"Stretch or not strech" of aircraft designs

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Coral Sea did save Morseby, but Morseby remained under threat.

New Guinea is a very mountainous jungle island. The knife like ridges of the Owen Stanley range proved an insurmountable barrier to Japanese ground forces, who were based on the north side of the Island (see Buna and Lae on the map below) whereas Port Morseby was really the only viable port for the Allies on the South side. Milne Bay was a tiny undeveloped outpost with a small landing strip on the Eastern tip of the Island and the battle there was an attempt by the Japanese forces to do an end-run around the edge of the island (using invasion barges) so as to get to Port Morseby. See the map:



Had the landing succeeded, the Japanese Army was to continue up the coast to Port Morseby. The Australian and American aircraft which sunk the invasion barges and strafed the Japanese troops were based mainly in Port Morseby. Only after the battle was Milne Bay developed into a proper base.


Make sense?
 

Well, while I agree the operational history of the P-39 in "Western" hands looks poor, it certainly did well for the Russians, and on paper at least later model P-39s look pretty good. WWIIaircraftperformance.org shows an initial climb rate for the P-39Q of 3,470 dropping down to 3,307 by 10,000 ft. That is quite good. Top speed was 385 mph with the two .50 cal wing gun pods. P-39N shows a top speed of 398 mph at standard WEP of 57" Hg. That again is pretty good. And again, probably attainable in the field when removing wing guns and front armor.

As for the 37 mm gun being popular and mounted in many Soviet fighters, it ISN'T the same 37 mm cannon as in the Airacobra.
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And that is news? I don't believe I ever made the claim that the Soviets adopted the Oldsmobile M4 autocannon. However, I do see a link to the Soviets designing their own, slightly better 37mm guns, on the theory that one 37mm aircraft mounted cannon is much more similar to another 37mm aircraft mounted cannon, vs. say a 12.7mm machine gun or a 20mm.

Why did the Soviets adopt that specific caliber instead of going to say, 30mm like the Germans and Japanese did or just packing on more HMG or light 20mm cannon like the British and Americans.


This is again part of the long established postwar myth. The shorthand is that P-40s racked up claims against obsolete Italian biplanes and open cockpit Macchi 200 and Fiat G.50 fighters. The reality is that those aircraft contended first with Gladiators and later Hurricanes. The arrival of the Tomahawk at the end of 1941 hastened the rapid removal of those types of planes from the Italian TO&E. The British Tomahawk pilots of units like 112 Sqn enjoyed a short period of 2-3 months of engaging obsolete Italian fighters and German Bf 110, which were replaced by the far more capable Macchi 202, which was roughly equivalent to a Bf 109F according to almost all of the pilots on both sides and every country.

By the time the first Kittyhawks arrived in early 1942 the older Italian fighters, as well as the similarly vulnerable German Bf 110 were relegated to fighter bomber, coastal patrol and night time duties while the Macchi 202 took the forefront. JG 27 also demanded that their Bf 109E be phased out and replaced by far more capable Bf 109F2. So this is what the RAF had to contend with in their Kittyhawk I and Ia for six months and they took a beating. It only ended with until the arrival of US Merlin (not Allison) powered P-40Fs as well souped up P-40K's and a few Spitfires and P-38s all starting in mid-1942. None of the previously listed Allied fighter units found the MC 202 an easy mark, incidentally.

The greatest success by P-40s in the MTO were by American fighter groups flying Merlin powered P-40F and L, as well as two British squadrons with the same aircraft. Their victories were almost all against Bf 109F and G model and Macchi 202 (and later 205*). For example as you can see here the US 325th FG claimed 133 aircraft while flying P-40's - which broke down to 95 Bf 109, 26 Macchi MC 202, and the other 12 being miscellaneous transports etc. The only claim for one of those obsolete Italian fighter types was for one (1) MC 200 damaged. I hope that helps clear this persistent myth up a little bit at least in your mind.

From accounts I have seen, the "didn't fare so well" was mostly because the British tried the wrong tactics against the lightweight Japanese fighters. A Spitfire may turn pretty well, but a Hayabusa turns better.
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Bad tactics and poor training on type were very common among all the Allies in the early days of the war. It may indeed be part of the problem with the P-39, maybe some of the other types lent themselves better to relatively unseasoned pilots.

Golodnikov stated that typically after 3-4 combats, the engine was changed. That kind of time between overhauls would have been commented upon if it were by American units.
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If you read the interview Golodnikov also talked a lot about the problems they were having with what he called "oil culture" and keeping dust and dirt out of the engines, and with winterization which required them to drill holes and add drain plugs to every fluid reservoir in the aircraft, sometimes using silver spoons confiscated from regional villages to use as solder. Most of the early P-40 units were worn down by maintenance problems particularly during the winter.

