Rising Sun warbirds

[syscom3]

The Zero seems to have been a dead end evolutionary wise. Excellent plane to start out the war, but was eventually neutralized by better allied designs.

At Chino 2000, I was talking with a 475th FG pilot and he mentioned that no matter how much training the Allied pilots had, there was always someone who didnt believe how deadly the Zero could be, and once in awhile they would pay the price.

Several years ago I worked frequently in Japan and had some interesting conversations with my Japanese colleagues, and one of them summed up the state of Japanese aircraft industry in 1942....."we could build lots of existing planes.....or.....design new planes, but we didnt have the resources to do both".

[Parmigiano]

Originally Posted by evangilder

Armor would help, but it adds weight, as well as a bigger engine would. These could also effect the performance of the airplane.

Exactly Evan, it would have moved the zero attitude from the 'turn-and-burn' to 'boom-and-zoom' side, like the evolution that Spitfire and 109 had.
Less endurance and manouvrability traded for higher speed, payload and durability, that was the right recipe from 42 to 45!

I just mentioned the aileron per analogy, because I remember it cured the same issue on the spitfire, whose fabric surfaces were 'balooning' at high speed making the stick unmovable. I think it was fixed during MkV production with aluminium covered ailerons.
I read that the zero was improved in high speed handling by cutting the wingtips and fitting smaller ailerons, but I believe the old saying 'there is no plane better than her engine' and 1100hp were about half the power of the competition.

[Parmigiano]

Originally Posted by evangilder

Armor would help, but it adds weight, as well as a bigger engine would. These could also effect the performance of the airplane.

Exactly Evan, it would have moved the zero attitude from the 'turn-and-burn' to 'boom-and-zoom' side, like the evolution that Spitfire and 109 had.
Less endurance and manouvrability traded for higher speed, payload and durability, that was the right recipe from 42 to 45!

I just mentioned the aileron per analogy, because I remember it cured the same issue on the spitfire, whose fabric surfaces were 'balooning' at high speed making the stick unmovable. I think it was fixed during MkV production with aluminium covered ailerons.
I read that the zero was improved in high speed handling by cutting the wingtips and fitting smaller ailerons, but I believe the old saying 'there is no plane better than her engine' and 1100hp were about half the power of the competition.

[evangilder]

Ballooning is not the problem with the ailerons in the Zero, it is the size. I would agree that smaler ailerons would have helped as the stick forces were the problem with the large ailerons. Obviously it would require quite a bit of engineering as added weight needs to be balanced right or the CG changes and thus the manueverability gets effected. Even then though, weight itself will also decrease manueverability somewhat.

[FLYBOYJ]

Ballooning on control surfaces will normally not occur when the fabric is new and in good condition. Early in the war I would guess "Irish Linen" was used which could easily weaken if put under continual strain and weather....

[R Leonard]

It didnt matter if the F4F took four, or five hours really, becaue theyre were more planes, engines, and
better trained maintenance crews to do the job. the zeros werent produced in good enough numbers, . . .

Huh?

First we hear how it takes hours to change out an engine on an F4F, which wasn’t true.

Now rises the specter of thousands of F4Fs outnumbering the A6M series production. Well, that, also, is untrue.

A6M series production:

A6M1: 2 prototypes
A6M2-11: 64 includes 21 that could be considered prototypes
A6M2-21: 1429
A6M2-K: 517 includes 7 prototypes
A6M3: 3 prototypes
A6M3-22: 1541
A6M3-32: 340
A6M5: 2151
A6M5a: 105
A6M5b: 2330
A6M5c: 93
A6M6c: 1577 includes 1 prototype
A6M7: 490
A6M8: 1 prototype
Total A6M series production: 10,643

Of course, if you want to include the A6M2-N production of 327 including 4 prototypes, that gives a production
result of 10,970.

Now, F4F production:

XF4F-2: 1
F4F-3: 285
F4F-3A: 95
XF4F-4: 1
F4F-4: 1169
XF4F-5: 1
XF4F-6: 1
F4F-7: 21
XF4F-8: 2
Total F4F production: 1576

And if you want to add in the FM series of 1060 FM-1 and 4777 FM-2 that makes a total of 7,413; still somewhat
short of the non-float type A6M’s total of 10,643

And if we look at the primary contemporary antagonists, the F4F-3, F4F-3A, and the F4F-4 production versus
the A6M2-21, A6M3-22, and A6M3-32, and don’t count prototypes, the production totals were 1549 for the
F4F types and 3310 for the A6M types. Thus, we find the F4F production was less than half the contemporary
A6M production. We should also keep in mind a couple of other factors, such as the F4F-3 and F4F-3A did
not serve on carriers after May 1942 and not as a land-based front line fighter after June 1942. And that,
while A6Ms were confined to the Pacific theaters, F4Fs also served in the Atlantic, and were, thus, not all
committed to Pacific operations.

I guess that’s another theory out the window, F4Fs did not outnumber their A6M counterparts, in anyway
you want to count it.

. . . and the same can be said about the pilots, maintenance crews, and powerplants. I repsect
the IJNAF and the IJAAF because they accomplished alot with what they had, but the americans, could outpace
them in technology, trainign, and numbers.

So, are you saying that the Japanese did well in spite of their almost ubiquitously abysmal long term
strategic planning? I’d pose, rather. that their results were exactly the results of their planning. They went
into a war that they could not have possibly won in the first place, basing their entire strategic concept on
what they thought the US would do instead of thinking about what the US could do.

Regards,

Rich

[FLYBOYJ]

Great stuff Rich! Yep - the Japanese planned for a 6 month war - how many times did Yamamoto say that?!?!

[R Leonard]

I re-read the report, and I still have the impression that the zero was holding very well or outperforming
the other aircrafts.

I guess I don’t read it the same way.

- the lower performance above 500 kmh (300mph) fall in a limited envelope of use, most of the dogfight
was below that speed. It only tells that zero should not try to escape by diving and could be escaped in a steep
dive, assuming there is enough space below.

I believe the point was to remind USAAF pilots to avoid engaging in low speed turning contests and keep their
speed above the A6M2s optimal performance envelope (or maybe I’ve just read too many of these reports
or talked to too many pilots).

- the zero SN 4593 was recovered after a forced landing due to engine trouble. The machine landed
wheels down on a marsh, breaking landing gear, flipping over and breaking tail, propeller and canopy
in the process: not a small damage, that had to be rebuilt without any supporting documentation. It seems
fair to assume that a factory-fresh zero would have probably performed a bit better. Consider that probably
(unless the US manufacturer behaved against their natural attitude to competition) the US fighters sent for
comparison were in mint conditions.

And how do the performance statistics the tests revealed compare to the Japanese reported performance.
The Japanese rated the A6M2 variously at between 316 and 330 mph. What did the US tests find? How
shocking . . . they only pushed it up to 326 mph! I wonder what a high-time, well and truly used, A6M2
would turn up as opposed to a nice, clean, and tweaked, factory fresh, edition or even this rebuilt version.
The reality is that the average aircraft in action on one side is going to run up against the average aircraft
in action on the other; so what is important is not what the squeaky clean aircraft can do, but what the aircraft
that just returned from it’s 100th sortie can do. This is a fairly obvious observation. I see nothing in the
report to indicate that any of the US aircraft involved were factory fresh. Looks to me like old number 4593
was pretty well pushed to it’s limit.

One has to ask oneself, if you’re going to repair an enemy aircraft in order to test its capabilities, does it
not make sense to repair it to the highest operational extent possible? And if you’re going to test it, are you
not going to push to see exactly what it will do? Would any other courses provide the performance information
in which you’re interested?

Let’s look at some of the damage to #4593

4593 engine (USN Photo from my collection)


4593 being shifted for shipment (USN Photo from my collection)


4593 ready for shipment. Note damage to vertical stabilizer (USN Photo from my collection)


4593 under repair by USN personnel at North Island NAS
(USN Photo from my collection)


4593 under repair by USN personnel at North Island NAS
(USN Photo from my collection)


And in its operational condition

4593 in 1944 (USN Photo from my collection)


4593 in 1944 (USN Photo from my collection)


4593 in 1944 (USN Photo from my collection)


4593 in 1944 (USN Photo from my collection)


4593 in 1944 (USN Photo from my collection)

- the engine cut-off is reported only for this zero, at least I never heard/read of this as a general problem
of the machine. Also because the US pilots (.. that were NOT slow in learning) would had used this as a
standard escape tactic, like the 109 pilots did with the early spits.

On the other hand I’ve read that the problem was corrected in later (the 22, 32, and 52) models.

- Although the pilots who flew the zero were surely great pilots they did not know very well the ship,
and were probably not in condition to 'squeeze' the best out of it, while the pilots in the local planes of course
knew them 'like their pockets' : put a Saburo Sakai in the cockpit and the zero would had performed better in
climbs and turns!

I don’t suppose that Eddie Sanders being the Assistant Flight Test Officer at Anacostia NAS might imply that
he knew a little bit about how to wrest the available performance out of an aircraft? Flight Test was where
USN aircraft types were put through their paces prior acceptance. Sanders was in charge of testing
fighter types. Further, when #4593 was tested against the F4F and the F4U, Sanders was flying the USN
types. Flying the A6M2 was Cdr Fred Trapnell ("Mister Test Pilot") who was head of Flight Test, was USN
jet pilot # 1, established the Naval Air Test Center at Patuxent NAS, and started the test pilot school there.
And our unidentified USAAF pilots from Eglin Field? What do you suppose was their unit mission? Having
had some exposure to USN test pilots (plural) from that era, I would observe that these are not average
pilots, but rather some folks who really knew what they were doing and were very serious about it.

All this, specially if you read the comparison with the F4F where no numbers are given but just a kind
of concerned statements (..zero was superior in speed and climb at all altitudes above 1000 ft .. superior
in ceiling... no comparison between the turning circles... in combat F4F is basically dependent in mutual
support..) states that at the end of 1942 the zero model 21 was at least a terrible customer for the US planes,
and that the new generation of US fighters (Corsair) was better than the Zero.

When you re-read the Summary #85 report you should be able to ascertain that it is a USAAF document.
It clearly states that it presents the information from the Eglin AAF Proving Ground Group (the USAAF
equivalent of the USN Flight Test group at Anacostia NAS) addressing test conducted with the A6M2 against
the P-38, P-39, and P-51 in detail. Small wonder that the information on the tests with those particular
aircraft are in greater detail as the Summary was to be issued to USAAF squadrons. The information on
tests against the F4F and F4U is merely summarized as those are not USAAF aircraft. The service politics
are obvious. While there were USN squadrons that operated P-51s, and even Spitfires, I can’t think of any
USAAF squadrons that operated F4Fs or F4Us.

What was not highlighted is the fragility of the zero in sustaing battle damage.

This was something they already knew and appears in debrief reports. For example, I have debrief interviews
from Lt Cdr John Thach and Lt Noel Gayler made at BuAer in the summer of 1942 that clearly note the interesting
phenomena when one’s rounds strike home on Japanese aircraft, generally, and A6M2s, specifically.

The problem of the japanese fighter is that it was not substantially improved in the following 3 years,
with an evolution path similar to her western counterparts (because of HQ policy? because the structure could
not hold more power and weight? because no better engines were available?), making it completely
obsolete by 1943.

True. What most tend to forget is that the A6M was originally designed to face the enemy the Japanese were
facing in China, both in terms of aircraft types and in the tactics and quality of the tactics employed by
the Chinese. Once the initial conquering rush, against mostly ill-prepared and ill-supplied adversaries, was
over and it became markedly difficult for the Japanese to marshal overwhelming numbers at any
particular point, coupled with finally better supplied and better prepared adversaries who were not flying
Russian cast offs or using, such as they were, Chinese tactics, it became a different ballgame. The A6M
series design really did not lend itself to many improvements and was, as Syscom3 eruditely noted, a
evolutionary dead end.

Regards,

Rich

[FLYBOYJ]

Rich, you are truly amazing!

[evangilder]

Another great post Rich. The pictures are outstanding!

[Parmigiano]

Rich, your posts are always great!

Our 'disagreement' seems to be the interpretation of the report, so here is what I understand by reading the document:

A - vs USAAF planes
1 - all tested planes, except the F4F, are faster than the zero in level flight
2 - Zero can outturn/outmanoeuvre all tested planes below 300 mph at any height, except P38F above 20.000 ft where zero is superior only in slow speed turns.
3 - Zero has better zoom acceleration/climb/dive than any other type
4 - Sustained climb relative performances depends on the opponent aircraft :
- vs P38F the zero is better up to 18.000 ft, then the P38 is better
- vs P39 the Zero is less performing up to 12.500 ft and better above that height
- vs P51 (Allison engine) the zero walks away in climb up to 15.000 ft, no test above because of P51 engine problems. P51 is much faster than zero in level flight and in dive. (this is no surprise, the P51 and zero are almost at the opposite concept of fighter planes. Also it is clear that the P51 was basically a prototype, still far away from his real potential)

About relative acceleration, it is not clear if the tests are started at the optimal speed for the US fighters or for the zero (being the starting speed always different it may be that the test is run at optimal speed for the US fighters)

- P40 was not tested because of engine problems (question: this test was important, why they did not get another P40 or a replacement engine? Maybe because, knowing the performance of the P40 vs P38-P39, they could extrapolate the results? And so, why they did not even put a line of comment about that?)

B - vs USNAVY planes
The chapters of Zero vs F4F and F4U are not detailed (and you explained the reason why), but the summary seems very clear :
- vs F4F : the zero is always superior or equal to the Wildcat
- vs F4U : the Corsair is almost always superior to the Zero
btw, is there any copy of the Navy pilots detailed report? In the first page they say 'Navy pilots handled the trials against F4F-4 and F4U-1', so it seems likely that this team had prepared a detailed report for the Navy.

In summary, I believe that my original impression " ... is superior or holding well in comparison to the US planes, except with the Corsair " is correct.

This, as I had made clear, is valid as a 41-42 snapshot, we all know that the Jap plane was not significantly improved afterwards, while P38, P51 and F4U were strongly developed.

This was my reading of the official document, where do you disagree?


To follow instead are the comments about my speculations:

Originally Posted by R Leonard

I believe the point was to remind USAAF pilots to avoid engaging in low speed turning contests and keep their
speed above the A6M2s optimal performance envelope (or maybe I’ve just read too many of these reports
or talked to too many pilots).

This makes a lot of sense, point is that 300 mph is quite a high speed for 1941-42, normally far above the normal cruise speed and flight envelope.
It became 'normal' with the next generation of fighters, and we all agree that the Zero did not kept the improvement pace.

Originally Posted by R Leonard

One has to ask oneself, if you’re going to repair an enemy aircraft in order to test its capabilities, does it
not make sense to repair it to the highest operational extent possible? And if you’re going to test it, are you
not going to push to see exactly what it will do? Would any other courses provide the performance information
in which you’re interested?

Originally Posted by R Leonard

I don’t suppose that Eddie Sanders being the Assistant Flight Test Officer at Anacostia NAS might imply that
he knew a little bit about how to wrest the available performance out of an aircraft? Flight Test was where
USN aircraft types were put through their paces prior acceptance. Sanders was in charge of testing
fighter types. Further, when #4593 was tested against the F4F and the F4U, Sanders was flying the USN
types. Flying the A6M2 was Cdr Fred Trapnell ("Mister Test Pilot") who was head of Flight Test, was USN
jet pilot # 1, established the Naval Air Test Center at Patuxent NAS, and started the test pilot school there.
And our unidentified USAAF pilots from Eglin Field? What do you suppose was their unit mission? Having
had some exposure to USN test pilots (plural) from that era, I would observe that these are not average
pilots, but rather some folks who really knew what they were doing and were very serious about it.

Look, I don't mean to say that US test pilots were not exceptional pilots or that the team did not take seriously the job.
Fact is that planes performances depends on many parameters, and assuming that a Mitsubishi test team (pilot+service engineers) with thousands of hours in the type knows how to manage a zero better than a USAAF or NAVY test team is not offensive and not irrealistic. Unless we assume that Jap test teams were inferior professionals.
For sure the US teams knew every tip and trick of P39, P40 etc. (best manifold pressure, mixture, prop pitch, trim settings etc. for every flight condition) and fly the planes at their best, PERHAPS they simply had no time to learn all the tips and tricks for the zero.

Look at this quote from another thread posted by wmaxt:
"Belive it or not I have a comparison (From Doc's page I think) that shows two Spit IX and P-38F. The Spits out turned it but the P-38 was right in the middle of the 2 Spits performance curves, who had different Prop reduction ratios."
If this 'small' difference in settings is enough to make the difference in performances, why should we absolutely exclude that the tested zero was not optimally tuned?

cheers
sandro

[F4D]

I like Japanese planes...in truth I like all planes.

My favorite Japanese fighter was the Nakajima Ki-84 "Hayate" (allied code name "Frank"). What a shame it had so many manufacturing problems.
One of those too little too late deals. A fine looking ship with the muscle to
back it up.

It was designed to replace the Hayabusa and required the maneuverability
of the Hayabusa with the speed and climb of the Shoki.
Also it had to have heavy guns,amour protection and self-sealing tanks.
A maximum speed of 400 to 420 mph and able to operate 250 miles from base with a combat rating of one hour and thirty minutes and wing loading of no more than 34.8 lbs/sq ft.
It was to use the Army version of the NK9A Homare radial and have two 20mm and two .50cal guns.

But it never made the speed 394@21800 ft, but could dive at 496mph in test flights.

[FLYBOYJ]

Originally Posted by F4D

I like Japanese planes...in truth I like all planes.

My favorite Japanese fighter was the Nakajima Ki-84 "Hayate" (allied code name "Frank"). What a shame it had so many manufacturing problems.
One of those too little too late deals. A fine looking ship with the muscle to
back it up.

It was designed to replace the Hayabusa and required the maneuverability
of the Hayabusa with the speed and climb of the Shoki.
Also it had to have heavy guns,amour protection and self-sealing tanks.
A maximum speed of 400 to 420 mph and able to operate 250 miles from base with a combat rating of one hour and thirty minutes and wing loading of no more than 34.8 lbs/sq ft.
It was to use the Army version of the NK9A Homare radial and have two 20mm and two .50cal guns.

But it never made the speed 394@21800 ft, but could dive at 496mph in test flights.

The Frank was a great aircraft, I think it was probably the best fighter to come out of Japan during WW2, but it definetly didn't have the maneuvability of the Oscar.

[F4D]

The Frank was a great aircraft, I think it was probably the best fighter to come out of Japan during WW2, but it definetly didn't have the maneuvability of the Oscar.

It did fall short of many of the design specs I listed but was a great bird.
I would have liked to have seen the Ki-83 go beyond the test phase. It could have been something.
Oh well... jets did them all in anyway.

[R Leonard]

Our 'disagreement' seems to be the interpretation of the report, so here is what I
understand by reading the document:

A - vs USAAF planes
1 - all tested planes, except the F4F, are faster than the zero in level flight
2 - Zero can outturn/outmanoeuvre all tested planes below 300 mph at any height,
except P38F above 20.000 ft where zero is superior only in slow speed turns.
3 - Zero has better zoom acceleration/climb/dive than any other type
4 - Sustained climb relative performances depends on the opponent aircraft :
- vs P38F the zero is better up to 18.000 ft, then the P38 is better
- vs P39 the Zero is less performing up to 12.500 ft and better above that height
- vs P51 (Allison engine) the zero walks away in climb up to 15.000 ft, no test above because
of P51 engine problems. P51 is much faster than zero in level flight and in dive. (this is no
surprise, the P51 and zero are almost at the opposite concept of fighter planes.
Also it is clear that the P51 was basically a prototype, still far away from his real
potential)

I recall reading somewhere that this was, indeed, a straight P-51.

About relative acceleration, it is not clear if the tests are started at the optimal speed for
the US fighters or for the zero (being the starting speed always different it may be that
the test is run at optimal speed for the US fighters)

Something I wondered about, too. There are references though to starting from a
common speed.

-P40 was not tested because of engine problems (question: this test was important, why
they did not get another P40 or a replacement engine? Maybe because, knowing the
performance of the P40 vs P38-P39, they could extrapolate the results? And so, why they
did not even put a line of comment about that?)

Having some idea how these things work, the tests were conducted at North Island NAS,
a place not particularly known for having spare P-40s lying around, The gents from Eglin
AAF undoubtedly brought their own planes with them from Florida and when the P-40
decided not to cooperate, then they were just out of luck. Even if they could locate a
nearby P-40 unit, I seriously doubt the CO would be willing to loan one of his planes to
some hot-shot test pilot from Florida to fly in some sort of flight test at a naval air station.

B - vs USNAVY planes
The chapters of Zero vs F4F and F4U are not detailed (and you explained the reason
why), but the summary seems very clear :
- vs F4F : the zero is always superior or equal to the Wildcat
- vs F4U : the Corsair is almost always superior to the Zero
btw, is there any copy of the Navy pilots detailed report? In the first page they say 'Navy
pilots handled the trials against F4F-4 and F4U-1', so it seems likely that this team had
prepared a detailed report for the Navy.

I have been unable to find a report specifically giving the results of tests against USN
types.

In summary, I believe that my original impression " ... is superior or holding well in
comparison to the US planes, except with the Corsair " is correct.

This, as I had made clear, is valid as a 41-42 snapshot, we all know that the Jap plane
was not significantly improved afterwards, while P38, P51 and F4U were strongly
developed.

This was my reading of the official document, where do you disagree?

I don’t know if I would actually use the word “disagree.” Certainly, the results of the
tests were clear. I suspect the difference is in the interpretation of the purpose of the
report. I tend to put more of a 1942 era spin on it, having gone over this and other
reports in detail with some who actually flew this plane and had more than a modicum of
experience in the arena of flying against A6Ms. In short, while possessing detailed
comparisons, mostly relating to climb performance, it is the intent of the report that is of
significance.

The purpose of the report is to identify for the USAAF pilot who might find himself in
those Pacific Theater areas where he will encounter some, to say the least, difficulties in
dealing with the A6M problem. It also points the way to avoid those situations in which
the A6M is in its optimal performance envelope and play to what strengths one’s own
aircraft might enjoy.

There are features in the report that are at odds with the reality of air combat in the
Pacific. For example, and especially in the 1941-1942 period (at least in the USN end
of the business with which I, admittedly, am most familiar) most air-to-air fighter
engagements were fought at 10,000 feet or less. This is primarily due to the nature of
air-to-ship strikes. The attacker must get down to where the ships are, therefore the
defending CAP or the strike escorts must meet in that area where the attack group is
moving towards its final attack position. You see this over and over again at Coral Sea,
Midway, Eastern Solomons, and Santa Cruz (although there is the rare exception such
as the Japanese strike escort breaking off from their charges and attacking the Enterprise
strike group as they passed each other during the Santa Cruz action). So for the most
part, in actual action, these fighters are finding themselves at, when compared to air-to-air
action in Europe, relatively low altitudes. Performance at 20,000 feet is interesting, but it
was not the, then, norm in the Pacific. The purpose of achieving these higher altitude in
the Pacific was to get above ones adversaries so as to accumulate the speed advantage of
an overhead approach.

Thus the opening sections of the report (Conclusions, Recommendations, Offensive and
Defensive Tactics, and, then, later, the Flying Characteristics section) are what are
important, the effective rules of the game for fighter pilots to remember in order to, at the
least, survive encounters with the A6M. All that follows is the background from which
these conclusions were drawn; providing specific information on where one’s aircraft
might be at some particular advantage or disadvantage. For example, one might note the
surprising performance in climb of the P-39 versus the A6M at altitudes below 15000
feet, hardly what one would expect from an aircraft with a reputation as a clunker. Too
bad there’s no discussion of relative maneuverability between the two types.

This makes a lot of sense, point is that 300 mph is quite a high speed for 1941-42,
normally far above the normal cruise speed and flight envelope. It became 'normal'
with the next generation of fighters, and we all agree that the Zero did not kept the
improvement pace.

But was 300 plus miles per hour unusual for combat situations in the fighters of the day?
Well, bearing