One of you said you had a translated flight manual for the Ki-84.
According to the theater interrogation reports all they were able to find on the Ki-84 was the prototype flight manual which was issued to the training unit.
Quite possibly that is what you had.
Do you have any more info?
The reports were that the 1st armed & armoured proto flew at 388mph. The 4th proto flew at 392mph.
That is official.
Then the interrogation teams interviewed
some engineers who said for the pre production version (which saw combat)
they changed the exhaust to individual stacks to give some extra power with their estimate (backed up by every other Japanese plane that used the technique) that it would give 9-10mph extra.
In my book that makes it 401mph armed and armoured. For the production version there are no surviving official papers, so again the engineers were interrogated.
The engineers stated that for the production Ki-84 the cowl was cleaned up and various other minor changes.
Those changes would probably add speed not subtract it.
The speed quoted in every book, game etc has to have a source; some of the early writers sourced the -THINTS others sourced earlier authors.
In my opinion that is a sloppy way to write a book or article.
392mph is only mentioned one(1) time in the official literature, for the 4th prototype. The first writers didn't have anything else to go on so the shrugged and said 392 sounds good. What else could they do?
However, many people if they hear something enough times they will decide it must be true. Sometimes mistakes are made...
There are still British pilots from WW2 that claim shooting down an He113...
do you think they really did?
The 4th proto Ki-84 used an 1800hp engine and that engine was also used in the initial production version.
The majority of Ki-84's were equipped with the 1990hp -21 or -25 engine however.
My guess is that the early production plane could do between 392-400mph with the standard operating fuel.
The model-21 engine planes could probably do between 401-414mph with
their fuel and engine problems.
Ki-84-2:
There was no recovered official papers for this plane. So the interrogaters continued with the engineers who stated semi-quote: The Ki-84-2 being a partly wooden plane was expected to be about 5mph slower than the Ki-84-1
and in pre production armed & armoured flew at 415mph at 20,000ft.
Again, the Ki-84-2 was equipped with the 1990hp engine.
So, with all of these pieces my thought is that with a good engine and 94 octane fuel the Ki-84 could fly 420mph.
408-410 would be a good number to use in a game for the 1990hp version.
I am not trying to step on anyones toes, i am just trying to share my thought process on this.
I have to have something to show for all of my time at NARA! :D
Michael
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Oh, and i agree that the Ki-84 was an excellent plane in most ways better than the P51 or P47 (yikes! that is heresy! burn him!)
but the reason you might fly something else is because the Ki-84 was a dog over 23,000ft.
Useless against B29's. Or their escort fighters at high altitudes.
Much of the saved weight was because of the lack of a real supercharger.
In fact the supercharged version, which never went into production, was a slower aircraft.
Mike
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Originally posted by Michael Johnson
One of you said you had a translated flight manual for the Ki-84.
According to the theater interrogation reports all they were able to find on the Ki-84 was the prototype flight manual which was issued to the training unit.
Quite possibly that is what you had.
Do you have any more info?
Hi Michael,
It's been a long time since I've read it so my memory is vague on it. I don't recall it anything about it being based on a prototype, but that doesn't mean that it wasn't.
I received a bunch of data about 5 years ago when we first started and I thought that was in there, but I'm no longer certain as I can't seem to find it. It's possible that that was something I had when I worked on a previous game and no longer possess it. I believe it came from the Wright Patterson archives, but I'm not sure of that either. I still have some boxes I need to search through and hopefully it will turn up.
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TY ,Michael Johnson , for taking the time to expound hear for us I find this all very interesting.
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Originally posted by Michael Johnson
Oh, and i agree that the Ki-84 was an excellent plane in most ways better than the P51 or P47 (yikes! that is heresy! burn him!)
but the reason you might fly something else is because the Ki-84 was a dog over 23,000ft.
In historic events played in the game, this is always a problem for the Japanese. The blue planes and USAAF planes dominate them at high alt.
But most of Aces High is played in a mixed-plane environment that often becomes a low-alt gladiator pit, and in those situations most of us expect the Frank to dominate.
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Originally posted by Michael Johnson
I have to have something to show for all of my time at NARA! :D
I've been told that NARA should have more than one report on Wright field tests on Ki-84 but no one seems to be able to find them.
