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Durability rating of aircraft

 
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Durability rating of aircraft - 1/28/2006 12:23:59 PM   
el cid again

 

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Status: offline 		In a thread on transports Treespider suggests we keep the duribility rating of transports as is and decrease the durability of all other planes "to increase the operational losses."

Now I am not sure if durability ratings affect operational loss rates?

And Nick reports that INCREASING durability DECREASES air to air combat effects - so I assume DECREASING it would also INCREASE air to air combat effects. Do we want to do this?

I once objected to Nick's approach of just changing durability to get the results we want to have. There is no formal technical definition of what durability is - and I am reluctant to tamper with what I do not understand.


But - IF we understand what durability should mean in a relative sense (which plane gets more and which less and why) - THEN we can play with multiples (incuding fractions) of the values we get - until we have the results we like. HOW to get the relative values in the right ball park I will make a quick and dirty first pass attempt at below - specifically seeking comments about how to do it better.
Post #: 1
Factors affecting durability - 1/28/2006 12:30:26 PM   
el cid again

 

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Status: offline 		The things that should affect the durability rating of an aircraft include:

1) The sheer size of the aircraft. Larger aircraft are harder to damage significantly. As size increases durability increases, but not in direct proportion to the size. The function needs to be set with some minimum size = 1 so that a small glider with no engines and no armor gets a rating of 1.

2) The number of engines. This is a linear function. The more engines, the more durable the aircraft, and every engine counts.

3) Protection - more or less represented by the armor rating in the databse. I thought this was always a 1 or a 0 - but I find at least one case where it is a 2 - so other values are possible. This factor is very important. But we do not want 0 armor to negate the other factors. So we ADD ONE to the armor factor - and then multiply the rest of the factors by the result. IF there is NO armor, the protection factor is 1 - and we preserve the rating. If there is normal armor, the protection factor is 2, and we double the other factors. If the plane is a Sturmovik, with an unusual armor factor of 2, the protection factor is three, and we triple the rating of other factors.

(in reply to el cid again)
Post #: 2
First pass durability equation - 1/28/2006 12:33:18 PM   
el cid again

 

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Status: offline 		The first pass equation should look like this:


Square Root [ ( Empty Equipped Weight in pounds / 1000 ) + Number of Engines ] * ( 1 + Armor Factor ) = Durability rating of aircraft

(in reply to el cid again)
Post #: 3
Durability ratings of unarmored aircraft table - 1/28/2006 12:44:21 PM   
el cid again

 

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Status: offline 		EEWt No Engines Protection Factor Durability
Armor rating = 0
2,000 lbs 1 1 2
4,000 lbs 1 1 3
9,000 lbs 1 1 4
9,000 lbs 2 1 5
16,000 lbs 1 1 5
16,000 lbs 2 1 6
25,000 lbs 1 1 6
25,000 lbs 2 1 7
36,000 lbs 1 1 7
36,000 lbs 2 1 8
36,000 lbs 3 1 9
49,000 lbs 2 1 9
49,000 lbs 3 1 10
49,000 lbs 4 1 11
64,000 lbs 2 1 10
64,000 lbs 3 1 11
64,000 lbs 4 1 12
81,000 lbs 2 1 11
81,000 lbs 3 1 12
81,000 lbs 4 1 13
100,000 lbs 3 1 13
100,000 lbs 4 1 14
100,000 lbs 6 1 16
121,000 lbs 4 1 15
121,000 lbs 6 1 17
121,000 lbs 8 1 19
144,000 lbs 4 1 16
144,000 lbs 6 1 18
144,000 lbs 8 1 20

(in reply to el cid again)
Post #: 4
RE: Durability ratings of armored aircraft table - 1/28/2006 12:51:04 PM   
el cid again

 

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quote:

EEWt No Engines Protection Factor Durability
Armor rating = 1
2,000 lbs 1 2 = 4
4,000 lbs 1 2 = 6
9,000 lbs 1 2 = 8
9,000 lbs 2 2 = 10
16,000 lbs 1 2 = 10
16,000 lbs 2 2 = 12
25,000 lbs 1 2 = 12
25,000 lbs 2 2 = 14
36,000 lbs 1 2 = 14
36,000 lbs 2 2 = 16
36,000 lbs 3 2 = 18
49,000 lbs 2 2 = 18
49,000 lbs 3 2 = 20
49,000 lbs 4 2 = 22
64,000 lbs 2 2 = 20
64,000 lbs 3 2 = 22
64,000 lbs 4 2 = 24
81,000 lbs 2 2 = 22
81,000 lbs 3 2 = 24
81,000 lbs 4 2 = 26
100,000 lbs 3 2 = 26
100,000 lbs 4 2 = 28
100,000 lbs 6 2 = 32
121,000 lbs 4 2 = 30
121,000 lbs 6 2 = 34
121,000 lbs 8 2 = 38
144,000 lbs 4 2 = 32
144,000 lbs 6 2 = 36
144,000 lbs 8 2 = 40

(in reply to el cid again)
Post #: 5
RE: Durability ratings of special aircraft table - 1/28/2006 12:58:14 PM   
el cid again

 

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Status: offline 		IL-2 10,000 lbs 1 engine armor rating 2 protection 3 = 12
IL-10 14,000 lbs 1 engine armor rating 2 protection 3 = 15
CG-4A 4,000 lbs 0 engines armor rating 0 protection 1 = 2
Ku-8 4,000 lbs 0 engines armor rating 0 protection 1 = 2

[Note that gliders are "combinations" with a tug - so the glider durability is added to the tug durability for a total combination durability. The CG-4 is towed by a C-47. The Ku-8 is towed by a Ki-21 or Ki-49.]


(in reply to el cid again)
Post #: 6
How to use this data - 1/28/2006 1:07:06 PM   
el cid again

 

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Status: offline 		This data can be used as is for the purposes proposed by Treespider. It should significantly increase attrition losses (both regular and due to air combat).

For example, a C-46 is rated in CHS as durability 43. This system gives the same aircraft a durability of 9.

If the attrition is too high, then simply apply a K factor. Multiply all values by 2, then 3, then 4, etc until you get the result you want. But in all cases the RELATIVE rating of planes will remain the same. Bigger planes will get more points than smaller ones - but not in direct proportion to size. Multi-engines will get more points than planes with fewer engines - and each engine counts equally. Armored planes will get a lot more points - generally double an otherwise identical unarmored plane. Very heavily armored planes (at least Sturmovik and its successor) will get triple.

Now for Nicks purposes, the same values can be used - but presumably with a much higher K factor - at least 6 (which would make the C-46 factor 54) - and more likely 9 or 10 (which would make the C-46 be rated at 81 or 90). But once again, the RELATIVE factor for each aircraft would remain the same. But in this case, the problem addressed by Treespider would be exaserbated - normal attrition would decline - assuming Treespider is right that it is related to durability at all. Since this seems to be too low, one wonders if getting lower air air combat lethality by raising durability is a good idea?

This proposal is to set up the potential for testing. I will create a database with this values set for all planes if anyone wants to test it. It will take me one day.

(in reply to el cid again)
Post #: 7
RE: How to use this data - 1/28/2006 9:25:13 PM   
witpqs


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From: Argleton
Status: offline 		el cid,

Durability 40 is a hard coded break point of some kind. I forget exactly what it is, but I believe it was introduced in a patch. I think it had to do with reducing the damage that fighters cause to bombers, but like I said I forget precisely. Maybe someone else out there remembers?

One comment. I wonder if an armor rating of 1 should really double the durability, a 2 triple it, etc. That seems quite excessive. For one thing the code already accounts for the armor rating in the combat model. If modifying durability based upon armor value is necessary to better approximate reality, maybe a much smaller factor. You propose

"... * (1 + armor factor) ..."

Perhaps something like (changing the fudge factor as desired)

"... * (1 + (0.1 * armor factor) ) ..."

or

"... * (1 + (0.2 * armor factor) ) ..."

or even

"... * (1 + (0.3 * armor factor) ) ..."

Just a thought.

(in reply to el cid again)
Post #: 8
RE: How to use this data - 1/29/2006 12:12:53 AM   
el cid again

 

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quote:

One comment. I wonder if an armor rating of 1 should really double the durability, a 2 triple it, etc. That seems quite excessive. For one thing the code already accounts for the armor rating in the combat model. If modifying durability based upon armor value is necessary to better approximate reality, maybe a much smaller factor.


It does appear to me that armor is a really big deal so my first guess is that if present it doubles durability. See Saburo Sakai in Samouri among others. And the amount of armor does NOT seem to be modeled - it is basically a "yes - no" proposition - which I think is too simple - except the IL-2 gets "double yes" for what may be sound reasons (bullet proof windscreen of major proportions, massive armor, and even the forward "skin" of the aircraft holding the engine is just a massive armor tube). However, a proper understanding of how much it matters would be based on detail analysis of results. IT would be a PHD kind of study - hard to do because you don't get to try the same plane with and without in combat very often! I like your comments though - it is what I was looking for.

(in reply to witpqs)
Post #: 9
RE: Durability rating of aircraft - 1/29/2006 2:36:04 AM   
treespider


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From: Edgewater, MD
Status: offline
quote:

In a thread on transports Treespider suggests we keep the duribility rating of transports as is and decrease the durability of all other planes "to increase the operational losses."



Not necessarily to the exclusion of other ratings. Perhaps instead of increasing durability to compensate for increase in firepower as somepeople have done we reduce evrything .....of course testing would have to be done to see if this were feasible....and I only suggest it as a way to increase the anemic OP loss rate witnessed currently in the game.

_____________________________

Here's a link to:
Treespider's Grand Campaign of DBB

"It is not the critic who counts, .... The credit belongs to the man who is actually in the arena..." T. Roosevelt, Paris, 1910

(in reply to el cid again)
Post #: 10
RE: First pass durability equation - 1/29/2006 6:53:33 AM   
Daniel Oskar


Posts: 123
Joined: 12/15/2000
Status: offline 		I agree with what you are trying to do here on principle, but us not knowing exactly what durability means in the code may have you proceeding on some faulty assumptions. I don't think you can assume that size alone should be the determining factor in durability. In an extreme example the WWI Gotha GV bomber is significantly larger and heavier than a P-40. It has a second engine. There is no way it is more durable than a P-40. Size is a factor, as are materiels of the aircraft, construction, design, armor, ect... Number of engines does not really give you more durability either. There are a couple old aviation axioms I would like to share. Why does an airplane have 2 engines? Because it won't fly on one. The purpose of a second engine is to enable you to get to the crash site. On a twin if you lose an engine you lose 50% of your available power, but 80% of your climb performance. Even in a powerful twin you will drift down from high altitude to your single engine ceiling. And considering most pilots in the time frame we are looking at were low time, less than 500 hrs, engine failures may cause operational losses due to inappropriate procedures, going below VMC, ect... Just some items to consider.

(in reply to el cid again)
Post #: 11
RE: Durability rating of aircraft - 1/29/2006 3:23:04 PM   
el cid again

 

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quote:

Not necessarily to the exclusion of other ratings. Perhaps instead of increasing durability to compensate for increase in firepower as somepeople have done we reduce evrything .....of course testing would have to be done to see if this were feasible....and I only suggest it as a way to increase the anemic OP loss rate witnessed currently in the game.


I am taking your suggestion seriously enough to divert a few days to it.
I think it has the unintended benefit of also helping to fix the AAA problem - losses to AAA are not high enough either.

Now I have addressed air air combat and AAA combat in other ways. By reducing range and reducing the effect of machine gun weapons (which seems greatly exaggerated relative to cannon) - and combining this with using a different speed system which already appears to help - I hope to help. I also have hope that air air combat will get a code fix - for greater than 50 plane per side combats. At the same time, I hope to change the relative performance of planes to better reflect their real weapons and real abilities (some have too great or small a ROC or speed, etc, or fictional weapons, or range advantages which are either fictional in most cases). I SUSPECT (no testing yet) that changes in durability may actually prevent one sided air combats being quite so common for technical reasons. And I have asked some questions privately - to see if this is worth investigating or not?


(in reply to treespider)
Post #: 12
RE: First pass durability equation - 1/29/2006 3:33:49 PM   
el cid again

 

Posts: 16922
Joined: 10/10/2005
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quote:

I agree with what you are trying to do here on principle, but us not knowing exactly what durability means in the code may have you proceeding on some faulty assumptions. I don't think you can assume that size alone should be the determining factor in durability. In an extreme example the WWI Gotha GV bomber is significantly larger and heavier than a P-40. It has a second engine. There is no way it is more durable than a P-40. Size is a factor, as are materiels of the aircraft, construction, design, armor, ect... Number of engines does not really give you more durability either. There are a couple old aviation axioms I would like to share. Why does an airplane have 2 engines? Because it won't fly on one. The purpose of a second engine is to enable you to get to the crash site. On a twin if you lose an engine you lose 50% of your available power, but 80% of your climb performance. Even in a powerful twin you will drift down from high altitude to your single engine ceiling. And considering most pilots in the time frame we are looking at were low time, less than 500 hrs, engine failures may cause operational losses due to inappropriate procedures, going below VMC, ect... Just some items to consider.


Thank you for your comments. This is hard stuff: generalizations are rarely always correct - and simplified models must generalize. [Thus I know of twin engine planes DESIGNED to fly on one engine, and that is SOP in airliner design today. But that does not make your axiom wrong in general - because it is right in general.] All we can hope to do is make a model that is generally right. The point about a Gotha may be valid - although I must admit I suspect it IS more durable than a P-40 - measured in terms of how many hits of a particular caliber it takes to kill it. But the engine principle applies less to a Gotha than to most planes - it is really a powered glider - and it is very underpowered! All I mean by engine count helps is that losing one engine is a lot more critical when you have only one than when you have several - if you see what I mean.

Remember this is only one field used by the air combat model (and also apparently by AAA combat and operational attrition algorithms). So it will be easier to hit a less maneuverable plane - it will be easier to hit a slower plane - it will be easier to hit a plane with less ceiling - etc. There is more to the picture than just "how well can it take it if hit" - and that is really all we are trying to say with this factor. I bet it is a lot harder to hit a P-40 than a big, slow Gotha! So even if it takes more hits to bring the Gotha down, it is not likely to be that hard to get more hits - if you have enough airpower in contact. And I don't think a Gotha is dangerous in an offensive sense - although there are exceptions. [A US Army Peiper Cub in the Battle of the Bulge scored an air air victory - using a .45 caliber M1911 pistol! And there is a case of an LB-30 on the hump run downing a Japanese fighter with a BAR fired out the window of the co-pilot!]


(in reply to Daniel Oskar)
Post #: 13
RE: First pass durability equation - 1/29/2006 3:38:51 PM   
el cid again

 

Posts: 16922
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quote:

I agree with what you are trying to do here on principle, but us not knowing exactly what durability means in the code may have you proceeding on some faulty assumptions


Right you are and I am nervous as a wet hen about it. I would pay real money for algorithms and definitions, and sign a non-disclosure agreement too. But testing will suffice to get it right. Or to determine we must leave this alone. I am mildly optimistic. But it is hard - even professionals with all the data sometimes break things when they fix something!

(in reply to Daniel Oskar)
Post #: 14
RE: Durability rating of aircraft - 2/7/2006 5:27:45 AM   
el cid again

 

Posts: 16922
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Status: offline 		Testing indicates the formula should be:

[Sqr Root ( Empty Weight / 1000 ) + No Pilots + No Engines + Structure)]

The variable K should be 1 if the intent is to use durability to address attrition. It should be 2 or 3 if the intent is to approximate the present system with better relative values for planes. It should be 4 or more if the intent is to use durability to drive down combat losses.

IF the durability is similar to present in range, bigger planes will take about the same attrition but small planes will take more operational attrition and more AAA attrition. Big planes should suffer less in air air combat.

Structure Scale:
1 = Fabric, wood, cloth or airship made of anything
1.5 = Metal fame with any combination of metal and non-metal coverings - including control surfaces.
2 = All metal
2.5 = Metal Frame with normal WITP armor
3 = All metal with normal WITP armor
4 = All metal with special armor (Schturmovik)

< Message edited by el cid again -- 2/18/2006 1:20:06 PM >

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Post #: 15
RE: Durability rating of aircraft - 2/7/2006 2:25:53 PM   
Sardaukar


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From: Finland/Israel
Status: offline 		I'd also modify with use of the aircraft. I think transports should be inherently more durable because they are not used in combat (usually).

(in reply to el cid again)
Post #: 16
RE: Durability rating of aircraft - 2/14/2006 4:22:45 PM   
el cid again

 

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quote:

I think transports should be inherently more durable because they are not used in combat (usually).


Please explain. It appears to me that the correct thing is to rate them properly. If NOT involved in air combat, they won't take any air combat losses (or AA losses). And if they are involved, then the rating works as it should. I do not see an issue here. But maybe I am not understanding your meaning?

(in reply to Sardaukar)
Post #: 17
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