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Russian planes are made out of ?

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i wasn't sure but I thought the German mineshell was a reaction to the low damage inflicted on British aircraft in the BoB. That's why I said HE in my above post and not Mineshell.

 

Still very interesting thread. And let's not forget all the time a single German cannon hit removes your entire vertical stabilizer. That is particularly vexing for me since the aircraft is in otherwise perfect condition but un-flyable. I have seen the vertical stabilizer fall off axis aircraft, but it seems much more common for VVS aircraft to lose it. Damn shame too.

 

Yep, the VVS fighters sometimes seem to have a glass tail.  OTOH after a head on pass sometimes my trusty Fw feels strange so I hit F2 only to conclude I'm missing half the stabilizer and elevator. So you gotta watch out for those  :russian_ru:  AI on ace level.......

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From a design perspective both the the German and Russian designs use the same stressed skin or monocoque construction: The good point with these types of designs  is that in general there are so-called alternative load paths if you take damage. What this means is that if you take a cannon hit in the wing for example, as long as it does not destroy a single point of failure point like a spar fitting or severs the spar itself, you can expect to survive. However, you will then have a plane that has lower load capabilities and the wing will flex more and if the cannon shell instead blows a hole in the wing and severs some stringers the load will take alternative paths to circumvent the damaged area meaning a higher load on adjacent structural members so you better not push your ride as hard as usual in these circumstances but you will survive.

 

So these aspects of the damage tolerance can be expected to be the same for both German and Russian planes. However, the difference you see in damage tolerance in-game could be explained by the following differences:

 

First of all AFAIK Willy Messerschmitt but a premium on weight. He believed that the foundation for superior performance was weight control so he kept a very tight control on that meaning that there is less damage tolerance built into the plane. This gives you the good P/W factor which in turn gives the 109 the good climb performance etc. but comes at the price of a more fragile structure.

 

Now the next part is speculation on my part (albeit an educated one since I have done wing structural engineering myself  ;) ) Since the Russian planes are made out of wood, they flex more under load than an aluminium construction (Young’s modulus is lower for delta wood than aluminium). My theory is that the Russian designers had to dimension their designs not from an ultimate load factor perspective but from a deformation perspective since if the structure flexes too much under load you get problems at high speeds like wing twist (lift resultant in front of wing flexural center) flutter and/or aileron reversal problems. This means that by virtue of being designed from a flexural perspective the Russian design can be expected to be heavier but have a larger margin towards structural failure, i.e. structurally more damage tolerant.

 

So yes, all other things being equal, I would expect a LaGG or Yak to be more damage tolerant and to be able to absorb more cannon rounds than a 109 just like you are seeing in the game! :hunter:

Nicely said ! Thank you for this post!

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You're welcome! Just my $0.02 so no guarantees but it does make sense that delta wood structures could be tough IMHO......

 

This image (albeit a 30 mm Mk108 round versus a Spitfire) has been posted a lot before but it's always sobering to see what Minengeschoss can do. :o:

 

post-23617-0-74746600-1458484140_thumb.jpg

Edited by Holtzauge

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there is loads of those pictures around :)

 

jCBZHix.jpg

^this one a 30mm

and this one a 20mm
uMXz2UQ.jpg

 

more nice stuff:
0A6e0J2l.png

translation: HS 124 wing, shot at witch 2 and 3cm (that 20 /30 mm for the imperial people ;) ) mineshells. the 3cm mineshell destroyed and area extending over several panels

and because it looks nice some cut aways. 
30mm Minengeschoss
weapon22.jpg

and a normal 30mm HE shell

weapon21.jpg

 

 

 

Edited by 6./ZG26_Asgar

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Is that last hit on the P-47 really from a 20 mm? If so then it looks like the MG151 can dish it out pretty well as well then......

 

BTW: I think the bottom 30 mm shell shown is the API round: Both the HE and M-geschoss had fuze in nose AFAIK.....

Edited by Holtzauge

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well, it's actual combat damage on that P-47 not a test so it's probably 2-3 hits maybe, but either case yes, the 20mm can dish out. as i said. it's almost 20g of PETN (1g of PETN equals 1,7g TNT)

the Mineshells were good. i mean, it's obvious once you know that the French and Britsh copied the Mauser MG 213 revolver cannon design (ADEN and DEFA 540) and both used Mineshells. 

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The LaGG-3 and La-5 for example have a reputation for their very sturdy structure due to specially treated wood and so on. Pilots who flew these models appreciated that a lot. In return, they are very heavy airframes.

 

In short: many Soviet aircraft were indeed "bullet sponges", but this also made them heavier than their German counterparts, lower Vnes and etc. It's a trade-off.

 

 

I have read evidence that wooden craft could absorb quite a bit of damage.

