Why the early war Japanese fighters were structurally fragile and unarmored?

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ColesAircraft said:
Easily, when the only person in the world who owns four Zeros says so.
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And the last time he flew one?

And kudos to him, but at the same time I see no substancial evidence supporting his claim about the Camarillo Zero
ColesAircraft said:
There may likewise be some pro-American bias in this as well on the part of some pilots. I don't know. I just thought I'd help answer the questions posed in this thread with my experience.
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In your experience have you ever flown any of these aircraft (or similar)?
Ok, I'll but that, but according to thouse who fly the Camarillo Zero, the fact that an 1830 is on the front end of the aircraft means little under 200 knots.
ColesAircraft said:
But, Jeez! Now I know why I avoid posting in forums. Put this effort into debating heath care or something.


Ron Cole
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We would if this was a boaring political forum.
 
As far as we know at the Planes of Fame, there are reasons for the Japanese approach. When we restored our A6M5 Model 52 Zero, with the original engine, we had the help of the original designer, Jiro Horikoshi. Accoring to him, the Japanese Military was interested in the absolute most maneuverable monoplane fighter in the world. They were working on a larger more powerful radial, but didn't have it yet.

So, he set out to use the radial avaiable. In order to get the required performance and strength, some things had to be left out. It was the only way to meet the requiremnts, and Japanese pilots were considered expendable ... until veteran pilots fell into short supply. Then the new recruits were considered as expendable, but the veterans weren't.

Anyway, the Zero is as strong as a P-51 Mustang when everything is complete, but it rapdily loses strength when battle damage begins to accumulate. A lot iof the skin is .032" Aluminum instead of .040 or thicker, as on western fighters of the time .... but WE were flying more powerful engines and they weren't. The Nakajima Sakae was based on the Gnome-Rhome 14, but was a Japanese design and not interchangeable with the GR 14 at all. It was reliable, too, and still is.

Later, the A6M8 was designed with a 1500 HP engine, but never made it into service.

It might be interesting to point out the Me 109 was similarly design with minimalist design philosophy. There are three wing attach points. When all three are there, the plane is srtong and robust. If you lost one attach point, the wing departs company with the aircraft at the slightest provocation. That is why most American fighters have multiple wing attach points ... for ruggedness after sustaining battle damage. Of course, we are not the only people who do that, and I do not mean to imply that.

I only mention the design practice since the Japanese designers were hamstrung by the available power and still managed to produce a lightweight fighter that could perform with the best in the world when it came out and for several years thereafter. Therein lies a pretty great achievement, even if at the expense of robustness. The fact that they didn't follow up with a more powerful design faster is not the fault of the designer or even of Mistubishi ... it was war and the IJA and IJN were responsible for not thinking of the long-term effects of sticking with a lightweight design when newer Allied fighters designed to combat the existing aircraft were coming down the pike.

The German high command was likewise responsible for the fact that they were still flying the Me 109 in 1945 instead of batches of Ta 152's and the like.

Other countries, the U.S.A., Great Britian, and Russia notably all fielded later designs that took into account for the opponents the previous generation of fighters were facing. If Japan and Germany had done the same, and had proceeded with the manufacture of same, things might have been much more "interesting" in 1945. Good thing for the Allies they didn't.

I can say this about our Zero at the Planes of Fame, it is strong, reliable, and VERY maneuverable ... just as designed. We are still flying on the same engine the airframe was captured with in 1945, and it is running just great!
 
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I am not judging it based on ground observations. I am basing it on conversations with people who actually FLY the aircraft that exist and fly today.

ColesAircraft said:
And, indeed, the myth that the Nakajima Sakae was a copy of any other engine originated in the bigoted environment of wartime when whites couldn't conceive that the Japanese were capable of independent ingenuity.
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I have heard that argument before and from what I have read and seen, it had basis from other engines.

I am familiar with Mr Harada and while I respect his work and knowledge, he has never flown any of those aircraft. I have spoken with at 5 different people that have flown the Zero at Camarillo. There are currently two Zeros there. The second one showed up last August prior to the airshow and is a sister ship to the Camarillo one, both found on Babo Island airfield.

Don't assume because I attend airshows and take photographs of airplanes that I don't know about them.
 
