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General Forums => Aircraft and Vehicles => Topic started by: brady on February 16, 2003, 12:36:31 PM

Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 12:36:31 PM: The following is the report of a Zero 21 flown aganst an F4F-4 in the states, the Zero was recovered from Akutan Island in the Alutions and then repaired and sent to to San Diego whear the tests were conducted in Augast of 1942.

p.27 Zero Fighter by Robert C. Mikesh

" The Zero was supiour to the F4F-4 in speed and climb at all altitudes above 1,000 ft, and was superior in service ceiling and range. Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed. In a dive, the two planes were equil with the exception that the Zeros engine cut out in in pushovers. There was no comparison between the turning circles of the two aircraft due to the relative wing loadings and resultant low staling speed of the Zero. In view of the foregoing, the F4F-4 type in combat with the Zero was basicaly dependent on mutual support, internal protection, and pull-outs or turns at high speeds where minimum radius is limited by structural or physiological effects of acceleration (assuming that the allowable acceleration on the F4F is greater than that of the Zero.) Howeaver, advantage should be taken where possible, of the superiority of the F4F in pushovers and rolls a high spped, or any combination of the two."
Title: F4F-4 vs Zero 21
Post by: F4UDOA on February 16, 2003, 01:08:02 PM: I have a copy of the original report if you are interested.

Although I must say that the results of these test have very little bearing on head to head results of A/C in AH.

Not because of any great flaw in AH. More the result of what happens when misconception is put aside and actual test are performed with two A/C in a side by side comparison. In other words the manufactures don't always tell the real story.

Many on these boards put these kind of test in a propaganda catagory and discount the results. I think they are the BEST indication of the actual performance of these A/C.
Title: F4F-4 vs Zero 21
Post by: thrila on February 16, 2003, 01:18:31 PM: Quote
Zeros engine cut out in in pushovers

Sorta like the spit I and hurri I?

Didn't know the zero had problems like that.
Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 01:45:13 PM: Thrila, I have had this book for years but was looking through it this am again, and was very interested in this myself.

Another thing I found very interesting is that in the test the Wildcat was:

"There was no comparison between the turning circles of the two aircraft"

In AH they are quiet close imo.

Howeaver later in the book a pasage describes the FM-2 and the Zero 52, and the two are much closer in turn radious, in fact the heaver later model Zero gains only one turn in 8 over the Wildcat.

I realy wanted a more detailed account of the P40 vs the Zero but unfortunatly the P40F they had on hand was not able to do the test do to the fact that they could not get it to preform reliably enough to do the test. While the Zero preformed withought flaw all through the flight testing, which included matchup's aganst the P51, Coursare, P38,and p39.
Title: F4F-4 vs Zero 21
Post by: Innominate on February 16, 2003, 01:51:31 PM: Quote
Originally posted by brady
T
"There was no comparison between the turning circles of the two aircraft"

In AH they are quiet close imo.

Between the f4f or fm2 and either zero, there is absolutly no competition in turning ability. The zero can get inside the f4f with virtually no effort needed.

Anyone know what model zero this was?
Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 01:54:54 PM: F4UDOA: Somthing you might find interesting( i agree by the way):

"The mere gartering of flight data figures to be compared with similar data of another aircraft is often incocnclusive since flight conditions are not always the same. A true test was to have both aircraft pitted together under the same set of circumstances."
Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 01:56:59 PM: Zero 21, as stated above.

I have quiet a lot of time in the A6M5, just since tour 30, I have around 369 kills in it, tours older than that I have had 300 or so kills in it in some tours, having said that, I realy must say that I find it handels pret close to the wildcat tunrning wise, their is no Big turning advantage, unless i use flaps, which on ocahsion i do aganst wildcats.

The A6M2, I have only some 39 kills in the A6M2 in the same time frame, some 6 or 8 of which are ostys, I must say howeaver that in the time I did spend in it that I was Very suprised to find that it did not easly out turn a wildcat, not at least to the extent that the above statement indicates it would.

My F4F-4 time is considerably lower howeaver, yet what time i did spend in them was with the knowledge that if flow right I could turn fight Zero's, somthing that the above statement would sugest was not posable.
Title: F4F-4 vs Zero 21
Post by: Soulyss on February 16, 2003, 02:39:52 PM: I was a little surprised at the wildcats turning ablility. But I'd still have to put the solid advantage in turning to the Zero. Early in the fight the wildcat can hold it's own but as the fight progresses and speeds drop lower and lower the zero just keeps on turning and turning. And pretty soon the zero ends up behind the wildcat. Whether the difference is pronounced as it "should be" I have no idea. :)
Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 03:08:30 PM: Well, I think it realy boils down to what plane you are talking abot, the A6M5 and the FM-2 behave prety much as i expected, and prety much as the book sugest's(and other books I have do), it is when you lok at the A6M2 and the F4F-4 that the turning issue ariese.
Title: F4F-4 vs Zero 21
Post by: Innominate on February 16, 2003, 04:07:36 PM: Quote
Originally posted by brady
it is when you lok at the A6M2 and the F4F-4 that the turning issue ariese.

I still dont understand what you're talking about...
The only thing that can compete with the a6m2 in a turn is the val.
Title: F4F-4 vs Zero 21
Post by: Hooligan on February 16, 2003, 04:21:15 PM: This thread is illustrating why opinions are so useless when comparing flight data.

Quote

There was no comparison between the turning circles of the two aircraft ..

In Brady's OPINION, this statement does not match the AH FMs at all.

IN Innominate's OPINION, this statement does match AH very well.

The statement itself is only opinion, and obviously an erroneous one at that. First of all it is not concrete. It does not say (for example). At stall speed the Zero 21 could turn 360 degrees in a circle of radius X while the F4F-4 only turns 240 degrees at a radius of 1.25X. Secondly the phrase "there was no comparison..." is dramatic and virtually content free. Of course there are meaningful comparisons that could be made. The best turn rates and best turn radiuses and turning data at a variety of set speeds could all be provided. If the report actually provided the comparitive data rather than saying it didn't exist, you could check the FMs against concrete numbers and have something meaningful to talk about.

Hooligan
Title: F4F-4 vs Zero 21
Post by: Frogm4n on February 16, 2003, 04:41:40 PM: killing zeros is easy, just make sure you have alt on them, and if you dont make it dive. that pos will compress and lose all turning ability.
Title: F4F-4 vs Zero 21
Post by: Soulyss on February 16, 2003, 04:55:33 PM: Well put Mr. Hooligan. :)
Title: F4F-4 vs Zero 21
Post by: brady on February 16, 2003, 06:37:49 PM: Well I had intended to conduct a pissing match( i have a big blader ya know:) ) to determine the winner, but Hoiligan is totaly right. I gues it is a starting point howeaver to conduct a more in depth studdy, clearly imo....the Wildcat turns to good(F4F-4, or the Zero dosent(A6M2), Proving when and why howeaver is another mater interly.
Title: F4F-4 vs Zero 21
Post by: Karnak on February 17, 2003, 02:11:32 AM: In the test of the A6M5b vs. the FM2 that I participated in, the conclusion was that the A6M5b dominated the FM2. If the A6M5b has the alt, all the FM2 can do is dive away and run because the A6M5b will never lose the E advantage and can simply BnZ the FM2, the FM2 will lose E on each break turn and will soon be helpless.

My experience of the A6M2 vs the F4F-4 is that the F4F-4 turns well enough that the A6M2 can never bring his cannon to bear on the F4F-4 and actually be able to see the F4F-4 at the same time. The muzzle velocity on those Type 99 Model 1s sucks. An A6M3 with Type 99 Model 2s would be vastly more leathal to the F4F-4, and more appropriate for most scenarios.