 

"Construction consisted of a combination of plywood covered over in fabric that made the Yak-1 both easy to produce in large numbers and generally easier to maintain. Additionally, such a structure could withstand greater damage from enemy guns."

 

 

It wasn't a pure playwood.

 

No mystery there. It was robust construction that could withstand some damage, but came at a price of high weight of every object made of it. 

 

 

I think there are a lot of misconceptions here.. while wood is an awesome material for planes it is not in any way more "robust" then metal. It was used in plane construction for it´s weight saving ability, since it is a directional material.. in a way very similar to modern composites, as it also consist of fibres in a matrix. It is also very fatigue resistant due to this and can fly for ages, if cared for right. But it´s "cared for" charecteristic is also it´s weakness, it needs be kept dry. AND that is why is treated with substances.. to try co counter this tremendous weakness, all those things don´t make it any more capable of bearing more load, but just somewhat preserve this capacity to bear load by preventing it to shape form and deconstruct when wet.

 

Historians or other writers saying "it could withstand more battle damage" because it was wood, simply have no clue about engineering. Build the same structure in wood and in metal and shoot at it.. and you will see the metal structre with equal damage will still be bearing more load until failure. That is simple physics. If it wasn´t so, you would see todays tanks and machineries beeing made out of wood...

 

What does make a difference, though, is construction principle. And with metal, the construction of the "ouside" covering of planes shifted to lot more loadbearing roles. And that´s why i think the post below from Holtzauge goes into the right direction albeit I would assume very much that his assumptions about the same "constructive principles" are not entierly correct. I haven´t looked into a laggs wing, but I have worked on plenty of wooden wings.. and usually on one-spar designs only the so called "D-box" combination of mainspar and plywood leading edge is where the wooden skin is primarily loadbearing. It is a construction method going back to the fokkers of the first world war... and I would be surprized if the Lagg was different. The rest of the wooden covering is there mostly for purely aerodynamical reasons.

 

But that plywood wing nose wich takes the torsion forces is also very sensitive to damage, any tiny hurt there and the plane is grounded..

 

 

 

 

From a design perspective both the the German and Russian designs use the same stressed skin or monocoque construction: The good point with these types of designs  is that in general there are so-called alternative load paths if you take damage. What this means is that if you take a cannon hit in the wing for example, as long as it does not destroy a single point of failure point like a spar fitting or severs the spar itself, you can expect to survive. However, you will then have a plane that has lower load capabilities and the wing will flex more and if the cannon shell instead blows a hole in the wing and severs some stringers the load will take alternative paths to circumvent the damaged area meaning a higher load on adjacent structural members so you better not push your ride as hard as usual in these circumstances but you will survive.

 

So these aspects of the damage tolerance can be expected to be the same for both German and Russian planes. However, the difference you see in damage tolerance in-game could be explained by the following differences:

 

First of all AFAIK Willy Messerschmitt but a premium on weight. He believed that the foundation for superior performance was weight control so he kept a very tight control on that meaning that there is less damage tolerance built into the plane. This gives you the good P/W factor which in turn gives the 109 the good climb performance etc. but comes at the price of a more fragile structure.

 

Now the next part is speculation on my part (albeit an educated one since I have done wing structural engineering myself  ;) ) Since the Russian planes are made out of wood, they flex more under load than an aluminium construction (Young’s modulus is lower for delta wood than aluminium). My theory is that the Russian designers had to dimension their designs not from an ultimate load factor perspective but from a deformation perspective since if the structure flexes too much under load you get problems at high speeds like wing twist (lift resultant in front of wing flexural center) flutter and/or aileron reversal problems. This means that by virtue of being designed from a flexural perspective the Russian design can be expected to be heavier but have a larger margin towards structural failure, i.e. structurally more damage tolerant.

 

So yes, all other things being equal, I would expect a LaGG or Yak to be more damage tolerant and to be able to absorb more cannon rounds than a 109 just like you are seeing in the game! :hunter:

 

like I said above.. I seriously doubt that the outer skin on a wooden wing in a Lagg or Yak has the same load to bear then the metal skin on other planes.. save for the nose/spar combo. And there is the main difference. Wood is not magically able to absorb more damage, even though in some cases it´s directional "fibre" structure can be beneficial for stopping crack extension (in direct comparision to metal) but that really should be minor issue. Another aspect could be pressure buildup. as a mineshell explosion in a metal compartment would likely be able to build up more pressure then in a wooden one, or the fact that lower density wood may in some cases even be less likely to trigger the fuse of projectile, depending on it´s sensitivity.. but all of that doesn´t make wood per se any more "damage resistant" and I think that the wooden wings in BoS may be even a bit too sturdy.