PRO has a short report on Seafire vs Ki-84 tested in Clark field and there is also a short technical report on various Japanese planes.
gripen
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Originally posted by Michael Johnson
Oh, and i agree that the Ki-84 was an excellent plane in most ways better than the P51 or P47 (yikes! that is heresy! burn him!)
but the reason you might fly something else is because the Ki-84 was a dog over 23,000ft.
Useless against B29's. Or their escort fighters at high altitudes.
Much of the saved weight was because of the lack of a real supercharger.
In fact the supercharged version, which never went into production, was a slower aircraft.
Mike
Michael, you ever get to the Zoo often ? ;) A bunch of us a couple years ago met up down there for a little tour of the facilities.
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Of course! I live 2 miles away!
lots of fun.
My sister & brother-in-law both were air force officers in Dayton so i made it down to Wright-Patterson all of the time when i was a kid.
Mike
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Aye, I am about 40 minutes from there and will be making a trip down to the Zoo next weekend.
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A few years ago, I sent off to the Smithsoian Institution inquiring about:
Captured German & Japanese Air Technical Documents.
The Smithsoian has a ton of this material, and it can be obtained, by filling out a request for that you can get from them @:
Archives Division, Room 3100
National Air and Space Museum
Smithsonian Institution
Washington DC 20560-0322
Initialy I requested a listing of files they had on various Japanese planes, and I receaved several pages listing referance material for all kinds of Japanese aircraft.
I can not recall specififcaly if I requested data on the Frank, though their are some files they list as having for it:
Real 3744 Frame 134
Title: New Japanese army aircraft Frank 1 and Peggy 1 and miscellaneous developments.
Abstract: Technical descriptions and discussion of the designe characteristiscs of the Army Fighter Frank 1,.....
I did get a ton of referances for the P1Y1, Ki-102, and N1K2, amongst other types.
This packet I sent to Pyro (I photocoppyed the one I received), some years ago, the donw side to this wealth of infermation is that it takes some time to get it, once you fill out the forms it takes 8 weeks to get the material.
The documents in general come from:
" In the finial days of ww2 the advancing allies captured a number of German and Japanese documents on various technical subjects. The United states Army Air Force (later the USAF) had a number of these documents microfilemed by the Air Documents Divishion. Technical Infermation Section (T-2), Air Material Comand, at Wright Field, Ohio (now Wright-Patterson AFB). This microfilm serries containes documents pertaining to aircraft and aeronotical subjects, including aircraft manuales, flight test reports, and engenering studies of aircraft. The Material does not Include compleat sets of drawings for aircraft. Most of the documents are in the original language, while most indexing and tittle pages are in english.*"
* Although in the lists I have prety much all the material seams to be fully translated.
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One page of referances for materials that can be obtained show as an example:
(http://www.myphotodrive.com//uploads/649_Smithsionian ref.1.jpg)
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Another:
(http://www.myphotodrive.com//uploads/649_Smithsonian ref.2.jpg)
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NASM microfilms appear to contain wide variety of documents, not only captured german and japanese documents but stuff like RAE reports and intelligence material like that TAIC report mentioned above. Normally only descriptions of the documents are written in english but there seems to be some translated documents among (like japanese translation of the german wind tunnel test on the P-51 wing).
Quality of the microfilms tend to vary a lot; I ordered some microfilms on Bf 109G some time ago and some of the frames are totally unreadable while some are very clear. The good news is that the documents were not destroyded after filming and USAF gave large part of them back to Germany and Japan in the sixties or seventies. I don't know what happened to the Japanese documents but german stuff was scattered to various archives in Germany (at least Bundes Archive and Deutches Museum).
Documents were microfilmed purely in random order and AFAIK they have not moved file cards to computer database yet, so looking for something specific will be quite time consuming project despite you have copies of the file cards. In my case I co-operated with some other people which helped a lot and reduced costs (one microfilm costs IIRC $25).
gripen
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First off, sorry for posting similar questions in two different threads, just stumbled across this one.
To Pyro: I hope you found that manual! :)
To brady: What do your documents say about the performance of the Ki-84?
To butch2k: What's the difference between the 2nd and 3rd columns?
