ki84 speed????

[Mitsu]

Hmmmm, I just thought if HTC keeps current AH Ki-84-Ia, and if they model 1945 Ki-84-Ib with HA-45-21 engine and 20mm*4 cannons and max speed 660km/h.....

[Shamus]

Not being a student of WW2 aircraft performance I can't really comment on the KI84's capabilities per that period, only on game play.

I find it a cute fun little plane kinda like a high performance Zeke.

Its high speed handling is quite poor, makes a 109G2 seem like a pony

I never flew any of the other sim's, but everyone was talking about what a monster it was and the possibility that it should be perked in here..somewhat comical really.

shamus

[busa]

It was too long although I wrote the text which contributes to this BBS.

http://homepage2.nifty.com/amraam/ah/tmp/bbs002.txt

The performance table of Homare is exhibited.

http://homepage2.nifty.com/amraam/ah/tmp/bbs002.zip

The control force of the elevator of Ki84 adds a heavy reason.
It is the same as the teachings which the pilot of P51 says.
When it controls like Aerobatic plane, it is for losing energy.
And it is based on experience obtained from employment of Ki33 and Ki44.
The elevator whose response is too good caused disintegration in mid-air.
Moreover, the elevator of Ki44 was past effectiveness to wing load.
For this reason, the pilot pulled the stick too much at the time of landing, and accidents occurred frequently.
It was thought by employment of Ki44 that a combat flap was unnecessary.
The switch of a combat flap was not attached in the stick in Ki84.

It was difficult for Ki84 after landing for a tail gear to make it ground.
The character was the same before grounding.
It was difficult to even ground three landing gears simultaneously.
Although there were many pilots who have a negative idea in the character of Ki84, IJAAF did not change Ki84.
(Probably, as for such a pilot, Ki100 should be given. It was estimated that Ki100 could be fought on a par with three sets of Ki84.)
The rightness of the plan was accepted in the air combat in the China continent.
And it turns out that the character follows difficulty on air combat with U.S. navy airplanes.

I have almost no time to fly, since it is fighting with English now.
However, it is thought that Ki84 in AH has the pitch characteristic which excelled for combat at high speed.

Thank you.

[oboe]

Thank you busa, for all your effort to uncover the facts of Ki.84 performance.

Some suprising findings in your linked document regarding Japanese performance testing of the Ki.84 against  various American aircraft.

 Notably:
=============================================
   . P-40 initial acceleration better than Ki.84
   . Speed of Ki.84 and P-51 almost the same (wonder which P-      51?  China had Allison-equipped P-51As in I'm not mistaken)
   . Ki.84 dive is superior to P-51
   . F6F is better than Ki.84 in speed, climb and acceleration.
==========================================

These findings, it seems to me, conflict with one another.  For example, I don't know why Ki.84 would outclimb P-40 but not out-accelerate it.

Also, P-51 should be superior in speed to F6F, but findings indicated the Ki.84 and P-51 were roughly the same in speed but inferior to the F6F.

[F4UDOA]

Here is some of the Wright Pat test results.

 

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.

[Shane]

the f6f is undermodeled.

[F4UDOA]

Continued

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.
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 INTERNATIONAL, VOLUME 10, NUMBER 1, JANUARY 1976

[Mitsu]

Originally posted by busa
As compared with more heavily built with the same engine, the@small propeller has not offered the outstanding climbing performance.

By the way, I think this is right but wrong in a way. First off, The Gross weight of N1K2-J is 3800kg, Ki-84-Ia is 3600kg. The Ki-84-Ia is lighter. The propeller diameter is, N1K2-J 3.30m, Ki-84-Ia 3.00m. 30cm shorter than N1K2-J's one. But Ki-84  engineer chose shorter prop for reducing weight.

Also it's not an apt comparison though, The La-5FN has an outstanding climb performance with small propeller (3.00m/3-blade, it seems an inefficient prop on the surface). Although It's 300kg lighter than Ki-84 and it has the same power engine (1850hp).

Turn back to N1K2-J and Ki-84-Ia, The propeller efficiency is offset by weight and engine power. The important thing is choosing appropriate propeller to each aircraft. The Nakajima engineer did it, otherwise the climb performance of Frank would have been decreased in Army test, even in USA's test.

[Kweassa]

Wow, Busa... the combat trials quoted in the first link is quite shocking. It matches none of our previous concepts of what the Ki-84-Ia should be like.

 What it DOES match however, is the often recited fact(or myth?) that the production Ki-84s were frequently plagued by engine malfunctions and could never achieve its full potential under ideal conditions - hence the derated engines.

 I'm not sure what the source is, but I seem to recall pilot comments that goes, "even the Hayabusa is better than this!",  or ,  "never ride a Ki-84 assembled in '45. They will fall apart during flight".