 

on the other hand, steel frame-fabric covered structures like the huricane or yak fuselage are really very dificult to damage by shooting, simply because there is so little to substancially hit. Unfortunately that does not apply for it´s contents like aircrew, tanks etc.

Edited by Dr_Zeebra

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I think there are a lot of misconceptions here.. while wood is an awesome material for planes it is not in any way more "robust" then metal. It was used in plane construction for it´s weight saving ability, since it is a directional material.. in a way very similar to modern composites, as it also consist of fibres in a matrix. It is also very fatigue resistant due to this and can fly for ages, if cared for right. But it´s "cared for" charecteristic is also it´s weakness, it needs be kept dry. AND that is why is treated with substances.. to try co counter this tremendous weakness, all those things don´t make it any more capable of bearing more load, but just somewhat preserve this capacity to bear load by preventing it to shape form and deconstruct when wet.

 

Historians or other writers saying "it could withstand more battle damage" because it was wood, simply have no clue about engineering. Build the same structure in wood and in metal and shoot at it.. and you will see the metal structre with equal damage will still be bearing more load until failure. That is simple physics. If it wasn´t so, you would see todays tanks and machineries beeing made out of wood...

 

What does make a difference, though, is construction principle. And with metal, the construction of the "ouside" covering of planes shifted to lot more loadbearing roles. And that´s why i think the post below from Holtzauge goes into the right direction albeit I would assume very much that his assumptions about the same "constructive principles" are not entierly correct. I haven´t looked into a laggs wing, but I have worked on plenty of wooden wings.. and usually on one-spar designs only the so called "D-box" combination of mainspar and plywood leading edge is where the wooden skin is primarily loadbearing. It is a construction method going back to the fokkers of the first world war... and I would be surprized if the Lagg was different. The rest of the wooden covering is there mostly for purely aerodynamical reasons.

 

But that plywood wing nose wich takes the torsion forces is also very sensitive to damage, any tiny hurt there and the plane is grounded..

 

 

 

 

 

like I said above.. I seriously doubt that the outer skin on a wooden wing in a Lagg or Yak has the same load to bear then the metal skin on other planes.. save for the nose/spar combo. And there is the main difference. Wood is not magically able to absorb more damage, even though in some cases it´s directional "fibre" structure can be beneficial for stopping crack extension (in direct comparision to metal) but that really should be minor issue. Another aspect could be pressure buildup. as a mineshell explosion in a metal compartment would likely be able to build up more pressure then in a wooden one, or the fact that lower density wood may in some cases even be less likely to trigger the fuse of projectile, depending on it´s sensitivity.. but all of that doesn´t make wood per se any more "damage resistant" and I think that the wooden wings in BoS may be even a bit too sturdy.

 

on the other hand, steel frame-fabric covered structures like the huricane or yak fuselage are really very dificult to damage by shooting, simply because there is so little to substancially hit. Unfortunately that does not apply for it´s contents like aircrew, tanks etc.

 

Actually in aircraft structures you always use the skin as a load bearing member if you can: A stressed skin structure, be it of wood or metal, is extremely efficient and usually the load bearing limit is defined by the buckling loads. Now the resistance to buckling is proportional to the square of the panel thickness which actually favours "plywood" compared to metal. In addition, I'm pretty sure the Russian used ply with tri-axial layups much like in modern composites which gives as good a torsional resistance as possible.

 

I also think saying that since wood was in general replaced by metal in WW2 designs that this means that the Russian wooden designs were somehow inferior is a fallacy: Actually the design principles used in the Russian wooden fighters is today very much alive and quite applicable to modern composite structural design. IMHO they did a very good job with the material they had at their disposal and looking at sectioned drawings of these planes is a pleasure I think.

 

Now if you look in the La-5 Samolet for example, you will see that the wing has a two spar design and I'm pretty sure they did not just rely on the D-cell on the forward part but also on the box formed by joining the forward and rear spars with load bearing ply. At least that is what it looks to me when I look at the sectioned wing drawing in the Samolet. Overall, I find the La-5 beautiful from a structural standpoint and as I said before, If those guy's back then would have had access to unidirectional carbon fibre and epoxy they would have cut the weight massively and flown rings around a metal Me-109 and/or Fw-190 using the same sound design practices they had for wood but by being able to lighten and stiffen up the design by utilizing carbon's superior mechanical properties compared to wood.

 

A carbon La-5 would have been a world beating design be sure...... :cool:

Edited by Holtzauge

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that's what the pilot flying it said in his report

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-snipp- the Mineshells were good. i mean, it's obvious once you know that the French and Britsh copied the Mauser MG 213 revolver cannon design (ADEN and DEFA 540) and both used Mineshells.

A yes, the MG213 derivate the DEFA, also carried by:

 

post-23617-0-40948800-1458491018_thumb.jpg

 

OT I know, but she's such a beauty ain't she............