Thrila,

Only the very early A6M2s suffered from the negative G cut out. The vast majority were fuel injected from what I've read.
Title: F4F-4 vs Zero 21
Post by: GRUNHERZ on February 17, 2003, 02:19:40 AM: "The Zero was supiour to the F4F-4 in speed and climb at all altitudes above 1,000 ft"

The AH Zero 21 is in no way faster than the AH F4F4 at all alts over 1000ft... In fact is is much slower for most of the low alt area - while that test clearly states it was faster at over 1000ft or at least equal in speed at sea level.
Title: F4F-4 vs Zero 21
Post by: Angus on February 17, 2003, 06:05:08 AM: IMHO the F4F is perhaps a wee bit overmodelled, and in such a way it does not compare to the Zeke in the same way as it did in Real Life. FM-2 should be nimbler and faster than the F4F by a significant bit, but is it?
BTW, the Zero is also overmodelled regarding diving speed and high-speed roll rates.
The Hurricane is good vs the Zero, not a lot of difference in turning there ;)
Title: F4F-4 vs Zero 21
Post by: F4UDOA on February 17, 2003, 10:12:20 AM: I should have posted this damn report at the beggining of this thread.

The A6M2 Speeds in AH are perfect as well as the climb speed are DOB.

The F4F-4 may be a bit overmodled as far as speed but it is certainly in the ballpark.

Here is the full report. Thank me later.

A6M2 test December 1942 (http://mywebpages.comcast.net/markw4/A6M2test.pdf)

Notice this.

1. The A6M2 outclimbs the P-38F up to 18,200FT.

2. Look at the climb of the early F4U-1 (No water injection) and tell me if it is modeled correctly in AH. At Mil power it should out climb the A6M2 up to 5,000FT almost equal to 19,000ft and superior above. I don't think so.
Title: F4F-4 vs Zero 21
Post by: brady on February 17, 2003, 12:15:21 PM: TY for posting that link so that all might be able to see it, the meat of that report is listed in full in the above mentioned book, and the pasage on the Wildact vs the Zero is the same verbatium as the one i listed above.

"The AH Zero 21 is in no way faster than the AH F4F4 at all alts over 1000ft"

"IMHO the F4F is perhaps a wee bit overmodelled, and in such a way it does not compare to the Zeke in the same way as it did in Real Life"

Ok, Grunherz, Karnak, and Angus: How do we prove this to such a degree that we can effect change>?

Clearly as F4UDOA has stated the wildcat is a :

"The F4F-4 may be a bit overmodled as far as speed but it is certainly in the ballpark. "

Now what are we missing, is their a wingloading issue hear that is effecting the F4F-4's turning abaility some numbers we can toss out their to prove our oppenion, are the spead/preformance numbers off enough to have fixed?
Title: F4F-4 vs Zero 21
Post by: HoHun on February 17, 2003, 01:32:41 PM: Hi Karnak,

>Only the very early A6M2s suffered from the negative G cut out. The vast majority were fuel injected from what I've read.

Considering how important this point was tactically, I'm surprised so little information can be found on it for most aircraft (including the Zero). Do you have any further information, or the book containing the information? I was wondering about the A6M's later versions, too.

Regards,

Henning (HoHun)
Title: F4F-4 vs Zero 21
Post by: Shuckins on February 17, 2003, 05:19:20 PM: The faster the Zero flew, the more it yielded its ability to turn on a dime, as well as its ability to roll around a point. The higher diving speeds attainable by the later model Zeros was virtually useless against U.S. aircraft because at speeds above 350mph the Zeros rudder and ailerons felt as if they were set in concrete. Any attempt to dive away from a Hellcat or Corsair was tantamount to suicide.

Against the F4F-4, the Zero managed to attain a matching diving speed, but a Wildcat pilot could lose it straight-away by doing a high-speed aileron roll while in the dive.

Shuckins
Title: F4F-4 vs Zero 21
Post by: Puke on February 17, 2003, 07:20:17 PM: My biggest gripe is my perception of the structural integrity of the A6M2. Just about every account I have read about the aircraft was that it really only took a few rounds in her to start her burning. She seems much more durable in AH...maybe a gameplay concession. I'm curious about the A6M2's roll rates too and will have to look into that in the linked document when I get the chance because the A6M2 and A6M5 should have a very noticeable difference in their roll rates.

Most Wildcat pilots that transitioned from the F4F-3 to the F4F-4 weren't very happy. The F4F-4 was the first model with the folding wings and had extra armor added and two additional guns which increased the weight w/out any increase in HP and thus was actually less maneuverable. But the F4F-4 began replacing units by the time of the Battle Of Midway and is probably the right choice in variant, though I prefer the Coral Sea's F4F-3s.
Title: F4F-4 vs Zero 21
Post by: Karnak on February 17, 2003, 11:53:30 PM: A6Ms underlying stucture was strong and sound. There simply wasn't any armor or self sealing fuel tanks. That's why it was vulnerable.
Title: F4F-4 vs Zero 21
Post by: Innominate on February 18, 2003, 12:00:06 AM: Quote
Originally posted by Puke
My biggest gripe is my perception of the structural integrity of the A6M2. Just about every account I have read about the aircraft was that it really only took a few rounds in her to start her burning.

Well, I can say with certainty that the a6m2 is one of the most durable fighters we have. (I've tested the amount of damage various fighters can take)

The a6m2 took more damage before breaking than the p47d30, typhoon, n1k2, f6f(and many others). The only catch is that it DOES burn extremly easily, and for quite a long time.
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 01:49:22 AM: My experance is that it burns more than any other fighter.Long is kinda subjective, i rarely have time to get it down, in fact I think I may ditched it like once ever,the A6M2 that is, I have managed to get the A6M5 down a few time's but I have a lot if time in that plane.

That damage assement kinda made me raise a couple eybrows to, in fact I think one is stuck....

Realy most of this is all just kinda BS, a lot of "impreshiuons", "openions". Hard data would be nice to see, I know that these are whear we all start though, to get curious enough to actualy get the data to effect change.

One pet peave of mine which is just presently "oppinion" is the hitting power of the Type 99MK I, which seams much less than that of the Type 99 MK II, these guns fired the same prodjectile, the ammo chains were 4/5th's HEI, the 5th round being APT, since most of the effect from these weapons is from the chemical component of the point impact rounds I am woundering if these is indead the case, I nead to get with a Squadie and test this out. Of course the hitting potential is substantialy less with the Type 99 MK I compared to the MK II, so this may realy be whats going on.
Title: F4F-4 vs Zero 21
Post by: Mitsu on February 18, 2003, 03:41:01 AM: Quote
Originally posted by thrila
Sorta like the spit I and hurri I?

Didn't know the zero had problems like that.

Nope, actually ZEKEs didn't have that problem.
I heard this thing was also discussed in WB2xx (ZEKEs had engine cut issue), and it has been fixed.
Title: F4f-3 and -4 were innovations
Post by: joeblogs on February 18, 2003, 10:13:38 AM: This was the first fighter to have an engine with a two stage supercharger, which gave an under-powered plane tolerable performance at altitude. Without this feature, we would look upon this plane as we do the early models of the P-40.

-Blogs

Quote
Originally posted by Puke
My biggest gripe is my perception of the structural integrity of the A6M2. Just about every account I have read about the aircraft was that it really only took a few rounds in her to start her burning. She seems much more durable in AH...maybe a gameplay concession. I'm curious about the A6M2's roll rates too and will have to look into that in the linked document when I get the chance because the A6M2 and A6M5 should have a very noticeable difference in their roll rates.

