Flight and damage models physics

[jokerBR]

1 hour ago, -DED-Rapidus said:

Everything is exactly the same as on the BF 109F 4 for example, 100%-the maximum loaded screw, 0% - the maximum light weight, everything is correct. Try again yourself RShift + and RShift -.

Thanks Rapidus. I have the propeller pitch mapped to an axis on my controllers. On a Spit, or Mustang, or P47, or whatever allied plane, when I put 100% pitch (move the axis to maximum), the RPM increases (i.e., you put 100% for take off, for instance). On the Hs129 it's the other way around - when you increase the pitch (moving the axis to the maximum position, and technochat also says 100%) the RPM engine decreases and the engine dies even before reaching 100%. I have to put the axis into "zero" position to achieve maximum pull. I think this is a bug, because the game doesn't allow us to have specific controls for planes, so I cannot reverse this axis just for german planes. So, 100% axis should also be 100% whatever it is mapped into game, and the effect in game should be the same.

[-DED-Rapidus]

@jokerBR, your arguments are logical, but as it is, so it will be.

On 9/4/2020 at 2:56 AM, J99_Sizzlorr said:

Brief description: The wings of following airplanes seem to be still too weak to fly them effecitvley in combat: Albatros D.Va, Halberstadt CL.II, S.E 5a, Sopwith Camel, Sopwith Dolphin, Spad XIII. 

You can be asked to specify which places were hit before the wings were broken.

[J99_Sizzlorr]

7 hours ago, -DED-Rapidus said:

[...]

You can be asked to specify which places were hit before the wings were broken.

Mostly wing area and fuselage. How does the control cable damage work? Is it a hitbox or a percentage chance to trigger with every hit?  

Edited September 8, 2020 by J99_Sizzlorr

[76SQN-FatherTed]

16 hours ago, -DED-Rapidus said:

 

You can be asked to specify which places were hit before the wings were broken.

 

Because the visual damage model is not the same as the physical damage model it is difficult to specify from the pilot's view.  Generally, the depiction of wing damage is a few holes in the linen. Those holes always appear in the same place (I guess they're decals), so it is impossible for the player to know whether they represent structural or cosmetic damage in the physical DM.

[No.23_Triggers]

@-DED-Rapidus  Another example to go with @J99_Sizzlorr 's post: 
 

 

[Cecil]

@-DED-Rapidus  Have you had a chance to test the P-51 damage model?  Do the devs know about it?  Any idea when it will be fixed?

Edited September 24, 2020 by Cecil

[-DED-Rapidus]

@Cecil, thank you, Yes, there are tests in the plans.

[422nd_Konnel]

Brief description:  Damage Model / Flight model 

 

Detailed description, conditions:

Dear developers, we know of the dedication and effort committed to improve and bring as close as possible to reality the experience of IL2 Players.
Thinking about it and wanting to contribute to this improvement, I show here a video about how the damage mode implies in the flight of aircraft.

See the difference in effect caused by the damage in the video above.

Would a reassessment be possible with regard to the damage caused, thus being able to equate its effects on all aircraft?

We pilots who have flown for some time know that this is not only an isolated fact as shown in this video, but a constant one.
Thank you very much.

 

 

[JGr8_Leopard]

In the last update, the speed of moving the stabilizer to the Fw190 was changed. It moves very quickly, with one short press it changes by 5-10%. Easy to click and immediately change to 20 +%. Before that, it was comfortable to move with an accuracy of 1-2%. It is very difficult now to establish the exact value. Movement speed increased by 50% or more. Fw190 A3 A5 A8.

[-DED-Rapidus]

On 9/26/2020 at 10:40 PM, =ABr=422nd_Konnel said:

Brief description:  Damage Model / Flight model 

 

Detailed description, conditions:

Dear developers, we know of the dedication and effort committed to improve and bring as close as possible to reality the experience of IL2 Players.
Thinking about it and wanting to contribute to this improvement, I show here a video about how the damage mode implies in the flight of aircraft.

See the difference in effect caused by the damage in the video above.

Would a reassessment be possible with regard to the damage caused, thus being able to equate its effects on all aircraft?

We pilots who have flown for some time know that this is not only an isolated fact as shown in this video, but a constant one.
Thank you very much.