I could be wrong but the engines seem to be almost the same while the difference in performance is fairly drastic (presuming that 6&9 is a typo for 679 km/h and S.L. (Sea Level?) 584 km/h)
Time to altitude also seems markedly improved if I'm reading it correctly.
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I dont have the actual documents just he referance cards showing the info neaded to order them, howeaver On another thread regarding this topic I posted a Link provided by Wotan refering to the question at hand that provides a lot of evadance suporting the 420mph spead.
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Ya know, you make this a limited plane, AKA, limited to the CT in certain scenarios....I'm sure you'll draw A LOT of people there.....
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Hmm, Cannons and 420mph I think this will have to unperk my hog ;)
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Here is a text copy of the Wright Pat report.
Viewed from the cockpit
The following account of the characteristics of the Hayate was prepared by one of the USAAF test pilots responsible for evaluating a Ki.84-I-ko which had been recovered at Clark Field, Luzon, and transported to Wright Field, Dayton, Ohio, after preliminary testing by a Technical Air Intelligence Unit pilot in situ whose task it was to ready the fighter for the subsequent tactical trials in the USA. The evaluation at Wright Field comprised a total of 11 1/2 flying hours but the test programme was frequently interrupted by failure of exhhaust stacks as a result of the poor materials used in their manufacture coupled with inefficient welding. Problems were also experienced with the hydraulics.
THE COCKPIT of the Hayate was entered from the port wing root walkway and was facilitated by a retractable step and a push-in type handhold at the wing trailing edge, and a second retractable step just below the cockpit sill, these being extremely well located and making for easier access than offered by con-temporary AAF fighters. The stamped metal pilot's seat could be adjusted vertically by means of a handle on the left side, but the locking pin in this particular aircraft did not always engage, with the result that the seat had an annoying tendency to shift under g force changes. The AAF shoulder harness that had been fitted for the test programme was anything but satisfactory, affording no protection for the pilot whatsoever in the event of a crash landing as no stress member had been installed over which the straps could be passed and in the event of an accident involving longitudinal deceleration, the sheet metal seat back would undoubtedly have failed and the pilot would have struck his head on gunsight or instrument panel.
The layout of the cockpit itself was, in general, satisfactory, with the flight and engine instruments logically grouped, the former being arranged on the upper centre portion of the panel with the latter below. The flap and undercarriage controls were situated on the lefthand side of the floor, with the elevator trim wheel and engine control quadrant against the lefthand side wall. No fiight-adjustable aileron or rudder trim tabs were provided, preventing the aircraft being trimmed for hands-off flight. The auxiliary electrical panel and ignition boost control containing circuit breakers were below the instrument panel on the right; the internal and external fuel selector valves and fuel cooler and primer controls were on the righthand side of the floor, and the cowling and oil cooler flap controls were on the upper right cockpit side, together with the radio equipment. The auxiliary hydraulic pump was further aft on the righthand side and the mechanical up-lock release was on the left side of the cockpit floor.
The wobble pump, primer and starter button, all being on the right, kept one hand rather busy in starting, and it soon
became obvious that the Hayate handled rather poorly in taxying owing to inadequate braking action, a condition aggravated by the inefficient design of the rudder bar and toe brake assembly. Use of the brakes was mandatory for "S"ing in order to obtain a measure of forward vision. At the same time, braking had to be strictly limited in order to prevent overheating and locking as a consequence. It proved difficult to get the tailwheel to castor and vision for taxying was certainly not improved by the narrow cockpit and rearward position of the seat, but the actual take-off characteristics were good, with negligible torque effect if rated power was applied gradually. On the other hand, if power was piled on, full right rudder and some braking were necessary to counter the strong pull to port. Three-point take-offs could be safely executed at 95 mph (153 km/h) IAS with normal rated power or above, initial acceleration being normal with either 15 deg flap or no flap at all. At 150 mph (241 km/h) IAS only some four seconds were required for undercarriage retraction, this process producing no loss in altitude or sinking feeling and negligible trim change, and it was immediatcly obvious that initial climb rate wasextremely good, although no performance climbs could beattempted owing to flying time restrictions.