  • Upvote 1

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Back on topic: Here is a section of the wooden Mosquito wing which utilizes the rigid box formed by the forward and rear spar. In addition, the upper load bearing skin is protected against buckling due to wing bending loads by using plywood both on top and bottom of the upper wing stringers which is not necessary on the lower wing panel which will carry mostly load in tension, i.e. no risk of buckling at positive g-loads. Consequently, the wing as designed will be effective both to carry both bending loads and torsional loads.

 

Also, the Mosquito fuselage featured a sandwich design with dual plywood skins covering a balsa core much like a modern carbon fibre/divinycell or honeycom panel....

 

post-23617-0-58848100-1458492412_thumb.jpg

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Interesting discussion - I know next to nothing so I will sit down and learn quietly :biggrin:

 

A short picture from the other side: a Bf-109 wing hit by a ShVAK burst. Decidedly smaller and less catastrophic holes than the 30mm mine shells, but more than enough to ruin somebody's day.

 

Shvak_bf109.jpg

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Il-2 under fire (in russian).

Look on photos!

http://maxpark.com/community/2039/content/2103620?_utl_t=ok

 

tmpVN9JnN.jpeg

 

tmp768aIU.jpeg

 

Looks like a few of those Il-2's made it back even after being hit with 37 mm AAA. That's one tough coockie......

Interesting discussion - I know next to nothing so I will sit down and learn quietly :biggrin:

 

A short picture from the other side: a Bf-109 wing hit by a ShVAK burst. Decidedly smaller and less catastrophic holes than the 30mm mine shells, but more than enough to ruin somebody's day.

 

Shvak_bf109.jpg

 

Yes, when you see those pictures you know where the devs of the "old" Il-2 versions got the inspiration for the graphical DM back then.  ;)

 

BTW: IIRC then the ShVAK in addition to the explosive damage we see here also had a high muzzle velocity, i.e. good kinetic damage potential as well....

Edited by Holtzauge

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If you also take a closer look at that Shvak hits, the amount of smaller holes and punctures is far greater than in the areas affected by Minengeschoss. While the blast of the German round is outstanding, it seems it produces far less shrapnel's.

Edited by =LD=Hiromachi

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If you also take a closer look at that Shvak hits, the amount of smaller holes and punctures is far greater than in the areas affected by Minengeschoss. While the blast of the German round is outstanding, it seems it produces far less shrapnel's.

 

Yes, but IIRC then the idea with the M-geschoss was just that: Pure explosive damage so they made the casing out of drawn steel to make room for more explosive content, i.e. little potential for shrapnel but with a far greater explosive effect.

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yes because the experience the Luftwaffe made in combat was that pure explosive damage is way more effective on the structure of planes than shrapnel damage. at least that was the mind set behind Mineshells

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Yes, but IIRC then the idea with the M-geschoss was just that: Pure explosive damage so they made the casing out of drawn steel to make room for more explosive content, i.e. little potential for shrapnel but with a far greater explosive effect.

That means that structural damage is rather limited to the area of the explosion, and while the hit area is greatly affected (almost annihilated) anything out of the area seems keep the shape. Though this is relative, a direct hit into a wingspar means the whole wing can be lost while a direct hit into the middle of the wing may cause a very mild results. 

It's interesting design, though one has to admit its very ... simple, lets produce thinner wall of the round and fill as much HE as possible. Sort of a brute approach  :biggrin: But extremely effective as we can see. 

 

Other thing I can see here (only presumption though) is a very limited potential for ignition. The blast effect is so rapid that any possibility of petrol or petrol vapor being set on fire could be nullified because of this. 

 

That's a hell of an interesting topic to discuss.

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That means that structural damage is rather limited to the area of the explosion, and while the hit area is greatly affected (almost annihilated) anything out of the area seems keep the shape. Though this is relative, a direct hit into a wingspar means the whole wing can be lost while a direct hit into the middle of the wing may cause a very mild results. 

It's interesting design, though one has to admit its very ... simple, lets produce thinner wall of the round and fill as much HE as possible. Sort of a brute approach  :biggrin: But extremely effective as we can see. 

 

Other thing I can see here (only presumption though) is a very limited potential for ignition. The blast effect is so rapid that any possibility of petrol or petrol vapor being set on fire could be nullified because of this. 

 

That's a hell of an interesting topic to discuss.

actually, no not simple at all. actually the allies didn't know, how the Germans manged to produces shells with such thin walls that would not explode in the gun while being fired, for quite a while. that why they copied the production process after the war

 

at least that's what the documentaries say :P

 

here some random youtube video were they talk about plane armament even though the video is a bit pointless. for some reason they only shoot solid shot 20mm

 

https://youtu.be/moreRketqek?t=615

Edited by 6./ZG26_Asgar

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Ugh, I wasnt clear, sorry. It so ingenious and simple idea itself. I can however totally understand its not simple to manufacture and make working, Japanese failed to produce their own version of such round, stopping and 11+ grams which is 7 grams short of German round.

Edited by =LD=Hiromachi

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I think it's the way shrapnel spread and penetration is handled myself. You can get hit anywhere by 20mm and it's almost always "Engine 1 damaged, fuel tank leak, player wounded". The ballistic model of 20mm shrapnel is, optimistic, to say the least.

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i think that's their solution for "more damage". I know that War Thunder did a similar thing. because it's easier to produce more damage with more shrapnel than with "more explosion" I assume it's similar here. and it makes sense if you think about the fact that the engine was made for WWI combat, there were almost no 20mm cannons. most damage is done by MG fire -> little metal slugs, same kind of damage shrapnel will produce

Edited by 6./ZG26_Asgar

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Yes. That might be sort of a simplification of the system. After all a complete simulation of various explosive and incendiary materials, shapes and forms of rounds as well as way the air-frame can be affected would be just ... tremendous job. 

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Mitsubishi A6M Zero.

Nakajima's team considered the new requirements unachievable and pulled out of the competition in January. Mitsubishi's chief designer, Jiro Horikoshi, thought that the requirements could be met, but only if the aircraft could be made as light as possible. Every possible weight-saving measure was incorporated into the design. Most of the aircraft was built of a new top-secret aluminium alloy developed by Sumitomo Metal Industries in 1936. Called Extra Super Duralumin (ESD), it was lighter, stronger and more ductile than other alloys (e.g. 24S alloy) used at the time, but was prone to corrosive attack, which made it brittle.[7] This detrimental effect was countered with an anti-corrosion coating applied after fabrication.

 

Wiki- Mitsubishi A6M Zero.

No armor was provided for the pilot, engine or other critical points of the aircraft, and self-sealing fuel tanks, which were becoming common at the time, were not used. This made the Zero lighter, more maneuverable, and the longest range single engine fighter of WWII; which made it capable of searching out an enemy hundreds of kilometres (miles) away, bringing them to battle, then returning hundreds of kilometres back to its base or aircraft carrier. However, that trade in weight and construction also made it prone to catching fire and exploding when struck by enemy rounds.[8]

 

Sorry , may be I was worng about that the Japanesse many planes were  maid of Wood .

The answere was that they the armor that was provided for the pilot , engine , critical points and self-sealing fuel tanks were not used and becoming common at the time for USAF aicraft . So Japanese planes wen were shoot start firing more easily may be for the self-sealing fuel tanks , engine or other critical points.

 

I was confused ,because  I saw in LA Chino Airfield the Heinkel He.162 and explainme that the plane had a small metal , Wood fuselaje and the wings , their frame and covering were entirely made of Wood.

 

My Thought is if the Lavochkin LA 5 is maid of Wood and resine special composite strong , has the same armor protection provided for the pilot , engine, other critical points for the aircraft and self-sealing fuel tanks ? That were becoming common at the time for other planes. or were not used in the Lavochkin LA 5 ?

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If you also take a closer look at that Shvak hits, the amount of smaller holes and punctures is far greater than in the areas affected by Minengeschoss. While the blast of the German round is outstanding, it seems it produces far less shrapnel's.

The shrapnels of the Minengeschoss are to small to do any damage to a plane even normal HE ammunition had seldom enough large shrapnels that would be a real danger to important systems

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Actually in aircraft structures you always use the skin as a load bearing member if you can: A stressed skin structure, be it of wood or metal, is extremely efficient and usually the load bearing limit is defined by the buckling loads. Now the resistance to buckling is proportional to the square of the panel thickness which actually favours "plywood" compared to metal. In addition, I'm pretty sure the Russian used ply with tri-axial layups much like in modern composites which gives as good a torsional resistance as possible.

 

I also think saying that since wood was in general replaced by metal in WW2 designs that this means that the Russian wooden designs were somehow inferior is a fallacy: Actually the design principles used in the Russian wooden fighters is today very much alive and quite applicable to modern composite structural design. IMHO they did a very good job with the material they had at their disposal and looking at sectioned drawings of these planes is a pleasure I think.

 

Now if you look in the La-5 Samolet for example, you will see that the wing has a two spar design and I'm pretty sure they did not just rely on the D-cell on the forward part but also on the box formed by joining the forward and rear spars with load bearing ply. At least that is what it looks to me when I look at the sectioned wing drawing in the Samolet. Overall, I find the La-5 beautiful from a structural standpoint and as I said before, If those guy's back then would have had access to unidirectional carbon fibre and epoxy they would have cut the weight massively and flown rings around a metal Me-109 and/or Fw-190 using the same sound design practices they had for wood but by being able to lighten and stiffen up the design by utilizing carbon's superior mechanical properties compared to wood.

 

A carbon La-5 would have been a world beating design be sure...... :cool:

 

I wasn´t suggesting that the russian designs where "inferior".. but most wood wing designs are definatly not "monocoque" and non-load bearing wood skins are comonplace, in a way because it stems from a very old design tradition of saving weight by fabrik covering.. which then often got replaced by plywood. It goes back to the fokker planes in ww2 but is still in use today, a modern wooden wing would for instance be the Junkers Profly "Banjo" or  Jodel Robin sold in todays world. Revoultionary designs like the mossie with is doubled up shells are more the rarity and overall I think it is safe to say wood has been replaced by metal during WW2 for a reason.

 

I´m a huge fan of wooden wings and just spent my weekend repairing one.. for over a year in the workshop.. so I´m a bit torn on the "easy" repairability. I mean sure, you can always shift in and replace any bit on the wing, with relativly simple tooling, but good lord is it an amount of work hours instead just doing a double-up riveted in metal repairpatch ;=)

 

the lagg really seems to have a heavy duty wing with an relative uncommon 2-spar (or 1 + 1/2) design.. high rib-density and a D-nose.

struc6.gif

Edited by Dr_Zeebra

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The shrapnels of the Minengeschoss are to small to do any damage to a plane even normal HE ammunition had seldom enough large shrapnels that would be a real danger to important systems

The following is from "SOVIET CANNON - A COMPREHENSIVE STUDY OF SOVIET GUNS AND AMMUNITION IN CALIBRES 12.7MM TO 57MM" by Christian Koll.

Shvak 20 mm ammunition, page 127 :

Performance: When hitting the 0.9 - 1.5mm thick duralumin sheet skin of an aircraft wing (wing thickness between 90 and 280mm), the OZ projectile creates an entrance hole measuring 150x160mm and an exit hole measuring 160x165mm.

The projectile fragments may destroy control rods, hydraulic conduits, electrical cables or the cooling system of the aircraft engine for example. Additionally, the OZ projectile with K-6M nose fuze has some armour piercing capability. It defeats 7mm of homogeneous armour at a distance of 200m and at a striking angle of 90°.
VYa-23 cannon, page 189:

Performance: When hitting the 0.9 - 1.5mm thick duralumin skin of an aircraft wing, the OZ and OZT projectiles create an entrance opening of 260mm diameter and an exit opening of 500mm diameter. The tracer outlines the trajectory of the projectile from 100 - 150m in front of the muzzle to 1,200m downrange. It burns with a bright rose colour for 1.0 - 1.8 seconds.

Sh-37 cannon, page 362 :

Performance: When striking an aircraft wing with a duralumin skin thickness of 0.9 - 1.5mm, the OZT projectile blows an entry hole of 226 - 505mm diameter and an exit hole of 714 - 874mm diameter. Because of the high blast effect, sometimes entire skin panels with an area in excess of one square metre are torn from the wing. The high explosive tracer projectile usually produces up to 20 fragments that have a weight in excess of 10gm. Additionally, a large number of small fragments is created. The largest fragments are capable of penetrating a

steel plate of up to 10mm thickness. With its high explosive incendiary filler, the OZT projectile is capable of igniting kerosene in fuel tanks. When encountering an armoured target, the OZT shell is capable of penetrating a 15mm thick steel plate at a distance of 200m and at a striking angle of 90°. The tracer of the OZT projectile burns for up to 1,500m. The same tracer is used for the BZT projectile as well.

 

Below I bring an example coming from different part of the world, picture presents P-36 hit by a 20 mm HET round from a Zero. Hawk belonged to 2nd Lt. Philip Rasmussen :
foqu.png
 
66hv.png
Source of pictures : "Exploding fuel tanks (...)" by R. L. Dunn
 
I'd say that rounds of this caliber were capable of producing large enough shrapnel to damage control linkages, radio, electrical systems or potentially wound if not kill pilot. 
Edited by =LD=Hiromachi
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Can someone explain this to me , I've been playing this game for about a year or so and I'm noticing that Russian planes can take 5-6 or more 20mm shots and fly away. While all it takes for a German 109 is a strafe (1-3 shots) and you're either dead or running for your life. 

Didn't know wood/plastic can take some much damage. They should probably remove all of the metal/steel used on today's jets and ask Russians for their wood due it seems to be better than any other metal.

I have to say that I am no newb, I can hit my targets pretty well but I don't like bullet sponges. Breaking a wing or setting a Russian plane on fire is like hitting the lottery, when ever it happens it feels like Christmas. 

