The gamer vs the sim/history buff P47

[Panthera]

1 minute ago, unreasonable said:

 

No: look at the table. The line for the 3cm B kill (which includes A) reads

 

Engine       0.065

Structure   0.333

Pilot          0.040

Fuel tank  0.038

Overall       0.424   

 

The components add to 0.476 - greater than the overall probability: this shows that the possibility of hits affecting more than one component was taken into account.

 

If it was showing the probability of hits being due to location in engine, structure, pilot or fuel tank, then it would follow that there is a probability of a kill being due to a hit on some other component  of 0.576

 

Perhaps you can tell us where the majority of hits that cause kills are if they are not on engine, structure, pilot or fuel tank? 

 

Separately in the report there are several charts and graphs showing the Single shot probability of damage by weapon type and plane with no subdivision into engine, etc. These would make no sense if  your interpretation is correct.

 

Yes ofcourse the probability of a hit causing damage to more than one component was taken into account, I didn't say it wasn't? Like I said a pilot could be killed by shrapnel from a wing strike, which no doubt is considered, otherwise the report would in effect be saying that a direct hit to the cockpit would only mortally wound the pilot with 4% probability - I trust you can see how absurd that would be?

 

Bottom line is that the report is about the probability of a single hit downing the aircraft, and if so where the fatal damage was most likely to be done by that single hit, which with overwhelming likelihood would be due to structural damage.

[unreasonable]

4 minutes ago, Panthera said:

@unreasonable Ok, I think we're going to have to agree to disagree on what the US OR analysis really is telling us, at least partly. 

 

But I trust we can agree that a P-47 surviving 9 hits by 30mm HE(M) shells isn't remotely realistic? I mean even if we go by the US OR probability analysis and add up "single hit" effects (i.e. no cumulative dmg effect), then a P-47 reaches the A category with 84% probability after just 3 hits. Ingame the P-47 can take 3 hits to the SAME area and still fly.

 

 

A P-47 surviving 9 3cm shell is extraordinarily improbable, I grant you that.  In my current testing of the 3.7cm Flak 36 they survive 1 hit less than 50%, and so far none have survived 3 hits.  That is a bit worse for the P-47 than I would expect from the study, and certainly does not suggest a general under-powering of HE, but I need to build up the sample size to be sure.

 

I have not done in testing of the 3cm shell, since the AA will not fire it and flight testing is hard.  Given the results in the study I would expect the overall results in hit survivability to be broadly similar, if the AA was firing it, maybe with a different mix of engine vs structure kills.   

 

All I am trying to do here is establish a reasonable base level of RL kill probability based on the best OR that we have. I know it is not perfect;  firing from multiple angles could change the picture, as the report itself states, but it is still better than assuming that all results should be like the worst case (for the target) scenario.

 

 

 

[Panthera]

But do you really feel that all of the british firing results were "worst case" scenarios? I mean there were multiple wing and fuselage test firings conducted, every single one resulting lethal damage. Add to this that the tests were on the ground with no stress being put on the airframe at all. 

 

 

Edited December 7, 2018 by Panthera

[unreasonable]

8 minutes ago, Panthera said:

 

Yes ofcourse the probability of a hit causing damage to more than one component was taken into account, I didn't say it wasn't? Like I said a pilot could be killed by shrapnel from a wing strike, which no doubt is considered, otherwise the report would in effect be saying that a direct hit to the cockpit would only mortally wound the pilot with 4% probability - I trust you can see how absurd that would be?

 

Bottom line is that the report is about the probability of a single hit downing the aircraft, and if so where the fatal damage was most likely to be done by that single hit, which with overwhelming likelihood would be due to structural damage.

 

They did take into account hits on more than one component at once, but even if they had not what you are saying would not follow: the report is simply saying that if you get a hit, you will get a B kill due to a PK with a 4% probability.

 

I agree: but that probability for the P-47, B kill and 3cm shell case is ~ 0.40,  not close to 1.00 for an A kill (or insta-kill) as looking at videos etc might suggest and it seems some players want.  (Although it might be a lot closer to 1.00 for a Spitfire: pity they did not test that as well).

 

 

 

[Bremspropeller]

35 minutes ago, unreasonable said:

BTW - "Nope" is not an argument. 

 

I wasn't arguing.

 

36 minutes ago, unreasonable said:

Again: what you are doing is refusing to read in the report what is explicitly stated there: the very title is " Airplane Vulnerability and Overall Armament Effectiveness". The fact that they used a different engine to assess engine damage shows that the available resources were limited: that is all.