This discussion seems lively, doesn't it? The propeller on our Zero is Japanese and is interchangeable with a Hamilton Stanard since it was made under license in Japan to H-S drawings.

The Sakae 21 engine is Japanese and is NOT interchangeable with a Gnome-Rhone 14 or any other Gnome -Rhone. The Japanese made improvements and built their own design ... and it is reliable and well made. If you own the 1944 Fighter Conference proceedings, you will see that the Zero is the ONLY fighter in the group that didn't experience a mechanical failure in the flight tests. Surely that says SOMETHING about the Japanese Sakae 21 engine, huh? Ours still runs great every time we crank it up, and it's 70 years later. It is the ONLY example flying and it is DEAD reliable so, unlike the American or British or Russian radials, we have a population of ONE and it runs great all the time.

MTBF? ..... LONG .... in our experience ...

I'm impressed with it, even if it IS a lower-power engine.

Of course, I also think the Zero is the prettiest radial-powered fighter ever made ... and that may be personality fault that is not correctable ...
 
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Evanglider wrote: "Don't assume because I attend airshows and take photographs of airplanes that I don't know about them."


I assumed no such thing, as I never assume anyone I don't know and have never met is ignorant just because their information may be counter to what I thought I knew. But a few here don't extend to me the same courtesy. This is my first post here in two years. I shared what I know based on my life's work studying and writing about this subject - almost exclusively. That doesn't mean I know it all, and that doesn't mean people aren't entitled to completely disagree with me and say so. But I'm of the opinion that when someone takes the time to share their knowledge with others, it should be received with the grace with which it was provided - not picked apart for the sake of a good argument without so much as a polite "thank you". At the same time I admit that I find online forum discussion to be typically argumentative and sometimes abusive; it often rubs me the wrong way, which is why I rarely contribute.

I shared my information, which was my intent. I'm an aviation artist. That's my living and my business. I don't have time to argue for the sake of arguing. To each his own, but that's not my idea of a wise expenditure of effort. I apologize if that sounds condescending.

As for what I wrote previously: I may not be pulling detailed stats off of Wikipedia but for most of my life I've broken bread with the men who actually fought in these machines, test flew them, and influenced their design. With all due respect I'm not going to have what I learned from those men, and elsewhere, overturned by anything anyone has to say here - at least insofar as wartime configurations are concerned. That the Zero's performance "suffers dramatically" without its original Sakae . . . I thought that was a universally accepted given fact. I've heard it from so many sources over the years that I can hardly quote only one, though Harada made it especially clear and he's absolutely in a position to offer valuable insight on the matter. I also recall a report written shortly after the CAF's Zero made its first test flights that confirmed that as well. Every Zero owner I know in the world goes to extreme lengths to try to find and restore an original Sakae for reasons other than originality - it's a requirement to make a Zero fly like a Zero!

If anyone doesn't want to believe that or agree with it - that's fine. If anyone wants to be rude and fight over it - I have airplanes to paint.


Ron Cole
 
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A terrific contribution! I once sat in that Zero with the engine running. That was years before the landing gear accident and I hear that another opportunity such as that will probably never happen again. But it was glorious! I sat in the Raiden, too, thanks to Steve Hinton and a screwdriver - before Ed Malony had the cockpit of that aircraft spray painted metallic green. It was still all original Mitsubishi 'bamboo' at the time. My last visit with that bird, which is my favorite aircraft in the world, revealed the extent to which the spar cap exfoliation has taken its toll. Even in 1987 Steve warned me not to "move around too much" in the cockpit for fear of landing gear collapse. But short of a full and expensive restoration there is little that can be done.

It was nice to hear from someone close to those birds. Speaking of which, I'm off.


Ron Cole
 
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i'm not a engineer, not a mechanic and i not understand this things, even i've not the driving licence for car. But the GR 14K and Nakajima Sakae they look very different from the "numbers" bore and stroke are different (also the proportion are different), the GR-14K has around same weight with more displacement so the construction was different, etc..
 
As in other parts of life there are people that disagree. We all have different sources and different points of view on things. I have helped work on the CAF Zero, spoken with several of the pilots that fly the remaining Zeros as well as a couple of them that flew them during the war.