Excellent handling and control
Once the canopy was shut it became apparent that the cockpit left something to be desired from the viewpoint of comfort for a normal-sized pilot owing to the severely restricted head room, and the design of the seat coupled with lack of provision for rudder pedal adjustment would obviously have resulted in some discomfort during extended operations. However, body room was ample and heat level and ventilation volume were found to be good for warm weather operation at low and medium altitudes cold weather operation would have been another story owing to lack of cockpit heat. Despite a some- what narrow canopy, combat vision was excellent in climbing flight when gentle "S"turns were necessary. The cockpit noise level proved to be fairly normal for a radial-engined fighter without an exhaust collector ring, and the vibration level was definitely lower than that of the A6M5 Zero-Sen, especially at high speed, and comparing fairly closely with that of most contemporary US fighters.
It was quickly ascertained that, in general, the handling and control characteristics of the Hayate were superior to those of comparable US fighters and particularly in the low speed regime. The roll rate and turning radius were found to be slightly inferior to those of the A6M5, but control feel was very good; rudder and aileron forces were light, well correlated and produced quick, positive changes of attitude. Elevator forces, although heavier than those of the rudder and ailerons, were not objectionable and progressed with g forces with no apparent lightening. No flat spots or control reversal tendencies were encountered over an IAS range of 74 to 350 mph (119 to 563 km/h). There were little changes in directional trim between 150 and 350 mph (241 and 563 km/h), but the rudder control became extremely sensitive at 300 mph (483 km/h) lAS. sensitivity reducing somewhat at higher speeds.
As previously mentioned, flight adjustable trim was provided for the elevators only and the trim control worked easily, but excessive play at the cockpit end of the device resulted in some difficulties in the initial pre-setting of the tab, although very little trim change was necessary throughout the level flight speed of the aircraft. Only slight longitudinal trim changes occurred with opcration of the undcrcarriage and flaps. The lack of in-flight trimming for the ailerons or rudder did not seem serious, although a rudder trimmer would undoubtedly have improved the Hayate's capabilities as a gun platform. As flown, the Hayate had been rigged with too much right rudder trim and the attendant starboard wing heaviness proved something of a handicap in evaluating stall and handling characteristics accu- rately. However, the stability of the aircraft appeared to be very satisfactory. Yaw tests indicated some lateral oscillation, although not of a serious nature.
The stalling characteristics of the Hayate proved to be quite normal and stall warning occurred early enough to prevent a stall developing if recovery procedure was initiated promptly. In clean condition with power off at 8,000 ft (2440 m) the stall warning consisted of shudder and elevator buffet at 108 mph (174 km/h) IAS. The actual stall, which came at 102 mph ( 164 km/h), proved clean and the Hayate was stable with little tendency to drop off on a wing. and the ailerons and rudder remaining effective well below stalling speed. With the wheels and flaps down and the oil cooler shutters open, but the cowl flaps and canopy closed, the stall warning--occasionally accompanied by severe canopy buffet came at 92 mph ( 148 km/h) IAS and the actual stall occurred at 90 mph (145 km/h) with the nose dropping straight through. Again, there was no indication of instability.
With power on, undercarriage down and full flap, the Hayate did not stall. The rudder became inadequate below 81 mph(130 km/h) IAS and at this speed heading could be maintained
by use of full right rudder and right aileron. The ailerons became inadequate for maintaining altitude below 74 mph (119 km/h). the Hayate yawing left at this speed and then rolling with any further decrease in speed, but control was readily recovered by an increase in airspeed and a slight decrease in power.
Manoeuvrability was good; rolls, loops, Immelmanns and turns being executed with ease at normal speed, although well
co-ordinated manoeuvres proved somewhat difficult owing to the lack of in-flight aileron and rudder trimming. Handling on the approach and during landing was very good, with no undesirable characteristics or ground looping tendencies manifesting themselves, and vision, too, was good during the approach, although less than adequate after the flare was made. After extension of the undercarriage below 160 mph (257 km/h)and the application offull flap at 130 mph (209 kmh), a three-point landing could be satisfactorily executed (with elevator trim set for zero stick force) using speeds of 120 mph ( 193 km/h) over the fence and 110 mph (177 km/h) just off the runway, the actual touch-down being made at 92 mph ( 148 km/h). The Hayate landed easily. with all oleos soft, and was stable during the landing run which was pleasantly short. Crosswind landings could be made comfortably, but the brakes were relatively poor, although rather better than those encountered on the Ki.43-II Hayabusa.