 

 The LaGG-3 had a poor power-to-weight ratio that made it slow, unresponsive, and tricky to handle. Soviet pilots soon joked that its LaGG designation stood for Lakirovanny Garantirovanny Grob – the Varnished Guaranteed Coffin.

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And what is funny is that it wasn't like that from the beginning, first LaGG prototype (I-301) was a great machine - heavily armed (2x7.62, 2x12.7 and 23 mm), fast (600+ km/h top speed) and great handling made it superior to Yak prototype that was mediocre at best. Than someone made poor decisions and weight greatly increased, leaving it hampered and much harder to handle. And so Yak became a symbol of Eastern Front while LaGG was a synonym of a coffin. 

I always considered Lavochkins much higher than primitive Yaks. 

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And what is funny is that it wasn't like that from the beginning, first LaGG prototype (I-301) was a great machine - heavily armed (2x7.62, 2x12.7 and 23 mm), fast (600+ km/h top speed) and great handling made it superior to Yak prototype that was mediocre at best. Than someone made poor decisions and weight greatly increased, leaving it hampered and much harder to handle. And so Yak became a symbol of Eastern Front while LaGG was a synonym of a coffin. 

I always considered Lavochkins much higher than primitive Yaks. 

Oddly enough both the LaGG-3 and Yak-1 have about the same top end speed. Both rather slow ,but as you say one became notorious the other was consideredd a savior.

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I wasn´t suggesting that the russian designs where "inferior".. but most wood wing designs are definatly not "monocoque" and non-load bearing wood skins are comonplace, in a way because it stems from a very old design tradition of saving weight by fabrik covering.. which then often got replaced by plywood. It goes back to the fokker planes in ww2 but is still in use today, a modern wooden wing would for instance be the Junkers Profly "Banjo" or  Jodel Robin sold in todays world. Revoultionary designs like the mossie with is doubled up shells are more the rarity and overall I think it is safe to say wood has been replaced by metal during WW2 for a reason.

 

I´m a huge fan of wooden wings and just spent my weekend repairing one.. for over a year in the workshop.. so I´m a bit torn on the "easy" repairability. I mean sure, you can always shift in and replace any bit on the wing, with relativly simple tooling, but good lord is it an amount of work hours instead just doing a double-up riveted in metal repairpatch ;=)

 

the lagg really seems to have a heavy duty wing with an relative uncommon 2-spar (or 1 + 1/2) design.. high rib-density and a D-nose.

struc6.gif

 

Well you may have examples of non load bearing plywood skins (could you post some examples of this applicable to designs like the Russian fighters BTW?) but if you are suggesting that the LaGG and Yak did not have load bearing skins then I don't agree. The skins will carry both torsional and bending loads even in a 2 spar design like the LaGG and Yak. In fact the only efficient way to carry torsional loads in a wing is by using closed box sections which is pretty much standard in an unbraced wing. I'm pretty sure that both the D-cell formed by the forward spar and nose section and the box formed by the two spars and covering plywood in between carry the lions part of the torsional load in these designs but I don't read Russian well enough to decipher what the La-5 and LaGG Samolet says so I'm basing this on what I can read from the drawings and what I know of structural design. In addition to their role to carry torsional loads, all but the parts close to the wing root will also carry a substantial bending load which will be transferred into the front and rear spars at the root.

 

I notice you seem to get hung up on the way I use monocoque: Maybe you thought I referred to monocoque in the sense that the shell carries all load? If so then of course I don't mean that. Basically all aircraft are however of stressed skin construction meaning that the skin carries a substantial part of the load. However, the load bearing is usually limited by buckling so you need stringers and bulkheads/ribs to increase the elastic buckling load limit by making the unsupported panels small. Now you increase the buckling load by doing this but at the same time the stringers will carry the load as well. Doing this structural dimensioning is tricky and different companies have different procedures and tables for doing this. Anyway what I am trying to say is that unbraced WW2 type fighter wings are all stressed skin structures to a larger or smaller extent. Some may only use the D-cell forward of the spar while others use basically all the wing up to the rear spar as a load bearing box but they will all be of stressed skin construction be they made of wood or metal.

 

I also notice you are referring to Fokker designs and I guess you mean WW1 right? In that case remember that a WW1 scout is a very different piece of work compared to a WW2 unbraced design since in a WW1 scout the spars only carry compression or tension loads, not bending loads, and that the torsional loads are carried in the braces so no need for a "skin" to carry torsional loads meaning you can use fabric covering. Edit: The exception of course being the thick winged Fokker designs which did not use bracing to carry torsional load AFAIK, i.e. must at least partly have been of stressed skin construction as well.....