In other words there were several other reasons why engines would rapidly wear out on a P-40 in Soviet use particularly in the early days. I still do not believe overboosting was any more widely practiced among the Soviets than the Americans, Australians or British (per the famous Allison memo)

I believe the "exactly what was needed" is a conclusion based on hindsight. My Son calls that "hindsight bias".
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Interesting concept, and I understand the point. But I think my explanation is a bit misunderstood. I'll get into that more in my reply to Shortround6

The problem with non-strategic materials / wood construction is that it is labor intensive, the result is not particularly strong and is relatively heavy for its strength.
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Lets not forget the many great successes with laminated wood construction the most famous being the Mosquito, arguably the best and most effective aircraft in it's class in the entire war. I would also add to that the later more mature versions of the Yak series. Making plywood was more labor intensive but it took advantage of a material (birch etc.) that the Soviets had in abundance and with skilled labor techniques which had a long tradition in Russia. Sophisticated processing of birch bark goes back centuries in Russia, it was used for paper in Veliky Novgorod. So they had people who could do that work which was a great benefit. And ultimately, the early problems with things like defective paint eating through wing coverings and plywood delaminating due to moisture and so on were fixed just like the severe engine, landing gear, canopy opening and various other problems they had which I suggest were largely due to having to move all their factories.

One expedient they eventually settled on was to put a thin layer of bakelite over the skin of the Yak-9 as climate protection, which is pretty clever.

gradually replaced with aluminum pieces as production went on. Now that would be pretty silly if the wooden pieces were the optimal choice.
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Wood was an expedient for several reasons - the decision to make the Mosquito out of wood was originally to save on strategic materials. Sometimes it works out better to keep the wood, sometimes it was better to replace it depending on availability, production capacity and other factors. Wood certainly had it's downside particularly in certain types of environments (Mosquito apparently wasn't so good in Burma for example).

Engine is the biggest expense and probably weight for an aircraft but superchargers aren't a simple or cheap part of an engine and impellers in particular can require special and rare materials.


The MiG 3, which performed pretty well above 15,000 ft, proved that high altitude capability wasn't necessary and was a waste of resources, particularly since the Mikulin engine was so heavy.

The Spitfire Mk.V wasn't particularly fast at low altitude and many Spitfires that were shipped to Russia were pretty well used before they were sent.

- Ivan.
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Quite a few of the early P-40s and P-39s were also clapped out.

S

*The Macchi 205 looked almost exactly like a 202 and was often claimed as such.
 
I think the Soviet outlook is kind of typified by the Ak-47. You could have another rifle with a lighter or heavier caliber which was more accurate or had a longer range, but from the Soviet point of view they want a weapon which works 99% of the time so that they can be sure it's available when needed. If your platoon of 50 men has 99% of their rifles which have (just to make up a number randomly) a 200 meter effective range working effectively, that is better than than the enemy who has 60% of their rifles which have a 300 meter effective range functioning because they are prone to stoppages and are hard to maintain in field conditions.

Soviet planners needed to make fighters which not only performed well in the flight envelope they needed them to (basically low altitude) they also needed them to function in the winter and be maintainable in very rough field airstrips by peasant mechanics working out in the elements and who may not have a long history of working on cars like an American kid might have had.

An early model Yak-7 may not have been quite as good on paper as a Spitfire V or a Kittyhawk III, but if the former has an 80% availability in February while the latter have a 30% availability the Yak-7 is definitely superior for Soviet purposes.

There is a bit of a mystery here related to the P-39 which in spite of being foreign with an American engine that required very clean oil and fuel, and had the same Winterization challenges at least in theory, but seemed to hold up better in the Winter than the other lend-lease types. One reason may be the location of the engine. Another probable reason is the 4 month workup they did before deployment. Another reason with later models is that Bell incorporated some Winterization mods in the factory.

Whatever the reason the P-39 didn't have the same problems with Winter serviceability that the other lend-lease planes had and that was another major reason why the Soviets liked it.
 
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Hello Schweik,

We are in agreement with the performance numbers of Airacobras. Not bad for a 1942 aircraft. Pretty mediocre for 1944.
I will ask you the same question you asked me earlier: Where did you get the information for what armor was removed by the Soviets?
I find that to be very odd because the Soviets appeared to be very conscious about the CoG problems with the aircraft.


As I commented earlier, the ONLY similarity is bore diameter. It is like comparing the 12.7 mm Breda HMG to a .50 BMG. The power level is pretty different. The Soviets had the high powered 37 mm cartridge in service in the Sh-37 as the not-quite-successful predecessor to the NS-37.
As for choice of caliber, The probably chose 37 mm for the same reason they chose 23 mm and 45 mm for calibers for their aircraft cannon. I haven't looked for it, but I would guess there was probably a 30 mm in development as well.
As for why the Soviets DIDN'T pack on more HMG or 20 mm, The simple answer is that they DID.
Note that aircraft that could support that kind of armament such as the Lavochkin La-5/La-7 eventually were armed with 3 x 20 mm B-20 guns. Those probably had to wait until a lighter alternative to the ShVAK came along because the weight of their armament package was limited for performance reasons.
As for the Yakovlev fighters, they simply didn't have the room for more guns. Eventually they pretty much settled for a single 20 mm and a single 12.7 mm. The 37 mm and later the 45 mm guns were mounted only on their "Heavy" fighters.