Most Wildcat pilots that transitioned from the F4F-3 to the F4F-4 weren't very happy. The F4F-4 was the first model with the folding wings and had extra armor added and two additional guns which increased the weight w/out any increase in HP and thus was actually less maneuverable. But the F4F-4 began replacing units by the time of the Battle Of Midway and is probably the right choice in variant, though I prefer the Coral Sea's F4F-3s.
Title: F4F-4 vs Zero 21
Post by: Puke on February 18, 2003, 11:01:36 AM: My interests lay with the Pacific War much more than the European war and though you'll never find any graph showing the susceptibility to fire for the Zeke, the many readings I've completed all make great point about this. In fact, I just finished "The First Hellcat Ace" last night and he always makes point about how the Zekes he shoots catch fire and explode very easily (with very little rounds, he becomes known as "One-shot McWhorter".) When he's back in the fray over Japan in 1945, he's then surpised that they take a few more bullets and states he learns they now have the self-sealing fuel tanks. I too think the Wildcat and Zeke are maybe too similar in terms of manueverability in AH (with the edge going to the Zeke still), but I also think they are too similar in durability. I think it's Joe Foss who states it isn't if you'll be hit in the Wildcat, but only a matter of when...and this is the one factor the Wildcat should markedly have over the Zeke which is not apparent to me in this game.

Heck, the pilots didn't even want the extra two guns on the F4F-4 and were happy with the four-gun arrangement on the F4F-3, that's all that was needed, just a few bullets to make them early Zekes pop.
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 12:22:44 PM: If have a lot of time in Zero's and my experance with wildcats is more of from the prespective of having them in my sights than the other way round. But I will say this about the wildcat.

It is very tough, it asorbs Type 99MK I cannon ammo like a freaking spunge, if you dont focuse your fire it is capable of taking the whole ammo load from an A6M2. Granted if you can focuse your fire on a weak spot like the tail or cockpit it takes only 10 to 20% of your ammo(20mm) to effect enough damage to make that part fail, now this is for a round that is suposed to be 99% as destructive as the Hispano 20mm, that is a lot of damage asorbation.
Title: F4F-4 vs Zero 21
Post by: HoHun on February 18, 2003, 02:41:02 PM: Hi Mitsu,

>Nope, actually ZEKEs didn't have that problem.

Do you have any source for that? The A6M2 (serial number 4593) flown by Tadayoshi Koga, recovered and test-flown by the Americans after its crash on Akutan, seems to have displayed negative G cut-outs, and though some minor changes were necessary to make the A6M airworthy again, it looks like the carburettor still was original.

Regards,

Henning (HoHun)
Title: F4F-4 vs Zero 21
Post by: Widewing on February 18, 2003, 04:27:16 PM: Quote
Originally posted by Innominate
Between the f4f or fm2 and either zero, there is absolutly no competition in turning ability. The zero can get inside the f4f with virtually no effort needed.

Anyone know what model zero this was?

Zeke 21 is the A6M2.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: Squire on February 18, 2003, 04:33:13 PM: The A6M2 out climbs and out turns the F4F-4 in Aces High. Hard data on both a/c was already shown after extensive tests in AH, and the data posted on the "Midway" forum. Have a read:

http://www.badz.pwp.blueyonder.co.uk/Files/pdf/Midway.pdf

Read the A6M2 vs F4F concusion at the very end of the doc. That imho is the final word on the matter, unless somebody wants to do better research.
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 05:48:48 PM: That document is in conflect with that which is stated in the flight test results.

Not that the testing that was done was bad, it does prove that the Wildcat in AH is faster than it apears that it should be. and that it preforms better than it should up to 5000 feat.
Title: F4F-4 vs Zero 21
Post by: Squire on February 18, 2003, 07:12:57 PM: Fact remains the F4F is out turned and out climbed by the A6M2 at any alt.

Have a look at this file for speeds, it shows 284mph at sea level for the F4F-4 (FM-1):

http://www.214th.com/ww2/usa/f4f/f4f.pdf

For info, my understanding is the A6M2 did not suffer any neg-g problems, this keeps coming up as a debating point too. Warbirds modelled its A6M2 with the neg-g cut, and then after Pyro did some more historical digging, removed that feature in the next update, so it didnt. Thats all I recall off hand.
Title: F4F-4 vs Zero 21
Post by: Widewing on February 18, 2003, 08:01:21 PM: There are many factors to consider in comparing the A6M2 to the F4F-4. Certainly performance must be measured at various altitudes. Moreover there is no lack of data on each type. Nonetheless, everything can be boiled down to simple facts. The A6M2 held a considerable advantage in wing loading. It had a comparable power loading. Bottom line: Advantage Zero.

Naturally, that is not the whole story. Such factors as durability, battle damage resistance and fire power count as well. In these three areas the Zero lagged far behind. Yes, it carried two 20mm cannon. But these were not especially effective except at close range. Supplementing the cannon were a pair of 7.7mm rifle caliber machine guns. On the other side the Wildcat brought six .50 caliber machine guns to the party. In an effort to keep weight to a minimum, the Zero lacked the weight of structure built into the tank-like F4F-4 (a Wildcat weighed more than twice what a Zero did, and was of smaller exterior dimensions). Wing skins were of very light gauge aluminum, and easily wrinkled under the aerodynamic loads of the higher speeds associated with air combat in WWII. Zeros also lacked self-sealing fuel tanks and anything vaguely resembling armor plate. Ultimately, the Zero proved to be a rather frail aircraft, prone to major airframe failures due to relatively minor battle damage. They also proved to be highly flammable, with a single bullet hole in the fuel tanks being enough to turn it into a flying pyrotechnic display. On the other hand, the Wildcat proved durable beyond belief. There was no dive speed redline imposed, simply because it could achieve terminal velocity without over-stressing the airframe. Indeed, the F4F was able to survive loading in excess of 12 g without structural failure. Zeros tended to come apart under just half of that loading. Early Zeros where saddled with a speed redline barely above 400 mph. Wildcats could push past 500 mph without concern.

In AH, there are several aspects to the modeling of the Zero that do not conform to the known facts. Its survivability is vastly better than reality. When set on fire, the aircraft is unaffected and the pilot, apparently clothed in multiple layers of NOMEX can continue to fly and shoot until his aircraft finally explodes (as I recently rediscovered). The reality of this is that any fire within the wing (which is integral to the fuselage) will rapidly fill the cockpit with flame and/or smoke. I have seen Zeros absorb multiple hits from 20mm and fly on without apparent damage. Yet, it has been established beyond question that the Zero was among the worst front line fighters in terms of combat durability, being routinely ripped apart by single mount .30 cal guns of dive bombers and torpedo planes. My view of the damage modeling of the Zero in AH can be summed up in a single word - gamey.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 09:41:46 PM: Their are many "gamey" aspects to AH, and most of the damage you were refering to as gammy is ealy assocated with all other aircraft in one way or another, seeing multiple hits of 30mm MK 108 on allied fighters and them being"ok" after word could be described as gammy. I have in my time in AH loged over 1600 kills in the Zero's, i can say withought hesitation that it is the frailest fighter in AH, and that after it starts burning 30 seconds is about all u have till that wing comes of, and it burns easer than any other fighter in AH, even the A6M5 with better fuel tank protection burns quicker than all but perhaps the A6M2.
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 09:56:23 PM: A couple pasages from: Americas Hundred Thousand.

p. 490:

" The peek role rate of the F4F-3 was just under 70 degrees per second at about 250 mph IAS. At 350 mph IAS roll capabality fell off to about 50 degrees per second.
The F4F-4,with lots of added weight, was much less maneuverable, and was called uncomplimentary names by it's piolets, such as "A TBD-1 with a torpedo; has the feal of a fully-loaded torpedo plane","unresponsive","Generally sluggish, compared even to F4F-3s and F4F-3as", "Pitifully inferiour to the Japanese Zero in Maneuverabaility", and "An overloaded clunker".
The FM-2, though more powerfull and agile than an F4F-4, had generally similar characteristics. Although the controls were considered effective, it was"heavy to manuaver; needs lighter controls", and had"Heavy controls; heavy elevators in a turn'. In adation "heavy ailerons and slow rolling',and again "Heavy rudder in a turn'. So the general consensus was the controls,were effective and nicely harmonized, were "Heavy".