 

 

in version 4.502, there were many changes in the damage model and we are planning to study this issue soon, please be patient.

[357th_KW]

This appears to be related to the most recent patch, but it's hard to say.  Either way, the .50s have devolved to almost totally ineffective: 

 

[-DED-Rapidus]

@VBF-12_KW, 

 

[=J18=FritzGerald]

I was flying the bf109, different versions, the E3, and G6, on the Berloga server, first time I've flown them since the last update. I was shot a tiny bit but the machine gun rounds only impacted on the wings, the little damage/technical hints did not say that there was any damage, and my wind screen did not have any sort of oil on it, got out of combat and then about a minute to 5min later my engine starts reporting major damage and then dies, I have tracks for two flights where this happened, have not tested this in single player. I have a very good ping to the server and that it isn't a lag shot that hit me.

Will make tracks available if necessary.

Salute!

-Gerald

[-DED-Rapidus]

@=AW=Leftenant_Gerald, Yes, let's see the tracks.

[=J18=FritzGerald]

Tracks PM'ed!

Salute!

-Gerald

[CountZero]

21 hours ago, =AW=Leftenant_Gerald said:

I was flying the bf109, different versions, the E3, and G6, on the Berloga server, first time I've flown them since the last update. I was shot a tiny bit but the machine gun rounds only impacted on the wings, the little damage/technical hints did not say that there was any damage, and my wind screen did not have any sort of oil on it, got out of combat and then about a minute to 5min later my engine starts reporting major damage and then dies, I have tracks for two flights where this happened, have not tested this in single player. I have a very good ping to the server and that it isn't a lag shot that hit me.

Will make tracks available if necessary.

Salute!

-Gerald

Are you sure you didnt fly them to long on Emergancy power ? even if technical tips are turned on messages that inform you about timers expired are broken and work only when instrument panel option is turned on and most servers dont use that option as it shows instruments in hud.

[=J18=FritzGerald]

25 minutes ago, CountZero said:

Are you sure you didnt fly them to long on Emergancy power ? even if technical tips are turned on messages that inform you about timers expired are broken and work only when instrument panel option is turned on and most servers dont use that option as it shows instruments in hud.

yes I am sure, in both flights I kept the power mostly just in combat mode, although for some short parts (only a few seconds I had it in emergency mode) and both times my engine cut out after less than or aout a minute of just spawing in. I will post a video here if that would help make it clearer.

Salute!

-Gerald

[=J18=FritzGerald]

 

[-DED-Rapidus]

On 1/28/2021 at 12:03 AM, =AW=Leftenant_Gerald said:

yes I am sure, in both flights I kept the power mostly just in combat mode, although for some short parts (only a few seconds I had it in emergency mode) and both times my engine cut out after less than or aout a minute of just spawing in. I will post a video here if that would help make it clearer.

Salute!

-Gerald

It is not clear, I would like to see the devices with the temperature of oil and water.

[=J18=FritzGerald]

1 hour ago, -DED-Rapidus said:

It is not clear, I would like to see the devices with the temperature of oil and water.

How would you like me to do that? I don't remember checking them while I was flying. so it wouldn't show up in the track, is there a way that I can do that for you?

Salute!

-Gerald

[354thFG_Drewm3i-VR]

28 minutes ago, =AW=Leftenant_Gerald said:

How would you like me to do that? I don't remember checking them while I was flying. so it wouldn't show up in the track, is there a way that I can do that for you?

Salute!

-Gerald

Cockpit view so we can see the gauges.

[=J18=FritzGerald]

Will see if I can do that, not completely sure, sometimes I fly with a mouse from the outside, just because I didn't have time to set up all my trackir/joystick but I'll see if I flew those from the inside.

Salute!

-Gerald

[Ghost666]

Start the track and use the L-alt+F1 camera view, then you can look around with the mouse.

[=J18=FritzGerald]

40 minutes ago, Ghost666 said:

Start the track and use the L-alt+F1 camera view, then you can look around with the mouse.

Thank you so much sir!

Salute!

-Gerald

[=J18=FritzGerald]

 

First, then second flights in order as with first video.