You can figure out the performance figures as easily as I can and what you just stated says quite a lot.
First of all, I would say that from a performance standpoint, the C.202 was inferior to a Me 109F. Speed was similar to F, but engine power was identical to a low altitude rated Me 109E.
The C.202 also generally has pretty low firepower. Typical is a couple Breda 12.7 mm and MAYBE a couple rifle caliber wing guns.
The fact that the P-40K was considered "souped up" is a clear indication that the battles were happening down near ground level. At altitude (12,000 feet or so and above), the P-40K had no advantage over the earlier Kitthawk Mk.IA. / P-40E.


You are totally ignoring evidence in this case. Regarding clean oil, note that late model P-40 had built in dust filters for the carb intake.
Also note that Golodnikov states 3-4 COMBATS, not 20 or so flights. In other words, it was the need to operate at absolute maximum power levels that was wearing out the engines and not exposure to the harsh environment.
He also stated very early on that the P-40 had poor acceleration and climb, so they would over-rev it and "take what the aircraft could give" rather than what the manual stated.
Another side note is that from general accounts, the same kind of thing was happening to the Airacobra. I don't know about P-40, but Airacobra has a built in heater in its oil reservoir, so congealing oil should not be a problem.

Note also what the Allison memo was stating: They were agreeing to new Emergency Power limitations knowing that they would still be held accountable for a reasonable time between overhauls. 3-4 Combats is NOT a reasonable time between overhauls.


First of all, the Mosquito is an entirely different kind of beast. It is a bomber. It is not stressed to the same strength level as a fighter.
The technology used to manufacture material for aircraft construction isn't really comparable to the historical techniques used to make furniture grade plywood. It isn't even close.
Regarding a thin layer of bakelite, what do you suppose the weight penalty was for something like that?
As for weather and moisture resistance, their construction was not as was shown at the end of the war as I mentioned earlier.

Schweik said:
The MiG 3, which performed pretty well above 15,000 ft, proved that high altitude capability wasn't necessary and was a waste of resources, particularly since the Mikulin engine was so heavy.
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How do you conclude that the MiG 3 was a waste of resources because the engine was so heavy? The aircraft offered a capability that other aircraft didn't have. The Soviets obviously didn't come to the same conclusions you have regarding their need for high altitude aircraft because they continued to experiment with them throughout the war.

Schweik said:
Quite a few of the early P-40s and P-39s were also clapped out.
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I don't know about the P-40s, but as far as the early P-39s, many were newly built in batches that never served with US forces and were already rejected by the British by that time.

- Ivan.
 
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My only source is really various translated interviews on that Lend-Lease website which I think you are familiar with, plus a little bit in books like Black Cross Red Star and so on. No hard evidence like government documents or anything. You can see in some photos etc. that they have removed the wing guns, I don't claim to know about the armor definitively.


The NS-37 was the widely used one.

As for the Yakovlev fighters, they simply didn't have the room for more guns. Eventually they pretty much settled for a single 20 mm and a single 12.7 mm. The 37 mm and later the 45 mm guns were mounted only on their "Heavy" fighters.
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Actually, that is far from the truth. Yet another cliche. I had myself been told this many times including on this site until I learned differently. The Yak-9T was a major early variant with the 37mm NS-37, and 2,748 were produced. They were given to the squadron and later flight leaders of nearly every Yak-9 squadron at one point in the mid-war. There was also the Yak-9TD and a (to me) unknown number of the Yak-9U (some had the 23mm VYa + two 12.7mm mg instead), plus the Yak-9UT which had the Nudelmen N-37 again.

So quite a few of them actually had powerful 37mm guns. As for whether a 37mm cannon is just like any other gun I disagree wholeheartedly but don't care debate it forever. I think the P-39 armament and the subsequent ubiquity of the 37mm on Soviet fighters is not a coincidence. I admit that would be hard to prove but so is the reverse.

You can figure out the performance figures as easily as I can and what you just stated says quite a lot.
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Right back at you!


This is yet another canard that has already been put to bed on this board multiple times. Standard armament for most of the active variants of the MC 202 was 2 x 12.7mm HMG and 2 x 7.7mm LMG. Compare that to it's original Luftwaffe contemporary the oft praised Bf 109 F2 with 1 x 15mm MG151 HMG (or 'cannon') and 2 x 7.92 LMG. They were comparable in performance (370 mph for the MC 202, with 3,560 ft / min climb, ceiling 37,700 ft) vs according to his 371 mph for the Bf 109F-2 with initial climb 3,320 ft per minute, ceiling 37,000 ft) and the 202 was said to be slightly more agile.

