VPB IL2  The Damage Model & Weaponry

As discussed elsewhere, much of the IL2 sim's damage modelling is quite unrealistic, and indeed daft. It is lacking categorically in any sense of logic; no pattern can be deduced with respect to the quantification of durability scores within this system save for cases of outright favouritism or sabotage. In most respects, it seems as if DM scores have been allocated without any reference to structural science or aviation history; popular aircraft generally receiving better scores and less popular examples lesser ones. This may be conceptual failure on a whole new level, or perhaps worse.

Now, to be sure, one can see clearly by reading any forum topic or other internet related discussion on this matter that the average aviation enthusiast and sim pilot has not the slightest understanding of period aviation structures. No clue whatsoever. This observation, although disappointing, should probably not come as much of a surprise. The durability of aircraft structures, their behaviour when subjected to damage and other such related concepts are highly technical in nature, requiring a great deal of study and education to grasp. These are not activities which are embraced by modern society and its 10 second attention span, and so we can understand that such deliberations will elude most persons.

Very well... but they should not elude the designers of an historical flight sim. This is simply unforgivable ignorance; indeed, almost wilful ignorance, like some kind of thumbing of one's nose at historical accuracy or science. Appalling...

Right, well, in any event, what are the major problem areas with DM quantification in the IL2 sim? In the first case, we can look at the relatively straightforward matter of aircraft engine durability. Since the coders of the sim are indeed not experts on this topic-- despite any self-delusion to the contrary-- we can accept that they will have no detailed knowledge of the properties of individual motor types. That said, they should obviously be aware that radial engines are more robust than in-line types; firstly in that they have no liquid cooling component, and secondly in the fact that the various cylinders are external to the crank case [thus any penetration of the cylinder results in oil loss proportional to that unit, not to the entire engine as with an in-line type]. It should also be self evident that engine durability is normally a fixed value per motor type, installed in whichever machine, expect in the specific case where some kind of limited armour protection is to be simulated which cannot be achieved with the 3d model. Some minor adjustment per case of engine durability might be acceptable where extra vulnerability was evident in the cooling system on a certain design, given that cooling systems do not (inexplicably) exist in the IL2 sim DM.

Alas, the 1C team does not seem to understand any of these concepts at all. Engine durability with the DM is assigned per aircraft, not per engine, and with wildly different values. Alarmingly, these values are irrational-- they seem to change only on the basis of the aircraft's general popularity, not on any discernible technical grounds. It can be tricky to attempt to quantify some of these vulnerability concepts, to be sure. If one looks at statistical loss data, and the like, one might say that a radial engine is approximately three times less vulnerable to battle damage than an in-line engine. Or thereabouts; certainly this represents an area for some discussion and debate. However, relatively speaking (relative properties, as always, being so utterly critical to making a good DM), we would expect that if a typical in-line engine (Merlin, let's say) had a durability of 100, then a typical radial (Wright Cyclone) would have 300, or something like that.

Naturally, in IL2 sim we do not see anything of the kind. Here are some actual examples from the sim's DM:

- R-R Merlin 6x family as mounted in the Spitfire-- Durability = 70 / identical Packard license-built V1650 in the P-51D = 350
- DB605 mounted in the Bf 109 = 150 / identical motor in the Bf 110G = 100
- Junkers Jumo 211 in the Ju 87 = 100 / identical motor in the He 111H = 200
- Packard V1710 family mounted in the P-40 = 220 / same motor in the P-38 = 400 / same motor in the P-39 = 80
- M-105 family mounted in all Yak fighters = 70 / same motor in the Pe-2 = 50/80 (obviously different port to starboard, don't you know)
- M-105 family mounted in the LaGG-3 = 50 / same motor mounted in the P-40 M-105 field mod = 220
- Wright Cyclone mounted in the P-36 = 220 / M-25 (license-built Cyclone) in the I-16 = 100
- AM-35A mounted in the MiG-3 = 100 / same engine in the Pe-8 = 500
- G-R Jupiter in the Hs 129 = 100 / the same in the Me 323 = 300

...Right, enough. Tragically, it would seem that only one explanation fits the evidence which we retrieve from the DMs-- childish favouritism. This is quite literally the petulant stuff of school boy back-biting, where the 1C team fancied design A, so it was made to be "better" (harder to shoot down, for example), and they did not like design B, so it was made to be "worse" (easier to shoot down). Sadly, one may also guess with consummate ease exactly which aircraft in the sim will be subject to inflation, and which to sabotage. This nonsense is cheating on a grand scale; quite exactly of the type of which we have warned previously.

Engines are only the beginning of the DM data. There are approximately 37 entries in this section of the FMD file; the engine portion only takes up four 'slots' [yes, that does mean that two of the Me 323's engines are indestructible as they have no DM]. The remaining 34 entries are similarly misused, typically, and always with the same illogical bent. However, it would too much to examine them all, so let us now turn our attention to the Central Fuselage (CF) score (one entry). This is the key value when determining the structural vulnerability of the aircraft's main fuselage component.

In a normal development environment, those who have no expertise in the matter of aeronautical structures and structural engineering could be expected to use one of a few options when faced with the reality of assigning a score to this part of the aircraft. Firstly, with no understanding of the topic, the team might simply make them all the same. Alternately, they might assign a value based upon the weight of the structure; greater mass = greater durability. This would not be historically accurate in all cases, of course, but it would be a step in the right direction for someone with no relevant knowledge. With funding, they would be best off to seek the advice of a bona fide expert, and have that person assign the values. Depending upon time & resources, three reasonable solutions.

Despite any such options, is it already obvious what, in fact, the 1C team have done in IL2? We presume that it should be. The assignment of CF durability scores in the DM is another case of baseless, irritating favouritism, preposterously inflated for favourites, and equally absurdly sabotaged for disliked designs. Moreover, one may again predict with ease which aircraft will receive either respective treatment. Were it not so tragic, this entire business would be comical.

A brief review of some of the absurd CF scores the IL2 sim's DM is in order (to illustrate). As a central benchmark, one would likely choose these examples of rather typical single-seat fighter fuselages, all moderately built monocoque all-metal structures with typical frame spacing and riveted dural/aluminium sheet. The aircraft's CF score from the sim is given in parenthesis after the type: Bf 109 (500), Spitfire (400), C.202 (600), P-39 (300), Ki.61 (500). These scores, in relative proportion, are nonsensical. There is no basis in structural engineering to ascribe more than a 10% difference to any of these fuselages, and indeed such proportional assignment historically would be the direct opposite of what we find in the DM. More ruggedly built structures-- where one might expect a 125-150% greater durability rating-- might include: P-51 (800), P-40 (800), Fw 190 (500). Larger aircraft with similar construction would be expected to be rated higher still, perhaps 200-300% greater depending upon their size and specific manufacture: F6F (600), F4U (600), P-47 (1200), Tempest (400).

As truly ridiculous as these totals are, however, it was for certain countries' designs that 1C poured over their scorn and derision with deliberate sabotage. There are no prizes for guessing the victims; a few examples will suffice. Designs with a tough semi-monocoque spruce or birch ply laminate construction with laminate sheet or resin-fabric skinning would be expected to receive a CF rating at least 150-250% greater than the above benchmark, depending in one case (even more) on the size of the structure: I-16 (300), MiG-3 (300), Mosquito (500). Extremely robust wood-plastic and laminate strip construction with resin-fabric covering must be rated relatively at 300% of the benchmark, at the least: LaGG-3 (300), La-5 (450).

Moreover, how does one handle bolted or jointed heavy gauge steel tube structures, which in an aviation sense are virtually indestructible (Hurricane), or-- heaven forbid-- welded heavy gauge steel tube construction using armour plate alloy steels (Yak fighters)? These are difficult judgements to make indeed, trying to quantify such structures in this milieu. Naturally, of course 1C had no difficulties of any kind: Yaks (400), Hurricanes (400).

And so on... How many pages and articles do we have now? Are there any which do not conform to this pattern? Oh dear....