[DD_Arthur]

You blew your engine up both times by giving it too much throttle for too long.

[CountZero]

1 hour ago, =AW=Leftenant_Gerald said:

 

First, then second flights in order as with first video.

For me this just confirms that engine timers is what killed your engine in both times, and as message that warns you about it is buged you cant know in heat of battle you wasted time game gives you:

Game spec say:

109E7:

Boosted power (up to 1 minute): 2400 RPM, 1.4 ata

109G6:

Emergency power (up to 1 minute): 2800 RPM, 1.42 ata

 

You can safe use 60s anything abow is random fail time, and to recover 1s of use you need to not use it for 13s, or 1min recovers after 13min flying on combat or continuous and so on.

[=J18=FritzGerald]

Ah, thank you for the analysis, I was just really confused because I've run it for longer on that high of a throttle for longer, but I'll check and make sure I was managing the engine settings correctly, hadn't flown them in a bit, must have forgotten what I needed to do.

Sorry for bringing up something that wasn't a bug.

Salute

-Gerald

[-DED-Rapidus]

@=AW=Leftenant_Gerald, everything is fine, the main thing is that we figured out the reason)

[=SqSq=SignorMagnifico]

On 2/7/2021 at 6:25 PM, =AW=Leftenant_Gerald said:

Ah, thank you for the analysis, I was just really confused because I've run it for longer on that high of a throttle for longer, but I'll check and make sure I was managing the engine settings correctly, hadn't flown them in a bit, must have forgotten what I needed to do.

Sorry for bringing up something that wasn't a bug.

Salute

-Gerald

The chance of engine failure is random for every few seconds you run it in excess of the specified limits. Sometimes you can get away with exceeding it for a minute or two with no repercussions, and other times, the engine dies quickly. In either case, it’s important never to exceed those engine timings since you can never be too sure how quickly your engine will fail.

[=J18=FritzGerald]

1 hour ago, =SqSq=SignorMagnifico said:

The chance of engine failure is random for every few seconds you run it in excess of the specified limits. Sometimes you can get away with exceeding it for a minute or two with no repercussions, and other times, the engine dies quickly. In either case, it’s important never to exceed those engine timings since you can never be too sure how quickly your engine will fail.

Nice to know! Thank you sir for the information! Didn't know that before.

Salute!

-Gerald

[QB.Shallot]

Brief description:

The damage model changes which were made in version 4.005 (released in April 2020) changed how AP and HE ammunition interact with an aircraft’s aerodynamic and structural performance. Since those changes went live, there has been a distinct disparity between HMG’s that contain a HE component (Russian UBS 12.7mm and German MG131) and those that do not contain a HE component (US M2 .50).

 

Detailed description, conditions:

In real life, the MG131 and UBS both contain approximately 1.5g of HE in an explosive round with a 50/50 mix of AP/HE in the belt. It is worth mentioning that this is 8.3% of the amount of HE found in the Minengeschoß shell. The US M2 .50 that is commonly found on most American aircraft in IL2 fires the incorrect ammunition for the BoBp timeframe, being just a pure AP slug, instead of the ubiquitous API ammunition that was used in the latter half of WW2. The following testing is focused on the disparity between the two classes of weapons purely within the context of airframe damage. Anything other than aerodynamic damage is out of scope for these tests. The two testing factors presented below cover damage to the wing of another aircraft either structurally (the spar is damaged enough that the wing will detach under load) or aerodynamically (enough damage was done to significantly hamper the flight characteristics).

 

Methodology:

 

A series of tests were conducted in a controlled environment: the Combat Box training server. All tests were recorded using the recording feature and matched with the sortie logs (extracted from the server using IL2Stats). The raw server logs have been preserved as well and will be supplied upon request. Testing in this way eliminates any possibility of netcode or lag issues since the number of rounds hitting the aircraft comes from the server and not the client recording. Each test was done at the same altitude with the same atmospheric conditions. All firing was done from zero degrees angle off tail and zero closure from a range of 100-200m. After each shot, we carefully observed the effect before deciding whether or not more shots were required to reach the desired outcome for the test - this can be verified by the time between shots in the sortie logs (i.e. we were not firing any more rounds than necessary to reach the desired effect).  All tests were conducted using one of three ammo types: the German MG131 (which was recently changed to have a 50/50 mix of AP/HE ammo), the Russian UBS 7.62mm (which also has a 50/50 AP HE MIX), and the M2 .50 (which has no HE component). All tests were done shooting at the center of the left wing of each target airframe. All test data is available for download here.