Does that sound like our Wildcat?

"Maximum G limits were (for the FM-2) 7.5g up to 7700pounds and 7.0g up to 8200 pounds gross weight."
Title: F4F-4 vs Zero 21
Post by: Karnak on February 18, 2003, 09:57:22 PM: brady,

Not to quibble, but the Mossie burns as easy, and burns faster than the A6M5b. Once a Mossie is on fire it has about 10 seconds to live.
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 10:31:38 PM: "Fact remains the F4F is out turned and out climbed by the A6M2 at any alt."

It is not that the Zero does not turn better, it is the degree by which it does than I am interested in, imo, based on my readings the Wildcat turns better, handels better, and preforms better up to 5 thousand feet than it should, acording to the test conducted in San Dieago the Zero was:

"The Zero was supiour to the F4F-4 in speed and climb at all altitudes above 1,000 ft"

"There was no comparison between the turning circles of the two aircraft due to the relative wing loadings and resultant low staling speed of the Zero."

The 5 thousand foot isue is important in that most of the combat in AH takes place bellow that height.

Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)

So Squire, is that speed listed in your chart for 285 on the deck with wep? Is that a player tested figure or did u get it from your chart?
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 10:33:44 PM: I feal your pain Karnak, but I am on a mishion hear man get a book out and help dude....:)
Title: F4F-4 vs Zero 21
Post by: brady on February 18, 2003, 11:35:38 PM: GRUNHERZ:

"I do think the Zero is too resitant to fire damage - however I do not think its full flight performance advanatages over F4F4 are fully present in AH. Even US tests showed zero was as fast on deck and starting at 1000ft faster at all alts - not the case in AH at low alts in any strech of the imagination. This gives the F4F4 an added advantage it never had - being able to disengage at will at any altitude. In real life they could only dive away but in AH an F4F4 can simply run away even on the deck. I also think the loe speed manuverability advantage of zero is negligent over a light F4F4 - the wording of the USA test made it clear there was no need to even consider this aspect as the zero had a profound superirity. Roll rate on zero is very sluggish at any speed - this does not match the reports about finger light instant control response at low speed by Saburo Sakai who knew a thing or two about zeros. I feel these discrepencies give the F4?F4 a much greater 1v1 dogfight capability vs zero than what matches the hitorical record - the F4F4 defeated zero by teamwork and slahing diving attacks from a superior altitide position not by individual manouver as is now possible in AH."
Title: F4F-4 vs Zero 21
Post by: Widewing on February 19, 2003, 12:03:09 AM: Quote
Originally posted by brady
A couple pasages from: Americas Hundred Thousand.

p. 490:

" The peek role rate of the F4F-3 was just under 70 degrees per second at about 250 mph IAS. At 350 mph IAS roll capabality fell off to about 50 degrees per second.
The F4F-4,with lots of added weight, was much less maneuverable, and was called uncomplimentary names by it's piolets, such as "A TBD-1 with a torpedo; has the feal of a fully-loaded torpedo plane","unresponsive","Generally sluggish, compared even to F4F-3s and F4F-3as", "Pitifully inferiour to the Japanese Zero in Maneuverabaility", and "An overloaded clunker".
The FM-2, though more powerfull and agile than an F4F-4, had generally similar characteristics. Although the controls were considered effective, it was"heavy to manuaver; needs lighter controls", and had"Heavy controls; heavy elevators in a turn'. In adation "heavy ailerons and slow rolling',and again "Heavy rudder in a turn'. So the general consensus was the controls,were effective and nicely harmonized, were "Heavy".

Does that sound like our Wildcat?

"Maximum G limits were (for the FM-2) 7.5g up to 7700pounds and 7.0g up to 8200 pounds gross weight."

A few points.

If we read Dean's other book, Report of the Joint Fighter Conference, from which many of the comments you quote originated, we find the following for the FM-2 after all pilots had test flown the aircraft.

Rudder: 4 reported high force required, one thought force was average, two others found them light. Four others said "good".

Ailerons at high speed: 6 thought effort was high, one thought it was light. Two others simply said "good". Effectiveness was rated as good by 5, fair by 3.

Elevators received glowing reports, everyone thought they were very good.

Scanning the individual pilot reports I find that some pilots found it heavy on the controls, others thought the opposite. All very subjective.

Ultimately, however, it was concluded that the FM-2 was the best American dogfighter below 10,000 feet. This is especially noteworthy when we look a the other planes tested, which included the P-51D, P-47M, F7F-1 and XF8F-1, as well as several Corsairs.

Virtually every fighter received mixed reviews, wih the exception of the two new Grumman fighters, the F7F-1 and XF8F-1. These completely wowed the test pilots. The only significant complaint about either was the poor rear vision of the Tigercat. Grumman's Bearcat prototype left most of the test pilots in complete awe. The general concensus was that all the Bearcat needed was some improvement in directional stability. Grumman promptly added a dorsal fin to the XF8F-1 and eventually increased the rudder area of the F7F to enhance low speed control.

I have found several accounts by Japanese pilots who were very much surprised by the vastly improved performance of the FM-2. They thought that they were fighting F4Fs, but the older Wildcats never turned or climbed like this new one!

In the game, the F4F-4 can't compete with the FM-2. The later model is lighter, faster and climbs far better.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 12:33:24 AM: So It could be said that in Americas 100K we have the distilled asesment of his findings from that and posably other sources, which post dates the earler work you sighted.

Saying it handled best out of all American Fighters is also some what subjective, American Fighters are not realy know for their handeling.

Well I did use FM-2 to dogfight 2 at time N1K2-J's which neaded to use flaps, and got them both, and I have used it aganst other Georges suxcesfully as well. But this is as "subjective" as the Japanese piolts saying that the FM-2 was a better turner than the F4F-4.
Title: F4F-4 vs Zero 21
Post by: Sox62 on February 19, 2003, 01:22:52 AM: A good book is Eric Bergurud's "Fire in the Sky,Airwar in the South Pacific"

In it he shows that the Wildcat was not nearly as inferior to the zero as everyone thinks.The first generation U.S. fighters more then held their own.

The F4F could (if they had any alt) ALWAYS dive away from the zero by diving steep in a slow turn.

Add to this self-sealing fuel tanks,and armor that the zero NEVER had.

There is an anecdote from a Japanese ace where he unloaded into an F4F,and was amazed because it simply flew away.He also stated,"You could always tell if it was a Japanese or American fighter that crashed into the ocean.The Japanese fighter would leave a fire on the water,the American fighter an oil slick."

Another ace(I can't remember which one) hated the cannon the zero had-low rate of fire and muzzle velocity.He stated he wished his zero had .50's.

The book is an interesting read.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 01:59:39 AM: "In it he shows that the Wildcat was not nearly as inferior to the zero as everyone thinks.The first generation U.S. fighters more then held their own."

Well it is not being disputed that men like those in VMF 121 did good, the issue at hand is how well did AH do in modeling the Wildcat, at present this is in dispute. It is also widely held even by the US Navy/marines that the wildcat was "decidely inferiour" to the Zero.

"The F4F could (if they had any alt) ALWAYS dive away from the zero by diving steep in a slow turn. "

Anyplane with suficnt alt to acheave a break away spead could dive past and break away from another plane, heck give me 20 K and will pull away in a C47:), the above test clearly staets that given an equile start the wildcat could not dive away.

"Add to this self-sealing fuel tanks,and armor that the zero NEVER had."

