Probably the most significant upgrade in DM will come when they actually model more specific parts, with full internal and external modelling.
One thing IL2/FB is good, is that the combat conditions upon expecting a kill is very different with each plane according to armament. A cannon armed plane would usually achieve kills in FB like it would in AH - by knocking out entire surfaces and causing fatal structural damage.
However, .50 armed planes are very different in IL2/FB in that they require a concentrated burst over a certain period of time - they rarely inflict structural fatalities, but very often cause internal damages.
The most likely cause of death by .50 armed planes in IL2/FB would be fires and engine seizures. A plane might withstand a burst or two from .50 armed planes, but usually on the third or fourth hit something is bound to be destroyed - a high probability of oil and fuel leaks, pilot wounds, and fires.
In AH2, with an exception of few planes that is notorious for catching fires, it is actually very rare thing to catch fire at all. Usually it is a plane that has already sustained fatal structural damage and going down in flames. It is very rare for a plane to catch fire first, and that become the cause of being shot down.
Also, a full internal damage modelling has some very interesting types of damages available. The most interesting case I've experienced in IL2/FB was a machine gun burst damaging my throttle systems. I don't know what the heck happened, but maybe the AP round snagged a throttle floodgate or something. I've found out that the throttle won't respond anymore! The only way I could reduce speed during the landing was to shut down the engine completely - and sometimes even that doesn't work!!
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So, I think there would be two large fields in which AH2 could be upgraded in DM.
One would be a full overhaul in the DM itself, where damageable parts are redone, so the plane has fully depicted internal and external parts, with different damage levels.
Like flakbait wrote, a plane with engine damage would leak just fuel or oil, but would be able to pull full power until the lubricant/fuel runs out. However, a plane famed with tough and durable engines such as the P-47 might get a piston head shot out, with rough handling and vibrations and etc., not pulling full power, but the engine still operational and stable, nonetheless.
Also, it'd be good to see damage levels depicted differently in control surfaces. Like, it'd be really cool to see an aileron that is not just cleanly "snipped off", but ragged and tattered by enemy fire, with reduced levels of efficiency. It wouldn't lose its function totally as it is now.
Ofcourse, the damage itself could be different. A non-functioning aileron is not the same thing as a missing aileron or a tattered aileron.
In effect that'd bring out also some very interesting tactical differences in planes - ie. if a cannon armed plane would strike an aileron with cannon shells it'd be much more likely that the entire aileron be ragged and tattered, perhaps fall off with a few hits. However, if a .50 armed plane would hit an aileron it'd be more likely the penetrated shells damage the aileron control cables, rather than the aileron surface itself be damaged.
Looking by the end result, a damaged aileron, destroyed aileron, aileron that fell off from its joints.. all could be the same in result. Perhaps the developers might not feel a need to model three different status of a control surface when essentially the result is the same. But however, the gamers like detail. God is in the details, too. Small and insignificant it may be, but such small differences with unique 'twists' in how the damage is dealt, would increase the feel of the game greatly.
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The second field of possible DM upgrade would be a full, cosmetic makeup. Initially people expected a lot from HT's comments that 'bullet holes will appear exactly where shells landed', but I guess a lot of people were disappointed with it.
The damage itself doesn't look bad, but it is way too limited. It only appears on the upper surfaces of the wings. The fuselage, sides, and underbellies show no damage at all. A simple 'textured method' would suffice, as seen in IL2/FB.
There are a lot of small but cool ideas to be shown off in this field. Like for instance, "hydraulics damage". This would be really cool to watch. A plane underfire gets its gears damaged. You could just handle it the way it is now in AH2, but it would really be something, if in some cases the damage to the gears relieve hydraulic locks and the gear droops down from the damaged plane. Man, the immersion would be unbelieveable if we see something like that.
Many small ideas can be tried out. Like, the way we 'perceive' damage by hits. Shoot a cannon shell, see it connect, explode on the target surface, throwing up a ball of smoke, flame, powdery debris.. that visual alone would make it really feel good.
I've recently noticed that on some four engine-bombers, the oil leaks on the engines would be also be perceivable from the externals. I think something like this is a step in the right direction.
So let's keep the ideas coming