 

Battery 1, Structural Damage:

 

Our first battery of tests were focused on wing breakage (how many rounds does it take to cause structural failure of the wing). All of these tests were conducted using the 109G14 as the target. The average, minimum, and maximum number of rounds required to cause structural failure of the wing are as follows for each weapon type (ordered ascending by effectiveness):

 

Weapon type	Average rounds	Minimum rounds	Maximum rounds
Russian UBS 12.7mm	24	16	35
German MG131	24.6	20	32
US M2 .50	30	23	36

 

From these tests, we can conclude that the effectiveness of each weapon type with respect to structural failure is relatively close in performance. Let it be noted that on average the MG131 and Berezin UB HMG’s are 25% more effective at causing structural damage than the Browning M2.

 

Battery 2, Aerodynamic Damage:

 

Our second battery of tests focused on creating an aerodynamic penalty (i.e. firing the minimum number of rounds required to create an appreciable drag penalty). Firing at only one wing and looking at the visual damage, we found a direct correlation between the visual damage observed on the wing and a speed reduction of the aircraft hit. The first change in the visual modelling of a wing surface (which we will refer to as “level one damage”) creates no appreciable drag penalty (2-5 km/h). With additional shots on the wing, the next visual indication creates a significant drag penalty (which we refer to as “level two damage”). We did observe additional drag penalties when more than one section of a single wing have visual damage (e.g. the tip of the wing, the center of the wing, and on some planes the inner portion of the wing) and when components fall off (e.g. aileron, flaps, wheel covers, etc). When this occurred during a test, we removed them from our test results to keep things consistent - all of our tests for aerodynamic damage are the minimum number of shots required to achieve “level two damage” to the middle section of the wing and nothing more. Below are the effects observed for the aerodynamic damage described:

Airframe	Max continuous	Level one aero damage to one wing	Level two aero damage to one wing	Percentage speed loss for level two aero damage
109	454kmh	451kmh	405kmh	10.79%
P51	309mph (497kmh)	308mph (495kmh)	285mph (458kmh) / 267mph (429kmh) †	7.8% / 13.68%
190	495kmh	493kmh	465kmh	6.06%

† two levels of damage observed beyond level one for the same wing segment

 

What we discovered was that it literally is not possible to achieve level two aerodynamic damage with the M2 .50 before structural failure occurs on the wing of a Bf-109G14. For these tests, we used the FW-190D9 instead as it can sustain a lot more punishment before structural failure occurs. The average, minimum, and maximum number of rounds required to cause level two aerodynamic damage to a wing are as follows for each weapon type (ordered ascending by effectiveness):

 

Weapon type	Average rounds	Minimum rounds	Maximum rounds
Russian UBS 12.7mm	3.4	2	5
German MG131	3.4	2	7
US M2 .50	83.4	77	87

 

Conclusion:

 

From these tests, we can conclude that the effectiveness of each weapon type with respect to structural damage is relatively close, however the aerodynamic damage is drastically different. Weapon types with a very small HE component immediately cause a significant aerodynamic penalty making the target aircraft slower and more difficult to maneuver. In order to achieve the same effect with similar AP ammo, you must shoot 2,352% more rounds than you do with HE ammo.

 

A pilot using a HMG with an HE component can cause crippling damage with a single hit. This can be confirmed by using the single MG131 or single UB machine gun present on German and Russian medium bombers. Effects include a 40+ km/h speed penalty at cruise settings as well as making the aircraft far less maneuverable.

 

A pilot using the M2 .50 is hard pressed to cause any sort of crippling damage to an opponent's airframe before the structural integrity is compromised. There is little difference between an undamaged aircraft and one with level one aero damage applied to its wings, and even less if the hits happen to be on the fuselage. When fighting a Bf-109, an allied player will sooner tear the wing off of his opponent than cause an appreciable drag penalty.

