Top 3 mistakes per country, in field of military aviation

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

The A6M3 performed much better than P-39D or P40E at altitude.

No, it was A6M2 that performed better than P-39D and P-40E at altitude. That was clearly indicated by combat over Australia, Dutch East Indies and New Guinea in 1942. The supercharger enabled it to engage targets at 20,000 feet without problems , and up to 30,000 feet if it was really necessary.
Here is a quote from "Eagles of the Southern Sky" book ( Eagles of the Southern Sky ) :
"After the war, former RAAF No. 75 Squadron pilot Pete Masters would recall his time fighting the Tainan Ku. On the performance of Zeros he wrote : There was much more we know now that we didn't know before we got to New Guinea, like the ability of Zeros to outperform us, contrary to what we had learned before we arrived. We were told that Japanese Zero was an upgraded copy of the Harvard Trainer as used by the Empire Air Scheme in Canada. It was underpowered and flimsy with very light aluminium and canvas cladding sometimes joined by canvas at the extremities. It had no armour plate to protect the pilot, and although it was reputed to fly higher than the Kittyhawk it was much slower and inferior in almost all its characteristics, including firepower. I am now sure that all this misinformation came about because very few Allied fighters had encountered Zeros in combat prior to New Guinea and those that had in Malaysia, the Phiilippines or elsewhere had never had a chance to examine the real specifications of this amazing aircraft at close quarters.

In fact when I at last saw a Zero on the ground and crawled all over it I too was amazed at the rigidity of its structure and its apparent fighting qualities from the cockpit. In our combat assessments at Port Moresby during the 44 days we fought, we soon concluded that head-to-head combat between Kittyhawk and Zero was unwise, and at altitudes above 20,000 feet was simply dangerous.
They were much more maneuverable and could outclimb us in the ratio of two or three to on. What they didn't have was our weight and pilot protection with 1/2 inch armour plate behind the pilot and in the firewall. Our battle plans therefore always included a desire to get above the enemy, if possible into the sun, and then to break away and come back for another shot. If we had height we could always get away from the Zero but with equal skills as pilots on both sides, the Zero always had the advantage at the same height and also could maneuver much more effectively above 20,000 feet where the Kittyhawk would tend to "fall out of the sky".
"

Sakae 12 still maintained over 800 HP at 20,000 feet which is as much as on Sea Level at rated power. That's quite good actually.

However, both P-40B and P-39C were at least as good, and were better than contemporary A6M2. The good (not great) altitude capabilities of Zero, prior 1943, were very much a function of no protection, light guns' weight and light ammo load, and less due to having some great engine.

Exactly same thing can be said about mentioned by you aircraft, P-40B had no protection and instead of 6 .50 caliber machine guns it had only 2 in fuselage and 4 .30 cals in wings. Was 1.500 lbs lighters as well. P-40B still was climbing slower than A6M2 and its speed decreased fast after 15,000 feet. Allison engine was not delivering enough power at those altitudes.
P-39C also had no protection for pilot or self sealing fuel tanks, it did not have two additional .30 cals added in D model. And climb performance was marginally better if compared to A6M2.

So not sure what makes them ... better ?

In regard to weight of the armament, I think its rather a positive feature that gun is both reliable and light. No designer wants a lot of added weight.

Once it acquired protection (but not for fuel tanks), better armament and heavier ammo load, both speed and RoC plumeted.
You mean once it acquired three more 13.2 mm Machine guns, bulletproof windscreen, armored plate behind pilot seat, underwing racks to carry air-to-air rockets and 250 kg bomb ? Obviously. But thats also because Sakae 31 was not performing as expected with water&methanol injection and engine was reversed to a similar performance of Sakae 21.

The Kinsei, in the A6M8 prototypes, restored the loss and added some performance, but it was too little, too late.
It only restored the performance ... to a level of 1943 A6M5. The aircraft reached 563 km/h which is marginally slower than A6M5 which had a top speed of 565 km/h, the time to altitude was improved by mere 11 seconds. However landing speed has increased, thus indicating also a higher stall speed. Aircraft definitely had inferior flight characteristics, including the maneuverability.

We already had that discussion how brilliant it was be to fit A6M with Kinsei engine. Except it was not ...

And yes, the IJN, and/or it's suppliers, failed in procurement of next fighter to replace the Zero, while they squandered many resources and time fiddling with floatplane fighters, plus with separate land-based fighter.
This statement is absurd.

In 1940 the Mitsubishi received from the Kaigun Koku Honbu Gijutsubu the preliminary specifications for the 16-Shi Carrier fighter which was intended to replace the Zero. It was intended that the new aircraft, which would not be available in quantity for several years, would become the Navy's standard carrier fighter when the Zero had reached its limit in modification and improvement.

However, in 1940 the Mitsubishi was experiencing serious difficulties in the development of the 14-Shi land-based interceptor (J2M Raiden); the company was plagued by a shortage of competent engineering personnel and the lack of a satisfactory engine for the J2M Raiden design. These circumstances delayed the 16-Shi carrier fighter program for at least a year.
But despite eventually solving problems with J2M the development was again postponed. In the autumn of 1941 Horikoshi became seriously ill and did not recover until several months had passed. The Navy preferred not to undertake the design project without my active participation. First engineering meeting to plan the new fighter was held on 14th April 1942, at the Japanese Naval Air Research and Development Center. In the long interval which had elapsed, the plane was renamed the 17-Shi carrier fighter.

From Horikoshi memoirs on A7M :
In the light of past experience, I estimated that at least three years would be required to place the new fighter in actual operations. Because of the poverty of our industrial potential, frequent changes in fighter-aircraft types were a luxury we could ill afford, and my activities were always influenced by this situation. I thought it imperative that we concentrate our efforts on the principle of holding aircraft types to a minimum. To utilize to maximum efficiency the nation's limited manpower and personnel, we took special pains with the fighter project to insure an airplane superior in performance to that expected of the enemy three years hence.

The failure in providing a successor of A7M was than a combination of bad luck and stubborn Navy, Kaigun Koku Honbu Gijutsubu forced on Horikoshi a decision to use NK9K which proved unable to deliver expected power and effectively making aircraft underpowered. Horikoshi from the very beginning tried to lobby for much better developed Mitsubishi MK9A which not only delivered more power but was also very reliable and could be maintained by even less experienced ground crews. His opinions were rejected until flight tests carried on A7M1 in June 1944 proved that Homare engine is not a good choice here and during a meeting in late July decision to use MK9A was taken.
A7M2 first flew in October 1944 and all tests indicated that aircraft finally had very good performance and characteristics. It could be finally put into production.

But then on December 7th 1944 a heavy earthquake in Oe-machi where Mitsubishi plant was located damaged the factory sufficiently to prevent any production there. 5 days later B-29s bombed Oe Airframe Works of the Mitsubishi in Nagoya temporarily suspended all production activities, and few days later B-29s made their first attack against the Daiko Engine Works of Mitsubishi in Nagoya and, on 18th December, returned to batter the Oe Airframe Works. The air raids smashed machines and production lines, killed hundreds of workers, and threw the great factories into a wild state of confusion. The New Year brought even worse air attacks; the Daiko Engine Works received the heaviest blows. It was hugely unfortunate for the Japanese that this tremendous engine plant was so badly hit, for it was responsible for the production of the Mitsubishi MK9A engine. At the same time Jiro Horikoshi fell sick, and development was continued Yoshitoshi Sone. But it wasn't until end of the war when Mitsubishi could start delivering A7M2.

The failure in providing a next generation fighter was as mentioned a combination of bad luck, stubborn Navy leaders and Mitsubishi lacking manpower to work on multiple projects. It had nothing to do with other manufacturers, who had their own designs to work on. No Air force is based only on fighters and Navy obviously had to call for other types of aircraft.

Sidenote here is that Horikoshi claimed later on that Navy would choose from the very beginning MK9A than fighters could be delivered before B-29 seriously started bombing Japanese mainland.

In hindsight (and perhaps a bit of foresight) the Zero should have gotten the Kinsei much sooner.
Which is exactly when ? Kinsei 40-series was rejected during development by Horikoshi himself. Series 50 became available in extremely limited numbers in 1942.

Mitisubishi had wanted to fit it after the first prototypes had failed to make the desired speed with Zuisei engines. The Japanese navy insisted on the Sakae engine, in part due to the extra range they expected.