Later models did have this feature.
Title: F4F-4 vs Zero 21
Post by: Squire on February 19, 2003, 02:05:57 AM: Its a standard F4F-4 (FM-1) or so thats whats indicated on the sheet. Have a look and decide for yourself. Max speed is max speed , and 285 at sea level is what it did according to that test. Its not my data, and I have no way of "proving" anything indicated. I can only show you the data, and you can make what you will of it. Maybe its crap, maybe its closer to the truth. I have no way of knowing, I never flew a Wildcat.
Title: F4F-4 vs Zero 21
Post by: HoHun on February 19, 2003, 02:07:46 AM: Hi Widewing,

>There was no dive speed redline imposed, simply because it could achieve terminal velocity without over-stressing the airframe.

It would be more accurate to say that Wildcat was inherently safe in a dive because it had too much drag to reach dangerous speeds in the dive, and the elevator became too heavy to overstress the airframe.

The FM-2 manual states that a stick force of 100 lbs has to be applied and held for a moment before the Wildcat even begins to pull out of a terminal velocity dive. No chance to pull excessive Gs with a flick of the wrist :-)

Regards,

Henning (HoHun)
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 02:21:33 AM: Ok, squire, so most likely it is refering to the later models at WEP as indicated in Americas 100k, since the above test clearly states:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

I was realy asking about the first link you posted, I infered (perhaps incorectly) that the data and charts on that page were derived at from AH player testing or AH flight figures provided by HTC. And not from outside sources, for as we all know AH and the real world dont always jive.
Title: F4F-4 vs Zero 21
Post by: Innominate on February 19, 2003, 04:42:02 AM: Quick offline test.
(Numbers are not exact, errors are rounded down for the a6m, up for the f4f)
5000feet, no flaps, 25% fuel.

F4F-4: 185mph 3.2g's
A6M2: 185mph 5g's

F4F-4: 150mph 2.5g's
A6M2: 150mph 3.g's

F4F-4: 130mph 2.1g's
A6M2: 130mph 2.9g's

If anyone would verify these numbers it'd be helpful.
The f4f's sustained turn was right around 150mph,
From this test, it's obvious that the a6m2 has a very large turn radius advantage on the f4f-f. Though the closeness of it at 150mph is a bit odd, since the a6m seems to be able to maintain about the same g-load down to 130mph. (Though maybe I just wasnt pushing it)

BTW: does anyone have the formula for speed + gload vs turn radius handy?
Title: F4F-4 vs Zero 21
Post by: Sox62 on February 19, 2003, 05:59:44 AM: Quote
Originally posted by brady
"In it he shows that the Wildcat was not nearly as inferior to the zero as everyone thinks.The first generation U.S. fighters more then held their own."

Well it is not being disputed that men like those in VMF 121 did good, the issue at hand is how well did AH do in modeling the Wildcat, at present this is in dispute. It is also widely held even by the US Navy/marines that the wildcat was "decidely inferiour" to the Zero.

"The F4F could (if they had any alt) ALWAYS dive away from the zero by diving steep in a slow turn. "

Anyplane with suficnt alt to acheave a break away spead could dive past and break away from another plane, heck give me 20 K and will pull away in a C47:), the above test clearly staets that given an equile start the wildcat could not dive away.

"Add to this self-sealing fuel tanks,and armor that the zero NEVER had."

Later models did have this feature.

You miss the point.Maybe the later models did have rudimentary self-sealing tanks(never any real armor).But the later models at this point were fighting OUR later models.Namely the F6F,the P-38,and the Corsair.

The F4F's never fought the later models.

Check the book out-it's an interesting read.The Japanese pilots seemed to consider a P-40 or an F4F a pretty even match.(This was after the very early part of the war when the U.S. had changed their tactics,and stopped trying to turnfight the zero)
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 12:25:43 PM: Ok, check out this spead chart for AH planes, and keep this statement in mind:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

What is wrong in AH Why the descrepency?
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 12:30:48 PM: Sox, I am not to shure what your point is m8t, were debating handeling and spead isssues hear presently, durabality was a side issue and was not realy in to much dispute. Anadotal evidance is not realy going to help decide the issue.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 01:45:02 PM: The Report sighted above clearly states that the Zero had a Maximum speed of: 270mph at sea leval and 287mph at 5,000.

Now since the F4F-4 in AH has no wep, and since max speed preformance figure from Americas 100K states:

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

Now this from the report:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed"

1) The F4F-4 is in AH to fast on the deck.

2) The test height was higer than indicated

3) The True deck spead of the F4F-4 is in dispute

4) The Zero is to slow on the Deck

5) I am on crack and the figures are right

Of the 5 above reasions for the problem at hand either 2 or 3 seam the most likely.
Title: F4F-4 vs Zero 21
Post by: F4UDOA on February 19, 2003, 02:41:21 PM: Widewing,

You said

Quote
Ultimately, however, it was concluded that the FM-2 was the best American dogfighter below 10,000 feet. This is especially noteworthy when we look a the other planes tested, which included the P-51D, P-47M, F7F-1 and XF8F-1, as well as several Corsairs.

Could you tell me where in The Joint Fighter Conferance this conclusion was reached?
Title: F4F-4 vs Zero 21
Post by: F4UDOA on February 19, 2003, 03:03:17 PM: Brady,

I feel your pain.

The funny thing about HTC and flight models is this.

1. They only use source documents for American flight models.

2. They do not consider head to head A/C test as source documents or valid reference material.

This is also a problem for me because I have a number of test similar to the A6M2 test which show results that vary greatly from the AH FM.

In fact when it comes to the FM-2 you are in fact reading the wrong test report.

Read the test between the A6M5 vrs the F6F-5, F4U-1D and FM-2. You will jump of a bridge after that one.

It can be found in the "Warbird History Zero". It contains both reports back to back.

For instance the FM-2 should outclimb the A6M5 by 400FPM up to 4K. Aslo the FM-2 with a 1350HP engine was only 6MPH faster on the deck than the A6M5 and 4MPH slower than the Zeke at 5K. The FM-2 have a top speed of 321MPH at 13K and the Zero 335MPH at 18K.

Also the A6M5 could outclimb the F6F-5 by 600FPM up to 9K. But was equal to the F4U-1D in climb to 12K where the F4U was 500FPM better.

None of this is represented in AH.

Also the results from the FW190A5 vrs F4U-1D and F6F-3/ P-51B vrs F4U-1A are not used in AH except to represent the P-51B and FW190A5.

Flight manuals are also not used as you might expect.

Basically as long as the information is close they will not change it. Believe me I have tried.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 04:37:11 PM: F4UDOA, my book By Mikesh, contains the same Flight test between the A6M5 and the FM-2 that u referd to, but I wanted to try and stay focused on the A6M2 vs F4F-4 issue since the A6M2 is the only early war Japanese fighter we have and this preformance issue between the F4F-4 and it is creating what I would consider a non historicaly corect Matchup in the CT. I thought about going to bat on the A6M5 later.

So in a Nut Shel your telling me I am screwed huh? That I have done I can do and that non of this is somthing HTC will listen to?
Title: F4F-4 vs Zero 21
Post by: Squire on February 19, 2003, 04:43:05 PM: Brady. I cant understand why you keep asserting that the F4F-4 in the data I included was a late model.

It states right on the data sheet that its an F4F-4 (FM-1).Thats the 1942 model of the Wildcat. Its sea level speed is indicated as 284. Its engine is a P.W. R1830-86, the date on the test is July 1943.

The late model F4Fs could do 280 on the deck "with nuetral blower" yes, thats referring to the F4F-8 (FM-2) with wep. With the blower engaged it could do near 300, as it does in AH. "

As far as "wep" goes, thats a very artificial method AH uses, Im sure all the early F4Fs had what the pilots referred to as "emergency power" which is simply the highest rpm without destroying the engine.