Again, almost every pilot in action at that time was in agreement that the 202 and the 109 were roughly equivalent in North Africa, Germans, Brits, Aussies, and of course the Italians all said the same thing. The MC 202 was respected and feared, it certainly was not considered an easy kill for a Spit V or a P-38.

The Bf 109F-4 trop, which didn't arrive in the Middle East until mid 1942, was a bit faster yet (~ 380 mph), and G-2 trop by fall a bit more (385-390), but the MC 205s were arriving by the Battle of Pantelleria in Feb of 1943 so that is not too far behind.

The only 'inferior' aspect of the Axis planes fighting in the MTO was that they had to have tropical filters, but all fighters on every side had that problem. The British planes probably suffered worst of all with their dreadful Vokes filter.

The fact that the P-40K was considered "souped up" is a clear indication that the battles were happening down near ground level. At altitude (12,000 feet or so and above), the P-40K had no advantage over the earlier Kitthawk Mk.IA. / P-40E.
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The P-40K was definitely a low altitude bird but it was able to pull 1,580 hp at lower altitude ranges (and not quite so low as Shortround6 sometimes implies) at normal by the manual WEP, (not overboosted) down around 5,000 ft or below, so even if you started a fight at 20-25,000 ft a Split-S and a full power dive could put you into a very comfortable zone for the K in about 90 seconds, which was convenient in case you got in any trouble. Also made it very difficult for Axis aircraft to escape in a dive.

But to be clear - the F/L were considered the front line weapon against the Bf 109 & MC 202 because they were comfortable above 20- 25,000 ft., which was about the top of most of the fights.


Golodnikov actually contradicted himself because he indicated a longer engine life later in the interview, I always assumed he was referring initially to the early days of using Kittyhawks and later to the later days. The other issue they faced in Russia is that many of the Lend Lease planes they got in the first year and a half were already clapped out from fighting in the Middle East etc.

We can pick that Golodnikov interview apart in detail if you want, we clearly read it differently, but the bottom line is I don't agree there is any evidence of the Soviets overboosting more than anyone else was. They were just less familiar with the engines and operating with an even more precarious logistics tail.


Again, to me the Mosquito was a fighter, albeit not in the same category as a single engined bird, but it did maneuver and did high G turns and so on. As for the industry and training aspect of the wood, again I disagree, I have actually read academic papers about this.


They ditched the MiG 3 as soon as they had enough other fighters to replace it on the front line and the heavy engine contributed to it's lousy (almost useless) performance and dangerous handling traits at low altitude. Of course they experimented with everything, including long range four engined bombers, just in case. But that doesn't mean they really intended to use them.
 
Maybe there is quite a bit of bad information about Soviet aircraft and guns but sometimes explanations are actually rather simple.

The reason the 37mm was so popular around the world dates back to the 1890s and very early 1900s when in the same treaties that banned the Dumdum bullets they prohibited shells smaller that 1lb (or the metric equivalent) from containing high explosive. It turns out that 37mm was about the right bore size for 1lb hollow ( space for explosive) shells given the fuses and High explosives of the day.
Once a country (or gun/ammunition factory) is tooled up to make a caliber they are usually very resistant to change. It is also easier to experiment with new projectiles in an existing caliber/bore size, or make test barrels even if the rate of twist is different. The Russian use of the 45mm caliber also dates back many years when for some reason they adopted it for a 3pdr naval cannon instead of the more common 47mm diameter that most of the worlds 3 pdr guns were. This may have started out as a different way of measuring things. Like bore diameter vs diameter including depth of grooves? Or diameter of shell body vs diameter of driving band?
In any case the Russian (pre soviet) 45mm naval gun provided the basis for the 45mm Soviet army anti-tank and tank and tank guns and they in turn provided the basis for the 45mm aircraft gun/s. You could use some of the same barrel making machinery and shell making machinery even if the barrels were different lengths and thickness or the shells were different lengths/shape.

The Soviets were particularly constrained as their machine tool industry was very limited.

Soviet multi gun fighters include around eight hundred 5 gun Mig 3s but the underwing 12.7mm guns were often removed before combat to improve performance.

From Wiki so take it as you will. on the Lagg-3

"The I-301 airframe was partially made of delta wood (a resin-wood multi-ply veneer composed of very thin, 0.35 to 0.55 mm, birch or pine wood veneer and VIAM-B-3 a phenol-formaldehyde resin, baked at high temperature and pressure) used for the crucial parts. An unpleasant surprise encountered during the production of the prototype was the adhesive used in the delta wood caused skin irritation and safety procedures needed to be devised for workers.[2] This novel construction material had tensile strength comparable to that of non-hardened aluminum alloys and only 30% lower than that of precipitation hardened D-1A grade duralumin. It was also incombustible and completely invulnerable to rot, with service life measured in decades in adverse conditions. "

Italics by me. This is most definitely NOT furniture grade construction no matter how skilled the local woodworker/cabinet maker is unless he had access to special veneer lathes, the resin and the curing oven and method of applying pressure he cold not make any replacement parts. (of course no British aircraft fitter/wood worker could make replacement parts for a Mosquito either with common woodworking tools)
I would note that the calms for the longevity/durability of the material strongly echo the claims made for at least one wood veneer/composite resin form of construction used in the US. Which turned out to be as true as the Russian claims. In other words a fair degree of overclaiming.