 Now, this presents an interesting comparison with the La-5FN. The La-5FN we see in most combat sim games. The Soviet quality of aircraft construction has seen a steady increase in its quality by 1944, but before that many planes were known to be prone to malfunction or not reaching full potential, and there are numerous accounts of La-5FNs with much lower performance than expected(such as the Rechlin tests, or other quotes on limited WEP, lower max speed/deck speed, ventilation problems and etc etc..) So IIRC, it seems that there was never really a "standard set" of La-5FNs in the first place, at least not until 1944. The typical "La-5FN" one would epxect of late 1943, would be a mixed-up, jumbled version of upgraded La-5s and -5Fs that were as much plagued with numerous quality problems, and showing much lower performance numbers than the one depicted in AH.

 IIRC, the "perfect", "ideal" La-5FN with full 10 minute emergency power and the currently listed speed, would not be seen until the La-7 came out - hence, the "La-5FN" we see may not be considered "typical" of La-5FNs but rather, more likely one of the last batch of La-5FNs.

 What interests me is, if my view on this is correct, the chosen representation of the aircraft in the case of the La-5FN, is an ideal version without any quality problems, because the Soviets never went through the trouble of derating anything and hardly made any kind of such documents, whereas the chosen representation of the Ki-84, is a derated model(no WEP) with limited engine performance, because the Japanese had documented such facts.

 In that sense, if the Ki-84 we see would be a "typical" Ki-84 in real life, then by that methodology a lot of planes in AH2 would also have to be "derated" if any such documents turn up. For instance our AH Spit5 with +16 boost would definately not be a typical 1941 version, (and if I understood Wotan correctly in past discussions) and the Bf109F-4 and G-2 and such, would also have to be derated to its "typical conditions".

  What do you guys think?

[Karnak]

I didn't think the +16 Boost Spit V was a good idea when it was first done.  I didn't know about the Bf109F-4 and Bf109G-2 until I read Wotan's post about it.

What I would rather see is HTC simply reuse their art assets and give us more versions.  Give us a Spitfire Mk Vb ('41) and a Spitfire Mk Vb ('42).  Do the same with the Bf109F-4 and Bf109G-2.  Take the 3D model of the Spitfire F.Mk IX and reuse it for a Spitfire LF.Mk IX, take the Bf109G-6 and use it for a Bf109G-14 model as well.  Keep the originals, but copy the artwork over with a new name and new flight model.

Do this whereever they can get the data.  More models means that there are more options in the MA and a lot better scenario and CT capabilities.


As to the Ki-84's reports, it is odd that Busa's Japanese report says the P-51 out turns the Ki-84 easily and the US test F4UDOA posted says the Ki-84 out turns the P-51H easily.  Its like they're in an argument and saying the other guy's toy is better.  Kinda like people arguing about a CT setup and who has the advantage.

[busa]

Thank you for exact informations, F4UDOA .

We have a report of TAIC and others only for a few.
I want to know.
Is there any way we receive  report of other Japanese planes?

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

I say about the reason for having exhibited Combat evaluation.

These are the impressions in Air combat which carried out engagement from the state which is not fixed.
The information for guessing the maximum performance of Ki84 and other airplanes may be included in these texts.
But it is not necessarily truth.
Probably, this information should not be quoted as it is especially about speed.
It is not thought that it had been flying at the maximum speed like AH.
Of course, F6F cannot be faster than P51.
And, of course, the turn performance of Ki84 is better than P51

I think it important what tactics both sides took.
And I think it important why such a result was reported.
I think that you will understand Ki84 more by investigating and guessing it.
And probably I think that the report brought about by this IJAAF is an unexpected result for many people.


The addition about Homare.

The engine indicated by documents was the same performance as Hmare12.
took the place of around February, 1944.
That is, all of mass-produced henceforth at the February, 1944 time were the same performances as Homare12.

differs from in a performance.
But the employment with these two same engine was applied.
However, it is unknown whether similarly it treated by IJAAF.
Since IJAAF did not plan to have adopted , it does not have data.

To Mitus

It is the following which I tried to say. .
The climb performance of Ki84 is not better than N1K2-J.
As for the climb performance of Ki84, it is good whether it is smaller than C6N (noDT).
(This is based on company data of Nakajima) .
It is clear that the cause's it is in a small propeller.


Thank you.

[Kaz]

F4UDOA thank you for posting the test.
Is there any data to go along with the test such as giving the weights of each aircraft(Ki-84-I-KO, P-51H, P-47N), fuel loadouts, MP/RPM settings etc.?
I think that would give more credit to the report.

[Muddie]

Did you check the plugs?




QUOTE]Originally posted by Pyro
Crap, found the problem.  It's not making full power.  Argh. [/QUOTE]

[humble]

This is the part that I find baffling....

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


According to this the P-47N/P-51H just marginally faster????

[F4UDOA]

Busa,

I have the A6M2 and A6M5 reports in full. I will post them, they are excellent reads.

I also have a small .JPG that list the performance of the Wright Pat test although I am not sure of it's origin or validity.

I will post shortly.