 

It also shows that a detailed assessment of aircraft damage was not sought after. It was a test to get information about caliber-effectivity. Hence the less than overwhelming detail in damage-assessment and all the trivia in the second part of the report.

 

37 minutes ago, unreasonable said:

f they were only doing a general report into comparative damage output they just needed to do a ranking of MV, weight of shot, HE effects, RoF etc like the various other comparative studies that have been done.  This study is not limited to that issue.  The introduction discusses whether test results can help see if structural changes in future aircraft will alter vulnerability. 

 

No. They were interested in caliber-effectivity, which is not a mere table-comparison of MV, RoF and weight of fire. Especially when talking thin-cased HE ammo, one needs to assess the chemical (read: explosive) damage on target. The report fails to assess this in deatil, however.

There is no dicussion of failure-modes of primary or secondary structure. There is no discussion of the loads brought onto the airplanes to simulate flying conditions, or if the airplanes just stood on the ground without any stress- and load-path analysis.

 

41 minutes ago, unreasonable said:

Read Part 1: Basis for Assessments of Damage. They give detail of how the damage in test firing is recorded and assessed. In great detail.  Not only are probabilities given for the damage types by gun, but the confidence limits are given. (And BTW these do take into account compound damage in the assessment - see page 9 of the report).

 

Unless we're reading two diferent reports, they aren't.

There is no damage-discussion whatsoever in the report and no mention of how the damage was assessed in deail.

It is mentioned, hoever, that the damage-assessment relates to a great deal to the knowledge of the inspector. Duh!

 

It mentions the BRL Memorandum Report 437 to note deeper discussion on the topic, though.

 

[unreasonable]

18 minutes ago, Panthera said:

But do you really feel that all of the british firing results were "worst case" scenarios? I mean there were multiple wing and fuselage test firings conducted, every single one resulting lethal damage. Add to this that the tests were on the ground with no stress being put on the airframe at all. 

 

 

 

Clearly in the US OR report these were not the results obtained. So I am using the P-47 as a base case. If you take an example of a test in which every "hit" = at least an A kill, you actually have less information, and so far apart from the speculation in the previous post about Spitfires, I have not said anything about the effects of mineshells on other aircraft. 

 

All I am trying to do at the moment is compare the US test results for the P-47 with whatever match I can make in game to see if they are in some reasonable alignment. 

10 minutes ago, Bremspropeller said:

 

 

It mentions the BRL Memorandum Report 437 to note deeper discussion on the topic, though.

 

 

Yes it does, which in the absence of that document suggests to me that the work that you assert was not done or sought after was done.  The report contains the results of the trials and analysis to date with a summary of the method used: it does not purport to be an in depth description of every piece of analysis done in reaching the conclusions. 

 

If you choose to believe that a report entitled "Aircraft Vulnerability and Overall Armament Effectiveness" is not in fact even partly about aircraft vulnerability, even though it uses pages to discuss exactly that, then that is your choice and there is nothing left to discuss.  

Edited December 7, 2018 by unreasonable

[Panthera]

Btw, these are the conclusions of all the hits on the Blenheims tested (every single one considered lethal):

and some pictures of different Blenheim wing hits:

 

Edited December 7, 2018 by Panthera

[Velxra]

On 11/23/2018 at 10:10 AM, II./JG77_motoadve said:

 

Sim guy/history buff , is informed, have read the history about the planes/ conflict, wants the airplane as accurate as possible even if it means downgrade or upgrade it from what the sim is showing,and making it harder to fly/fight, cares about immersion/history feeling/uses the airplane gauges , no GPS, no techno chat. For him its a simulation.

 

Sim guy trying to explain gamer to reason about why this or that needs to be changed [or a certain few planes] seems fragile compared to history and real pilots accounts = waste of time, gamer thinks he is whining and wants  advantage so he wants to make his plane better and get more kills.

I think there are a lot more gamers that joined lately than simulator/aviation /history enthusiasts, good for business,  they joined because its the best simulator and not arcade, but have gamer mentality.

 

 

I fall under this category and from my experience here, I can say this community becomes quite nasty when you dare to mention their "precious" has a flaw or the system as a whole has a fatal flaw. Funny enough, it took years of research with both hidden ingame data and real world data to formulate a provable data based problem in the game beyond "this just feels incorrect". Those results were shown in the latest game update regarding the damage model which "select" groups for years claimed it was just german whiners not getting their way or russians just wanting more bias. Now those same people calling others whiners are praising the update or are complaining that the game is now too hard all of a sudden. I am all for the simulation aspect of the game and when one piece of the game behaves more like magic instead of real world I want it adjusted. Sadly there is always someone to argue against you for something, no matter the data provided.