BTW.......Bakelite is a phenol-formaldehyde resin. So putting a layer of it on the outside surface of the wing should have been not much of trick.

Schweik said:
As for the industry and training aspect of the wood, again I disagree, I have actually read academic papers about this.
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Well, the vast majority of furniture in the 1930s (or earlier) was not impregnated with resins or baked in autoclaves.

Schweik said:
1,580 hp at lower altitude ranges (and not quite so low as Shortround6 sometimes implies)
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Allison's suggested limits for the -73 engine was 1580hp at 2500ft using 60in of MAP. this may not include RAM which might add several thousand feet in level flight but at what altitude could the P-40K hold 60in of MAP when climbing or after pulling a high G turn?

The tales of 1700hp require very low altitudes, straight and level flight and/or over revving the engine.
Please note that the 8.80 supercharger gear engines were also rated at 1490hp at 4300ft at 56in of MAP. At both altitudes that is all the supercharger will supply without the Help of RAM.





The Yak-9UT is a bit of misdirection. It was supposed to take the 23mm gun, the 37mm gun and the 45mm gun pretty much interchangeable. About 282 were built(?), However the question is timing, how many were built before the war ended? the N-37 is supposed to be a post war gun going into service in 1946. Obviously since it takes a number of years to get an aircraft gun into service more than a handful could very well have been installed in several different Yak 9s for testing. There are claims that YAK-9UTs did fly over Berlin in the closing days of the war but one source makes no mention of which gun they were equipped with.
 
Shortround6 said:
Soviet multi gun fighters include around eight hundred 5 gun Mig 3s but the underwing 12.7mm guns were often removed before combat to improve performance.
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Is that supposed to be news?

And yes, the early aircraft grade resin-plywood laminates they made were quite sophisticated, though it took them a year or two to perfect. The Russian version of this was quite unique and made extensive use of local materials, like birch which they had in vast acerage. I don't think they were able to get any balsa though...

Italics by me. This is most definitely NOT furniture grade construction no matter how skilled the local woodworker/cabinet maker is unless he had access to special veneer lathes, the
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Making things out of laminated wood veneers goes back to the Bronze Age (in that specific region and well beyond). Mechanized lathes go back to the 14th Century. Various forms of plywood construction were a major industry in Russia since Czar Alexander II. You should quit while you are ahead.

BTW.......Bakelite is a phenol-formaldehyde resin. So putting a layer of it on the outside surface of the wing should have been not much of trick.
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Shortround, I get the feeling sometimes when you are moving a little beyond your areas of expertise, you just fill in the gaps with pure fluff...

Yes bakelite is a resin. What it is not is plywood. It essentially an early, nearly indestructible form of plastic, which was particularly popular in the 50's. The precise properties vary depending on what they put into the mix, but generally speaking it's quite sturdy. Here are a few artifacts made out of it:


I don't know if you have ever handled one of these old bakelite Ak-47 magazines but they are hella tough. Bakelite made a very useful protective coating for the Yak 9.


This is rather predictable... please note I made no mention of 1,700 hp and didn't make any performance claims based on overboosting. Whether it's 1580 at 57" or 1550 at 60" is not a sufficient variance to be worthy of yet another side debate - but lets just say I find your insinuations of P-40K falling out of the sky if they attempted a high G turn at either throttle setting quite unlikely. Please note this Oct 1942 AAF test of a P-40K (lightened to simulate a P-40N) shows an estimated b.h.p. of 1480 hp (and 378 mph) at 10,550 feet which it says was critical altitude for W.E.P. of 57" (critical altitude for climbing -at 3,720 feet per minute- was at 8,000 ft also at 1480 hp, by 10,000 that was slowed to 3,440 feet per minute... definitely with no ram whatsoever by the way). So no Shortround I don't think they would have any trouble putting out another 100 hp at 5,000 feet, and I remain quite comfortable with my previous assertion, your every effort to obfuscate the issue notwithstanding.


Yes old bean but you seem to have glossed right over the Yak-9T, built in 1942 and put into the field in early 1943, of which over 2,700 were built! And which, I apparently wasted my time to point out, were issued to almost every Yak squadron commander in the VVS at one point. Hardly a token experimental effort.
 
