Japanese Zero vs Spitfire vs FW 190

[BiffF15]

Hey BiffF15,

The Martlet vs Seafire part of my post was not referring to the diagram I posted.

I have been assuming that the "steep turn" referred to in the previous posts was started from similar velocity as in the rest of the maneuver comparisons (ie first one aircraft starting in trail then again with the other in trail). The lead aircraft begins a climbing turn (approximately a helix) and the trailer tries to follow and get in position for a shot.

Apparently the Martlet was better than the Seafire at this maneuver.

The only way I can figure this could work is if the Martlet trades excess Ps to increase turn rate and/or decrease turn radius depending on the aircraft velocity, while climbing (or should it be phrased the other way around?).

ThomasP,

The size of an aircrafts turn circle and his rate will vary / breathe in and out depending on where his nose is pointed, where the throttle is, and how hard the stick actuator is pulling.

If an aircraft is 10 degrees nose up, in a 60 degree bank and the pilot pulls hard on the stick, yes his turn circle will shrink (temporarily) and his rate will increase (temporarily). Once the pilot scrubs off enough airspeed (and he will as he is cashing in airspeed to obtain his greater rate and or his smaller radius of turn). Eventually his radius will open and his rate will drop as he doesn't have unlimited energy.

If an identical plane / pilot did the same maneuver as the above guy and he was level his radius would stay smaller and rate higher for a longer. Same set up with the nose 10 below the horizon at the start will hold his smaller radius / increased rate the longest, hence the reason even with new super thrusty jets the fights go downhill.

There is a saying called "go up blow up", and while not always applicable is when you are defensive and a guy is trying to gun you.

Going down allows Gods G to be brought to bear to help you sustain your max performance of your a/c.

Another way to look at it is imagine a long bolt, standing vertically complete with threads. Your a/c is inside the bolt and its nose will follow the threads as you go down in a tight spiral. However, as you go down the a/c will perform better due to the denser air and the threads will get closer together. Starting high the threads are further apart, descending into thicker air allows them to be much closer together. That's not to say you will jump into a defensive spiral and stay there, as your opponent will or can do other maneuvers to force you to react or change what it is you are doing.

Cheers,
Biff

 

[Schweik]

He also flew Kittyhawks in 76 Sq RAAF in Milne Bay during the Battle for Australia 1942

Did your grand father have anything to say about the Kittyhawk?

 

[nuuumannn]

But really you can pick any of the Griffon Spits and the Zero is outclassed.

Completely. The Griffon engined Spit was in a class of its own. There is a story involving Spitfire test pilot Jeffrey Quill and a Spitfire ("any Spitfire"), Arnim Faber's captured Fw 190 and a Typhoon, where the Fw 190 was to be pitted against the two Brits in a fly-off. Hawker expected the Typhoon to outperform the two, but Joe Smith of Supermarine had other ideas, having just fitted a Griffon to the Mk.III prototype, so off he sent Quill in the Spit against the other two, where he promptly trounced them both in performance. This got Griffon engined Mk.XIIs into service and eventually the 'stop gap' XIV, which had supreme performance and gave the Spit the edge against its opponents again.

As for the poor Zero, Horikoshi had pushed for the fitting of the more powerful Mitsubishi Kinsei engine from early on, but the navy heads stifled this plan and it never really evolved to the same extent performance wise as the Spitfire did through the installation of firstly the two-speed, two-stage Merlins, then the Griffon. Then again, it was never intended that the Zero remain in service for as long as it did and its designers knew this, the programe to build what eventually became the A7M was begun in April 1942.

There is also the issue of the philosophy behind the aircraft itself; once it became apparent that its replacements were not going to enter service sooner than they did, the designers were keen to keep the Zero as light as possible, resisting all and any attempts at introducing too much weight, which would have crippled the principal advantage the aircraft had over its superior enemy fighters, its low speed manoeuvrability. In subsequent variants from the A6M5, the wing skins increased in thickness and reluctantly and belatedly, survival innovations such as self sealing tanks and armour plating were introduced. Horikoshi knew the Zero couldn't keep up with advanced fighters such as the Hellcat and Corsair performance wise, so modifications were made sparingly to enable its advantages to remain.

People who believe the light construction and lack of self protection was a fatal weakness fail to grasp this, but there was active resistance to the introduction of these features by the designers, not because the Japanese were heartless, but because in order to maintain an edge - any edge against superior opponents, the aircraft had to continue to play to its strengths. Remarkably, in this the designers succeeded, as the wee tale about the US airman and the Aussie Spit pilots attests to.

The defining A6M5 and sub variants was brought in because the Mitsubishi J2M Raiden, which was to suppliment the Zero as a land based interceptor was lagging in development and efforts had to be made to compensate time wise in getting it into service. The Zero 52b and 52c variants introduced the self protection and heavy firepower to counter the Hellcat, and the 53c, A6M6 had the water-meth injected Sakae, which proved troublesome in a vain attempt to extract more performance, although again, Horikoshi pressed the navy to release the Kinsei for installation. This didn't come until the A6M8, which was, to all intents and purposes too late, but offered more power in the Kinsei, an armoured windscreen and the removal of self sealing tanks (! - those who state it had a fatal flaw would be astonished!) and their replacement with an extinguishing system. Its first flight and introduction into service was delayed by US bombing raids.

 

[nuuumannn]

Is there any performance data from the A6M8 prototypes? It might have been a little rocket ship

According to Bob Mikesh in Zero Fighter (Zokeisha Publications, 1981);

"The Navy accepted the first prototype of the A6M8c on 25 May 1945, and one month later took delivery of the second. maximum level speed was recorded at 308kts (355mph) at 6,000m (19,700ft) along with the ability to climb to that altitude in 6 min 50 secs. Although this maximum level speed was 48kts (55mph) slower than the F4U-1D at that altitude, it showed a halt in the trend toward deteriorating performance which had prevailed since the spring or summer of 1944 in all Japanese aircraft. test pilots who flew the Model 54c overwhelmingly agreed that this was the best model of the Zero yet produced."

 

[Admiral Beez]

Then again, it was never intended that the Zero remain in service for as long as it did and its designers knew this, the programe to build what eventually became the A7M was begun in April 1942.

That's a fair timeline, had they stuck to it. The Grumman Wildcat first flew in Sept 1937, with its replacement the Hellcat not flying until nearly five years later in June 1942.

 

[nuuumannn]

That's a fair timeline, had they stuck to it.

The problem they had not sticking to it was manifold. The navy had a big say in the course of the Zero's career and arguably stifled its and the A7M's development due to lack of foresight, such as the decision to incorporate a less powerful engine in the Zero until it was too late to make a difference, for example, as well as inevitable development delays, not least of which was bombing raids on aircraft factories. the Reppu mock up and thousands of drawings were destroyed in one raid in March 1945.

 

[Schweik]

Short list of Zero's faults:
- IJN has no radars worth speaking about in 1942
- USA is reading a lot of Japanese mail
- USN was expected to behave like Japanese admirals want, not like US admirals want
- pittyful state of fleet AA guns (both in quality and quantity)
- pittyful state of IJN damage control
- no 'bodyguard' ships for the carriers
- wrong doctrine of IJN, like attacking ground targets with carrier-borne aircraft instead of ship guns etc
- waste of design resouces and time and still not coming out with replacement to the Zero itself
- no emphasis on new pilots' training, and protection once airborne
- dividing the forces of IJN in May/June 1942
- failure to deploy submarine screen around Midway in timely manner, and not bothering to report to the fleet when that happened
- Shokaku left in japanese waters during the Battle of Midway

What a flawed fighter.

Point well taken!

Another:

- no significant air-sea rescue system in place despite available assets to do it

 

[Admiral Beez]

Point well taken!

Another:

- no significant air-sea rescue system in place despite available assets to do it

Which is nuts, considering Japan's sizable investment on long range flying boats, like the Kawanishi H6K and H8K. The shorter ranged Aichi E11A is essentially an IJN Supermarine Walrus, the latter of which picked up many a downed RAF and FAA aviator.

When you have a limited supply of trained pilots and a very limited means of replacing them, why wouldn't you focus on keeping the pilots you have alive?

 

[Admiral Beez]

The problem they had not sticking to it was manifold. The navy had a big say in the course of the Zero's career and arguably stifled its and the A7M's development due to lack of foresight, such as the decision to incorporate a less powerful engine in the Zero until it was too late to make a difference,

Which is also nuts. When the 940hp Zero first flew in April 1939 there were several fighters with well more than 1,000 hp in service or flying in prototype form, such as 1,150 hp the Mk II Spitfire, 1,529 hp Fw 190, etc.

 

[Schweik]

All aircraft have the potential to be fatally flawed. It's just a case of when the circumstances of the moment happen to coincide with one of that plane's weaknesses. Early on, the performance and firepower of the Zero, largely due to its lack of protection, kept that lack from causing crippling losses. But as soon as it started to encounter planes with equivalent firepower and superior survivability, even if with somewhat lesser performance, that lack became a critical flaw.

The point is really that all military aircraft designs did have flaws. The notion that every fighter should be able to fly 400 mph at 30,000 ft and have an initial climb rate 4,000 feet per minute, four cannons with plenty of rounds and armor and self-sealing tanks, and in spite of all that stuff also a 1,000 mile range.... is ridiculous. Many successful combat aircraft in WW2 had one or more elements of the above, but some of the most successful had very few of them. In the early war especially, before combat engines were achieving their utmost in power, it was always a matter of which elements did you want to sacrifice for others that you wanted more.

For England that meant sacrifice everything not needed (especially range / endurance) for an excellent point defense interceptor to defend the Island from an enemy with bases 30-50 miles away. For Japan, it meant to sacrifice everything for long range to defeat enemies across the wide Pacific, with a main opponent 5,000 miles away - and the overwhelming advantage in agility to win carrier battles where high lethality 'pwnage' and winning the one crucial air battle without regard for attrition, is what mattered most (at least initially). I.e. to protect your aircraft carriers.

Any warplane is a package deal; in modern parlance, a "weapon system", consisting of the plane, the aircrew training and proficiency, and the operational doctrine and tactics.
Given that perspective, the A6M2 was the best possible fit for the IJNAF in 1941. The only other potential contenders, IMHO P40 and F4F, were each incompatible with the other 2/3 of the IJNAF "package".
The biggest mistake of the Japanese was the failure to trade a little of the Zero's awesome agility advantage for self sealing tanks and pilot armor to bring a 1940 fighter to 1942 standards.
Cheers,
Wes

And it's something we know was possible because they did eventually do just that with the A6M5, but it was just done too late to matter.

They also needed to do the organizational changes Juha mentioned and things like an air-sea rescue program. All of which may have been a bridge too far.

 

[Schweik]

A flaw is only "fatal" if it results in an unacceptable loss rate. The planes (of all combatants) that made it back to base "full of holes" are the ones that weren't hit in an unprotected vital spot. I'm sure they all engendered faith and gratitude in their pilots. But when your long range fuel tanks and your cockpit and your lubrication system are unprotected, there's a lot less area left to punch "harmless" holes in.
As long as your performance and tactics are sufficiently superior to keep enough formidably armed opponents from getting a good shot at you, you're able to dominate. But when their tactics and performance catch up, and it's your turn to take a beating, your vulnerability to fire becomes a fatal flaw IMHO.
Cheers,
Wes

Another strategic consideration - blitzkrieg vs. attrition war

 

[PAT303]

Which is nuts, considering Japan's sizable investment on long range flying boats, like the Kawanishi H6K and H8K. The shorter ranged Aichi E11A is essentially an IJN Supermarine Walrus, the latter of which picked up many a downed RAF and FAA aviator.

When you have a limited supply of trained pilots and a very limited means of replacing them, why wouldn't you focus on keeping the pilots you have alive?

I've said that this all along, the fatal flaw of the Zero was its inability to protect the IJN's most valuable assets, their pilots.

 

[Schweik]

A couple of points
a) 2 x 20mm and 2 x LMG was quite a decent amount of firepower for a good part of the war
b) Another reason for the Japanese loss of pilots was the reluctance to use parachutes in the early part of the war. I have read a number of stories where they either didn't carry them, or had to be ordered to wear them. Remember the greatest fear of a Japanese combatant was to be captured, and the use of a parachute significantly increases those chances.
c) Whilst your observation that the Japanese aircraft tended to be less well protected is true, to rely on gun footage to prove the case is 'flakey'. I have seen a number of footage films of British, German and American aircraft catching fire.

It's worth keeping in mind, there was nothing magical about aircraft armor. Armor and self-sealing fuel tanks were no guarantee of survival. They certainly helped, but even very well protected planes like Fw 190s certainly caught fire and exploded (as you can see in gun camera footage), and their pilots often died - in fact while I don't know the precise percentage a large proportion of FW 190 pilots, probably most of them, did in fact die. Arguably the most heavily protected aircraft in the war, the Soviet Il-2 bomber, had one of the lowest crew survival rates of any plane in the war. Probably lower than the A6M. Some aircrew bailed out repeatedly but surviving bailouts was also not guaranteed, it took a certain amount of skill and / or luck to survive bailing out of a damaged aircraft. Then landing in your chute was another crap shoot, as was evading captivity in many cases (or surviving long enough in a little rubber dinghy - if you were lucky- to be found and picked up by that Sub or PT boat).

When you look at sustained heavy engagements during WW2 in fact, especially in the hot period of the mid war, the odds were against combat pilots in general with or without armor. Most pilots were eventually getting killed, captured or maimed on all sides - by enemy pilots, enemy defensive gunners, by flak / AAA, and quite a bit by accidents. The armor, protected fuel tanks, parachutes, air-sea rescue systems and so forth just improved the odds a little bit. But if you go through the day by day air histories, front line fighter pilots had a fairly high attrition rate and probably a majority of them died in most Theaters during the more intense periods of combat. I'd guess from Shores MAW probably 1/3 to 1/2 of shoot downs of the well protected aircraft resulted in a fatality. Prior to the more modern types coming into Theater maybe it was more like 2/3.

But if you bailed out and somehow made it back to base, you didn't get to go home - unless you were too injured to fly you went back into another fighter and went back up again. So eventually the odds were against you. Of course all this made a difference to your unit. If the Japanese lost 4 planes per week and the US lost 8 but recovered half of the pilots (and could replace their aircraft), they are still basically on an equal footing. Over time and many iterations that makes a big difference in attrition. But for the individual pilot the situation is still pretty grim.

 

[Schweik]

I believe the problem is the initial acceleration. The Spitfire accelerated slowly in the dive at the beginning allowing a pursuing Zero to get in a really good burst. Spitfires aren't as durable as many other allied fighters, P39 had the same issue with the rear mounted engine. A P40 has a great roll rate, so a Zero drops on your tail, you can easily out roll him, so in an instant your on your back, it also accelerated quickly in a dive, so by the time the Zero finished its roll and was on its back, the P40 was safely out of range. P40's and Wildcats were also extremely tough, both being able to absorb quite a few hits before they make their escape, the Spitfire, while tougher than a Zero, did not enjoy that reputation.

P-40 pilots developed two "escape maneuvers" which were critical in their survival, and later success against Zeros and Ki-43s. The first was the simple Split-S into a vertical dive downward, good but not 100% safe. Often combined with side-slipping and that sometimes led to a spin which itself could be intentionally or otherwise used as an escape maneuver (though it seems nuts to me).

The second escape manuever was some kind of outside loop or roll which led then to a dive, this was apparently much harder to aim at and much safer if the enemy aircraft was close. A6Ms were not slow.

Against A6Ms specifically they would also continue to roll right in the dive because the torque of the Zero prevented them from rolling right much at high speed. Thus in the pull-out they go in a different direction. But this didn't work against Ki-43s. Both major Japanese fighter types though had speed limitations around 400 mph, particularly the K-43, so they would be left behind as the P-40 approached 480-500 mph.

However it was tricky and dangerous to attempt a high speed dive escape. You had to keep track of your instruments to make sure you were diving fast enough but not too fast, your RPMs were in the right range and in the P-40 you had to make trim adjustments as the speed changed to maintain control. During pull out they often found themselves still being chased as pursuing zeros cut the chord so to speak. Quite often they



By the end of 1943 the 'outside loop' escape seemed to be pretty standard, US, RAAF, and RNZAF pilots mention it all the way from New Guinea to India. The more familiar they became with the process the more safely and reliably they could pull it off. But it took some experience getting to that point.

EDIT: corrected the direction of the roll / torque after my being pointed out by XBe02Drvr

 

[Schweik]

Interesting question: Why would a Spitfire, with its thin wing and sleek wind cheating shape, have an acceleration problem vis a vis its contemporaries, even in a dive? It has a thin, elliptical wing, which theoretically should give it just about optimum L/D for its aspect ratio at pretty much all useful angles of attack, thereby minimising induced drag. Parasite drag from its highly streamlined fuselage is about as low as it can practically go, leaving the radiator as a potential culprit. But then why aren't other contemporary liquid cooled fighters similarly handicapped?
Just speculating, I wonder if the wing angle of incidence relative to the thrust line would have anything to do with it. The Spit was designed in an era when fighter dromes were small with obstacles around them, and relatively short takeoffs and landings the norm. It would make sense in that case to mount the wing with its high speed airfoil at a slight positive angle of incidence relative to thrust line and fuselage centerline. Unfortunately, this means that when the pilot "unloads" (zeros the AOA) in order to maximise acceleration, the plane develops a desire to "tuck under" because of the downward canted thrust line relative to the chord line. So the pilot has to maintain a slight positive AOA to counter the "tuck" thereby incurring an induced drag penalty. The A4 Skyhawk was similarly afflicted, and for the same reason.
The other possibility is a thrust penalty incurred during the "unload", but weren't Spits V and above equipped with pressure carbs or fuel injection? Or at least the infamous orifice?
Any engineers out there want to jump in?
Cheers,
Wes

Very interesting, I've been wondering about that for years. Could be the answer.

 

[Schweik]

The 109 was a light aircraft (~6400lb for the 109F) but still only had 173 ft2 wing area but a P40 was typically at ~8500lb TO weight but with 236ft2 of wing area. Compared to a Hurricane or a Spitfire the P40 turn radius was terrible as would be expected for an aircraft with such high wing loading. The P40's high roll rate allowed it to enter a turn quickly, but it was terribly handicapped in terms of actual sustained turn radius.

That is an incorrect statement. The wing loading of the P-40 (between 31-35 lbs / sq ft depending on model and weight) was better than most other Allied fighter aircraft - the Spit and the Hurricane were the best of the bunch in that regard, but the Hurricane in particular was hampered by it's sluggish roll performance and high drag.

The Spitfire was the most maneuverable Allied monoplane fighter of the war (considering turn, roll and vertical maneuverability together) so few other types could match it.

No Allied fighter in large scale prduction could out-turn an A6M or Ki-43, including the Spitfire, the Hurricane or the P-40, but the turn rate or 'horizontal maneuverability' of the P-40 was considered one of it's main virtues, along with roll rate and dive speed / acceleration.

S

 

[Schweik]

ThomasP,

The scissors or roll maneuvers are a done to force your opponent to spit or flush out in front of you. They start with two opponents almost or near equal along each other's 3 or 9 o'clock.

The picture you attached shows a high yo-yo. If you look at the inset or Gods eye view (upper right in your attachment) you will see two fighters depicted with a thick and or thin line. The offensive plane is thin, the defensive is thick. Each line has three segments, representing equal times. The offender starts at the 7 o'clock of his adversary, cuts across his turn circle, and pulls up (represented by the "w" in his second segment of line). He then pulls his nose back down below the horizon as seen in his third segment and represented by the three slash marks. The high yo-yo would allow a lessor turning a/c to "out turn" a better turning a/c in theory. Reality is he doesn't out turn but uses the vertical in an uncontested manner. This maneuver today is easily defeated or neutralized and has been since the F15, F16, F18 arrived. It could have been defeated back in the day had the defender understood what was happening and countered it properly.

As for the Martlet Seafire fight, please understand that a steep climbing turn isn't trading energy/ speed for better rate, but trading it for altitude in which to attempt a high yo-yo or to negate an opponent attempting to high yo-yo on himself. Going up will lower your turn rate but in certain situations allow you to decrease your turn radius at the top of the maneuver (in the initial pull up you actually increase your turn radius).

A plane has one speed at which it generates its best rate (degrees per second of turn) or its best radius (smallest turn circle). These are not the same speed. The F-16 and F22 don't adhere to these last two rules.

Cheers,
Biff

The rolling scissors was one of the main tactics used by experten Bf 109F and (early) G model fighters against Spit V's, P-40s, & Hurricanes in the Western Desert whenever they either decided or were forced to enter close maneuvering combat (as opposed to bouncing their targets which was the preferred method). If course like any technique it could be countered but it could also be quite effective especially when suddenly deployed. It was also a good way to set your pursuing opponent up to be hit by your wingman.