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Continued.
General functioning
The Japanese instruments functioned well and appeared reliable with one or two noteworthy exceptions. The gyro turn indicator appeared to be binding inasmuch as only one-third needle width right or left was the maximum indication obtainable under any attitude or rate of turn; the caging knob was missing (or had been omitted) from the artificial horizon, making it impossible to cage the instrument for aerobatics or to erect the gyro after it had been upset--no gyro erection tendency was apparent in five minutes of level flight after up-setting, and the left fuel gauge consistently read lower than the right hand gauge although the fuel tanks theoretically fed evenly. Control friction was nominal on the ground, with no binding or roughness present, but interference between the auto mixture control and the stick became evident when an attempt was made to apply full left aileron when the mixture control was set normal.
The operation of the Nakajima Ha-45 18-cylinder radial was generally satisfactory throughout the series of flight tests, but while easy to start cold proved somewhat difficult when hot, the externally energized starter apparently having an insufficient torque rating. The engine ran somewhat roughly between 1,400 and 1,600 rpm and between 1,900 and 2,100 rpm, but the engine controls were smooth in operation with positive response. The engine control quadrant friction locks were unreliable, however, and rarely held the controls in fixed position, the auto mixture and supercharger controls creeping and the propeller control tending to vibrate at low rpm positions. Operation of the four-bladed electrically-controlled constant speed Pe-32 propeller was good, although it displayed a tendency to overspeed excessively unless extreme care was taken when power was being applied after a prolonged dive.
The hydraulic system usually worked smoothly but some difficulty was experienced with the hydraulically-operated undercarriage. On one flight, the mainwheels retracted only partway and on another retraction was completed but the up-locks would not engage. On both occasions repeating the cycle of operations appeared to clear the trouble. Prior to the delivery of this particular Hayate to Wright Field, the hydraulic pump had failed completely on one flight with the result that the wheels crept down. The auxiliary hand pump, which was connected to the reserve portion of the main hydraulic tank, worked well and its capacity was such that approximately 100 strokes were required to retract or extend the flaps, but its efficacy in so far as the undercarriage was concerned was not checked. In the event of a complete hydraulic fluid failure, the undercarriage could be unlocked manually and allowed to fall into place, the process being aided by yawing the aircraft until the indicator lights showed that the down-locks had engaged. One poor feature of the hydraulic system was the need to open and shut the by-pass. This had to be opened below 1,200 rpm to prevent the pump from overheating. The electrical system functioned well, with the exception of one instance of generator failure prior to take-off, but the location of the generator switch in the baggage compartment (which could not be reached by the pilot) was poor.
It was concluded from the test programme carried out at Wright Field that Hayate was essentially a good fighter which compared favourably with the P-sIH Mustang and the P-47N Thunderbolt. It could out-climb and out-mananuvre both USAAF fighters, turning inside them with ease, but both P-51H and P-47N enjoyed higher diving speeds and marginally higher top speeds. The light power loading and control forces of the Japanese fighter were to be admired, but it was not so well constructed as its US contemporaries, perhaps reflecting the slipping Japanese production standards at that stage of the war; it was obviously incapable of standing up so well as US fighters under continual usage and it was more demanding on maintenance. It revealed little effort on the part of its manufacturer to render its pilot's task easier or safer--it lacked fire extinguishers and means of emergency escape--but it was a sturdy little warplane and a very dangerous antagonist in fighter-versus-fighter high-g mananuvring combat when flown by a reasonably experienced pilot. **Test info and data received from magazine AIR NTERNATIONAL, VOLUME 10, NUMBER 1, JANUARY 1976
Here is a performance report that I hae labeled as being from Wright Pat although I have no proof that it is.
(http://home.comcast.net/~markw4/wright.gif)
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F4UDOA,
That performance data looks like it is the Japanese data from the first prototype.
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Great work F4UDOA.
I was thinking the same thing though, top speed in the last doc is shown as 388mph for the Hayate while the previous document states:
"....but both P-51H and P-47N enjoyed higher diving speeds and marginally higher top speeds."
What's marginally higher in this case?