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Yes, overclaiming was universal, but how much other airforces were overclaiming has no bearing on the P-39 i Soviet service. The success of the P-39 on the the Eastern Front is based on the claims of the Soviet pilots, i.e. how well they thought they were doing; that is what overclaiming does, distorting the perception of what was really achieved. What makes it so difficult to evaluate is the seeming lack of data; how many enemy aircraft did Soviet P-39 pilots actually claim?
 

So how many enemy aircraft did the Soviets claim to have shotdown after these strict rules were imposed, say from mid 1943 on?
 

Hello Schweik,
The model suffixes are a pretty good indication. T is Russian abbreviation for "Heavy", D is typically a Long Range version, U is an improved version.


There is actually a pretty big difference in power level between a MG 151/15 and a Breda 12.7 mm....
Here is a little bit of background on the Macchi C.202 and its production 'standard':

Serie I – Breda 100 Aircraft 2 x 12.7 mm – same as prototype
Serie II – Macchi 10 Aircraft 2 x 12.7 mm – same as prototype
Serie III – Macchi 140 Aircraft
Serie IV – SAI Ambrosini 50 Aircraft
Serie V – SAI Ambrosini 50 Aircraft
Serie VI – Breda 50 Aircraft
Serie VII – Macchi 100 Aircraft 2 x 12.7 mm & 2 x 7.7 mm – April 1942
Serie VIII – Breda 50 Aircraft
Serie IX – Macchi 100 Aircraft – Sep 1941
Serie X – Breda 100 Aircraft
Serie XI – Breda 150 Aircraft
Serie XII – Breda 150 Aircraft
Serie XIII – Macchi 50 Aircraft
Serie XIV and later not built due to surrender.

The Serie VII and "later" were the only versions to come from the factory with wing armament.
Some earlier versions were retrofitted, but many factory wing guns were removed for the simple reason that they were determined to be ineffective and adversely affected the aircraft's flying characteristics. Loaded weight increased from 2930 KG to 3069 KG (!).
That is the choice when there isn't sufficient engine power.
So, total production of 1150 aircraft only had 600 equipped with the wing guns from the factory although some had them added and some had them removed,


If you are really discussing tactics, all that proves is that the P-40K can lose altitude fast and get down to its comfort zone.
An opponent would be stupid to follow when the P-40 has gone completely defensive and can be BnZ'ed at will.
Even a short zoom climb would take it out of its best performance altitude.

Schweik said:
Golodnikov actually contradicted himself because he indicated a longer engine life later in the interview....
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We are mostly in agreement. Golodnikov contradicts himself quite a lot. The key point to take early in the interview is his mention of over-revving the engine. Can't hardly take that one back.


Lousy performance is relative. It was easily the fastest aircraft in Soviet service until pretty late in the war.
As for its quirky handling, there are plenty of reasons such as the aircraft's configuration, but I don't believe the heavy engine was such a big deal if the designers balanced things correctly.
I am very curious as to your source for the Soviet's "intentions" for equipment. They certainly were not going to be using equipment if they could not get it working right., but that doesn't mean they quit trying.


As I understand it, the thickness of the sheets and the impregnation of the resin make the actual type of wood being used not terribly important.
This materials is for all intents and purposes a solid block of resin with some wood fibers in it, so it really doesn't have much to do with centuries old techniques of working plywood.

Schweik said:
I don't know if you have ever handled one of these old bakelite Ak-47 magazines but they are hella tough. Bakelite made a very useful protective coating for the Yak 9.
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How many really THIN items made of Bakelite have you seen? One of the things worth mentioning is that those AK-74 magazines are HEAVY but then again, so are the AK steel magazines.


This test aircraft may have started life as a P-40K, but if you actually read the report, you will find that it has had the engine replaced with a V-1710-81. This is NOT the V-1710-73 as normally installed in P-40K.

- Ivan.
 

As the kids would sometimes tell me: "Dad, you can't math!"
The total from Serie VII to Serie XIII SHOULD be 700 aircraft though there is no guarantee that every aircraft in the "later" production runs actually was built with wing guns either. Different factories pretty much did their own thing and also a numerically later aircraft MAY have an earlier production date even if it is the same company running the show. Thus the Serie IX production is chronologically earlier than Serie VII.
There is also the problem that some of the later production batches may not have been completed due to Italy's surrender.
Some sources list total production as only 1070 aircraft.

Relevant statements regarding wing armament removal are actually, "Therefore the wing-mounted machine guns were usually removed in combat units." "It was difficult to down heavy bombers with just four machine guns (and more often it was only two)." "The Folgore displayed marked superiority over the Hurricane IIs, but its main shortcoming, the weak armament, was a problem."

The effect of the Folgore seems to be all out of proportion to the numbers involved.
In the summer of 1942, there were only 100 aircraft in service in North Africa. They were reinforced by an additional 30 aircraft in late October1942, but by early 1943, they were down to 54 serviceable aircraft.

- Ivan.
 
Schweik said:
Is that supposed to be news?
Click to expand...

Not news but counters your argument that the Soviets built what they wanted to (or needed). There were also (and not new information) I-16s with four guns and two of them were cannon. However there was always a performance penalty and and later planes often reverted to 4 machine guns.


AS has been pointed out already it didn't really matter if it was Birch or not although Birch was probably a very good wood to use for this purpose. The Balsa issue is a bit of a misdirection. Just because several airplanes are made of wood (or use wood for a large part of their structure) does not mean they use the same woods (or substitute one wood for another with similar construction)

A US aircraft using laminated veneer construction.

The prototype was left uncovered to emphasis the type of construction. The 2nd and 3rd(?) aircraft were fabric covered.
The "veneer" (which was actually the structural shell of the aircraft) was Honduran mahogany. The Fuselage skin was 1/8 in thick and and the wing skin (it used laminated wooden spars, wood not given in the description I have but the ribs were mahogany plywood) was 1/16 in thick.

The fuselage was made using a mold and the vinyl-resins were cured in an oven for one hour.

Now can someone explain to me how Ivan, now matter how skilled he was at making tables or dressers was going to repair such a structure in field using wood working techniques passed down to him for generations?

there was also the Timm "Aeromold"


"triple cross sheets of spruce plywood impregnated with phenol-formaldehyde (similar to bakelite)" quote from US Civil aircraft vol 8.
Again the plane's parts were constructed on molds and baked in ovens to cure the resin. In fact the first prototype was delayed for months while waiting for the delivery of the oven.


A veneer lathe is a special lathe built to "peel" a log in uniform sheets of wood. While you might be able to adapt a regular wood turning lathe or even metal lathe to such use (with a lot of work) they are both pretty useless as they stand. You need the special cutters/blades to do the 'peeling" and you need a lathe of the right size to get the sheets you want and you need a lathe capable of turing at the right speed to allow the cutter/blade to do it's thing. Too fast is going to give you a lot of splinters. Moden machines with modern cutters can be very fast. Many older lathes had a range of fixed speeds as they were driven by belts or gears.






Hmmm. pot meet kettle.
Bakelite dates to before WW I, it was very popular in the 1920s and 30s and by 1950s was actually fading from use. Bakelite as used in the products you show was still a composite material as it used some sort of filler material in the Resin. Usually wood but it could be cotton fiber or even glass fiber. Bakelite by itself is not very flexible, it does tend to crack rather than bend but that may depend on temperature?




Hmm, you quote a test using the wrong engine (supercharger gear) and I get accused of obfuscating the issue?




Well old bean, then list your Yak-9T and leave the Yak-9UT out of it unless your intention is to obfuscate the issue?

Please note that your listing of the use of the Yak-9T may point to one of the problems with it. It seems to have been issued to the most experienced pilots for the most part and not general run of the mill VVS pilots? If this armament combination was so great why didn't they issue the Yak -9Ts to average pilots (like an entire squadron or group ) to simplify logistics/ammo supply? I am sure that some squadrons/ groups were fully equipped (or nearly so) with Yak-9Ts but scattering scores of them across many squadrons with only 1 or 2 planes per squadron was not ideal from a logistics or maintenance standpoint.

This is a generalization but gun combinations that were good for experienced pilots (or experts) were often not good for pilots of lesser experience or skill. Germans with the Bf-109F and Early Gs may have suffered from this.
 
I think most of the difference between the P40 and the P39 in the Pacific simply comes from engine location. No matter how awesome your fighter is, eventually you are going to take hits. A P40 or Wildcat running from a Zero can get riddled pretty good from the back of the seat to the end of the tail and still come home. In fact I think the Wildcat was nearly impossible to shoot down from directly behind if the Zero was out of cannon ammunition unless he hit the oil cooler in the wing. The P39, even though it had a speed advantage over the P40 and a huge speed advantage over the Wildcat, could simply not take many rounds from behind because that's where the engine was located.

On the other hand, if the P39 would have had a turbocharger, it would have been great at intercepting bombers because the engine was behind the pilot and not susceptible to bombers defensive guns. Too bad it didn't....
 

Again I think you are missing the point about how the Soviets adapted to their circumstances. The I-16 which eventually got 20mm wing guns was developed based on experiences in conflicts like Manchuria and in the Spanish Civil War. The MiG-3 was developed in response to theoretical high altiude bomber capabilities going back to Giulio Douhet and Billy Mitchel based on the notion that "the bomber will always get through" and the intention to completely annihilate cities (which did happen later in the war though more to the Axis). The miscalculation on the part of nearly everyone was the notion that bombers could hit anything of Tactical importance from high altitude - the high altitude bombing rarely accomplished more than terror bombing of civilians. This was what the billions put into the Norden Bombsight (a far bigger investment than the Soviets put into the MiG 3).

Once Operation Barbarossa started it was clear they they had a different type of problem to cope with and began to adapt their designs accordingly (and ditch the dead wood pun intended). Much early Soviet war kit was essentially experimental - it's the same down on the ground with armor for light 'cruiser style' BT-7 tanks and the land battleships like the T-35 and T-28, all of which fell by the wayside to be replaced by what worked, mainly T-34s and Su-85s (plus some KVs).

The Germans went through a similar fighter development cycle initially - downrading the heavily armed but ponderous Bf 110 and eliminating wing guns on the Bf 109 in the upgrade from E to F, then later adding them back again in the later G models due to the need to knock down big heavy bombers and the heavily armored Il-2. But for the pure fighter role against single and twin engined aircraft, the single heavy-ish nose gun with a couple of LMG were sufficient.


Disagree, the type of wood definitely did matter, you needed a certain type of strength and flexibility, and light weight which is where the Balsa came into play (as the middle layer in a 'sandwich' between stronger veneers for planes like the Mosquito).


It may help to look at an actual soviet plane. It was not pure plastic or fiberglass. For example, this is part of a MiG-3



You'll notice it's not just plywood, the internal structure is partly of wood. This is also true for most of the earlier LaGG / La and Yak fighters. There is a lot of old fashioned woodwork going into the construction of these parts. No welding, and not just mechanical forming (though the plywood was formed and baked). Actually the earliest Yaks had parts of the wing and rear fuselage covered in cloth initially which was gradually replaced with plywood and finally duralimin or whatever alloy.



This is a scale model of a Yak 3. You'll notice the mix of wood and plywood construction. Later model planes like the -3 had internal metal spars which gradually took over from the wood. But the traditional skills of a wood factory worker, a wooden shipbuiler or even a joiner would not be completely out of place working on these aircraft.


Here is a scale model of the Mig-3 with the wood showing


Even the Il-2 had a considerable amount of wood


They were doing this both by hand and with water wheel powered machinery going back centuries. More modern factory based production started in Russia in the 1870's.

Hmm, you quote a test using the wrong engine (supercharger gear) and I get accused of obfuscating the issue?
Click to expand...

Mea culpa - I was looking for an entry on the P-40K in WWIIAircraftPerformance.org for convenience rather than transcribe something from one of my books that you wouldn't be able to verify, and that is the only entry I could find for the K on there. I read the report but missed the part about the engine swap.

Well old bean, then list your Yak-9T and leave the Yak-9UT out of it unless your intention is to obfuscate the issue?
Click to expand...

Quite to the contrary, I listed both as my understanding is that the majority of Yak-9UT were actually fitted with the 37mm gun. I think all of them are relevant though there were more, the -9T was the single most ubiquitous subtype with 2,700 made but there were also others in the Yak family with the big guns, and if you add them all together it adds up to quite a few flying guns out there on the battlefield. Probably 4,000 or 5,000 all told.


No it wasn't but that was the Soviet way. They built a lot of Yak-9T and of all the big gun conversions, it was probably the single most successful (quite a few internal changes had to be done to make this work). But distributions of new aircraft was quite haphazard in Soviet use. There were units operating Yak 1, Yak 7 and Yak 9's together, and later on Yak-1B, Yak-9 and Yak 3 together. Or P-40s and P-39s at the same time too.

Why this happened is subject to different interpretations but I think the guiding principle of the Soviets was mainly expediency. They wanted to get their best stuff out as quickly as possible. Brand new fighter types were also often given to Aces, HSU recipients and squadron or group leaders for similar reasons (because better pilots were less likely to get shot down). By the time the Yak-9T appeared, the Soviets were flying proper flight leader / wingman formations of 4 planes, and the wingman often didn't even get to shoot their guns - their job wasn't so much to score victories as to chase enemies away from their section leaders tail.

This is a generalization but gun combinations that were good for experienced pilots (or experts) were often not good for pilots of lesser experience or skill. Germans with the Bf-109F and Early Gs may have suffered from this.
Click to expand...

Quite true, no doubt. But the reverse is also true, better pilots often couldn't reach their potential with 'easy' planes.
 

Hello Pinsog,

The really vulnerable stuff in the back of the Airacobra is more like the Oil and Coolant tanks. There is a pretty heavy piece of armor plate behind the Oil Tank which can't have helped the aft CoG problem very much, but removing it would make the aircraft VERY vulnerable from the rear.
This CoG issue is why I asked when Schweik suggested that the Russians were removing the Nose armor.
Presumably he meant the piece that protects the reduction gear from the front.

Looking at the differences in weights between armor in the same location in different models of the Airacobra is quite interesting.
The thicknesses and weights vary by quite a lot. Also some armor such as that in the nose seems pretty worthless.
I believe that adjusting armor weights in different locations was the way that the designers were able to keep the CoG in a "reasonable" location despite equipment changes between models. In other words, it was really a form of permanent ballast.

- Ivan.
 
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