4.12.2 de-bugging

[Pursuivant]

Troubleshooting the A-20G Damage Model:

This one has a lot of little problems, but the big problem is FUEL TANKS

A) The damage model assumes that the fuel tanks are contiguous with the plane's skin, which was not the case. That means that many glancing hits to the wing and fuselage which realistically would have missed the tanks cause punctures.

B) In a few cases, bullets which completely miss the tanks still cause fuel leaks. Like here:

http://forum.1cpublishing.eu/attachm...1&d=1404378042

Note that damage which is just to the starboard engine nachelle has somehow managed to start a leak in the outboard fuel tank!

C) As is typical for just about all the planes in the game, single rifle caliber bullets cause much worse leaks than they should and ignite fires far too often.

Remember, by about 1940, at least for most planes, self-sealing tanks weren't just self-sealing, but usually blanketed by engine exhaust.

That means that you have to tear open the fuel tank to the point that the CO2 blanket no longer is effective, you also need to have way of vaporizing the gasoline (admittedly, not hard when there's a 200 mph wind blowing through a hole in the plane's skin), and you need a spark. Sparks are a bit harder to come by since aluminum doesn't spark and only something like every 10th bullet in the belt was Incendiary, tracer or explosive.

So, two .303 bullets in rapid succession against a full fuel tank are very unlikely to cause a fire because the gas hasn't had time to spill or vaporize and the integrity of the tank is still good. A burst of .303 bullets might do the trick if it tears apart the fuel tank and the fuel then contacts a hot engines. But, that's not an option for a fuel tank mounted at a distance from the engine.

What might cause a fire is several bursts of .303 fire which tear up the tank, followed some seconds later by another big burst of .303 gunfire, which can be assumed to contain an Incendiary, Explosive or Tracer bullet in the mix, and which hits gasoline vapor.

Example of bad damage modeling here, where two .303 bullets from the same burst started a fire in a previously undamaged fuel tank.

http://forum.1cpublishing.eu/attachm...1&d=1404378818

The other bullets which hit near the burning fuel tank actually hit behind the fuel tank, so the damage looks worse than it is.

E) Fuel fires don't go out when fuel is exhausted.

Example here:

http://forum.1cpublishing.eu/attachm...1&d=1404378916

This screenshot was taken about a minute after I lost fuel due to the fire. Since the fire presumably drew fire from other tanks, it's unlikely that there was any remaining fuel in the burning tank for it to use!


F) Fuel fires also deplete the fuel from ALL tanks, not just the tank where the fire is. I know that IL2 doesn't and can't really model fuel transfer or fuel shutoffs, but it wouldn't be hard to specify that a fuel fire just takes some percentage of fuel and then goes out.