As for your first question, the data in the "Midway" post was collected by its author, Badboy. It looks very complete to me.

Later.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 04:55:39 PM: Squire,

"I cant understand why you keep asserting that the F4F-4 in the data I included was a late model"

I am not, I am stating that in America's 100K they say that it was the speed for the late model.

"The late model F4Fs could do 280 on the deck "with nuetral blower" yes, thats referring to the F4F-8 (FM-2) with wep. With the blower engaged it could do near 300, as it does in AH. "

In AH they have the F4F-4 doing 284 on the deck, it has no wep, in the flight test they say that the F4F-4 and the A6M2 had the same speed on the deck, the A6M2 has a tested top speed of 270 on the deck, all things being equil so should the F4F-4 on the deck( per the flight test), howeaver in AH it is aprox. 15 mph faster on the deck than the test's indicate it should be.

"As for your first question, the data in the "Midway" post was collected by its author, Badboy. It looks very complete to me."

It is a very nice presentaion, howeaver real world and AH dont always jive, and their are a few issues that are in question, namely those that are being debated hear presently.
Title: F4F-4 vs Zero 21
Post by: Squire on February 19, 2003, 05:10:03 PM: I think perhaps there is much more of a grey area with the deck speeds of the A6M2, than the F4F. At least there is data out there for it, without arguments about how the IJN rebuilt its engine before it was tested, ect.

As for the F4F, well, there is data that shows the AH model is correct, there is also data that shows its off. Nothing new there I guess. I doubt we will ever get a definitive answer that will convince all.

Btw, my squad does training in the DA on a fairly regular basis (as Im sure you have all had ample fights in both types too), and I find in a 4 vs 4 the A6M2 has no trouble getting above and behind F4Fs. Still, you cant expect in the sometimes very large many vs many fights in AH events, that the A6M2 isnt going to get shot at quite a bit. Thats really the problem, and it was the problem for them in WW2. Air combat is confusing enough that it often negates technical advantages. Very little has been said about that on this thread. Just how carefull are they being? Not that that cant be applied to almost every other fighter, because it can. Pilot X asks "How come I got shot down in my Spitfire", well, because you dove low and turned at everything in sight, thats why.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 05:20:47 PM: "I think perhaps there is much more of a grey area with the deck speeds of the A6M2, than the F4F. At least there is data out there for it, without arguments about how the IJN rebuilt its engine before it was tested, ect."

This may well be to, howeaver the test findings are from a captured A6M2 that had virtualy nothing done to it, nothing that would effect it's preformance, so between it and the F4F-4 it think presently the Zero's speed is perhas the least disputable, while the F4F-4's speed referances seam to be convluted.

"As for the F4F, well, there is data that shows the AH model is correct, there is also data that shows its off. Nothing new there I guess. I doubt we will ever get a definitive answer that will convince all."

I am shure you are correct in this, nobody will be compleatly convinced, personal biases will always collor this no mater what.

The last part of your statement is also true, that is why I tryed very hard to use as many numbers in my argument as i could.
Title: F4F-4 vs Zero 21
Post by: F4UDOA on February 19, 2003, 06:11:49 PM: Brady,

Which book do you have? I am looking for the more data than what is in the book I have.

I have a feeling we are reading the book.
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 06:38:44 PM: The Book I have that quotes the flight test data, and does so verbatium, from the link you posted F4UDOA, is : Zero Fighter By Robet C. Mikesh Crown publishing 1981.
Title: F4F-4 vs Zero 21
Post by: Arlo on February 19, 2003, 06:41:49 PM: Hehe ... that "cracked" me up. :D

Quote
Originally posted by brady

5) I am on crack and the figures are right
Title: F4F-4 vs Zero 21
Post by: Widewing on February 19, 2003, 07:31:10 PM: Quote
Originally posted by brady
Ok, check out this spead chart for AH planes, and keep this statement in mind:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

What is wrong in AH Why the descrepency?

The java based chart you provided does not accurately reflect any of the speed at altitude charts I have for the F4F-4, especially above 17,000 feet. At 30k, airspeed should be 280 mph TAS. At 22.5k, airspeed should be 309 mph, not 293.

The AH speed chart conforms to those I have, and one you have in America's Hundred Thousand. I think AH got this one right.

Furthermore, I question the Zero's chart simply because the Sakai radial made only 415 hp at 30k, not nearly enough to sustain 310 mph up that high. Yet, the F4F-4's R-1830 was making 650 hp at that altitude. I realize this is the same curve as the AH chart, but I can't ignore the troubling lack of horsepower available without some second, unimpeachable source of data.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: Widewing on February 19, 2003, 07:56:50 PM: Quote
Originally posted by brady
Squire,

"I cant understand why you keep asserting that the F4F-4 in the data I included was a late model"

I am not, I am stating that in America's 100K they say that it was the speed for the late model.

"The late model F4Fs could do 280 on the deck "with nuetral blower" yes, thats referring to the F4F-8 (FM-2) with wep. With the blower engaged it could do near 300, as it does in AH. "

America's Hundred Thousand says, and I quote, "Late Wildcats could make about 285 to 295 mph in MILITARY power at sea level,"
Pg. 473, lower right paragraph.

It's referring to the F4F-4/FM-1 and FM-2 respectively. So, it seems that the AH model is accurate for both. Be content that they didn't select the F4F-3, which was faster than the Zero at its best altitude and climbed even better than the FM-2.

Accept it, the Zero 21 was a slug.. :D

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: brady on February 19, 2003, 07:58:10 PM: That still doesent realy clear up the deck spead issue with the Wildcat howeaver.

Since 95% of all combat in AH takes place bellow 10K, and 90% bellow 5k, that is my primary area of concern/ interest at present.

The whole point of this spead debat is derived from the evnets that took place on that day in Augast 1942, aparently HTC does not except such test flights as revelent, or so I have been told. The results of this test caused me to look at the speads of the Wildcat and in so doing I found some questionable evidance as to the sea leval spead, and general preformance issues regarding the two planes bellow 5,000 feat.

The deck spead of the F4F-4 is not 100% clear. It apears that acording to the test it should be slower, and Americas 100K is not to clear on this as well.
Title: F4F-4 vs Zero 21
Post by: Widewing on February 19, 2003, 11:11:02 PM: Quote
Originally posted by brady
That still doesent realy clear up the deck spead issue with the Wildcat howeaver.

Since 95% of all combat in AH takes place bellow 10K, and 90% bellow 5k, that is my primary area of concern/ interest at present.

The deck spead of the F4F-4 is not 100% clear. It apears that acording to the test it should be slower, and Americas 100K is not to clear on this as well.

Examine the speed graphs on page 473, graph 40 and page 595, graph 77A. They clearly define sea level max speed of the F4F-4 as 285 mph at MIL power.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: brady on February 20, 2003, 12:19:18 AM: But:

The book also states:

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473) "

Late model as defined elswhear is not a F4F-4.

Bellow we have the statment for the Testing in San Deigo, with a F4F-4 and the A6M2:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed"

So hear in lies the dispute, Why was the testflight different. Why the descrepency on the speads, what model of F4F is the chart refering to.