I will agree that the survivors aren't flown like they were in wartime, nor should they be, but I don't agree that the performance "suffers" with the P&W. Thankfully, they're flown as historical displays now instead of weapons of war. I believe that most Zero restorers want the Sakae engines for two reasons; one, they are rare and valuable and two it makes the aircraft more historically accurate. Wartime performance and MEP are not key items for these birds now. Honestly, I don't care what engine it has in it, as long as it flies and people can see it. Besides that, no one can hear the engine in my photographs.

Getting back to the original subject, I wouldn't call the Zero "Fragile". Lack of armor plate kept the plane lighter, and increased range and performance. Self-sealing fuel tanks weren't in some early American aircraft either. Some lessons are learned over time.

In regards to the engines, I have heard the Gnome Rhone 14k variant, and have also heard that it was "derived" from the P&W Twin Wasp. The Japanese were indeed building license twin-wasps before the war and I would guess the engineers of the time studied all foreign aircraft engines to see where they could improve/modify them. Does that mean they copied them? No, but like any good engineer, I am sure that the Japanese engineers looked at the other works to see what worked and what didn't and how changes could be made to original designs to come up withe something better. Obviously, they succeeded.
 
Ron, understand that on this site, there is a great wealth of information gathered, exchanged and debated and yes sometimes it turns into an argument. Like you many of us have spent many years around aircraft (I've been in the aviation business going on 34 years, have an A&P/IA, CFII and I have also worked on and flown several different war birds and jet aircraft), so when a "broad brush" comment is made, those of us who have worked on these war birds tend to question their validity and if there is something to be learned based on documented fact or direct information from a pilot of maintainer, even the better. I never thought you were condescending so please don't think any of our comments were, it's a matter of extracting and validating accurate information so we can all learn by each other's experience.

An old saying - validated performance numbers don't lie, oppinions can be debated!
 
I have an old copy of Flight Journal, where Corky Meyer writes about testing, I believe it was the Aleutian Zero, and he mentions that the engine in the plane was a copy, or license built copy of a American engine. I'll have to pull the magazine for the accurate info, it's part of my bathroom library. But IIRC, he states the engine was a copy even down to the American company's logo (cannot remember which American company he is referring to), which had I believe the middle of the logo had been altered with a Japanese stamp or design in the middle of the logo? Anyone have any info on this? I have had this question on my mind for quite some time, and this seemed like a opportune time to ask. Is Corky Meyer incorrect? Anyone have any info? I'll pull the magazine and re-read the article to get the exact details as they were written. It may not have been Corky, but that is the name that is sticking in my mind.

Thanks in advance. Great thread by the way, and thanks to all who have contributed.
 
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A number of other Zeros were captured by the Americans after the recovery of Koga's Zero in the summer of 1942, including a dozen A6M5s obtained after the fall of Saipan. A Grumman test pilot named Corwin H. "Corky" Meyer flew an A6M5a in October 1944 at a conference where the latest American, British, and captured enemy fighters were evaluated by test pilots in attendance.

Much later, Meyer wrote an interesting memoir of his flights. Meyer said the Zero looked "every bit the fighter" and regarded it as the "best looking fighter at the meet." He found it a delight to fly, and was surprised at the quality of manufacture, since in America at the time and indeed well into the 1960s "made in Japan" was the same as saying "junk". "The workmanship was superb and comparable to American quality. This was most amazing in light of the prewar Japanese products with which most of us had come in contact."

Meyer noticed that the Sakae 21 engine announced its Pratt Whitney ancestry by conscientiously displaying the Pratt Whitney logo with an eagle on it and the English term "Quality Reliability", along with the Nakajima name in Japanese. Although Meyer was 190 centimeters (6 foot 3 inches) tall, taller than any Japanese pilot, he found the cockpit surprisingly comfortable, though his feet felt tucked under him. He found one detail particularly interesting....

"Another un-American feature that must have given Japanese pilots mixed emotions was the protrusion of the 7.7-millimeter-type (0.303 caliber) gun butts six inches [15 centimeters] into the cockpit on either side of the instrument panel. I'm sure they gave a very macho feeling to the pilots when firing, with the racket, the nearness of the action, and the ability to unsort guns manually. With all the cordite fumes, I do hope the Japanese pilots had good 100% oxygen masks. Also, the gun butts must have been most disconcerting and disfiguring in a crash.