 

Nice to hear you spent time repairing a wooden wing this weekend. It's been years since I worked in a workshop (at the local glider club) but I especially liked repairing wooden wings and doping fabric. :)

 

While I have not worked on wooden wing designs myself I have done structural analysis and dimensional engineering on a composite wing which involved both the spars, fittings and wing torsional dimensioning and I can tell you that if you tried fabric covering on a LaGG or Yak wing instead of the plywood to save some weight my prediction is that you would not get very far due to excessive wing twist......

Edited by Holtzauge

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Just a small tidbit regarding the shrapnel vs explosive force debate.

 

You must also consider that the explosives were, likely, intended to go off inside the structure not just detonate on the outside. Explosives inside an enclosure are seriously magnified. e.g. inside the stressed metal skins, fuse, cockpit and wings.  I've been inside structures, for actually professional reasons, with very small amounts of explosives and the overpressure effect is remarkable compared to considerably more explosives on an open range. Even as a kid, wrapping tiny fireworks in various layers of duct tape could create a considerably different concussive effect. (Yes, i still have both eyes and ten fingers.)

 

I also think the efffect of shrapnel would be somewhat diminished on the largely hollow structures. They are not like later aircraft which can be packed with hydraulics and electonics. Shrapnel would be very effective against those types of objects. My helo was struck by 7.62 mm ammo in combat and even a simple AC battery was sufficent to stop those rounds. Shrapnel is often lighter than a high velocity rifle round and more of a danger to hoses and humans than AC skin and control rods/cables.

 

The combination of both is, of course, the desired effect. If chosing one over the other on a stressed skin AC I'd take shrapnel every day of the week. On thin skinned humans I'd prefer neither.

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The P40's wing was a twin spar design, but all metal of course...

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The DM in BoS is one of the things I'm really impressed with. Of course it's very difficult to judge objectively, but my subjective impression of the DM here is outstanding and the best I've seen by far. None of the earlier sims came close and the "other " now popular WW2 flight sim lags behind in this area IMHO.

 

In BoS I get the impression that you just need to get a few good hits in and the enemy is toast just like you would expect. Get some black smoke indicating engine damage and even if you don't follow it up (tried this a few times) the enemy's engine usually seizes up after a few minutes. Other times, I bagged a few with just a touch on the trigger (usually the pilot) and in other cases it takes a few consecutive passes. Sometimes you get fire, sometimes not. One experience I do not share with the OP is concerning the wing damage: A lot of the time the poor Yak or LaGG under my guns sheds a wing so strange that you don't see that because in my case it's quite common.

 

A lot of the times though I seem to shoot off the whole of the ailerons, elevator halves and rudders which maybe is a bit optimistic but I guess from a DM modeling perspective it's difficult and costly to model this scalable so a more "digital" perspective here may be necessary in the sim. What I have never seen is an explosion though.  OTOH I guess IRL this was pretty uncommon and some of the Russian fighters filled gas tanks with inert exhaust gases AFAIK.

A slightly different experience here. Of offline 123 victories solely on VVS aircraft I can say without a doubt that at least another 20 kills got away after being hit many times, up to 10 hits with MG151/20.  I kept reviewing my mission records and most of the survivors were Pe2 and IL2 although a good portion was also LaGG and La-5 with Yaks being the least survivors.

 

I never saw black engine smoke translating into engine fire on either fighters or bombers.

I never saw engine fire on fighters translating to explosion (bombers do explode from this however).  Fighters burn until pilot dies.

 

Most of the times I killed Yaks was because their controls seized, Laggs/La5 ditched from engine dying after few minutes.

 

I brought down just one fighter (it was a Yak) by blowing off outer wing structure and I hit wings every mission (obvious widest structure available to hit at an angle). Also, I never chopped off entire tail section, though I managed to blow off entire stabiliser two or three times.

 

I never saw a VVS plane engine seizing in seconds after being hit, they spill smoke but do keep on going for minutes after the hit.

 

Four times in 109 I was shot down - two times engine died seconds after just one hit, one time it spilled oil but kept going long enough for me to land.

I never lost a wing or tail etc. From those four downs one pilot death resulted from 37mm hit in the engine which then exploded on the 109.

 

My opinion is that in BoS Yaks and 109 are rather fragile with FW190/LaGG/La5 being very sturdy (I was never shot down while flying a 190).

 

Many times I approached IL2`s and hitting their oil radiator - gives no result apparently (historical weakness of IL2).

In IL2 1946 I learned to aim for the wings on IL2 - could slice off a wingtip with just one hit. This tactic does not work aswell in BoS.

Edited by Mac_Messer

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I've been saying this over a year now that the 20mm are almost useless.

I initially thought it was only the German 20mm that seemed useless, but recently I've been tearing into 109's to no avail.

It's to the point where I mostly use the smaller rounds since they penetrate the engine almost instantly. 

Edited by Y-29.Silky

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