Normal.
It's my understanding that the basic CFS3 engine is, like the vast majority of flightsims, unable to model bullet penetration. IOW, your bullet's all go splat like a bug on the 1st surface encountered, even if it's only a piece of canvas. Damage is only scored if that area of surface is covered by a hit box.
NOTE: I could be wrong about this, but if I'm not, this is a limitation we should keep in mind in this discussion. If I am wrong, then just ignore the rest of this wall o' text because it is all based on this assumption.
There are several implications to this lack of penetration. The most important in terms of getting quick kills is that you have to have a clear line of fire to the vitals. Consider the pilot. From the upper forward arcs, he's shielded by the upper wing. From below, he's protected by the fuselage. In real life, of course, this canvas and plywood wouldn't do him any good at all, but it's an absolute defense the way the underlying game engine operates (not OFF's fault).
Thus, no matter how high you set your bullet strength, you're not going to hurt the pilot if all your bullets hit some part of the plane before they reach his hit box. OTOH, I would assume that the whole damage system was designed with "normal" bullet strength in mind as realistic. Thus, if you set your bullets on strong, you will do disproportionate damage to the parts you hit per bullet than you really should. Thus, it seems that setting bullets above "normal" is a bad idea. We just have to live with the limitation of the game engine.
I also believe that the reason badly shot-up planes keep on flying more or less straight ahead is because they're so stable. I have yet to encounter any plane in OFF that falls out of the sky hands-off, even without setting the trim. This includes even the Camel. Thus, even with a dead pilot at the controls, the plane might go on straight and level for miles. There's a famous incident where this actually happened to a Quirk, which made a perfect and literally "dead"-stick landing far behind German lines after being shot up badly by 2 entire Jastas.
I think this is something that might need looking into. Maybe make it so that when a pilot dies, he almost always spawns a "ground-seeking" AI pilot to take his place
. Maybe later look into the inherent stability of such notorious cranks as the Camel and RE8.
On the subject of structural failure from direct gunfire, shooting wings right off doesn't appear to have happened very often at all in real life, so I have no trouble with it being rare in OFF. Bear in mind that to do this you have to hit the important structural part of the wing, which is a tiny fraction of the whole. And if the hit box for this is aligned along the main spar, I doubt strongly that you can hit it from behind, due to the aforementioned inability for bullets to penetrate. All your rounds stop on the canvas near the trailing edge, leaving the spar intact.
As to indirect structural failure, I define this as overstress, either before or after damage. I have broken quite a few of my own airplanes from too much G, too much speed, or getting too close to angry clouds (which appear to inflict both). The breaking point of my airplane appears to decrease as it gets damaged, too. I have seen AI squaddies dive steeper than I could survive and appear unharmed afterwards. So I'm not sure that AI planes can suffer overstress damage at all, let alone this becoming easier for them after I shoot them up.
HOWEVER, I will say that the vast majority of the hits I inflict on the enemy are from good rear hemisphere tracking shots, because I can't shoot well enough to hit them in high deflection
. I have to compensate for poor marksmanship by flying well. The corollary to this is that the vast majority of the hits I suffer are from high deflection snapshots, again because I fly well and don't let the baddies get on my 6 very often. I think this distinction is important in that it has a direct impact on the type and severity of the damage inflicted.
If bullets can't penetrate, then the traditional killing shot from astern is about the worst position from which to inflict fatal damage. You are very unlikely to get bullets into the vitals of pilot, motor, and fuel. The majority of your rounds will splatter harmlessly on the rear fuselage and wing trailing edges. About all you're likely to hurt is the functionality of the rudder and elevators.
OTOH, high-deflection shots usually present the target's entire planform. This enables you to get rounds into the hit boxes for the upper wing spar and aileron control wires, the Albatros radiator, etc. And the engine itself and the pilot are exposed in whole or in part during the pass as the angles change. You'll probably get some hits on the horizontal tail's inner boxes, too, at the end of your burst.
Anyway, these predictions are matched very well by my observations. I sit behind the enemy and hose him down to little apparent effect, while the enemy knocks me out of the sky with quick snapshots. I believe this is all due to the inability of bullets to penetrate. RB2/3D was exactly the same in this regard.