 

An exact solution will not be proposed here - we will not pretend to understand the IL2 codebase nor the historical accuracy standards that the IL2 team strives to achieve. We only ask that this information is considered as proof that the current state of these weapons doesn’t pass the smell test. Because this affects two very popular planes in the Battle of Bodenplatte expansion, we hope that something can be done to address this issue sooner rather than later.

 

Additional assets (videos, screenshots, logs):

(example of “level two” aerodynamic damage on multiple wing segments of a Bf 109)

 

(another example of “level two” aerodynamic damage to the wing of a Bf 109)

 

(another example of “level two” aerodynamic damage on two segments of the wing of a Bf 109)

(an example of what “level two” aerodynamic damage looks like on the wing of a Fw 190)

 

 

https://drive.google.com/file/d/1yDIdwCUpL-RactTGN0c72EphoEIIDVqq/view?usp=sharing

(dserver logs from testing on 2021-01-17)

 

https://drive.google.com/file/d/13WNR1rqszAr-adp56Vaqg1cMv-4AHDZl/view?usp=sharing

(dserver logs from testing on 2021-01-14)

 

https://drive.google.com/file/d/1Sd-S7XmzOyAE8wGWS-qnsMqN2vbL9hIF/view?usp=sharing

(in-game recordings and tacview recordings from testing on 2021-01-17)

 

https://drive.google.com/file/d/1IbQXsK6oWSd5Bs47zjN8MgXFvLoezufm/view?usp=sharing

(in-game recordings and tacview recordings from testing on 2021-01-14)

Your PC config data (OS, drivers, specific software):

• Windows 10 v1809

• IL2 v4.505

 

[354thFG_Drewm3i-VR]

What is going on? Last Patch around Christmas time:

 

https://www.youtube.com/watch?v=qm3J3djAFmg&feature=emb_logo

 

Now this, recorded today (ace ai for the p-47d-28 with 8 .50s) by me after patch 4.506: 

 

https://www.youtube.com/watch?v=Ofkt8FtpwBM&feature=youtu.be

 

[Angry_Kitten]

Noticed in my first hour of flying with it post update, there is two things that werent there before. 

 

1.  once my speed hits 360 km/h, my plane has this unresistable urge to roll RIGHT.  can take some left rudder and a slight roll to the left to get it to fly straight. 

 

2. below 1000m, it really likes to stall out and play "falling brick" if i try a steep dive. 

 

3.below 1000m its not safe to try a cork screw to get fast altitude. I seem to 100 km/h for 30-40 meters in altitude, when at 1200m+  i can gain 100m altitude for losing 100km/h.  

 

4. I paid extra for the P51-D, why hasnt anyone improved the cockpit photo for it?

[Han]

QB.Shallot - please stop.

 

13mm AP rounds makes makes 13mm holes in skin, or may be 13x25mm holes in case of shallow angle hit.

13mm HE round may do a hole up to 300mm in diameter approx.

 

Compare the hole surface and stop complaining aboгt this in every post please.

 

API rounds are very effective to demolish airplane systems, crew, may broke some airframe structure, fire up fuel or engine, make leaks and so on. But they obviously poor in serios damaging of airplane skin and aerodynamics in compare to HE.

[ZachariasX]

16 minutes ago, Han said:

Compare the hole surface and stop complaining aboгt this in every post please.

@Han , you posted an image of an SBD Dauntless that was hit by a Japanese 20 mm round:

 

 

In the military, I have seen plenty of 20 mm Oerlikons firing, and the damage HE does at sheet aluminium is very consistent with that image, it reflects the largest kind of damage you can have after about 1 m of travel after explosion. A HE round with contact fuze effectively detonates about 20 cm past impact. That is where the blast force happenes. Depending on how much stuff the fragments encounter, the spray of shrapnel is different. I think what you gave us as 20 mm effectiveness in the game is plausible. But not as for 13 mm.

 

13 mm HE do not do such, they make a smaller exit, mostly due to the far lower fragmentation and shrapnel energy post detonation. 13 mm is really far less effective than 20 mm. You would not see such a large exit hole as in the picture above and depending on what the bullet encounters, it would probably not look too different from a ball round. If the HE rounds would be that more effective, not just the Americans would have used them. In the game currently, you are at a significant disadvantage using ball rounds. Not so in the real world.