Admitly more tweaks in the update need to be done. But the game has improved leaps and bounds compared to the old unrealistic damage model and old AP ammo damage. Hopefully further old issues in the game engine will continue to be resolved. 

[unreasonable]

2 minutes ago, Panthera said:

Btw, these are the conclusions of all the hits on the Blenheims tested (every single one considered lethal):

and a picture of different Blenheim wing hits:

 

 

 

 

All useful no doubt but you must be precise: the list does not say that they are all lethal: seven of them say "probably lethal", one says "Doubtful" and one says "blind" which I assume here means that it did not explode.  (Something I think the game never models).  

[Panthera]

3 minutes ago, unreasonable said:

 

All useful no doubt but you must be precise: the list does not say that they are all lethal: seven of them say "probably lethal", one says "Doubtful" and one says "blind" which I assume here means that it did not explode.  (Something I think the game never models).  

 

Yes the one doubtful was an incendiary shell, not a HE(M) shell.

[MasserME262]

Every time I played the P-47 for ground attack, I got totally REKT. while I can ground attack on E7, Rata, 190 A3, Macchi, and so on, without too much problem. Or I am doing something really wrong, or the P-47 indeed is modeled to be fragile

[Bremspropeller]

22 minutes ago, unreasonable said:

Yes it does, which in the absence of that document suggests to me that the work that you assert was not done or sought after was done.  The report contains the results of the trials and analysis to date with a summary of the method used: it does not purport to be an in depth description of every piece of analysis done in reaching the conclusions. 

 

If you choose to believe that a report entitled "Aircraft Vulnerability and Overall Armament Effectiveness" is not in fact even partly about aircraft vulnerability, even though it uses pages to discuss exactly that, then that is your choice and there is nothing left to discuss.  

 

I'm not asserting it wasn't done, I'm asserting it's not noted in the report, so it can't be reviewed in depth and hence it's results have to be taken with caution, unless the assessment-methods are brought to light.

You're asserting it has to be okay, because somebody probably has thought about something.

 

If you want a scientific proof of something, you cannot halfway down the tracks take a corner and start assuming things and begin relying on blind faith that something was done and that the method used is bulletproof for the sake of your reasoning.

 

There is very little discussion about vulnerability in the report - reasons given before.

 

[unreasonable]

11 minutes ago, ME-BFMasserME262 said:

Every time I played the P-47 for ground attack, I got totally REKT. while I can ground attack on E7, Rata, 190 A3, Macchi, and so on, without too much problem. Or I am doing something really wrong, or the P-47 indeed is modeled to be fragile

 

From my testing I do not think it is fragile, when hit: but it is large. Huge actually compared to most fighters.  That means that for any given circumstances you will take more hits from ground fire thrown in your general direction. That somewhat cancels out the fact that the total number of "hitpoints" is higher. 

 

Which factor counts for more I could not tell you yet: I was in the middle of testing exactly that when 3.008 came out so now I have to do hours again! 

[Panthera]

Cleaned up version of report (Apparently translated from British to Russian and then back to British again, hence the weird wording sometimes):

 

British MK108 Trials

Fired projectiles:

 

HE - FZ

HE / T - FST

Incendiary (Inc.) - Incendiary

Shelling made from Mk 108

 

Attack against single-engine fighter

 

• Targets: Spitfire Mk11B, equipped with armor and controls, but without engines
• Shooting conditions: The wings were attacked directly from behind (direct astern), and the fuselage at an angle of rotation of 10 ° 

 

Details on test:

 

10 shots were fired (it is worth noting that the mortality of a single shot was evaluated in this and subsequent trials. In other words, damage from other shots are not taken into account when estimating the mortality of a shot).

 

The table with the results of the shelling:

Spoiler

 

2 shots on the fuselage and 1 shot on the wing immediately became deadly. Others would probably be lethal too. Due to the disturbing action of the explosion, coupled with serious structural and aerodynamic (stalling) damage, each of the shots can lead to the immediate destruction of the aircraft

Spoiler

 

Better than any descriptions of damage say photos and frames of filming. The numbering is in accordance with the table.

 

1. HE / T

Spoiler

 

Shooting: (already familiar to many):

Spoiler

 

2. HE

Spoiler

 

3. HE

Spoiler

 

Shooting:

Spoiler

 

5. HE

Spoiler

 

 

6. HE

50 small fragments struck the cabin. Several of them would have hurt the pilot.

Spoiler

 

7. HE / T 

Spoiler

 

8. Inc.

Entrance:

Spoiler

Damage at the exit of the projectile:

Spoiler

 

10. HE / T

Left view:

Spoiler

Right view :

Spoiler

 

___________________________________________________________________

 

Similarly, when attacking the forehead from the lower hemisphere with a pitch angle of 20 ° 2 HE, the shots on the wings were lethal in terms of both structural and aerodynamic damage.

Details on setting goals:

Spoiler

 

Aiming point:

Spoiler

 

The table with the results of the shelling:

Spoiler

 

Conclusion:

Inc., HE and HE / T are effective in inflicting lethal damage when firing wing and fuselage single-engine Spitfire fighters. For the most part, this requires one hit.

 

_______________________________________________________________________________________________________________________

 

Attack against a twin-engine medium bomber

 

• Targets: Blenheim IV , equipped with armor and controls, but without engines
• Shooting conditions: the wings were attacked directly behind, and the fuselage at an angle of rotation of 10 ° from this position.

 
11 shots were fired . Each of the 3 shots immediately destroyed the fuselage. 7 shots on the wings would probably be lethal, and the remaining 1 shotdid not cause damage, since the projectile did not detonate.

 

The table with the results of the shelling:

Spoiler

 

Damage photos and film shots. The numbering is in accordance with the table:

 

11. HE

Spoiler

 

12. HE / T

Spoiler

 

13. HE / T 

Spoiler

 

14. Inc.

The fuel tank was filled with water.

Spoiler

 

15. Inc.

The fuel tank was filled with water.

Spoiler

 

16. HE

Spoiler

 

17. HE / T

Spoiler

 

19. Inc.

The fuel tank was filled with water. Judging by the damage to the tank, the wing would have burned.

Spoiler

 

21. HE

Left view:

Spoiler

Right view :

Spoiler

 

Shooting:

Spoiler

 

Conclusion:

Inc., HE, and HE / T are effective in inflicting lethal damage when firing on the wings and fuselage of Blenheim-type twin-engine medium bomber. For the most part, this requires one hit.

 

 

Sources :

• Trials of German 30mm Ammunition, Gordon, HWB and Macdonald, JA, Orfordness reseach station FT343, May 1945
• 30mm Ammunition, Gordon, HWB, Orfordness reseach station FT359, August 1946
• Trials of Aden 30mm, HWB and Smith, AE, Technical Note No. Arm.440 Orfordness reseach station FT377 , July 1950 ( given comparisons withGerman 30 mm )

Edited December 7, 2018 by Panthera
Cleaned it up

[Ehret]

The Blenheim is of the same weight as the P-47. Just in case if someone tries an assertion that because "a bomber" goes down then the fighter "must necessarily" ever more so. The British had different load margins than in the US - if you check the history of the P-51H you will see that the NAA had to ask the Supermarine how to make a light fighter frame.

[Panthera]

@Mauf I tracked down the German test you were talking about, it was indeed one involving the early types of HE(M) shells (1939) against the wing of a Hs124, the cannons used being 30mm Mk101 and 20mm MG-FF:

 

[unreasonable]

1 minute ago, Bremspropeller said:

 

I'm not asserting it wasn't done, I'm asserting it's not noted in the report, so it can't be reviewed in depth and hence it's results have to be taken with caution, unless the assessment-methods are brought to light.

You're asserting it has to be okay, because somebody probably has thought about something.

 

If you want a scientific proof of something, you cannot halfway down the tracks take a corner and start assuming things and begin relying on blind faith that something was done and that the method used is bulletproof for the sake of your reasoning.

 

There is very little discussion about vulnerability in the report - reasons given before.

 

 

Every time the developers have to stick a number into a table for some calculation they have to make assumptions. I hope they make it based on the best available evidence.  This will rarely reach the standard of a "scientific proof" if you mean certainty - or some arbitrary confidence level - about the outcome.  Nobody is in a position to fly hundreds of real P-47s wired up for data recording over actual guns to get "proof".  This is a ridiculous standard.

 

The US OR result is the best available evidence for the particular cases they were considering and I am trying to test in game.  No-one thinks it is perfectly conclusive, but then in the real world outside laboratories it never is; but a conclusion still has to be reached and action taken. The British tests should also be taken into account: but I do not have a full write up of them: I very much doubt that the details of the tests are any better documented than the US tests. Their conclusions should also be treated with caution. 

 

Other people are welcome to do their own tests and produce additional data. Just do not expect everyone to get on board the "mineshell is broken" bandwagon 48 hours after 3.008 has been released.

 

 

 

 

[Panthera]

5 minutes ago, unreasonable said:

The US OR result is the best available evidence for the particular cases they were considering and I am trying to test in game.  No-one thinks it is perfectly conclusive, but then in the real world outside laboratories it never is; but a conclusion still has to be reached and action taken. The British tests should also be taken into account: but I do not have a full write up of them: I very much doubt that the details of the tests are any better documented than the US tests. Their conclusions should also be treated with caution. 

 

Just posted them above, IMO they're about as detailed as can be. Basically the only way they could've been more detailed was if they had mounted each aircraft in a spherical mount and shot at them from every possible angle whilst at the same time a pair of tethered Lancasters ahead of them would be running full throttle to simulate the effect of wind pressure  

Edited December 7, 2018 by Panthera

[unreasonable]

10 minutes ago, Panthera said:

 

Just posted them above, IMO they're about as detailed as can be. Basically the only way they could've been more detailed was if they had mounted each aircraft in a spherical mount and shot at them from every possible angle whilst at the same time a pair of tethered Lancasters ahead of them would be running full throttle to simulate the effect of wind pressure  

 

Well the first point to notice about the British results is that they were giving an assessment for hits at a defined aiming point: in the wing case for the Spitfire, 7 ft out from the wing root. So what their report shows, is that if you hit the wing there from below and ahead, you will get a very high probability of a lethal result, near 1.00.  What it says nothing about is what would happen if the hit took place at 1ft out, or 15 ft out.  

 

My hypothesis would be that as the hit location goes out on the wing the probability of a lethal result will start to drop. I would expect a hit at the extreme tip to be almost never lethal. Since  at no location can the probability be greater than 1.00, the sum of the probabilities of lethality at each location times the probability of a hit at each location must necessarily by less than 1.00    

[Ehret]

21 hours ago, Mauf said:

Mineshells primarily inflict damage by pressure from the explosion (shrapnel from the casing was actually pretty minor in comparison as it was pretty lightweight due to the thin projectile mantle). It's actually required to have a closed compartment that contains the pressure and therefore suffers from the blastwave.

 

So to reiterate: the P-47 construction is twice as heavy than the Spitifre, it's made with bigger margins than the British designs and it has about 4 times the internal fuselage volume. Closed compartment in the Spit aren't that close in the P-47 anymore. Yet, the HE damage tests of the former are raised repeatedly and again as some kind of definitive proof about the latter. In a contrast the official damage document which explicitly includes the P-47 is dismissed... Sounds like double standards.

[HR_Zunzun]

On 12/7/2018 at 4:01 PM, Ehret said:

 

So to reiterate: the P-47 construction is twice as heavy than the Spitifre, it's made with bigger margins than the British designs and it has about 4 times the internal fuselage volume. Closed compartment in the Spit aren't that close in the P-47 anymore. Yet, the HE damage tests of the former are raised repeatedly and again as some kind of definitive proof about the latter. In a contrast the official damage document which explicitly includes the P-47 is dismissed... Sounds like double standards.

 

Yes, I thought about this as well. Different wing, different results (although, in all honesty, we can't n say exactly how different).

A comparison of internal structure, materials and thickness would be helpful to guess.

Edited December 8, 2018 by HR_Zunzun

[Herne]

Didn't the spit have a revolutionary wing spar ? It wasn't a single solid spar but four or five much smaller ones linked together in a frame, at least for most MK's. My understanding was that this design was incredibly strong while intact, and more resistant to catastrophic damage than a single spar, although once compromised, I dare say you would want to me more careful with your G loading ?

[Panthera]

11 minutes ago, Ehret said:

 

So to reiterate: the P-47 construction is twice as heavy than the Spitifre, it's made with bigger margins than the British designs and it has about 4 times the internal fuselage volume. Closed compartment in the Spit aren't that close in the P-47 anymore. Yet, the HE damage tests of the former are raised repeatedly and again as some kind of definitive proof about the latter. In a contrast the official damage document which explicitly includes the P-47 is dismissed... Sounds like double standards.

 

At no point was the US OR analysis dismissed by anyone in here, at least not that I could tell. The conclusion of the US OR analysis is actually very sensible, concluding that there was a ~30% chance that a single random hit by 30mm HE would down the P-47.

 

The US OR analysis just doesn't address the questions we have, i.e. will a P-47 likely be able to fly on after 1 or 2 hits to a specific area, in this case its wings.

 

26 minutes ago, unreasonable said:

 

Well the first point to notice about the British results is that they were giving an assessment for hits at a defined aiming point: in the wing case for the Spitfire, 7 ft out from the wing root. So what their report shows, is that if you hit the wing there from below and ahead, you will get a very high probability of a lethal result, near 1.00.  What it says nothing about is what would happen if the hit took place at 1ft out, or 15 ft out.  

 

They actually used several aiming points along the wing span. Perhaps you missed it in the clutter of "reveal hidden contents" which admittedly turned out a mess.

[Bremspropeller]

1 hour ago, unreasonable said:

Every time the developers have to stick a number into a table for some calculation they have to make assumptions. I hope they make it based on the best available evidence.  This will rarely reach the standard of a "scientific proof" if you mean certainty - or some arbitrary confidence level - about the outcome.  Nobody is in a position to fly hundreds of real P-47s wired up for data recording over actual guns to get "proof".  This is a ridiculous standard.

 

You should go and read about "scientific proof" works.

It's a method, not a level of certainty. Two basic pillars are reproducability and peer review. Neither are met by the report.

 

The report does neither mention specifics about the test setup, nor does it discuss damage in any depth.*

It does not discuss where the boundary conditions on (e.g.) structural failures are, nor does it discuss how damage-assessment was taken and which environmental conditions were taken into account (e.g. load-condition of the wing-spars). One has to assume that it was just a static firing test.

 

It mentions some boundary conditions on the imaginery flight of the specimen, but it fails to go into any deeper detail as to how that includes actual in-flight loads of the structure or not.

It talks about some data-points being collected via extrapolation, but does not discuss which data-points these are and based on what assumptions it uses those as validated data points.

 

By any scientific or engineering standards, the report is of very little value quantifiing aircraft vulnerability and specificly vulnerability of the P-47, because it's written to give a relative comparison of caliber effectivity, which, again is different to aircraft vulnerability.

The fact that "aircraft vulnerability" is in the title does not make that issue go away.

 

1 hour ago, unreasonable said:

The US OR result is the best available evidence for the particular cases they were considering and I am trying to test in game.  No-one thinks it is perfectly conclusive, but then in the real world outside laboratories it never is; but a conclusion still has to be reached and action taken. The British tests should also be taken into account: but I do not have a full write up of them: I very much doubt that the details of the tests are any better documented than the US tests. Their conclusions should also be treated with caution. 

 

For reasons given above, the test is not evidence, but a mere collection of cloudy data points without any discussion of the results or how conclusions were come by.

 

The british test isn't very good either, but it goes into deeper detail in terms of (un)certainty ("doubtful", "probably"**) and it's backed up with pictoral evidence.

Also, one can see how the wings are structurally loaded and one can make basic conclusions for one self. Example:

One of the Blenheim pictures shows the web of the rear-spar blown out. As that is outside of the props/ jacks, the spar only has to carry bending and torsional loads of the wing outside the props/ jacks and hence it doesn't fail after the hit. That rear-spar would have completely snapped in the air as next to no bending force could be taken by the straps on top/ bottom.

 

The use of terms as "real world" and "laboratories" shows me that engineering isn't your profession.

___

* There are enough aircraft crash-reports on the net to see how a good description and discussion of stractural damage and -failure looks like.

** Would be interesting to see a definition for "aerodynamically fatal".

27 minutes ago, =11=Herne said:

Didn't the spit have a revolutionary wing spar ? It wasn't a single solid spar but four or five much smaller ones linked together in a frame, at least for most MK's. My understanding was that this design was incredibly strong while intact, and more resistant to catastrophic damage than a single spar, although once compromised, I dare say you would want to me more careful with your G loading ?

 

Not really. It had a forward spar  (with lots of D-profiles) that held most of the bending and torsional force and it had a secondary rear spar to help the forward spar a little and to attach the flaps and ailerons to:

 

Edited December 7, 2018 by Bremspropeller

[Herne]

6 minutes ago, Bremspropeller said:

 

 

Not really. It had a forward spar  (with lots of D-profiles) that held most of the bending and torsional force and it had a secondary rear spar to help the forward spar a little and to attach the flaps and ailerons to:

 

 

oh, thought I saw something about it on a documentary recently. Did a quick search and came across this which I grabbed from this link :-

 https://en.wikipedia.org/wiki/Spar_(aeronautics)

"A design aspect of the Supermarine Spitfire wing that contributed greatly to its success was an innovative spar boom design, made up of five square concentric tubes that fitted into each other. Two of these booms were linked together by an alloy web, creating a lightweight and very strong main spar.^[7]"

 

 

[Panthera]

Going to try and clean up the report above.

 

 

 

Edited December 7, 2018 by Panthera

[Ehret]

1 hour ago, Panthera said:

The US OR analysis just doesn't address the questions we have, i.e. will a P-47 likely be able to fly on after 1 or 2 hits to a specific area, in this case its wings.

 

Unlikely but possible. There are enough historic pictures showing just that - P-47s which returned with similar holes in wings or even without good of part the wing altogether. (like the one which collided with a chimney)

So yes - one would need some luck but it is possible.

[Panthera]

1 minute ago, Ehret said:

 

Unlikely but possible. There are enough historic pictures showing just that - P-47s which returned with similar holes in wings or even without good of part the wing altogether. (like the one which collided with a chimney)

So yes - one would need some luck but it is possible.

 

That is just the tip of the wing though, the aileron remained, so the pilot probably didn't have too much difficulty saving that one.

[unreasonable]

56 minutes ago, Bremspropeller said:

 

You should go and read about "scientific proof" works.

It's a method, not a level of certainty. Two basic pillars are reproducability and peer review. Neither are met by the report.

 

I know all about scientific proof, having trained first in Natural Sciences: and studied Philosophy of Science as well.  You can test in game according to the standards of reproducibility and peer review.  I do as do some others: I give people my results plus the missions, in which one variable at a time can be changed: they can run them themselves and check my results and calculations.  Where there are errors I correct them.   I give my own interpretation of the meaning of the results: on that the reader is of course able to form his own opinion. 

 

What we cannot do is reproduce complex historical events in an experiment: we simply do not have the materials to do it even if we had the time. The standard here is not and cannot be "scientific proof" in the sense that you mean. It can only be on the preponderance of the evidence. 

 

We have some evidence about what happens when you fire 3cm shells at Spitfires. We have some other evidence about what happens with P-47s.  Extrapolating from the Spitfire results to the P-47 is as problematic as extrapolation the other way around.  

 

56 minutes ago, Bremspropeller said:

 

 

 

[Ehret]

42 minutes ago, Panthera said:

That is just the tip of the wing though, the aileron remained, so the pilot probably didn't have too much difficulty saving that one.

 

A small part of the aileron held on one remaining hinge (normally are three). So more than just a "tip" - about 0.25x length wise of the whole wing. That is not even the most extreme like from the article (image 4). There are plenty of historic pictures showing planes returning with like "108" damage or worse.

Edited December 7, 2018 by Ehret

[Panthera]

 

27 minutes ago, Ehret said:

 

A small part of the aileron hold on one remaining hinge (normally are three). So more than just a "tip" - about 0.25x length wise of the whole wing.

 

There are two hinges visible:

 

and since the ammunition compartment isn't visible the cut must have occured at the fourth rip from the tip marked in red here:

 

Damage such as this wouldn't really hurt the load bearing ability of the wing as it's akin to a cut, and therefore it is not comparable to the damage we see in the British trials.

Edited December 7, 2018 by Panthera

[Ehret]

So there were 2 - my mistake, ok. It doesn't change that more historic pictures are available and some of them much more extreme like number 4 from the article.

 

Found a listed album with more planes, here. Mostly for the B-17 but still.

Edited December 7, 2018 by Ehret

[MasserME262]

3 hours ago, unreasonable said:

 

From my testing I do not think it is fragile, when hit: but it is large. Huge actually compared to most fighters.  That means that for any given circumstances you will take more hits from ground fire thrown in your general direction. That somewhat cancels out the fact that the total number of "hitpoints" is higher. 

 

Which factor counts for more I could not tell you yet: I was in the middle of testing exactly that when 3.008 came out so now I have to do hours again! 

you are probably right, but I have had better luck even with the 110, and that's a big one. Maybe it's just me

[Mauf]

3 hours ago, Panthera said:

@Mauf I tracked down the German test you were talking about, it was indeed one involving the early types of HE(M) shells (1939) against the wing of a Hs124, the cannons used being 30mm Mk101 and 20mm MG-FF:

 

 

That's the one I meant. So it seems it was earlier ammo type. Don't know how much the difference was between the old and new version. If indeed the newer filler and delayed fuse made such a big impact in lethality, maybe it warrants a look at. Granting that. But right now, I'm still more inclined that the strike angle and the specifics of the hit area had a much bigger impact on how much damage/lethality the mineshell actually ended up dealing.

 

3 hours ago, Ehret said:

 

So to reiterate: the P-47 construction is twice as heavy than the Spitifre, it's made with bigger margins than the British designs and it has about 4 times the internal fuselage volume. Closed compartment in the Spit aren't that close in the P-47 anymore. Yet, the HE damage tests of the former are raised repeatedly and again as some kind of definitive proof about the latter. In a contrast the official damage document which explicitly includes the P-47 is dismissed... Sounds like double standards.

 

I can't tell how much the increase in volume would affect things, that's where you need some physics boffins and also the volume the explosive filler would expand to in order to make any guesses. But the volume increase indeed was a point when it came to the B17s and their capability to take those mineshells. Reports indicate that the Luftwaffe were often fishing for lucky hits (fuel, bomb load, controls) rather than try to butcher them apart structurally.

 

It's not wrong to refer to the spitfire 30mm tests, they are perfectly valid. It's just important that it's clear where the limits of transferring those results are and one should err on the side of caution. I think right now, the DM reflects this okayish as it strikes a balance somewhere between the spit tests and the american tests. 30mm is not some sneeze at you, often enough one hit is enough to take one out of combat. That it's not necessarily a wing-off doesn't bother me that much.

 

A big factor was probably how much the metal skin of the plane was a structural component of the plane. The 109 wing and also the Spitfire wings required the skin as structural components. Without them, the wing was not stable enough (not talking about lift here). This was even more of a factor on the tail sections of these planes. I don't know the specifics for the P-47 wing. Supposedly (anecdotal alert), the Hurricane was more resistant to Mineshell hits as its construction was still very similar to WW1 planes with canvas wrapping instead of alloy skins (wings later got metal skin but the fuselage remained canvas all the way through me thinks).

Edited December 7, 2018 by Mauf

[Panthera]

42 minutes ago, Mauf said:

That's the one I meant. So it seems it was earlier ammo type. Don't know how much the difference was between the old and new version. If indeed the newer filler and delayed fuse made such a big impact in lethality, maybe it warrants a look at. Granting that. But right now, I'm still more inclined that the strike angle and the specifics of the hit area had a much bigger impact on how much damage/lethality the mineshell actually ended up dealing.

 

Well the detonator was changed completely as the LW weren't satisfied with the unreliably long delay, which in turn also caused a delay in the actual adoption of the Minengeschoss until it could be solved. As for the filler, the early types used PETN which has a TNT equivalent factor of 1.24, whilst the later types used Ha41 (Hexogen) which has a TNT equivalent factor slightly higher than that of RDX at 1.5+.

Edited December 7, 2018 by Panthera

[LukeFF]

[Eyes glazing over]...

[Panthera]

2 hours ago, Ehret said:

So there were 2 - my mistake, ok. It doesn't change that more historic pictures are available and some of them much more extreme like number 4 from the article.

 

Found a listed album with more planes, here. Mostly for the B-17 but still.

 

Well sure, but I think we can agree that they weren't pulling any crazy maneuvers after those hits? or that a second similar hit and they weren't coming home, right? 

 

In short I don't think I'm far off with my statement that it's highly doubtful that a P-47 could sustain two 3cm HE(M) shots to its wings and not go down. One hit? Sure I can believe that, and that already makes it a lot more resilient to fire than other fighters such as the Spitfire, and even some medium bombers. But two hits to the wings is seriously stretching it, esp. if its the same wing at which point I'd call it a miracle - esp. considering that the US OR gave just one randomly placed hit a 30% chance to down the aircraft within minutes, and a 42% chance that it wasn't coming home.

 

Thus when we see this ingame:

 

I think we are very much entitled to be sceptical of the dmg model, in a big way.

 

Edited December 7, 2018 by Panthera

[Ehret]

39 minutes ago, Panthera said:

Thus when we see this ingame:

 

I think we are very much entitled to be sceptical of the dmg model, in a big way.

 

That isn't the issue with the MK-108, only. The 37mm M4 is unreliable to the point of absurdity and the low cycling rate makes it like playing a lottery. Sometimes it feels the hit didn't register at all. It doesn't have to be a problem with damage models as such. In patch notes 3.008 is a reference about fixing a bug which resulted in some hits counted twice. Perhaps other hits, like ones from fragments aren't counted properly. The perceived problem with the HE could be just that - a subtle bug somewhere else.

Edited December 7, 2018 by Ehret

[Max_Damage]

7 часов назад, ME-BFMasserME262 сказал:

Every time I played the P-47 for ground attack, I got totally REKT. while I can ground attack on E7, Rata, 190 A3, Macchi, and so on, without too much problem. Or I am doing something really wrong, or the P-47 indeed is modeled to be fragile

It is a large plane and very easy to be hit It also has no armor to protect the engine or fuel so there you go.

[BR_Calinho]

During a attack, Bazilian pilot Raymundo da Costa Canário accidentally collided with the chimney of a factory, 
knocking it down. In the collision his airplane lost part of the right wing (1,28 meter), which did not prevent him from returning to the base

 

 

 

 

 

Edited December 9, 2018 by BR_Calinho