Why the differances in preformance between 1,000 and 5,000ft?
Title: that chart
Post by: joeblogs on February 20, 2003, 08:18:42 AM: Brady - where did that chart come from?
What program is that?
-Blogs

Quote
Originally posted by brady
Ok, check out this spead chart for AH planes, and keep this statement in mind:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

What is wrong in AH Why the descrepency?
Title: F4F-4 vs Zero 21
Post by: brady on February 20, 2003, 10:54:32 AM: I used to have a link to it but I misslyed it:(, It was done by a player, and fairly accurate, a Nice source to get you the feal for how planes preform in AH.
Title: F4F-4 vs Zero 21
Post by: Puke on February 20, 2003, 11:15:42 AM: This chart?

http://www.jannousiainen.net/online_sims/jg_4/index.htm

You have to scroll to the bottom of the page though.
Title: F4F-4 vs Zero 21
Post by: Widewing on February 20, 2003, 12:54:03 PM: Quote
Originally posted by brady
But:

The book also states:

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473) "

Late model as defined elswhear is not a F4F-4.

Bellow we have the statment for the Testing in San Deigo, with a F4F-4 and the A6M2:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed"

So hear in lies the dispute, Why was the testflight different. Why the descrepency on the speads, what model of F4F is the chart refering to.

Why the differances in preformance between 1,000 and 5,000ft?

Brady, I have already told you the the charts SPECIFICALLY refer to the F4F-4. It's annotated. Each type has its own curve and each is annotated.

Here's the quote again so that there is no misunderstanding:
"Late Wildcats could make about 285 to 295 mph in MILITARY power at sea level," This statement conforms to the charts. There is nothing to debate about this, it's there in black and white for all to see.

Now, when the Zero was tested in San Diego, did they test it with captured Japanese 87 octane avgas, or did they use the U.S. standard grade 100/130 octane avgas?

Something not mentioned is the fact that the F4F-4 pilot can engage low or even high blower, over-boost the engine and gain considerable speed over neutral blower. So could the Zero pilot, if and only if he had high octane fuel to minimize detonation. Burning that Japanese dishwater, I'd bet he melts pistons in 60 seconds. The F4F pilot may eventually damage his engine. But, the Zero pilot absolutely will damage his engine (unless he has the 100/130 avgas).

Remember, I'm not arguing that the Zero isn't porked. I'm arguing the F4F-4 IS accurately modeled. I feel that the A6M2 as modeled in AH does not live up to its reputation. But, then again, in the real world it didn't either, at least after Allied pilots discovered its weaknesses.

My regards,

Widewing
Title: F4F-4 vs Zero 21
Post by: brady on February 20, 2003, 01:04:15 PM: Ya thats it awsome chart.
Title: F4F-4 vs Zero 21
Post by: HoHun on December 29, 2004, 08:36:26 PM: Hi everyone,

I'm currently trying to figure out the Grumman fighters' performance. One information I can't seem to find is the gear ratio for the R-1820-56 used in the FM-2. It seems there were variants of the R-1820 with a 16:9 ratio as well as others with a 3:2 ratio.

The 16:9 ratio would appear to make more sense than the 3:2 ratio, but the FM-2 manual has a comment on not using more than 2500 rpm in the climb above 20500 ft due to propeller efficiency losses that suggests the 3:2 ratio might have been used.

Could anyone please help me with this information? :-) Thanks in advance!

Regards,

Henning (HoHun)
Title: F4F-4 vs Zero 21
Post by: FDutchmn on December 29, 2004, 11:00:28 PM: Quote
Originally posted by brady
with the exception that the Zeros engine cut out in in pushovers

Quote
Originally posted by thrila
Sorta like the spit I and hurri I?

Didn't know the zero had problems like that.

No, the Zero didn't have this problem. It is thought that the American engineers assembled the carburator wrong. The design of the carburator was such that it did feed gas even under negative Gs. With extensive documentation on the Zero in Japan, this issue is not noted in any of them. I will post a diagram of how it worked later... I got to go find it first.
Title: F4F-4 vs Zero 21
Post by: FDutchmn on December 30, 2004, 08:41:17 AM: Quote
Originally posted by HoHun
Hi Mitsu,

>Nope, actually ZEKEs didn't have that problem.

Do you have any source for that? The A6M2 (serial number 4593) flown by Tadayoshi Koga, recovered and test-flown by the Americans after its crash on Akutan, seems to have displayed negative G cut-outs, and though some minor changes were necessary to make the A6M airworthy again, it looks like the carburettor still was original.

Regards,

Henning (HoHun)

Hiya everyone,

There seems to be this notion that the A6M suffered from engine cut off in negative G conditions. However, this is not the case.

Here is the first page of an article written by Mr. Haruo Niiyama, the designer/engineer of the carburetor used on the Sakae21 engine.
(http://homepage3.nifty.com/flying_dutchman/reference/carburetor01.jpg)
The title says: CARBURETOR Mounted on "Sakae21": Zero's Air Combat Capabilities Supported by its Carburetor. The article is about 5 pages long, but I will not post all of it because I do not want to infringe copyrights, nor will I translate this directly. (I know that Mitsu or somebody sent me this article but I forget where this came from... I will search for that when I can get hold of Mitsu or when the public library opens... it's holiday season now.)

Anyway, in the article, it says that Mr. Niiyama specifically worked on the problem of effects of negative G, zero G, and excessive G conditions on the performance of the carburetor, since the 6th year of the Showa era (that's 1931). A number of innovations were tried from introducing a ball valve to a slide valve to modifying the needle valve. In the end, he was successful in having a carburetor capable of withstanding different G conditions. The changes to the carburetor was completed to the production planes by the 12th year (1937).

Since this is some four years before the outbreak of the war, I find it unlikely that Airman Koga's Zero was equipped with a carburetor that was in use some four to five years before.

The carburetor design was the float-type which was not in use for airplanes in the US. This may contribute to mistakes when an engineer who is not familiar with the parts when he re-assembles them after inspection.
Title: F4F-4 vs Zero 21
Post by: FDutchmn on December 30, 2004, 08:51:54 AM: oh geez... I just noticed that this something... this thread is almost 2 years old! What's it doing being revived anyway! :D
Title: F4F-4 vs Zero 21
Post by: Sikboy on December 30, 2004, 12:44:56 PM: Nice to see this thread again.

If nothing else, I think it reminds me how important the A6M3 is, with the 99II cannons. They may not be great, but they are a hell of a lot better than the 99I that we have on the A6M2.

I have high hopes that we'll see the 3 when (or not long after) the P-38G shows up.

-Sik
Title: F4F-4 vs Zero 21
Post by: HoHun on December 30, 2004, 08:30:33 PM: Hi Dutchman,

>oh geez... I just noticed that this something... this thread is almost 2 years old! What's it doing being revived anyway! :D

My fault - I liked this thread so well I thought I'd just append my question to it so all the context would be in easy reach :-)

I'm quite happy that you gave such a detailed answer to the old question regarding negative G carburetting as my interest in that one was still alive :-)

As that level of detail is what I'm looking for: Do you have anything on the maximum lift coefficient for the A6M (any model)? I've archived a low-resolution copy of a Japanese diagram someone posted here that shows spanwise lift distribution, but I'm interested in a single factor which I can't derive from that diagram.

(Information on stall speed and airspeed indicator calibration would be welcome, too.)

Thanks again! :-)

Henning (HoHun)
Title: F4F-4 vs Zero 21
Post by: HoHun on December 30, 2004, 08:34:39 PM: Hi again,

>The 16:9 ratio would appear to make more sense than the 3:2 ratio, but the FM-2 manual has a comment on not using more than 2500 rpm in the climb above 20500 ft due to propeller efficiency losses that suggests the 3:2 ratio might have been used.

OK, I've found out now that the R-1820 of the F4F-4 had the 3:2 ratio, which might explain some of the BuAer performance charts pecularities that confused me so far. Maybe propeller tip speeds are also significant for the F6F top speed topic also discussed 2 years ago :-)

Still, if someone could help me with data on the R-1820-56, it would be very much appreciated!