The Mitsubishi A6M Zero
 
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Ron Cole,

Our J2M Raiden has some serious intergrannular corrosion issues, but is a beautiful aircraft. When we finish the Bell YP-59A, I'd love to take a crack at the Raiden! It would require a new wing spar and spar caps, not to mention many other items including longeron, but could be done. The only question is whether or not the Planes of Fame staff wants the Raiden to be restored or prefers it as-is.

As for the Zero engine:

The Nakajim Sakae 21 is a Japanese design, not P&W and not Gnome-Rhone. They used design features taken fromm other radials, but ALL radials do that ... or else they're completely different engines.

There are other two-row, 14-cylinder radials out there, but the Sakae 21 is not a copy of any of them as far as I know.

I don't know about the Zero needing a Sakae to fly like a Zero ... it would seem the powerplant would be unimportant as long as the weight and power are close and the RPM range is similar. However, I don't really KNOW, so I can't argue the point at all. I'll ask about the weight, power, and RPM and see what comes up. We can find the weight, power, and RPM on the internet, but I prefer to verify with actual pilots and mechanics on an original A6M5 Zero to trusting Wikipedia ... which is wrong almost as often as Obama.
 


My understanding is that all other Sakae-like replacement engines are moderately larger than the Sakae and usually require new-build cowlings to accommodate them - at least that being the case with the A6M2 - and thus resulting in a host of modifications that go beyond just an engine swap, not to mention what that does to the center of gravity. Such issues resurrect the original problem with the Zero in terms of its relative inability to be modified in wartime to accommodate heavier equipment. It was the first aircraft in the world, it is believed, to have incorporated its duraluminum skin as a structural member. Before that, aircraft were structurally designed on paper to withstand certain forces, then covered to be aerodynamic - but that's how far the designers went to keep the Zero light. It doesn't suffer added weight well, in any form.

It's been my dream to see the Raiden restored, but I don't have much hope for that in the near future given its condition and the fact it most probably can't ever be made airworthy again. I know that it had languished outside in a park for many years before Ed acquired it. By then corrosion was already a problem and the aircraft suffered much from pilfering. The cockpit is still relatively complete - except for its gun sight, some instruments, and its throttle quadrant. I inspected the inside of the fuselage, and noted that it had been built at a period in the war when the previously standard Aotake primer had not been applied. There was an even coating of light corrosion plainly visible throughout and was probably worse where I couldn't see - but the original stenciled factory-painted serial number placard was still there! God knows what the inside of the wing looks like though. Today the wings noticeably sag, there's usually some exfoliated aluminum on the floor from were it falls off the exposed spar caps, and the left landing gear must have partially collapsed sometime recently - as there's relatively new damage to the wheel well area near the gear strut.

Someone please save her!


Ron Cole
 

From what I understand the Camarillo Zero's cowl is actually the same size as the original Zero cowl however there were internal components altered to accommodate the slightly larger P&W engine and again from what I understand the size difference is nominal. Eric might be able to get info on that as he's a regular around that aircraft but from what I read about the two engines the difference in diameter is about 3 inches. C/G issues in minor structural mods are usually non events and many times are easily remedied by using ballast in the nose or tail, if even necessary. As a matter of fact sometimes ballast is necessary to compensate for obsolete wartime equipment (mainly radios) removed during the restoration.

I don't believe the Zero was first aircraft to incorporate aluminum (or duralumin) skin as a structural member. I can recall portions of the DC-3 that had skin carrying a structural load and were repair sensitive if damage was over a certain size.
 
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The latter may be true. I only know that Jiro Horikoshi's design team had tried and failed to design on paper an aircraft capable of meeting the Navy's specifications due to weight until Mr. Horikoshi had the idea, presented as independently derived at, to incorporate the aircraft's skin in the design itself as a structural component. I think arguably the Junkers J.1 was probably the first aircraft anywhere to incorporate this idea - though very differently. But that's not the only instance of problem solvers independently arriving at similar, but not copied, solutions: another example being oblique firing cannon.

Someone also mentioned earlier that the Zero's controls "turned to concrete" at high speeds. True. I've heard it cynically stated that Kamikaze pilots would often have been unable to pull out of their dives even if "sense" came to them in their final moments. I know that, at least for the Japanese, rigidity in the control cable system was a required priority in aircraft design - until the Zero. Horikoshi's problem with the new aircraft was its unprecedented speed and the fact that as its speed increased there was a dramatic increase in the sensitivity of its controls. This was discovered during the A6M1's first test flight, along with vibration problems due to the two blade propeller (which was then switched to a three bladed variant). The rigid control cables of the prototype were replaced with cables that would 'give', and that solved the problem: as wind resistance on the control surfaces increased, the give in the control cables compensated, and the pilot did not experience the over sensitivity to input previously suffered at higher speeds. But what Horikoshi did not mention was how that solution impacted control at dive speeds. "Concrete" is thus an apt description for it.

All of this highlights some of my original point regarding Japanese philosophy and how it was independent of limitations posed by technology or economics. I understand that accepted theory, in the West at least, states that the Japanese merely made do with the best that they were capable of producing, maneuverable but under powered Zeros being in part the result. But I (obviously) disagree. Japanese aircraft were designed and produced for the offensive, and their doctrine emulated that as well. The Zero wasn't designed with armor plate in part because theoretically it would never be within enemy cross hairs to be hit in the first place. Yes, some of that was based upon pragmatic considerations of how armor would sacrifice performance, but there was also an element of uniquely-Japanese confidence within it. Why should the Zero ever need to escape a dogfight by diving, when it will rule every opponent it faces? These men typically refused to wear parachutes until late in the war, when they were ordered to - even then often using them only as seat cushions. Such wasn't fighter pilot bravado - it was indicative of a culture that permeated design boards and industry as well as the men at the front. A Japanese pilot was expected to maintain the initiative or fail, to fail meant death, and their equipment was designed with that idea in mind at the expense of everything else. Were they "fragile" machines by Western standards, incapable of taking hits? Absolutely. The Americans didn't nickname the G4M the Flying Lighter without good reason. But these things were not regarded by the Japanese as design faults until after the fact, when losses mounted and the fate of their culture demanded that they rethink their original ideas and adopt designs employed by their more successful enemies. To judge an aircraft like the Zero fairly, I think it should be seen at least in part through the eyes of its designers; in that it did exactly what it was designed to do, exceeding all expectations, sacrificing only that which was considered expendable.

The Japanese did not largely dispense with using parachutes because their industry could not manufacture them, and when the Japanese wanted to build heavy fighters with powerful engines (like the Shoki and the Raiden) the Japanese built them, and they were good machines. Thus the Zero was a product of a philosophy - not technological or economic frailty.


Ron Cole
 
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I apologize for getting piqued on the forum. My somewhat younger wife reminds me that a forum thread is not the same as guys talking at a table - though I stubbornly tend to brush off the idea that the etiquette should be any different. I sign my full name to what I write, removing 'anonymity' without a thought, and unintentionally making the discussion personal. I just assume that without signing my name, what speaks for my credentials when I spout off like a know-it-all?

But I was only trying to constructively add to the discussion, offering my information as points of potential interest. My history with Japanese aviation has very much been influenced by the Japanese perspective, as most of my connections to same have been the Japanese themselves. That is very different than what one might glean from the modern restoration and operation of these aircraft and their modern modifications - though I don't claim one perspective is superior to the other.

I'm reminded of how Japanese veteran pilots almost always refused to autograph Western-painted aviation artwork (in contrast to the vets of other nations - including Germany). In spite of all the handshaking and goodwill between former enemies that went on, there remained from the Japanese side a certain shame mixed with stubborn pride and a trace of bitterness - that the West was taking something from them that it had no right to take when it painted their airplanes - usually flaming at the guns of a P-40 - or restored a Zero for primarily Western air shows. These are somewhat generalizations, of course, but in my circles it was always taken for granted that the Sakae was an "irreplaceable" engine - for example - and that the Zero's performance "suffered dramatically" with an American made stand-in. I still believe that's true, though concede that some prejudice may be evident here from both sides. A real, unbiased, test regarding the matter would be interesting.


Ron Cole
 
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