Conversely the Yo Yo, but specifically the low-Yo-Yo, was the technique most favored by experienced US P-40 pilots in the PTO and CBI to out-turn A6Ms and Ki-43s while keeping their speed up. It was described in detail by a couple of Aces including Robert DeHaven.

 

[Schweik]

The low altitude cropped impeller MK Vs were capable of good performance in a limited altitude band.
We are told repeatedly how good the P-40 was at low altitude using high boost. A Spit V with the cropped impeller was within a few mph of a P-40 using 57in of boost (14lbs?) at around 3,000ft. The Spit was using 18lbs. but the Spit could climb around 1000ft/sec faster at low level.

Do you have those exact speed numbers at 3,000 ft? How much does 60" Hg work out to in boost again?

 

[Ivan1GFP]

The problem they had not sticking to it was manifold. The navy had a big say in the course of the Zero's career and arguably stifled its and the A7M's development due to lack of foresight, such as the decision to incorporate a less powerful engine in the Zero until it was too late to make a difference, for example, as well as inevitable development delays, not least of which was bombing raids on aircraft factories. the Reppu mock up and thousands of drawings were destroyed in one raid in March 1945.

Hello Nuuumannn,

I suspect that the Navy's choice not to switch the engine from Sakae 21 to Kinsei was made because of its experience going from Sakae 12 to Sakae 21.
When this was first done on the new and improved A6M3 Model 32 "Hamp", the fuselage fuel tank had to be reduced in size and because the Sakae 21 burned more fuel, the range was drastically reduced. This resulted in the brand new Type 0 Mark II being completely out of the fight at Guadalcanal and resulted in the creation of the Model 22 with restored wings and additional fuel tanks. The Kinsei in the A6M would have given even shorter range and also in 1942-1943 wasn't giving 1500 HP but more like 1300 HP.
The eventual installation of the Kinsei in A6M8 also resulted in the complete removal of all nose armament which in the A6M5c still left 2 x 20 mm cannon and 2 x HMG. With the earlier aircraft, the only armament left would have been those two 20 mm with about 100 rounds each which was hardly sufficient. At a cyclic rate of 480-500 rounds per minute, that works out to about 12 seconds of ammunition.

Note also that although the N1K-J and J2M were better performers and made great interceptors, neither had the range to perform the escort missions that the A6M could.

- Ivan.

 

[nuuumannn]

I suspect that the Navy's choice not to switch the engine from Sakae 21 to Kinsei was made because of its experience going from Sakae 12 to Sakae 21.

It would have been interesting to find out whether that was the case or not. Horikoshi wanted the 1,000hp Kinsei over the 950hp Sakai 12 right from the start, but was advised to take the Sakai, so had the Zero been built with the Kinsei, perhaps its career might have been different from the outset. The Sakai enabled the Zero to be a formidable fighter, but perhaps the navy should have placed the Kinsei in a Zero variant sooner, rather than leaving it so late and allowing Horikoshi and his team to produce the fighter around it, particularly when attempts to get the Sakai more power with firstly turbosupercharging in the A6M4, then water meth in the Sakai 31a in the A6M6c was not entirely successful... That ole would'a should'a could'a. With the A6M8 the drive was still to maintain some modicum of performance against superior fighters, so something had to give, regarding weight. It also had an extra fuel tank to make up for the higher consumption of the Kinsei.

Yes, the Kawasaki fighters were certainly excellent, but in the long run the other issue was that neither were carrier capable, so that aspect of the Zero's capability was not met either. The only true replacement for the Zero was the Reppu and the J2M and N1K1, which had its own fair share of issues with its extended landing gear until the better N1K2 meant that the Zero again was kept around for longer than necessary.

One thing puzzles me, I've read a few books on the Zero and I've never seen reference to this 'Type 0 Mk.II'. it's certainly not of Japanese origin that I'm aware of. Yes, the A6M3 differed from the earlier A6M2, with the Sakai 21 and the clipped wings, but does it warrant a "Mk.II" designation over and above "A6M3 Model 32"? The official Japanese designation translated to English was Mitsubishi A6M3 Navy Type 0 Carrier Fighter Model 32. No mention of a "Zero Mk.II" Someone else on this thread has done the same, but I've never seen it before. The fact is, the Zero changed little throughout its career, certainly not to the same degree as the Spitfire and Bf 109 for example and major changes were reflected in the change in numerical designation after "A6M".