(One preliminary result for the latter engine is that with water injection, it was cleared for a much higher boost than the supercharger would normally deliver :-)

Regards,

Henning (HoHun)
Title: R-1820-56
Post by: joeblogs on December 30, 2004, 11:30:48 PM: Everything I can find on this engine cites the two reduction gear ratios, which are used in versions of the Cyclone since the rated RPM was increased to 2600 RPM (later 2700 RPM) in the H series engines.

A Wright manual of that era shows two types of reduction gearing corresponding to the 3:2 and 16:9 ratios in a G200 series engine with two speed supercharger (I suspect for the Buffalo). I'll bet the choice of gearing depended on the propeller and constant speed unit selected. This might be done, for example, to avoid harmonic vibration between the propeller reduction gearing and the crankshaft.

Can you post the exact propeller and constant speed unit from the FM-2 manual? Also, can you post max RPM, HP, and manifold pressure at some stated altitudes. With that I might be able to match to some commercial or airforce tables.

-Blogs

Quote
Originally posted by HoHun
Hi everyone,

I'm currently trying to figure out the Grumman fighters' performance. One information I can't seem to find is the gear ratio for the R-1820-56 used in the FM-2. It seems there were variants of the R-1820 with a 16:9 ratio as well as others with a 3:2 ratio.

The 16:9 ratio would appear to make more sense than the 3:2 ratio, but the FM-2 manual has a comment on not using more than 2500 rpm in the climb above 20500 ft due to propeller efficiency losses that suggests the 3:2 ratio might have been used.

Could anyone please help me with this information? :-) Thanks in advance!

Regards,

Henning (HoHun)
Title: reduction gear ratios continued
Post by: joeblogs on December 30, 2004, 11:39:15 PM: If we have the max RPM of the engine, the length of the propller and the reduction gearing, we can calculate the maximum tip speed and see if we are getting anywhere close to transonic.

I doubt tip speed explains the speed question for the F6f. An easy way to check this is to verify that the reduction gearing on the Double Wasp used in the F4u is the same as for the model used in the F6f and then compare the propeller length on the two planes. I believe the F4u propeller was at least as large and the Max RPM of its engine (especially in later models) was higher. In that case, it should be the F4u with the propeller tip speed problem...

-blogs

Quote
Originally posted by HoHun
Hi again,

...

OK, I've found out now that the R-1820 of the F4F-4 had the 3:2 ratio, which might explain some of the BuAer performance charts pecularities that confused me so far. Maybe propeller tip speeds are also significant for the F6F top speed topic also discussed 2 years ago :-)

Still, if someone could help me with data on the R-1820-56, it would be very much appreciated!

(One preliminary result for the latter engine is that with water injection, it was cleared for a much higher boost than the supercharger would normally deliver :-)

Regards,

Henning (HoHun)
Title: Re: R-1820-56
Post by: HoHun on December 31, 2004, 04:47:05 AM: Hi Joe,

>I'll bet the choice of gearing depended on the propeller and constant speed unit selected. This might be done, for example, to avoid harmonic vibration between the propeller reduction gearing and the crankshaft.

Interesting aspect, I hadn't thought of that!

>Can you post the exact propeller and constant speed unit from the FM-2 manual?

It's a Curtiss Electric hub 05325D-A20 with blades 109354-12. The diameter (not found in the manual) seems to be 10 ft.

>Also, can you post max RPM, HP, and manifold pressure at some stated altitudes. With that I might be able to match to some commercial or airforce tables.

Four different versions of the R-1820-56 were used in the FM-2, two of them limited to 2600 rpm and two of them to 2700 rpm.

The Military Power engine curve common to all of them (at 2600 rpm):

Alt HP Boost
00000 1250 46.5" Hg
03400 1290 46.5" Hg
13000 0970 34.0" Hg/43.0" Hg
17800 1000 43.0" Hg
30000 0620 26.5" Hg

The R-1820-56 and R-1820-56W (with water injection) are limited to 2600 rpm throughout, the R-1820-56A is cleared for a 2700 rpm takeoff setting, and the R-1820-56WA (with water injection) is cleared for 2700 rpm in low blower, 2600 rpm in high blower.

Combat power with water injection is 50" Hg in low blower, 52" Hg in high blower with water injection, 46" Hg in high blower without water injection.

Enough water for 10 min operation is carried, 5 min continous operation at combat power is permitted.

The manual seems a bit confusing in claiming the non-"W"-engines do not have a combat power setting while it seems it should be possible to get 46" Hg in high blower without water injection.

The R-1820-56 apparently was used in the Dakota as well. For the R-1820-56AM2, an FAA document gives a 16:9 gearing and 1350 HP @ 2700 rpm, 48.0" Hg take-off power. This seems to be a good result as I'd linearly extrapolate 1340 HP for that combination, and usually expect less than linearly increased effect from higher boost/higher rpm.

Use of the R-1820-56 in the Dakota required a modified rudder balance tab as so much power would otherwise create dangerous single-engine characteristics 8-O

Regards,

Henning (HoHun)
Title: Re: Re: R-1820-56
Post by: joeblogs on December 31, 2004, 10:26:14 AM: Hohun:

Thanks, there should be enough detail here for me to match up to an engine with a different (i.e. commerical) designation number. I have a good crosswalk between military and civilian numbering for Pratt &Whitney engines, but I don't for the Wright engines used by the Navy.

-blogs

One issue that makes the late Cylcones a bit dfficult to match is that Wright adopted a new fin technique late in the war that significantly improved cooling of the heads. This, combined with a stiffer crankshaft, allowed for higher RPM and some additional manifold pressure. Unforthunately, I don't think these changes resulted in a new model number so it's not always clear whether a given engine used on a plane had these improvements or not.

-Blogs

Quote
Originally posted by HoHun
Hi Joe,

>I'll bet the choice of gearing depended on the propeller and constant speed unit selected. This might be done, for example, to avoid harmonic vibration between the propeller reduction gearing and the crankshaft.

Interesting aspect, I hadn't thought of that!

>Can you post the exact propeller and constant speed unit from the FM-2 manual?

It's a Curtiss Electric hub 05325D-A20 with blades 109354-12. The diameter (not found in the manual) seems to be 10 ft.

>Also, can you post max RPM, HP, and manifold pressure at some stated altitudes. With that I might be able to match to some commercial or airforce tables.

Four different versions of the R-1820-56 were used in the FM-2, two of them limited to 2600 rpm and two of them to 2700 rpm.

The Military Power engine curve common to all of them (at 2600 rpm):

Alt HP Boost
00000 1250 46.5" Hg
03400 1290 46.5" Hg
13000 0970 34.0" Hg/43.0" Hg
17800 1000 43.0" Hg
30000 0620 26.5" Hg

The R-1820-56 and R-1820-56W (with water injection) are limited to 2600 rpm throughout, the R-1820-56A is cleared for a 2700 rpm takeoff setting, and the R-1820-56WA (with water injection) is cleared for 2700 rpm in low blower, 2600 rpm in high blower.

Combat power with water injection is 50" Hg in low blower, 52" Hg in high blower with water injection, 46" Hg in high blower without water injection.

Enough water for 10 min operation is carried, 5 min continous operation at combat power is permitted.

The manual seems a bit confusing in claiming the non-"W"-engines do not have a combat power setting while it seems it should be possible to get 46" Hg in high blower without water injection.

The R-1820-56 apparently was used in the Dakota as well. For the R-1820-56AM2, an FAA document gives a 16:9 gearing and 1350 HP @ 2700 rpm, 48.0" Hg take-off power. This seems to be a good result as I'd linearly extrapolate 1340 HP for that combination, and usually expect less than linearly increased effect from higher boost/higher rpm.

Use of the R-1820-56 in the Dakota required a modified rudder balance tab as so much power would otherwise create dangerous single-engine characteristics 8-O

Regards,

Henning (HoHun) [/B]