 

Regarding the .05's just this: Almost any ball shot from the rear quadrant will find structure to compromise what is important to the wing. You well know how far a .50 will go throug a wing and do damage there along the way. There may be technical constraints to the DM model, but I dare to say it is obvioius that perfection is not reached yet.

[=FB=VikS]

Just to compare  it on visual example, here is a video  (only problem - its on russian - but i will drop cuts with timeline).

 

Firing are with DShK 12,7  with 12,7x108 (same ammunition used on UB).

 

Example of MDZ (HEI) effect on 200L barrels - kinda close to airplane skin:
 

 

- just look what it does with barrel skin.

 

And here, in the same video - BZT (API) on the barrels:

 

 

- much less damage on skin.

[ZachariasX]

One should not get lost in details.

 

A wing is not an empty barrel. It has a lot of hard things in it that both make a bullet tumble and make larger exit holes. To which degree it does so can be speculated about, but in the end I don't think the barrel is a very productive argument in the sense that a suitable solution can be found.

 

The model that is programmed for the purpose of coming up with specific damage in this game is an extremely refined one and as such certainly correct, in principle.

 

The problem is that one should never mistake the result of a simplification (any model always is) to brush aside a known bottom line. This is namely that ball or API 0.50 are similar enough to a HE mix to what they do on the victim to such a degree that the US didn't care to use HE rounds. If there were in practise differences in "time on target" as we have them in the game, then the whole user base of 0.50 guns would be nothing but outwardly dumb, especially given if there was someone that could make for practical puroses unlimited amout of ammo of any kind, it was the USA.

 

So yes, whlie it is plausible that ball rounds create less aerodynamical penalty than HE (I think this should be like that on average), the amount of rounds it requires to down an aircraft on average should not be all too different. You have a RNG on the bottom of your model anyway, so... I mean now it's just something that keeps poking the eye of the player.

 

But with this I want to conclude my comment on that. I am grateful and most happy you, the devs, go on forward with this great sim like you do. I'm know you will find ways to improve also this issue.

[C6_lefuneste]

1 hour ago, =FB=VikS said:

Just to compare  it on visual example, here is a video  (only problem - its on russian - but i will drop cuts with timeline).

 

Firing are with DShK 12,7  with 12,7x108 (same ammunition used on UB).

 

Example of MDZ (HEI) effect on 200L barrels - kinda close to airplane skin:
 

 

- just look what it does with barrel skin.

 

And here, in the same video - BZT (API) on the barrels:

 

 

- much less damage on skin.

Here are some picture taken from the "API" part of your impressive video (if I'm not wrong):

Entry hole is quite small, but that's not the case of output hole !

Morever I was totally impressed by the result of multiple impact on the same barrel. 

So, as we have fighters with 3 or 4 guns on the same wing, I wonder if it's possible to have this kind of mutliple impact in real life...

 

[Creep]

@=FB=VikS @Han First of all, I greatly appreciate you both taking the time to respond - I am sure you are both very busy! Regardless what you guys decide, I know you have the best interest of the sim in mind. With that said, I want to address the following:

 

5 hours ago, =FB=VikS said:

- much less damage on skin.

 

A smaller hole where the bullet enters, but not where it exits. 

 

A few other points:

1. I absolutely agree that for two bullets of a similar calibre and velocity, the one with an HE component should do more damage to the skin of the aircraft. How much more is the question. Right now it appears that the ratio is roughly 80:1 (based on our testing of HMGs against the skin of a 190 D9). To me, that is too large of a disparity - it just doesn't make any sense to me.
2. Our testing shows that AP-only HMG is really bad at creating aerodynamic drag, and it is slightly worse at creating structural damage too compared to similar HE rounds. How can this be? Surely it should be better at creating structural damage than the HE rounds?
3. The currently modeled ammunition for the late-war allied planes is AP only - not API. That's historically inaccurate and puts both variants of the P-47 and the P-51 at a disadvantage. The P-38 suffers too but not as much since it does still have HE cannon. 
4. Please take a look at this poll - it shows that the vast majority of players agree that there is something wrong with the way AP v HE is modeled: