50 cal Ballistics/Aircraft Damage Model Questions/Concerns

[USARStarkey]

Its a disconnect from visual to actual with DCS...

 

Certainly, but I contend that the visual disconnect does not explain the bulk of these issues. That being said, until my testing is done this is a moot point.

 

PS: has anyone had a chance to review my tracks? Not just to ED devs but anyone interested in this issue.

[Random]

I can confirm aerodynamic effects from damage. Few hits taken in the sabre led to it dropping the left wing during turns that wouldnt normally cause a problem

 

Also it took out the hydraulic lines to the landing gear (flying controls were still powered, wheels wouldnt come down and gauge reading zero)

[billeinstein]

If you have CA, you can test it on the ground by man controlled ground fire.

The f-86 can also fire when stay on the ground now.

It's fun.

[hattrick]

Damage does affect aerodynamic characteristics of your aircraft. Very evident. That being said I do feel it should fine tuned more as well as connecting the visual with the virtual.

[USARStarkey]

The aerodynamic effects caused by damage to the air frame are either infinitesimal or non-existent regarding some effects. The only thing that is "evident" is that the airplane might lose maybe a half a degree per second in turn or stall slightly worse even when the damage to the wing is something to effect of 2-3 3 inch wide holes and many others. Whatever the visual to virtual ratio, this is true even when the wing is just above complete structural failure. Aircraft only noticeably list etc if entire surface sections are gone: ie a third of a wing tip being shot off. I will post more once my testing is done.

[USARStarkey]

Preliminary Test Results, I will post both the Tacviews and Tracks later.

 

 

RESULTS OF HUMAN VS HUMAN P-51 MUSTANG BALLISTIC TESTING

 

Nature of Tests: First test was done by shooting only the wing of target plane and seeing how many hits were needed. It took 54. The rest of the tests were either done by shooting a stationary plane until it died or dog fighting. Most were stationary flying targets. Effects of hits were reported between bursts.

 

Number of Tests:9

 

Shortest Number of hits to achieve a kill: 47

 

Largest number of Hits to achieve a kill: 195

 

Average Hits to achieve kill: 117.4

 

List: 54,84,142,195, 174, 105, 90, 47, 166.

 

Opinion of tester: Issue is not as great in some ways as fighting the ai. Aircraft are subject to aerodynamic problems, although not as great as it should be. In none of the tests was the aerodynamic penalty enough to either cause the target to crash while maneuvering or need to fight the aircraft to perform a maneuver. In the most severe list, a very light counter on the stick was all that was necessary to counterbalance it. It is likely that it affected turn performance etc, but it did not prevent the target from easily performing maneuvers, seriously affect the targets ability to bring weapons to bear, or generally continue fighting. Most critical difference between ai and humans is the engine failure or complications from damage, which does not seem to affect ai at all. This aside, the amount of damage/complications is not severe enough. Average number of hits to down a non-maneuvering fighter at zero-deflection at a range of 200-500 yards was 117. In some cases as high as 195. If engine failure did occur, it almost always happened just before complete obliteration of the plane, or was that actual cause of obliteration due to fire or failure. Overall, the number of hits needed to down a plane is considered far too high.

[hattrick]

This is purely subjective and based solely on your opinion and skill level. Self admittedly your shots were fired from greatly varying ranges from 250 to 500!!!!! yards.. Did you get your sniper scope out for those? What experience or authority do you have to make the suggestion that 150-190 rounds is far to many to down a plane from BEHIND? You do realize that angle off and deflection shots cause WAY more damage to opponents aircraft/engine vs trying to hit from directly behind the enemy? Not to mention the issue of your convergence. You have a 300 yard convergence on the 51... you hitting inside of 300 yards and ESPECIALLY outside of it at ranges of 500 yards reduces GREATLY the strength and lethality of the rounds hitting your target. Beyond 300 yards your rounds are spreading out and not hitting in tight groupings, as well, the rounds have lost energy greatly and don't hit with as much power. All things you need to take into consideration before making blanket statements like "50 cal Ballistics/Aircraft Damage Model Ridiculous"

 

I have personally killed a human pilot's engine with only a quick burst and killed the pilot with a perfectly flyable plane left BOTH due to well placed (lucky) deflection shots.

 

Regardless, perhaps there is another sim out there that can better recreate your requested damage modeling and the many other things you seem to have problems with in DCS, if so... have you considered flying that one instead. If there isn't another sim, perhaps being happy with what you have is in order at some point.

 

<edit>

P.S. Does it look like I care about my rep? Downgrade me all you want brother.

Edited August 2, 2014 by hattrick

[USARStarkey]

This is purely subjective and based solely on your opinion and skill level. Self admittedly your shots were fired from greatly varying ranges from 250 to 500!!!!! yards.. Did you get your sniper scope out for those? What experience or authority do you have to make the suggestion that 150-190 rounds is far to many to down a plane from BEHIND? You do realize that angle off and deflection shots cause WAY more damage to opponents aircraft/engine vs trying to hit from directly behind the enemy? Not to mention the issue of your convergence. You have a 300 yard convergence on the 51... you hitting inside of 300 yards and ESPECIALLY outside of it at ranges of 500 yards reduces GREATLY the strength and lethality of the rounds hitting your target. Beyond 300 yards your rounds are spreading out and not hitting in tight groupings, as well, the rounds have lost energy greatly and don't hit with as much power. All things you need to take into consideration before making blanket statements like "50 cal Ballistics/Aircraft Damage Model Ridiculous"

 

I have personally killed a human pilot's engine with only a quick burst and killed the pilot with a perfectly flyable plane left BOTH due to well placed (lucky) deflection shots.

 

Regardless, perhaps there is another sim out there that can better recreate your requested damage modeling and the many other things you seem to have problems with in DCS, if so... have you considered flying that one instead. If there isn't another sim, perhaps being happy with what you have is in order at some point.

 

<edit>

P.S. Does it look like I care about my rep? Downgrade me all you want brother.

 

Several things.

 

1. It is obviously my opinion. In fact, if you read, youll see that I stated that. Way to go captain obvious.

 

2. Once again, if you read, we did some of he shooting from deflection while the target maneavered.

 

3. This one makes me laugh. Precisely what experience do you have to say that I'm wrong? As I recall, I mentioned some brief data earlier. We could go into more detail. Others here have agreed with me, so you basically just called all the them idiots as well. And if we want to get into real world experience, I have at least operated a 50caliber machingun. While not wholly relevant to a airplane necessarily, Ive seen what a single gun operating only at 500rpm can do to a motor vehicle as far out as 800 yards: clue, it isnt pretty. I could also cite gun camera footage and burst masses etc.

 

4. Good for you, nice singualr anecdote. This is why i included averages etc.

 

5. It is obvious from your vitriol that your post has nothing to do with furthering this topic and that you intent is just to defame me because of our personnnal dispute. Seems to me that the neg rep i gave fits the reason i gave it for.

[hattrick]

Several things.

 

1. It is obviously my opinion. In fact, if you read, youll see that I stated that. Way to go captain obvious.

 

You're welcome.

 

2. Once again, if you read, we did some of he shooting from deflection while the target maneavered.

 

Forgive me for being captain obvious again... but conducting a damage modeling test 9 times with varying distances and angles solves absolutely nothing.

 

3. This one makes me laugh. Precisely what experience do you have to say that I'm wrong? As I recall, I mentioned some brief data earlier. We could go into more detail. Others here have agreed with me, so you basically just called all the them idiots as well. And if we want to get into real world experience, I have at least operated a 50caliber machingun. While not wholly relevant to a airplane necessarily, Ive seen what a single gun operating only at 500rpm can do to a motor vehicle as far out as 800 yards: clue, it isnt pretty. I could also cite gun camera footage and burst masses etc.

 

Um. I never called you an idiot. In fact you are the only one who has decided to resort to name calling. As for real world experience I'm not getting into that as those that know me know my experience with aircraft. However I will say (whether you believe me or not, don't care) I have shot twin .50's off the bow of my Destroyer when I served back between '01-'06 so you ain't the only one who's fired one BUT none of that has anything to do with convergence and firing at purposefully armored aircraft designed to take hits.

 

5. It is obvious from your vitriol that your post has nothing to do with furthering this topic and that you intent is just to defame me because of our personnnal dispute. Seems to me that the neg rep i gave fits the reason i gave it for.

 

Actually to the opposite point. My reply is to voice my opinion about your opinion. My opinion is that your opinion is "ridiculous" based on my experience in DCS. I'm just as entitled to an opinion as you are. Or did I miss the disclaimer in your OP that stated only people who agreed with your opinion are allowed to post replies?

 

Any how, I see this has turned into a pointless back and forth so I'll take my leave. Please... continue without me.

Edited August 2, 2014 by hattrick

[USARStarkey]

You're welcome.

 

 

 

Forgive me for being captain obvious again... but conducting a damage modeling test 9 times with vary distances and angles solves absolutely nothing.

 

 

 

Um. I never called you an idiot. In fact you are the only one who has decided to resort to name calling. As for real world experience I'm not getting into that as those that know me know my experience with aircraft. However I will say (whether you believe me or not, don't care) I have shot twin .50's off the bow of my Destroyer when I served back between '01-'06 so you ain't the only one who's fired one BUT you or I firing a .50 cal has nothing to do with anything we are talking about here. Read up on convergence.

 

 

 

Actually to the opposite point. My reply is to voice my opinion about your opinion. My opinion is that your opinion is "ridiculous" based on my experience in DCS. I'm just as entitled to an opinion as you are, am I not?

 

Good day.

 

 

1. lol

 

2. This is a moot point. This test was preliminary for one. Second, statistically, I'd have to do a insane number of tests to get a decent plot. The point here is just to gather a little bit of data so this is more than just complete speculaton.

 

3. Lets not beat around the bush. You dont have to actually say it to get your point across. As for your experience with aircraft, something tells me that neither you, I, or anyone responsible for the making of any damage model in any sim went out shot the crap out of some ww2 fighters to seen what happens. Your point here is just plain nonsense. Nobody here has any real world experience with shooting up these planes, so I guess noone can have an opinion, including the makers of this game and others.

 

4. So let me get this straight. You just made a post telling me I had no business pontificating with regards to this subject for the aformentioned reasons. Now your upset because I supposedly told you that you couldnt have one? Firstly, that is contradictory as hell. Second, I never said anything of the sort. I said that manner in which you phrased your post makes it look as though you have other motives, not that you cant have an opinion. You are really good at not actually reading what I post-and then having something to say about things I didnt actually say, or bringing up issues that I have already mentioned.

 

5. Missed this one from your earlier post: DCS is my favorite sim for a variety of reasons. I am hardly the only person who makes complaints on here, in fact that makes up a very large part of what people post about on these forums. This bit of your thread is obvious fanboy apologetic drivel. Perhaps instead of wasting your time on here, you should go find a forum where everyone agrees with you, or a simulator that is perfect and no one can offend you with criticism of a game you have put on a pedestal. (also, you are once again telling me to go away and not have an opinion.)

Edited August 2, 2014 by USARStarkey

[NeilWillis]

So, who is right?

 

Unless you do go to the trouble of gathering sufficient data, then all this is pure speculation. Do you know what the DCS damage model is based on? Have you no doubts at all that you may just be biased, and jumping to the wrong conclusions?

 

I'm interested to know the facts, and this descent into a slanging match between two bosom buddies is not what any of us are here to read.

 

Has anyone from DCS got any comment regarding this speculative bug report?

[USARStarkey]

So, who is right?

 

Unless you do go to the trouble of gathering sufficient data, then all this is pure speculation. Do you know what the DCS damage model is based on? Have you no doubts at all that you may just be biased, and jumping to the wrong conclusions?

 

I'm interested to know the facts, and this descent into a slanging match between two bosom buddies is not what any of us are here to read.

 

Has anyone from DCS got any comment regarding this speculative bug report?

 

Of course it is speculative to a certain extent, and I like anyone else am subject to error. Even with large amounts of data, any damage model in any sim is to a certain extent speculative even.

 

That being said, not much has been discussed regarding the actual ballistics because that wasn't the direction the conversation went in. Several people agreed with my first post, and Sithspawn asked me to do more testing and send him tracks. I am still in the process of doing that testing, I was just putting up what I got so far.

 

Regarding the actual ballistics, Both the Navy and the USAAF considered 3 50cal equivalent to 1 20mm generally speaking. It took about 5 20mm to down a fighter typically. If you watch 50cal only planes gun cam footage, you will notice that they knock down enemy planes very quickly, or least set them on fire or cause an explosion.

 

The Table on in this website is in good agreement with the 1 to 3 ratio comparison with 20mm cannon. http://www.quarry.nildram.co.uk/WW2guneffect.htm

 

Here is some gun camera footage, ignore the rest of the video if you wish: https://www.youtube.com/watch?v=4Z2FFtu441s&list=LL9p_QEwysGYhs3YDKN0f60w&index=10

[vicx]

A debug mode that shows the damage would put these subjects to rest.

[Art-J]

Hattrick's reply reminded me famous quote from South Park...

 

 

... and it's equally ridiculous. I thought we're here to improve several aspects of the sim so we don't have to move to other platforms, huh? Well, it ain't so obvious for everybody it seems.

 

As for the convergence - surely it would be awesome if everyone could shoot exactly at 300 yds range, but I strongly doubt this is always the case for average online or offline pilot. Testing between 200 and 500 seems to cover average firing situations on servers.

 

Obviously, hitting outside of convergence results in unwanted spread, nobody argues this one I think. However, we're trying to investigate not only number of hits but penetrating power of a bullet as well, and from this point of view, a hit is a hit - with a effective distance of M-2 quoted for 2000 yds (although "effective against what", one might ask) hitting 100 yds plus/minus off 300 shouldn't make much difference, if any.

 

Looking forward to seeing more test results.

[effte]

Lots of ridiculous arguments thrown around here, and I think some debaters need to step back and think for a bit, both with regards to the "facts" they bring to the table and with regards to the tone of their writing.

 

A firing range of 500 yards discredits the results? Have a look at the ballistics of M2 .50 rounds. They're hefty pieces of metal, and have quite an outreach. Barret rifle ring a bell?

 

Armoured aircraft? Ever seen an aircraft? Weight is the name of the game, and thin alu sheet metal is the way to keep it down. Armour? Behind the pilot and in some cases another plate protecting part of the engine was pretty much it, in the pre-missile era*, as an attempt to reduce the risk of pilot or engine being taken out by one lucky stray bullet or piece of shrapnel. All the rest is thin skin, thin ribs, thin stringers. A .50 will cut through the structure like a hot knife through butter if it hits, be it from the rear, from above or on a sinusoidal path from wingtip to wingtip...

 

Built to take damage? Not quite. Aircraft are built with an eye at producing redundancy, alternative load paths etc, and that will improve resilience against damage as well, but if you start building flying tanks designed to suck up damage, you will only make sure that you lack the competitive edge needed to avoid taking all that damage and more. There are notable exceptions, mainly in aircraft specifically designed for the ground attack role - the Il-2 and A-10 are the most well known in this category - but in general the idea is to produce performance enough to be the one doing the damage rather than taking it. These objectives are mutually exclusive.

 

The best you can hope for is for the structure to be flimsy enough for projectiles to pass clean through, without depositing their kinetic energy. A .50 in a wing spar and you will not want to pull Gs until that spar is replaced. The safety factor is typically only 50%, without extra lightening holes in the webbing.

 

Convergence range is a factor for getting hits, but a hit is a hit is a hit, even if it was achieved outside of the convergence setting. Even at the convergence range, the idea has been to produce a dispersion pattern intended to maximize the chance of getting hits, rather than concentrating fire at the sight line. What does this say of the effectiveness of single .50 hits? That's practical war-time experience speaking. Early in WWII, some people had the idea of harmonization at a single point in space but this quickly proved ineffective and was dropped.

 

Modern aircraft, with only one gun, still go for the shotgun effect rather than maximum number of rounds on target, but through carefully engineered dispersion patterns rather than through gun harmonization. That's with explosive rounds though, so a totally different ball game.

 

As was written here, it was found remarkable enough to be recorded when aircraft got back with tens of .50 hits. Is it reasonable to see 100+ hits in more than extreme cases?

 

That'll have to do for now.

 

*) Self-sealing or foam filled tanks are not armour per se.

Edited August 2, 2014 by effte
Typos

[USARStarkey]

Just a note to those who are interested. More Data will be posted tonight.

[NineLine]

Guys, please discuss in a respectful manner, if you dont agree with results share your own....

[USARStarkey]

In the meantime, this image backs up what the two of you have said about dispersion patterns.

[effte]

Nice illustration. I created something similar when this debate came up in RoF. What's the source publication?

 

It displays another point worthy of nothing, which I forgot to include earlier: Being x yards closer than the convergence setting is as bad, if not worse, than being x yards further out, for getting hits. Two nicely tight dispersion patterns bracketing your sighting point and quite possibly missing completely.

[USARStarkey]

My previous tester is indisposed at the moment, so if anyone would like to be a target or vise versa just PM me. If I cant get anyone to test with, I might have to delay posting more results tonight.

 

In the meantime, I have been experimenting around with the APIT round in the game by modding it. Based on the ballistic chart I posed earlier, which equated the APIT rounds incendiary effects as being equivalent to 10% the he power of the German 20mm, I modified the 50cal APIT to have that value of explosive filler, or .0175. For comparison, the 23mm in game has .175 filler( I couldnt find the german 20 in the list) this is a crude solution and I just wanted to see what happened. I would like to note that from the stats list on the 50cal there does not appear to be any incendiary property and seems to just be a ap round with a tracer and slightly less mass. From experience DCS does not seem to model aircraft fire except when you lose a wing or engine anyways, which is probably a considerable part of the deficiency this thread is about.

 

Note: although its just for kicks, I have killed the ai dora with about 30 strikes around 5 times now with the new APIT round I made. Thats right, the depleted uranium Dora ai went down in 30 hits.

[Sabredog]

Yeah, sounds like the .50 cal could definitely use a damage boost against AI. I think the M134 is also a little underpowered.

[ZaltysZ]

The Table on in this website is in good agreement with the 1 to 3 ratio comparison with 20mm cannon. http://www.quarry.nildram.co.uk/WW2guneffect.htm

 

That site is brought up once in a while on various WWII sim forums, but the problem is it contains data obtained through very crude calculations. They were done on the basis of: muzzle velocity, diameter, mass of projectile, and percentage of HE/incendiaries. Such things as projectile shape, penetrator material, explosives used, incendiary compounds used, fusing were not taken into account. Authors agree that shells with high HE content have understated destructive power.

[Pilum]

Of course it is speculative to a certain extent, and I like anyone else am subject to error. Even with large amounts of data, any damage model in any sim is to a certain extent speculative even.

 

That being said, not much has been discussed regarding the actual ballistics because that wasn't the direction the conversation went in. Several people agreed with my first post, and Sithspawn asked me to do more testing and send him tracks. I am still in the process of doing that testing, I was just putting up what I got so far.

 

Regarding the actual ballistics, Both the Navy and the USAAF considered 3 50cal equivalent to 1 20mm generally speaking. It took about 5 20mm to down a fighter typically. If you watch 50cal only planes gun cam footage, you will notice that they knock down enemy planes very quickly, or least set them on fire or cause an explosion.

 

The Table on in this website is in good agreement with the 1 to 3 ratio comparison with 20mm cannon. http://www.quarry.nildram.co.uk/WW2guneffect.htm

 

Here is some gun camera footage, ignore the rest of the video if you wish: https://www.youtube.com/watch?v=4Z2FFtu441s&list=LL9p_QEwysGYhs3YDKN0f60w&index=10

 

Granted, I have only flown DCS a few days now and mostly looked at climb performance but I think you have a valid point here:

 

In the few tracks I've collected so far and analyzed the hit count it seems on the high side. Usually due to the hanging props antics I nail the AI in a few deflection passes when they are presenting the upper side in a vertical deflection shot so whatever is hit of the vitals are not going to be armour protected.

 

Even so, doing the hit counts it's like OP says: needing 50-100 or even more is not uncommon.

 

I also agree with the analysis: German WW2 analysis indicate twenty 20 mm hits needed to down a "Boeing". IIRC then the estimate was that about a quarter of that was needed to down a fighter.

 

Emanuel Gustin and Anthony Williams have a power table in the link has the rifle calibre 7.92X57 referenced as 1 in destructive power. They then access both the 0.5" M2 (12.7x99) and the MG151/20 (20x82) in terms of destructive power based on chemical and kinetic energy and come up with a power factor of 4.6 and 16 respectively, i.e. about a factor 3.5.

 

So doing the maths and assuming five 20 mm rounds needed, it should take about 18 M2 rounds to down a fighter:

 

5*(16/4.6)= 17.4

 

Of course, all of this depends on where you hit and 18 hits on the wing will not do, but on the other hand 18 in the engine, radiator, fuel tanks and pilot etc will.

 

So statistically, looking at tracks it seems reasonable that the average should land up in the twenties and not the hundreds :music_whistling:

[Pilum]

That site is brought up once in a while on various WWII sim forums, but the problem is it contains data obtained through very crude calculations. They were done on the basis of: muzzle velocity, diameter, mass of projectile, and percentage of HE/incendiaries. Such things as projectile shape, penetrator material, explosives used, incendiary compounds used, fusing were not taken into account. Authors agree that shells with high HE content have understated destructive power.

 

Ok, so in your opinion, what is a reasonable relative between M2 and MG151/20?

 

I have Gustin/Williams book "Flying Guns of WW2" and IMHO they seems to have their ducks in a row.

 

What sources do you want to cite?

[ZaltysZ]

Ok, so in your opinion, what is a reasonable relative between M2 and MG151/20?

 

I don't like such broad comparisons in context of "of how much it takes to down a fighter", because they tend to treat aircraft as monolithic target with hitpoints. In addition, there are different ammo types involved, which can make it look like comparing apples to oranges. I.e. even if it is possible to treat MG151/20 API round as upsized M2 round, what to do with Minengeschosspatrone, which is basically a small grenade (18g of PETN) designed to explode under the stressed skin of aircraft?

 

The only reasonable thing without going into very complex modelling, is comparing statistical data, i.e. pilot accounts or ammo spent per target downed. I have opinion, which is based on memoirs, that steady 1-2s burst with 6x.50 was enough for a kill. It is a lot of bullets, but such amount is "enough for a kill", and not necessary "needed for a kill".

 

I have Gustin/Williams book "Flying Guns of WW2" and IMHO they seems to have their ducks in a row.

 

Note that this site http://www.quarry.nildram.co.uk/WW2guneffect.htm belongs to the same Williams and it says:

 

In conclusion, while it is admitted that some elements of the calculations – especially concerning the relative weighting given to kinetic and chemical damage – are open to criticism, in practical terms the results stand up quite well. Changing the method of calculation affects some scores but has surprisingly little effect on the overall 'order of merit' of the destructiveness rankings. Where it does have an effect, it is generally to boost the scores of high-capacity HE shells while reducing those of lower-velocity AP cannon shells and AP bullets, which is validated by the Luftwaffe's decision to focus on chemical rather than kinetic energy in developing their aircraft weapons.

Their ducks might be in a row, but that row is still unordered and they acknowledge that.