This is not correct either. There was never a choice between Sakae and Kinsei. There was choice between Kinsei and Zuisei.
And Horikoshi explained :

Only when the engine has been selected can a designer produce a draft of the airframe. In case of Prototype 12 (12-Shi - prototype name of A6M) the Mitsubishi Kinsei Type 46 and the Zuisei Type 13 were listed as candidate engines, the Kinsei being the more powerful of the two. If we used the Kinsei, we could have an airplane with high performance and high speed in one jump. For just that reason I felt it should be selected. This was in keeping with my philosophy that it would be better to design a high performance fighter in one big leap rather than to eventually reach that goal by making numerous small improvements to a lower performance aircraft over the span of its lifetime.
But there was a fateful obstacle in using Kinsei: it required a bigger airframe. The Kinsei was more powerful than the Zuisei, and it also was larger, heavier, and consumed more fuel. Because of this the airframe would be larger than if a smaller engine were used, and the fuel weight would be greater. In order to carry the increased weight, the wing must be larger and the fuselage and tail would also have to be larger. This, in turn, would require a stronger landing gear and yet another increase in airframe size.
A quick weight estimate showed the airplane's weight would be about 3000 kg. This was acceptable for a land-based plane, but pilots accustomed to flying small 1,600 kg Type 96 fighters would not readily accept the heavy new fighter. And this would mean the loss of the Prototype 12 contract. In contrast, if we used the Zuisei engine, the airplanes weight was estimated to be about 2,300 kg, the wing span would be in the neighborhood of twelve meters with a wing area compatible with a good fighter performance.
I thought this was about the maximum weight that the pilots would accept. Instead of pondering the future of the aircraft, our immediate job was to win the contact. I decided, "Okay, let's get on with it." When I reported my decision to use the Zuisei to Mr. Hattori, he approved.
Source: Eagles of the Mitsubishi - The Story of Zero fighter by Jiro Horikoshi

Aircraft is always a compromise, and engine being a heart of the warbird affects all other systems - heavier and larger engine requires stronger and larger airframe, rises the amount of fuel that has to be carried to maintain the range, etc. etc.

And no, first prototype did not fail to meet the required speed. During first flight trials on 17 and 18 April 1939 aircraft reached a speed slightly over 490 km/h. After corrections (as you all know speed indicated by gauge in cockpit is not a true airspeed) the actual speed was recorded as 508 km/h. Requirement called for 500 km/h at 4000 meters.
Thus Mitsubishi satisfied the requirement during very first trials.

Sakae 12 was not installed by May :
Also, on this day (May 1st), the Navy Aeronautics Headquarters gave us permission to install the Nakajima Sakae Type 12 engine in the number three flight test aircraft and it was designated as the A6M2.

Granted the early Kinsei didn't have the power of the one fitted to the A6M8 but in 1942/43 it had about 100hp more at most altitudes (about 10%) than the Sakae. It's larger diameter would have meant deleting the cowl guns. It might not have given extra performance to the Zero but might have allowed the increases in protection and firepower without the decrease in performace that happened.
Kinsei 40 series was rejected. Kinsei 50 series delivered a lot more power but consumption of fuel was also much greater. And at that time range was crucial due to combat at Salomon Islands (hence why A6M3 model 22 was developed). So potentially yes, aircraft could be provided with protection, but that would reduce drastically its ability to escort bombers at ranges they had to operate.

The Japanese fell into the same trap the Germans did at times, in not spending enough effort in incremental changes in existing aircraft and trying to get a quantum jump in performance/capability with totally new designs.

No. Japanese did not fell into that trap. Japanese did something else, their policy was to do a great jumps with every following machine - > A4N -> A5M -> A6M -> A7M. But problem between A6M and A7M was that Mitsubishi was doing exactly what you suggested, spending a lot of time designing further improvements to A6M and developing J2M. Then extremly bad choice for an engine, problems with Horikoshi health and lack of personnel slowed down any progress.
 
I would say in general
1 Consider your enemy produces equipment as good as you do. I cannot see why Hampdens and Wellingtons were sent out in daylight when it must have been obvious they could not protect themselves from hurricanes and spitfires while everyone knew the Germans had the Bf109 before war was declared. How could it be thought the defiant could survive against the BF109. The same goes for He111s crossing the North Sea to north England and Scotland.

2 Consider outlandish possibilities your enemy may present you with, from Germany overrunning France in 6 weeks and producing jet fighters, to the UK managing to keep their aircraft off the ground and always intercepting your raids. Consider what you would do about an enemy doing 100% better in every way than you thought was physically possible 5 years ago.

3 Assume that as soon as a new technology is used it is completely understood by your enemy, who may already have it but not use it (as with window) and assume that your codes are broken as a matter of course.
 
Last edited:
No, it was A6M2 that performed better than P-39D and P-40E at altitude. That was clearly indicated by combat over Australia, Dutch East Indies and New Guinea in 1942. The supercharger enabled it to engage targets at 20,000 feet without problems , and up to 30,000 feet if it was really necessary
....
Sakae 12 still maintained over 800 HP at 20,000 feet which is as much as on Sea Level at rated power. That's quite good actually.

Thanks for the effort to type this out.
Yes, the A6M2 will have better power-to-weight ratio than either of the two US fighters above 15000 ft, meaning better climb, even of drag is a a bit greater than in those US fighters.

Exactly same thing can be said about mentioned by you aircraft, P-40B had no protection and instead of 6 .50 caliber machine guns it had only 2 in fuselage and 4 .30 cals in wings. Was 1.500 lbs lighters as well. P-40B still was climbing slower than A6M2 and its speed decreased fast after 15,000 feet. Allison engine was not delivering enough power at those altitudes.
P-39C also had no protection for pilot or self sealing fuel tanks, it did not have two additional .30 cals added in D model. And climb performance was marginally better if compared to A6M2.

So not sure what makes them ... better ?

My point being that there is no such thing as a free lunch. Want protection, on same HP? Okay, your rate of climb will be lower.
The P-40B featured 93 lbs of armor and external protection for fuel tanks, per 'US hudred thousand', pg. 236. The P-39C was also cosiderably faster than either P-40B or A6M2.

In regard to weight of the armament, I think its rather a positive feature that gun is both reliable and light. No designer wants a lot of added weight.

Apart from reliability (that nobody questioned anyway) and low weight, the costumer wants also certain muzzle velocity, rate of fire and ammo count. The Type 99-1 did not provied all of that, the Type 99-2 was far better. However, the price was weight, hence decrease in RoC.

You mean once it acquired three more 13.2 mm Machine guns, bulletproof windscreen, armored plate behind pilot seat, underwing racks to carry air-to-air rockets and 250 kg bomb ? Obviously. But thats also because Sakae 31 was not performing as expected with water&methanol injection and engine was reversed to a similar performance of Sakae 21.

This is it - no free lunch.
Further, water-methanol (ADI) has it's limits, the greater 'base HP' and better supercharger, the power gained is greater.

It only restored the performance ... to a level of 1943 A6M5. The aircraft reached 563 km/h which is marginally slower than A6M5 which had a top speed of 565 km/h, the time to altitude was improved by mere 11 seconds. However landing speed has increased, thus indicating also a higher stall speed. Aircraft definitely had inferior flight characteristics, including the maneuverability.

Something needed to be done, since the A6M5c lost 20 km/h, how much of RoC, and 700 m of service ceiling once it gained more firepower and some protection - no free lunch. It took the belated installation of Kinsei to restore the performnce lost.
Same happened to the Spitfire V - once it received cannons and external BP glass, the performance was back on Spit I level, despite more engine power.

We already had that discussion how brilliant it was be to fit A6M with Kinsei engine. Except it was not ...

Nobody said that A6M with Kinsei was brilliant. It was a belated effort to upgrade Zero.

This statement is absurd.

Ad hominem?

In 1940 the Mitsubishi received from the Kaigun Koku Honbu Gijutsubu the preliminary specifications for the 16-Shi Carrier fighter which was intended to replace the Zero. It was intended that the new aircraft, which would not be available in quantity for several years, would become the Navy's standard carrier fighter when the Zero had reached its limit in modification and improvement.

However, in 1940 the Mitsubishi was experiencing serious difficulties in the development of the 14-Shi land-based interceptor (J2M Raiden); the company was plagued by a shortage of competent engineering personnel and the lack of a satisfactory engine for the J2M Raiden design. These circumstances delayed the 16-Shi carrier fighter program for at least a year.
But despite eventually solving problems with J2M the development was again postponed. In the autumn of 1941 Horikoshi became seriously ill and did not recover until several months had passed. The Navy preferred not to undertake the design project without my active participation. First engineering meeting to plan the new fighter was held on 14th April 1942, at the Japanese Naval Air Research and Development Center. In the long interval which had elapsed, the plane was renamed the 17-Shi carrier fighter.

The IJN stride for Raiden as strictly land-based fighter is not a very good economy. Let Mitsubishi design a naval fighter, to replace Zero, then use it as a land based fighter once available in numbers - just like Zero was used.
Mitsubishi was not the only manufacturer in Japan. Why fiddling with floatplane fighter design by Kawainshi - attach the floats on a new fighter that is competing to be the next-gen carrier-borne fighter. Already done with Zero.

The failure in providing a next generation fighter was as mentioned a combination of bad luck, stubborn Navy leaders and Mitsubishi lacking manpower to work on multiple projects. It had nothing to do with other manufacturers, who had their own designs to work on. No Air force is based only on fighters and Navy obviously had to call for other types of aircraft.

Bad luck was absent when duplication at many requirements was present, also when IJN and IJA were trying to have a separate design for any application that might come to mind.
 
Yes, the A6M2 will have better power-to-weight ratio than either of the two US fighters above 15000 ft, meaning better climb, even of drag is a a bit greater than in those US fighters.

Not sure about it, one of the sources I have indicates following for equivalent profile drag area :
P-40C A6M2 model 21
5.05 sq. ft. 4.613 sq. ft.

A6M presented very clean lines while P-40 not so much, especially the landing gear and the way it was hidden in the wing added to the drag.

The P-40B featured 93 lbs of armor and external protection for fuel tanks, per 'US hudred thousand', pg. 236.
Maybe some did. But none at the outbreak of WW2 on the front. That is confirmed by various accounts from pilots who were stationed on the Philippines. There were three squadrons equipped with P-40 E which indeed were fully protected, there was one with P-40B which had no protection and one with P-35 which as well had no protection.

The P-39C was also considerably faster than either P-40B or A6M2.
There were 80 of them produced if I'm not mistaken ? It was considerably faster indeed. There was also P-43 which had considerably better altitude performance but Army decided not to push them to front-line despite great need.
But since they were not used they made no impact on events.

Apart from reliability (that nobody questioned anyway) and low weight, the costumer wants also certain muzzle velocity, rate of fire and ammo count. The Type 99-1 did not provied all of that, the Type 99-2 was far better. However, the price was weight, hence decrease in RoC.

What exactly decrease in RoC if I may ask ? Type 99-II was ... 10 kg heavier. Combined weight of two guns was still less than a single MG 151/20. The difference in weight was really negligible and effect on rate of climb would be none.

Something needed to be done, since the A6M5c lost 20 km/h, how much of RoC, and 700 m of service ceiling once it gained more firepower and some protection - no free lunch. It took the belated installation of Kinsei to restore the performnce lost.
Same happened to the Spitfire V - once it received cannons and external BP glass, the performance was back on Spit I level, despite more engine power.

A6M should have been dumped by then. That's what should be done. Full attention of the Navy should be given to N1K2-J and A7M2.

Ad hominem?
Argumentum ad hominem is an attack on an argument made by attacking the character, motive, or other attribute of the person making the argument. I dont attack You, your motives or attributes. I state that your statement was wrong, hence usage of word "absurd".
Nothing personal tomo, I respect you while disagree with your opinions :)

The IJN stride for Raiden as strictly land-based fighter is not a very good economy. Let Mitsubishi design a naval fighter, to replace Zero, then use it as a land based fighter once available in numbers - just like Zero was used.
Mitsubishi was not the only manufacturer in Japan. Why fiddling with floatplane fighter design by Kawainshi - attach the floats on a new fighter that is competing to be the next-gen carrier-borne fighter. Already done with Zero.

I agree that J2M was a waste of resources (even though it turned out to be one of the best fighters Japanese had) but decision to develop it was taken prior to decision of developing A7M.

Mitsubishi was not the only manufacturer but was the only sufficiently experienced manufacturer in terms of developing a carrier borne fighter. And seeing how A6M2 was superior to Ki-43-I I see no reason why Navy would turn to equally occupied with Army requests Nakajima.

Kawanishi had absolutely no experience with land based fighters. It took them 3 years to make out of N1K floatplane a capable fighter in form of N1K2-J. Besides, floatplanes played important role in Navy doctrine and their existence was necessary. At least that was seen that way back in the day. Now if we would leave N1K and let supposedly Mitsubishi make out of developed A7M a floatplane ... that would divide the attention of the major company into some smaller tasks which Kawanishi could deal on its own.

Also, it did not work so well with A6M2-N. It had shorter range than A6M2 despite addition of a big fuel tank in a float and performance was reduced. Fighter was still very liked and satisfied frontline needs but quickly need for a faster machine raised.

Bad luck was absent when duplication at many requirements was present, also when IJN and IJA were trying to have a separate design for any application that might come to mind.
Well, how else one can call a health problems of leading engineer at the begging and end of the project ? Or massive earthquake ?
For me its a bad luck.
Else indeed, duplication. I never could figure why those two could not co-operate. Hence why I mentioned that as first mistake of Japan.

On a sidenote, I always wondered how would it be if Navy replaced 7.7 mm in A6M with 12.7 mm used in Oscar. Two 12.7 mm and two 20 mm sound a lot more better. Weight difference would really be negligible and there was plenty of room to put it.
 
I would say in general
1 Consider your enemy produces equipment as good as you do. I cannot see why Hampdens and Wellingtons were sent out in daylight when it must have been obvious they could not protect themselves from hurricanes and spitfires while everyone knew the Germans had the Bf109 before war was declared. How could it be thought the defiant could survive against the BF109. The same goes for He111s crossing the North Sea to north England and Scotland.

2 Consider outlandish possibilities your enemy may present you with, from Germany overrunning France in 6 weeks and producing jet fighters, to the UK managing to keep their aircraft off the ground and always intercepting your raids. Consider what you would do about an enemy doing 100% better in every way than you thought was physically possible 5 years ago.

3 Assume that as soon as a new technology is used it is completely understood by your enemy, who may already have it but not use it (as with window) and assume that your codes are broken as a matter of course.

1 The bombers did alright in prewar exercises against Hurricanes because the umpires were using faulty assumptions to decide what got killed. Far too much weight was given to the bombers' defensive fire and far too little to the fighters offensive fire.
Bomber Command did not cooperate in Park/Dowding's immediate prewar exercises which meant that at Group level it had no idea that Fighter Command's 11 Group was achieving theoretical interception rates of 60%. The Bomber men also reckoned that flights or single aircraft would be less liable to detection and interception, something they continued to believe until the shooting war proved them wrong. In the wrong hands, even with Fighter Command's system, the bombers could still get through as Leigh Mallory famously demonstrated on one exercise.

2 There a limit to what can be fore seen. France was considered the preeminent land based military power in Europe in the 1930s. Her collapse in short order was literally inconceivable to prewar planners.
Others you mention were intelligence failures and/or a failure to understand novel systems and their impact. These things are always easy with hindsight :)

4 Generally the assumption that the enemy would soon understand new technology and counteract it was made. For example Bomber Command originally assumed that they would get limited use of Gee and initially resisted issuing the 'Lattice Charts' (the grid of Gee signals printed on special charts) to navigators for fear they would fall into enemy hands. It was only when the impossibility of the navigators using the system without them was demonstrated that the charts were issued.
It's what led to the early 'battle of the beams' and then a later electronic arms race. In 1940/41 nobody had imagined that Radio Counter Measures aircraft would be flying in numbers on most operations. This was an arms race decisively won by the British/Allies (in that order).

It is not necessary to assume your codes are broken, but you must acknowledge that they can be broken. For example,it was the German assumption of the impregnability of the various enigma codes, even in the face of evidence that they were compromised, that was the failing. All WW2 codes were vulnerable (some much more so than others) and the weakness is usually in the human operators who, like all humans, tend to become blase and lazy in their methods. Enigma was one of the first to largely, but, unfortunately for the Germans, not completely, remove the human from the system.

Cheers

Steve
 
Not sure about it, one of the sources I have indicates following for equivalent profile drag area :
P-40C A6M2 model 21
5.05 sq. ft. 4.613 sq. ft.

A6M presented very clean lines while P-40 not so much, especially the landing gear and the way it was hidden in the wing added to the drag.

The P-51D was at 4.10 sq ft, Fw 190A8 at 5.22, Fw 190D-9 at 4.77; bothFocke Wulfs were smaller and with thinner wing than Zero. Buffalo was at 6.27, stubby as it was, so I think the value you've posted for the Model 21 is too low. Talk 5 to 5.5 sq ft? Increased once the armament grew.
P-40 was as high as 5.71, P-39 as low as 4.63.

There were 80 of them produced if I'm not mistaken ? It was considerably faster indeed. There was also P-43 which had considerably better altitude performance but Army decided not to push them to front-line despite great need.
But since they were not used they made no impact on events.

USAF decided that pilot protection was a right thing to trade for loss of performance. In the long run, they were right.
Once the V-1710 received a 'faster' supercharger drive, both P-40N and P-39N were far better performers, especially under 15000 ft, and Zero, that started aquiring protection and extra firepower was not that better in any altitude range.

What exactly decrease in RoC if I may ask ? Type 99-II was ... 10 kg heavier. Combined weight of two guns was still less than a single MG 151/20. The difference in weight was really negligible and effect on rate of climb would be none.

There were two cannons, so 20 kg increase. 100 rounds of heavier ammo further tips the scales, especially when comapred with 60 rds of earlier Type 99-1. Addition of three 13 mm guns instead of two .303s adds another 70 kg, plus weight of heavier ammo.
BTW - the MG 151/20 was 20% heavier than the Type 99-2, not 100%, and Germans used more powerful engines, in smaller aircraft.




Argumentum ad hominem is an attack on an argument made by attacking the character, motive, or other attribute of the person making the argument. I dont attack You, your motives or attributes. I state that your statement was wrong, hence usage of word "absurd".
Nothing personal tomo, I respect you while disagree with your opinions :)

If you think my statement is wrong, than please say so.

On a sidenote, I always wondered how would it be if Navy replaced 7.7 mm in A6M with 12.7 mm used in Oscar. Two 12.7 mm and two 20 mm sound a lot more better. Weight difference would really be negligible and there was plenty of room to put it.

The Army type 12.7 was not regarded as particulary reliable?
Both IJA and IJN (and not just them) might've bought the Belgian developments of the Browning HMG, that was making 1000-1150 rpm prior ww2, and was offered on the market.
 
The P-51D was at 4.10 sq ft, Fw 190A8 at 5.22, Fw 190D-9 at 4.77; bothFocke Wulfs were smaller and with thinner wing than Zero. Buffalo was at 6.27, stubby as it was, so I think the value you've posted for the Model 21 is too low. Talk 5 to 5.5 sq ft? Increased once the armament grew.
P-40 was as high as 5.71, P-39 as low as 4.63.

I base it on 1976 publication titled : "Fighter Comparison Study No. 1 - The Curtiss P-40C vs The Mitsubishi A6M2 Model 21 Zero-Sen" by Murray Rubenstein which gives indicated above numbers.
Here is a brief description from the source :
How can the Zero-sen, with bulky radial engine, be cleaner than a P-40 with a liquid cooled engine ? To begin with, Zero-Sen's engine was nicely cowled, with a large spinner. It's wing was exceptionally clean and the greatest attention was paid to wing and tail fillets.
By comparison, the P-40 had its radiator chin-mounted (hardly the cleanest location), with bulges under each wing to house the landing gear struts. The P-40 had an interesting gear retraction mechanism, with the strut rotating 90 degrees so the wheel could lie flat directly behind the hinge point. As a result of the design options chosen by the designers of the P-40, the Curtiss fighter had marginally higher profile drag. Because its wing had a lower aspect ratio than that of the Zero-Sen, the P-40 induced drag was also higher.
So for now I will take it, since its actual written source.

Also, at the same time the armament grew (added drag of long barreled Type 99s) the shape of the engine cowling was improved and wing was changed, since A6M5 had shorter wingspan to improve roll rate .

Once the V-1710 received a 'faster' supercharger drive, both P-40N and P-39N were far better performers, especially under 15000 ft, and Zero, that started aquiring protection and extra firepower was not that better in any altitude range.

Which was also explained by Jiro Horikoshi :
No matter how the government tried to distort the news, these requests for redesign clearly told the story of the Zero's ordeal and difficult situation Japan faced. The most significant request was for bulletproofing [providing protection for pilot and fuel tanks], a feature which had not been even been mentioned in the Zero's initial planning requirements. Over the years, the lack of bulletproofing has frequently been mentioned as a weak point of the Zero. The reason for this shortcoming was that the aircraft could not afford the additional weight necessary for bulletproofing, given the requirement stipulated with respect to heavy armament, long range capability, speed and maneuverability. These items took priority over anything else, and since we did not have [at that time] reliable high-power engines, bulletproofing was sacrificed.

Zero was based on experiences gained in China, no need for protection was indicated in late 1930s when requirements were presented to Mitsubishi. Need for protection appeared later, when design was finished and any major changes would have to come at a price.

Anyway, P-39 even in improved models never became a favorite machine of the USAAF and pilots achieved in it relatively low success if compared to Corsair, Hellcat or others. While in regard to P-40 ... it achieved better performance not only because of the engine but also dropping some firepower and "unnecessary" equipment which effected in weight drop of over 600 pounds if compared to P-40E.

There were two cannons, so 20 kg increase. 100 rounds of heavier ammo further tips the scales, especially when comapred with 60 rds of earlier Type 99-1. Addition of three 13 mm guns instead of two .303s adds another 70 kg, plus weight of heavier ammo.
Well, I mentioned one. I assumed that basic math is obvious. But yes, 20 kg increase.

100 round magazines were used since A6M3 was delivered to the units, that is Summer 1942. A6M2s were also provided with those larger magazines eventually. So there was no gain in ammunition load related to the change of the guns.
And the loaded magazines of Type 99-II ammunition were not that much heavier, Shinpachi in one of his threads was kind enough to provide manual for Type 99 with weight tables for guns, additional parts and weight of ammunition. Weight of the 100 round magazine for Type 99-I was 37.04 kg, weight of 100 round magazine for Type 99-II was 39.3 kg.
That's a weight increase of ... 4 kilograms for two guns. With added weight of two guns that brings 24 kilograms.

Also, I thought this was related to a 1943 model ?

But when you mentioned 13.2 mm Type 3 MGs than there was further increase in load of Type 99s, since they became belt fed. Since A6M5a Type 99s carried 125 rounds per gun, total weight of 20 mm ammunition indicated in manual for A6M5 is 57 kg.

Now for the 13.2 mm Type 3 machine guns. Nose mounted has weigth indicated as 27.5 kg, weight of 230 rounds for it - 32.5 kg.
Two wing mounted - 55 kg and ammunition for them - 68 kg.

A pair of Type 97 machine guns had a total weight of 27 kg, weight of 1400 rounds was 48 kg.

So if I do a simple math the combined weight increase was 84.5 kilograms.

The Army type 12.7 was not regarded as particulary reliable?
No, thats not correct. It was reliable. What caused reliability problems was the Italian ammunition and Italian guns, here is a translation of "The Maru Mechanic" vol.45 (1984), page 27, about the 12.7 mm guns used for Ki-43 :
"Early models of Ki-43 used a "Type I" [i.e. Type-Italian] 12.7 mm cannon made in Italy (Breda-SAFAT I guess) to enhance the firepower of 7.7 mm. However, the explosive ammo [imported from Italy] often jammed Type I during flight. Japanese explosive 12.7 mm ammo (made in Japan) didn't jam Type I cannon, but there was a risk of explosion inside the gun barrel due to oversensitive charge, which was soon corrected. "
Provisional safety measure was taken by putting gun barrels into a steel tubes.

The risk of explosion during the flight was considered better than not being able to shoot at all [Italian ammo], hence they used Japanese ammo instead. Later on, once they replaced Type-i with Ho-103 12.7 mm cannons manufactured in Japan in combination with Japanese explosive ammo, the explosion accidents no longer took place.

Both IJA and IJN (and not just them) might've bought the Belgian developments of the Browning HMG, that was making 1000-1150 rpm prior ww2, and was offered on the market.

So could Germans, British, Soviets and French. But each of them favored their own developments.
 
I base it on 1976 publication titled : "Fighter Comparison Study No. 1 - The Curtiss P-40C vs The Mitsubishi A6M2 Model 21 Zero-Sen" by Murray Rubenstein which gives indicated above numbers.
Here is a brief description from the source :

So for now I will take it, since its actual written source.
A book != always creditable source. You will note that I gave bigger drag for the P-40 than that 'Study'.
Source for my numbers is the 'America's hundred thousand', a book, while not without a mistake (like 390-400 mph figure for the XP-39), is well worth a read. The chin radiator is indeed not ideal, but it is not that bad, it got there as an improvement over belly radiator (that was not that good as in the P-51) in P-40 and Typhoon.

If you wish to believe that Zero was more sreamlined than Fw 190D-9 or Spitfire, I have Brooklyn bridge for sale.

Also, at the same time the armament grew (added drag of long barreled Type 99s) the shape of the engine cowling was improved and wing was changed, since A6M5 had shorter wingspan to improve roll rate .

Shorter wing span does not mean that wing profile get thinner. Decreased aspect ratio adds drag.
Zero was based on experiences gained in China, no need for protection was indicated in late 1930s when requirements were presented to Mitsubishi. Need for protection appeared later, when design was finished and any major changes would have to come at a price.

Major changes were needed, since the aircraft don't fly by themselves, but trained and experienced men are needed to extract the true potential from them. No protection? Bad decision, since fighters engage not just other fighter, but also bombers and the like, plus they might come close to ground fire. Pilots don't grow on trees.
Not trying to bash the Zero here, the IJN needed to have the new design in the pipeline by the time 1st Zero squadron entered service.

Anyway, P-39 even in improved models never became a favorite machine of the USAAF and pilots achieved in it relatively low success if compared to Corsair, Hellcat or others. While in regard to P-40 ... it achieved better performance not only because of the engine but also dropping some firepower and "unnecessary" equipment which effected in weight drop of over 600 pounds if compared to P-40E.

Re. P-40N - laws of physics still apply, or, no free lunch. The USAF have had plenty to choose, no need for the P-39. Unlike the IJN for the carriers they have left - it was Zero or nothing.


...
So if I do a simple math the combined weight increase was 84.5 kilograms.

You're probably correct.

...
The risk of explosion during the flight was considered better than not being able to shoot at all [Italian ammo], hence they used Japanese ammo instead. Later on, once they replaced Type-i with Ho-103 12.7 mm cannons manufactured in Japan in combination with Japanese explosive ammo, the explosion accidents no longer took place.

Thanks for that. Looks like the problems with Army 12.7 mm were solved by late 1942/early 1943, at least after reading this: link.

So could Germans, British, Soviets and French. But each of them favored their own developments.

British were buying abroad, so did the Japanese, just on greater scale. Buying the pre-war Belgian design instead of Italian, French and/or American does not look like far fatched thing.
The Belgian gun would've come in handy for the Bf 109, Hurricane and Spitfire, and as defensive weapon for bombers, but the Europeans were also entitled to make mistakes ;)
 
What is often left out of simple comparisons of weapons is just what level of failure or malfunctions the various countries or services considered "unreliable" or excessive. Also what guns/ammo did on test stands on the ground vrs what they did in the air (especially while pulling 3-4 "G"s.
I am personally rather doubtful of the rate of fire of the pre-war Belgian Browning gun, at least at the level of malfunction/parts breakage that would actually be acceptable to some customers. I would note that Colt was the major producer of Browning patent firearms in the US while FN was the manufacturer in the Europe and for some of the rest of the world. There was some level of cooperation between the two companies.
The Japanese Navy 13mm machine gun was basically a copy of the standard .50 cal Browning adapted to take the French 13.2mm round used in the Hotchkiss MG already in use by the Japanese navy and Army. The round was little more than the standard .50 case necked up by 0.5mm and the neck shortened by 3-6mm (some batches/sources vary). It might even be possible to put a .50 cal round in a 13.2mm chamber, not a good idea to pull the trigger though :)
It took the US about 3 years to get the rate of fire (or a bit higher) that the pre-war Belgian Browning was claiming at a parts breakage and malfuction rate that was acceptable to the US authorities.
It is not 'magic'. The Breda-safat and the Japanese army 12.7 both used shorter rounds, 18mm shorter cases and shorter bullets so the overall cartridge was even shorter which allowed for shorter bolt/breech block travel per cycle. They could get higher rates of fire with the same bolt speeds and stress on parts.
Now individual armorers/gunsmiths (hackers) could certainly play with springs/file parts, drill holes to lighten things and get guns up to pretty high rates of fire but the US standard for parts breakage and malfunctions was for a round count (5000 rounds I believe) that would have seen a Russian Berezin UB replaced at least once if not twice ( one reason for the Berezin's light weight). The US certainly paid for that durability in weight.

Also when comparing guns most tables/charts give the weight of the bare gun. Some belt feed guns to not include the weight of the belt feed device like used on Hispanos. Most drum feed guns do not include the weight of the drum. Nobody includes weights of mounts/brackets/gun heaters/cocking systems and other bits and pieces.
One table I have for the Oerlikon FFS (which used a slightly longer round than the FFL or Japanese type 99 II)
shows a weight of 9kg for a 45 round drum, 10kg for a 60-65 round drum*, 12 kg for a 75 round drum and 13kg for a 100 round drum. weight per round of ammo was 240 grams.
*table says 65 round but may be a miss-print. It is the only place I have seen 65 round drum and making a 65 round and 75 round doesn't make sense, especially since we know they did make 60 round drums and plenty of them.
Even if it is printed if something seems too good to be true it just may be a miss-print.

I would note that these weights agree pretty well with the weights given for the Japanese guns, that is 37kg for loaded 100 drum. I wouldn't worry too much about a 2kg difference in weight out of 35-37kg.

I would note however that it does bring the weight of the 99 II a lot closer to the weight of an MG 151.
 
No protection? Bad decision, since fighters engage not just other fighter, but also bombers and the like, plus they might come close to ground fire. Pilots don't grow on trees.

The requirements for 12-Shi Carrier fighter were stipulated in October 1937. At that time the only military that decided to provide any protection for fighters was VVS. They introduced a 9 mm thick plate protecting pilots head in 1936 for the I-15 and I-16 fighters. Those fighter in late production variants were also provided with with a system of piping that captured engine exhaust gases, cooled them , and introduced into the fuel tank to reduce the oxygen content of the vapor left in the tank as fuel was consumed. Those were first measures taken to provide any protection.

Germany provided no protection for their early 109 E-3 and E-1 models, which was confirmed by examination of wrecks in Poland and France. However later on newly produced 109 E-4s were provided with two 8 mm thick bolt on armor plates, a head protection plate (about 29 pounds) and a back plate (53 pounds), this was also provided before Battle of Britain for 109 E-3 and E-1 models left in service. By July 1940 some of the 109s were also provided with bulletproof windshield.
Bf 109 E had no protected fuel tanks until the end of Battle of Britain and only protection was provided by a laminated bulkhead behind the fuel tank.

British introduced armor and bulletproof windshield in late spring or early summer of 1940, which as you have mentioned has affected the Spitfire performance. Armor has added for instance 73 pounds to the Spitfire weight. In fact first Spitfires with new windshield were given to No 92 Squadron in May 1940 when unit has entered combat. Spitfires in No 92 Squadron received armored plates in June 1940 as did a number of Spitfires and Hurricanes in other units.
In case of fuel tank protection the only thing provided was a "Linatex" which was a blanket of rubber and treated canvas of thickness no greater than 5 to 15 mm, it was provided first to the Hurricans and Spitfires (either retrofitted to older models or introduced to newly produced aircraft) in September 1940, though not all fuel tanks were even covered. In case of Spitfire the upper fuel tank in front of the cockpit was left uncovered, same was for the reserve fuel tank directly in front of the pilot of Hurricane. Protection was also claimed very inadequate against Luftwaffe armament.
And the reason all this was introduced ? Because RAF was sustaining heavy losses. Based on their experienced RAF decided to provide protective measures for their pilots.

It wasn't until 1941 when flexible rubber self-sealing fuel tanks became a standard on 109 F and than G models and on Spitfire IX and other models in the early days of 1942. For instance standard German fuel tank from that time was made out of an inner lining of rubberized fabric and layers of vulcanized rubber, think raw rubber, thick raw rubber and vulcanized rubber of a total thickness of 15 mm. The tank weighed 121 pounds if compared to 58 pounds for the Bf 109 E fuel tanks.

In regard to US efforts, a great emphasis was put on producing a full rubber fuel tank capable of resisting some damage of .50 caliber bullets and providing the armor protection, based on direct observation of Battle of Britain as well as industrial support that US shown by producing aircraft for France and Britain. By the end of 1941 a policy was introduced to provide every fighter aircraft with armor to protect pilot and basic form of fuel tank protection, but as I mentioned earlier only fully protected fighters in Philippines were P-40E. In regard to Navy F2A-3 was provided with such protection, having protected fuel tanks, bulletproof windshield and armored plate behind pilot back but that resulted in great weight increase over F2A-2 model and decrease of performance.
On contrary F4F-3 had neither armor nor fuel tank protection though there were plans to retrofit them but they didnt have them until Spring of 1942. And that also came with own problems, in April 1942 VF-42 or VF-3 Wildcats began to encountered troubles. Self-sealing fuel tanks began to leak, due to various forms of deterioration. Gasoline with high aromatic content used by the US Navy virtually attacked tanks, the rubber would blister and begin to slough off particles which would block fuel lines. This for instance disabled at some point 8 of 19 Wildcats operated by VF-42. Exactly same problem was encountered by Buffalo pilots in January 1942 or other fighters in similar time.

At the same time Japanese started developing A6M there was no other military that provided full form of protection and only Soviets provided a partial protection for a pilot. By the time A6M2 entered service in 1940 the first protective measures were taken by the RAF and Luftwaffe based on the losses they sustained and experiences of their pilots.
And what were the experiences of the Japanese ? A small group of A6M2 virtually wiped Chinese opposition shooting about 100 aircraft for the loss of no fighters, except for the two shot down by AA. Opening rounds of the WW2 again indicated no need to provide any form of protection and even Battle of Midway tragic for aircraft carriers, brought very positive comments on A6M2 combat performance.

So the statement that Japanese Navy sacrificed the protection in favor of performance is flat wrong. They could not give up on something they never had, and others only introduced at similar time after negative war experiences.

Source : "Exploding Fuel Tanks - Saga of Technology That Changed the Course of the Pacific Air War" by Richard Dunn, chapters 1 and 2.

Thanks for that. Looks like the problems with Army 12.7 mm were solved by late 1942/early 1943, at least after reading this
Yes, you can 100% trust Rick Dunn research. I mean US Government and NASA do, so ... :)

The amount of failures was decreasing through 1942, there is a report from early to mid 1942 indicating amount of damaged guns and parts of the guns and how they were repaired. Its in Japanese though.


Edit : Seems something got wrong with your quoting tomo and I missed first points. Sorry.

A book != always creditable source. You will note that I gave bigger drag for the P-40 than that 'Study'.
Source for my numbers is the 'America's hundred thousand', a book, while not without a mistake (like 390-400 mph figure for the XP-39), is well worth a read. The chin radiator is indeed not ideal, but it is not that bad, it got there as an improvement over belly radiator (that was not that good as in the P-51) in P-40 and Typhoon.

If you wish to believe that Zero was more streamlined than Fw 190D-9 or Spitfire, I have Brooklyn bridge for sale.
So there is a book and a book, now we go into argument my book is better than your book :) ? That sounds funny.

I dont have "America's hundred thousand", wanted to buy it long ago but price is to scary. Especially with shipping. Will get it at some point for sure though.

Anyway, the other source for the equivalent profile drag area I have is original Japanese edition of 堀越・奥宮の「零戦」 (Zero fighter) by Jiro Horikoshi and Masatake Okumiya. There was in 1958 (I believe) a translated to English version under same title, published by Cassell & Co LTD 35 Red Lion Square, London, W.C. 1; copyright by Martin Caidin, 1958. A small note at the bottom of the copyright page says that the book was made and printed in Great Britain by William Clowes and Sons, Limited, London and Beccles.

It provides a table with basic data, including Drag Coefficient, Wing Area and equivalent profile drag area :
抵抗係数 翼面積 (m2) 等価抵抗面積 (m2) (sq. ft.)
A6M1 0.0200 22.44 0.449 -> 4.832
A6M3 0.0215 21.53 0.463 -> 4.983

A6M2 would be between the two of those. It's a bit higher than what "Fighter Comparison Study No. 1" indicated, but still below 5 sq. ft.

And tomo, its not a matter of belief but matter of basing on some sources. You provided none for A6M, only assumed.

But thats less relevant if its cleaner than FW-190 or not. Original point you made :
even of drag is a a bit greater than in those US fighters.
Which in regard to P-40 is not correct and I refereed to that.


Shorter wing span does not mean that wing profile get thinner. Decreased aspect ratio adds drag.
You got any numbers for those possibly ? I mean for the wing.
 
Last edited:
1 The bombers did alright in prewar exercises against Hurricanes because the umpires were using faulty assumptions to decide what got killed. Far too much weight was given to the bombers' defensive fire and far too little to the fighters offensive fire.
Bomber Command did not cooperate in Park/Dowding's immediate prewar exercises which meant that at Group level it had no idea that Fighter Command's 11 Group was achieving theoretical interception rates of 60%. The Bomber men also reckoned that flights or single aircraft would be less liable to detection and interception, something they continued to believe until the shooting war proved them wrong. In the wrong hands, even with Fighter Command's system, the bombers could still get through as Leigh Mallory famously demonstrated on one exercise.
The exercises were run as gunnery training for the bombers from what I read, the conclusion was that (as well as I remember re defensive fighters) the more they send up the more we will shoot down, even a child can see that a Hampden or a flight of them cannot lay covering fire against attacking fighter.
2 There a limit to what can be fore seen. France was considered the preeminent land based military power in Europe in the 1930s. Her collapse in short order was literally inconceivable to prewar planners.
Others you mention were intelligence failures and/or a failure to understand novel systems and their impact. These things are always easy with hindsight :)
From the German advance in WW1 a calculation could be made on the improvement with mechanised infantry to produce a worst case scenario. From the fall of Singapore Pearl Harbour losses under Barabarossa at the start (Russian)and losses at Stalingrad and Leningrad (German) what could have been forseen wasnt.


4 Generally the assumption that the enemy would soon understand new technology and counteract it was made. For example Bomber Command originally assumed that they would get limited use of Gee and initially resisted issuing the 'Lattice Charts' (the grid of Gee signals printed on special charts) to navigators for fear they would fall into enemy hands. It was only when the impossibility of the navigators using the system without them was demonstrated that the charts were issued.
It's what led to the early 'battle of the beams' and then a later electronic arms race. In 1940/41 nobody had imagined that Radio Counter Measures aircraft would be flying in numbers on most operations. This was an arms race decisively won by the British/Allies (in that order).
That was the point I was making, in the war of measure and counter measure I get the impression that the winners were the ones who questioned everything and demanded proof of success not estimates. The best illustration I can think of is the V1 raids which were confirmed by turned or non existent spies but contradicted measured data.


It is not necessary to assume your codes are broken, but you must acknowledge that they can be broken. For example,it was the German assumption of the impregnability of the various enigma codes, even in the face of evidence that they were compromised, that was the failing. All WW2 codes were vulnerable (some much more so than others) and the weakness is usually in the human operators who, like all humans, tend to become blase and lazy in their methods. Enigma was one of the first to largely, but, unfortunately for the Germans, not completely, remove the human from the system.

The Germans always knew that Enigma could be broken (all codes can be broken) they were surprised at the scale and short time involved in i breaking as routine. What I meant was Assume your codes are being broken and no action is taken so as not to draw attention to the fact. When ever anything unusual happens where there is an unusual but plausible explanation other than your codes being broken, then take note and change your codes anyway. On all sides an almost religious faith in codes caused damage out od proportion to the cost effort in securing the syste,
Cheers

Steve

Steve I was just making general points, basically about false assumptions. If you take the first flight by the Wright brothers as a marker, then see the progress between 1914 and 1918 in aviation, looking at aviation in 1939 and projecting the same progress forward it is in hindsight no surprise that jet fighters, 1000 bomber raids, precision day and night time bombing, fused projectiles, radar laying of defences and guidance of fighters appeared, the only question was who got them first advanced them and made best use.
 
I have spent some time over the last 12 months researching aircraft production in WW2 and I would rate the Germans biggest mistake as refusing to change their first production priority from consumer products to military products until 1943. Hitler did not want to disrupt the peacetime economy so civilian cars and washing machines were given a higher priority than aircraft.

Compare that with the US and Britain where the car industry were drafted (well before the war in Britain's case) and produced tonnes of aircraft against Germany where the biggest auto producer, Opal, was not drafted until 1944.

Another big problem the German's had was their apprenticeship programme. This resulted in low numbers of highly qualified staff. The UK and US on the other hand used specialized training so they had a massive number of people with a high level of skill in a very small part of the production process. Although the German worker could do almost any job on the production line with a high level of skill, the Brits and Yanks could only do one job but do it much better.

The Americans designed aircraft to be machine made. Forming a wing or fuselage rib took seconds in a large press. The Brits were far more into wing ribs and other components made from dozens of small parts all riveted together - massively time consuming. There is a video at
View: https://www.youtube.com/watch?v=Qi6PdWHSVG8
showing how the fuselage frames on the Me108 were made. That makes the Brits look efficient.

For the Japanese I think the policy that most males must leave school at 15 to go into military factories and then on 16th birthday go into the military was almost as serious a problem as the refusal of the army and navy to cooperate on virtually anything. Instead of stable well trained factory staff with low staff turnover the Japanese had rapid staff turnover. They spent months training a person and then, as soon as he became fully proficient, lost him to the military.
 
...
Source : "Exploding Fuel Tanks - Saga of Technology That Changed the Course of the Pacific Air War" by Richard Dunn, chapters 1 and 2.

Thanks for the effort to type this all out.

So there is a book and a book, now we go into argument my book is better than your book :) ? That sounds funny.

I dont have "America's hundred thousand", wanted to buy it long ago but price is to scary. Especially with shipping. Will get it at some point for sure though.

My point was that even the most well researched and written books have mistakes, mis-prints and othe glitches, some more some less obvoiusly.

...
It provides a table with basic data, including Drag Coefficient, Wing Area and equivalent profile drag area :
抵抗係数 翼面積 (m2) 等価抵抗面積 (m2) (sq. ft.)
A6M1 0.0200 22.44 0.449 -> 4.832
A6M3 0.0215 21.53 0.463 -> 4.983

A6M2 would be between the two of those. It's a bit higher than what "Fighter Comparison Study No. 1" indicated, but still below 5 sq. ft.
And tomo, its not a matter of belief but matter of basing on some sources. You provided none for A6M, only assumed.
But thats less relevant if its cleaner than FW-190 or not. Original point you made :
Which in regard to P-40 is not correct and I refereed to that.

I was trying to put the numbers into a perspective, since drag figures for the Zero you've posted were suspiciously low. The Zero is supposedly more sreamlined (lower Cd0) than Bf 109F4, P-39, P-63, the aircraft with a shortcoming or two, but still with far more speed on same power used, than Zero.
I've given the flat plate for the P-40 that is even higher than what you've posted.

You got any numbers for those possibly ? I mean for the wing.

You might want to check out here, the greater aspect ratio (AR) means that Cd is lower.
 
A precis from Sebastian Ritchie's 'Industry and Air Power'.
The British aircraft industry employed just 41,000 people in 1935 of whom 7,000 were deemed administrative or technical. Fulfilment of the re-armament programmes obviously depended on an increase in these figures. The official government policy was that re-armament should not interfere with normal trade, compulsory transfers were out of the question. The aircraft industry would compete with civil industry for staff and labour, Britain was not a dictatorship.

There was a geographic problem too. In this period most of the British aircraft industry was located in the south of the country whereas the majority of the available and unemployed engineers were in the north. People were by no means as mobile (much less willing to leave their families and communities) in the 1930s as they are today. It's an aspect of social history rarely taken into account.

When the aircraft industry recruited unskilled workers from other industries it faced serious opposition from the unions.

Historians such as RAC Parker and Corelli Barnett have argued that manpower shortages in all types of labour seriously undermined the efficiency of Britain's wartime economy, including the aircraft industry.
In fact it can be shown that the British aircraft industry did make more efficient use of its manpower resources than the Germans, but it was never easy and in some areas there was always a shortage, most damaging was the shortage of mangers, draughtsmen and other technical personnel, not semi or unskilled labour.

Maintaining the level of qualified technical personnel for industry had nothing to do with the Air Ministry.It was the responsibility of the Board of Education. Efforts were made to improve technical education between the wars but were restricted by government retrenchment, lack of funds, and also by the resistance of industry to the daytime release of staff for training.
It wasn't until 1938-39 that 11 new junior technical schools were opened.
British universities produced about 1,000 graduate engineers per year, only about 100 qualified in 'aeronautics'.
Of the 1,200,000 students enrolled in technical institutions in 1939 only 50,000 attended full time.
When Blackburn approached the Air Ministry with a plan for a national policy for technical training for the aircraft industry it was day release that proved the insurmountable sticking point. The Air Ministry argued that

"it could not be party to any attempt to bring pressure on the aircraft firms to secure day-time release."

There were however private schemes, financed by the industry that would later gain Air Ministry support.
The pre-war sequence of short term re-armament programmes and a lack of longer term objectives proved the biggest obstacle to improving technical education
It was only the out break of war that finally precipitate a series of training programmes in technical colleges and universities, significantly increasing the number of qualified engineers.

Just a couple of examples of the effect of this shortage.
The need to economise in the use of design resources meant that less importance was placed on the introduction of new types and more on improving existing types.
It took 330,000 man hours to design the Mark I Spitfire. Only 620,000 man hours were needed to design ALL the subsequent wartime Marks
The same economic realities lay behind Rolls Royce's decision to abandon the Vulture engine in 1941. Hives wrote.

"We were certain that we could make a better contribution to the RAF both as regards quality and numbers, by developing the Merlin."

Similar arguments exist in other areas. Where the British far outstripped the Germans was in the organisation of labour. During the early stages of re-armament the British just about managed to fulfil the requirement for skilled labour. Like all contemporary aircraft industries it depended on a small highly skilled work force.
Importantly, from the outset, the British worked to increase the ratio of unskilled to skilled labour, by mechanisation, upgrading and subdivision of operations etc. This led to a 'de-skilling' of the work force which, combined with new manufacturing methods, led to significantly higher productivity (compared to the skilled processes).
There was a policy of substantial sub contracting to other firms as a means of alleviating shortages in the aircraft industry itself.

There were problems with this unskilled work force. In February 1941 productive hours equivalent to 41 Merlin engines had been worked at Glasgow, but only 15 engines had been produced. Hives was not amused. He wrote that

"Clydeside is seething with communism...it is inevitable that in any new factory we collect a lot of rabble, who seize control of the shop stewards and shop committee."

Roy Dobson, one of the outstanding managers of the period, wrote to the MAP informing it of problems at A.V.Roe's new Yeadon works.

"My main trouble so far as labour is concerned at Yeadon is the refusal of the workpeople to be properly disciplined, we having been constantly embroiled in the last couple of months in the difficult task of simply forcing discipline down their throats and trying to educate them to workshop conditions. All this is due to the fact that practically all the labour at Yeadon is one of the 'greenest' and most of it has never been in a workshop before and does not understand the necessities of production."

That there were problems is hardly surprising when you consider that the number of people involved in airframe manufacture rose from 15,000 in 1935 to 262,000 in 1941. The figures for aero engines are 12,000 to 133,000.

In 1940 973,00 British workers produced 15,049 aircraft with a structure weight of 59 million pound
In 1940 1,000,000 German workers produced 10,247 aircraft. I don't have a figure for structure weight.

These comparative figures got steadily worse for the Germans as the war continued.

Cheers

Steve
 
Uff, what a rough day. Writing papers for my university is so annoying ...

Thanks for the effort to type this all out.
I just felt necessary to put things into perspective. Because common view is that one side had all best protection right from the start and the other had nothing and made a huge mistake because of their negligence. In long term we know it was a mistake. But it came not because of negligence, but because of different experiences.
Navy in fact took an effort and certain teams were assigned for research, but they started comparatively 2-3 years later than British or Germans and the results would also come later. Army on the other hand decided to make small steps and field tested some protective measures, Ki-27b were tested with first generation self-sealing fuel tanks, Ki-21s were first Japanese bombers to receive armor plates before the outbreak of the world war two. And even though it did not became a standard, it allowed by 1943 to start producing Ki-43s, Ki-61s and other machines with armored plates and protected fuel tanks.
But this again was behind other Nations which had 2-3 years of experience in the field.

My point was that even the most well researched and written books have mistakes, mis-prints and othe glitches, some more some less obvoiusly.

But you still assume that only your book is right. I actually took 「零戦」and compared it to English edition, same tables and same results. There might be something missing and possibility of a mistake exists, but by far its closest source to technical aspects of a Zero.

I was trying to put the numbers into a perspective, since drag figures for the Zero you've posted were suspiciously low. The Zero is supposedly more sreamlined (lower Cd0) than Bf 109F4, P-39, P-63, the aircraft with a shortcoming or two, but still with far more speed on same power used, than Zero.

The Drag Coefficient is what it is, that's what was provided with table along with prop efficiency and so on.

But explain to me why do you assume they have the same power. I mean it looks like you compare all of them flat without taking into consideration the engine and thrust. Level speed is relation between thrust and drag. Even if the drag looks "suspiciously low" A6M2 is still an aircraft making 335 mph at 16,000 feet at rated power (so approximately 950 HP), with overboost it goes to 340-345 mph.
If compared to I-16 Type 24 (another radial engine after all) doing like 287 mph at same altitude with similar power from the engine ?


You might want to check out here, the greater aspect ratio (AR) means that Cd is lower.
I was still expecting some actual numbers. I mean you assumed something so I thought you had some numbers to base on. And I was very curious to see them, since I dont have any very detailed drawings on A6M airfoil.
 
Last edited:
Sorry if it sounded to you that I rate Western aircraft as the ones having all the best, from engines, armament to protection. Eg. Soviets 1st started to add protection to their fighters, others followed quickly or slowly. The point is that Zero received pilot protection when it was too late, the weight of protection and drag and weight from uprated armament cut speed, RoC and ceiling. Fuel tanks were never self-sealing? Zero never received engines of 1500, let alone of 2000 HP (no feasible), so I'd repeat again that IJN pilots, and hence carriers, and hence Japan, were forced to receive services of a lesser fighter than Japan was capable to produce. A fighter based around Ha-41, later upgraded with Ha 109 was a possibility, or using the Kasei, just that we move away from Kinsei theme.
Japan/IJA/IJN was in war from 1937, unlike RAF, let alone USAF. In 1937-late 1940 there was no Zero around. Nor there was Ki 43, that also wound up without protection from start.

But you still assume that only your book is right. I actually took 「零戦」and compared it to English edition, same tables and same results. There might be something missing and possibility of a mistake exists, but by far its closest source to technical aspects of a Zero.

Re. bolded part - don't jump to the conclusions. I've already stated that book has a mistake or two, and gave bigger Cd0 value for the P-40. If you have a better source for Cd0 values I've posted, then post them out.
In case original is stating one number/value, you can be sure that translation will state the same value. Same as many books wrongly stated that P-39 was used as a tank buster by VVS, repeating one from another.

But explain to me why do you assume they have the same power. I mean it looks like you compare all of them flat without taking into consideration the engine and thrust. Level speed is relation between thrust and drag. Even if the drag looks "suspiciously low" A6M2 is still an aircraft making 335 mph at 16,000 feet at rated power (so approximately 950 HP), with overboost it goes to 340-345 mph.
If compared to I-16 Type 24 (another radial engine after all) doing like 287 mph at same altitude with similar power from the engine ?

Please re-read my post. I've stated that, on same power used, they will be faster than Zero. Not that they have had same power, their engines were capable for greater power.
Eg. the heavy clunker P-39D with 7 guns aboard will do 360 mph at 6000 m (~19500 ft), using less than 900 HP. The lightweight (comparatively) and less draggy P-39C will do another 10 mph?
The lightweight A6M3 will do 340 mph, and still lightweight A6M5 some 350 mph, with 50-100 HP more.

I was still expecting some actual numbers. I mean you assumed something so I thought you had some numbers to base on. And I was very curious to see them, since I dont have any very detailed drawings on A6M airfoil.

Lower AR -> greater drag. I did not assumed anything, the equation is there in you invest the effort to read the linked part of the page.
 
Sorry if it sounded to you that I rate Western aircraft as the ones having all the best, from engines, armament to protection.
Hey mate, I'm not offended or something. I just know a common view on this or rather a given presumption.

The point is that Zero received pilot protection when it was too late, the weight of protection and drag and weight from uprated armament cut speed, RoC and ceiling. Fuel tanks were never self-sealing?
Yes, that is true. It received it only when it became absolute need and it was known that replacement (A7M) is not coming soon.
Also, I have manuals from Model 21 to model 63 series, and in section for model 52 upgrades (so model 52c) there are drawings for rubber covered fuel tanks. There is a cross section showing the inside of the tank as well as all layers of covering. It has separate drawings for main fuel tank in fuselage, two inboard fuel tanks and two small fuel tanks close to the wingtips.

No idea how many actually had them, but at least factory drawings indicate such existence.

Zero never received engines of 1500, let alone of 2000 HP (no feasible), so I'd repeat again that IJN pilots, and hence carriers, and hence Japan, were forced to receive services of a lesser fighter than Japan was capable to produce. A fighter based around Ha-41, later upgraded with Ha 109 was a possibility, or using the Kasei, just that we move away from Kinsei theme.
Problem is not if such aircraft could be built. Problem is if it could keep the requirements for range or climb time with added weight coming from a lot more fuel, presumably stronger armament, additional protection ?

Japan/IJA/IJN was in war from 1937, unlike RAF, let alone USAF. In 1937-late 1940 there was no Zero around. Nor there was Ki 43, that also wound up without protection from start.
Japan was in a very different war and as much as on the ground it could not defeat the Chinese, the combat in the air was rather favoring them.
And while Navy decided to focus on research only, the losses Army sustained during Khalkin Gol boosted it to field test first generation fuel tanks and some armored plates. No, first Ki-43s did not have protected fuel tanks, but by the end of production Model I such protection was introduced.


In case original is stating one number/value, you can be sure that translation will state the same value. Same as many books wrongly stated that P-39 was used as a tank buster by VVS, repeating one from another.
Well, it also lists drag coefficient for Ki-46, J2M1, J2M2/3, A7M1 and A7M2. And you most likely see them as too low as well. Perhaps something might be missing that we cant see because its a book, something that author could have assumed as obvious.

But thankfully I know someone who is into this business in reality and there is a simple way to check if things make sense or they dont.
Book gives following prop efficiency for A6M3 to A6M5 -> 0.76
If we put all this into simple verification :
7HkGRD.png

You just put mass, wing area, wingspan - those come from factory manual.
Speed and engine power come from flight manual and engine manual.
Propeller efficiency comes from same Jiro Horikoshi book.
I only didnt have exact Oswald so its a bit estimation. But it is close enough to prove that CD0 is not wrong, even if some inputs could not be 100 % certain this gives a clear view.

The lightweight A6M3 will do 340 mph, and still lightweight A6M5 some 350 mph, with 50-100 HP more.
There was no power gain between A6M3 and A6M5. They all used Sakae 21.
The actually thing that made the difference between them was addition of exhaust thrust, since the exhaust was changed from collective tubes going below the wings to individual stacks directed to the rear. This provided over 20 km/h speed gain.

Edit: Unless you mean in comparison to A6M2 ? In that case 0.0200 also is not applicable but closer to 0.0215.
First one is related to A6M1 with twin bladed prop and Zuisei engine.
 
Last edited:
The Americans designed aircraft to be machine made. Forming a wing or fuselage rib took seconds in a large press. The Brits were far more into wing ribs and other components made from dozens of small parts all riveted together - massively time consuming. .

By the time the USA were designing their aircraft the war was certain. The original orders for the Spitfire were for 310 aircraft. The Spitfire was never meant to do what it did it should have been replaced by other AC but wasnt, you have a completely different design philosophy when designing and producing 300 aircraft or 20,000
 
...
Yes, that is true. It received it [protection] only when it became absolute need and it was known that replacement (A7M) is not coming soon.

Need, whether absolute or not, arose in second half of 1942. The Zero with protection (52c) was available from Oct 1944.

Problem is not if such aircraft could be built. Problem is if it could keep the requirements for range or climb time with added weight coming from a lot more fuel, presumably stronger armament, additional protection ?

It could. The Zero carried one drop tank (66 gals?) and ~150 gals of fuel internally. Use two drop tanks and 170 gals internally. With Ha-41, a bit more with Ha-109 or Kasei.

Japan was in a very different war and as much as on the ground it could not defeat the Chinese, the combat in the air was rather favoring them.
And while Navy decided to focus on research only, the losses Army sustained during Khalkin Gol boosted it to field test first generation fuel tanks and some armored plates. No, first Ki-43s did not have protected fuel tanks, but by the end of production Model I such protection was introduced.

So we have two problems. One is well known - Army and Navy don't love each other, no information exchange. Another - 4 years until Army is installing meaningful protection, compared with eg. 1 year for RAF? Another year for Navy.

Well, it also lists drag coefficient for Ki-46, J2M1, J2M2/3, A7M1 and A7M2. And you most likely see them as too low as well. Perhaps something might be missing that we cant see because its a book, something that author could have assumed as obvious.

If you have the numbers, don't mind me, just post the stuff.

...
You just put mass, wing area, wingspan - those come from factory manual.
Speed and engine power come from flight manual and engine manual.
Propeller efficiency comes from same Jiro Horikoshi book.
I only didnt have exact Oswald so its a bit estimation. But it is close enough to prove that CD0 is not wrong, even if some inputs could not be 100 % certain this gives a clear view.
Thanks again for the information.

There was no power gain between A6M3 and A6M5. They all used Sakae 21.
The actually thing that made the difference between them was addition of exhaust thrust, since the exhaust was changed from collective tubes going below the wings to individual stacks directed to the rear. This provided over 20 km/h speed gain.

Agreed.
 
By the time the USA were designing their aircraft the war was certain. The original orders for the Spitfire were for 310 aircraft. The Spitfire was never meant to do what it did it should have been replaced by other AC but wasnt, you have a completely different design philosophy when designing and producing 300 aircraft or 20,000
However, the U.S. already had mass production in place for years before the war, prime example would be Ford, Chevrolet and Chrysler. Ford had pioneered a great deal of production-line aircraft manufacturing technology with their Trimotor, too.

The depression saw a scaled back output of products, but large aircraft companies like Lockheed, Consolidated, Douglas and Curtiss were using machine assisted production lines that enabled them to produce airframes quickly with lower overhead.

When the U.S. switched to a wartime production, numbers of produced units escelated dramatically, of course.
 

Users who are viewing this thread

Back