FW190 FM Change

[Herra Tohtori]

Well, considering the longest distance that you can set your convergence in the game is 1000 metres, the bullets won't rise all that much above the aiming line at that time.

If you want the maths, here goes:

The muzzle velocity of most weapons in the game is somewhere between 500-1000 m/s:

540 m/s for MK108
720 m/s for MG151/20
850 m/s for Browning .303-cals
890 m/s for Browning .50-cals
960 m/s for MG151/15

The bullet drop distance is simple to calculate:

y = ½ g t²

where

g = 9.80665 m/s²

t = bullet travel time

Notwithstanding the drag that the bullet experiences, which slows its velocity, we can still get some guidelines by assuming that the bullet travels at its muzzle velocity the entire way from the muzzle to the target.

So if we look at the slowest projectile here, MK108 grenade, and assume that the average velocity is something in the order of 500 m/s, we can determine that the travel time for 1000 metres convergence is two seconds.

Now we substitute this in the equation to determine how much the bullet falls during this time:

y = ½ * 9.80665 m/s² * (2 s)² = ½ * 9.80665 * 4 m = 19.6 metres

Now, to get how much higher the bullet must arc, you can divide this by two since the bullet first goes up, then down.

So, with the MK108 cannon, firing at level attitude to 1000 metres distance at 1000 metres convergence, the projectile should have peak altitude about 10 metres higher than the aiming line.

At 500 metres distance, 10 metres deviation above the aiming line is not easy to see, in fact on the computer screen it is not very many pixels; a single seat fighter aircraft's wingspan (or length) are of the same order of size, so there's your measure stick.

Note that the MK108 cannon is rather slow and you probably stand no chance of either hitting anything at that distance, or to accurately see the projectile arcing higher than the aiming line because the recoil will probably throw your sight around quite a bit.

With the faster projectiles, the effect is even less pronounced. The MG151/15 cannon projectile should pass the distance of 1000 metres in close to one second, and in that time, the projectile drop is only about five metres, and the peak altitude above aiming line is half that - 2.5 metres or close to that.

With MG151/20 projectile, you have muzzle velocity of 720 m/s; using nice round numbers we can say the average velocity for the projectile might be something around 700 m/s. That translates to about 1.43 seconds of flight time; rounding up let's say 1.5 seconds. 1.5 seconds gives a bullet drop of about 11 metres, and thus the peak altitude would be around 5.5 metres above aiming line.


Now, I don't know exactly HOW much the drag affects projectiles in distances below 1000 metres. If it's modeled physically accurately, then the heavier projectiles should technically retain their speed better while the smaller projectiles would decelerate faster due to their higher dragcoefficient/mass ratio (small stones have lower terminal velocity than big stones of same shape and density), but I don't think it will have that much of an effect on this rudimentary mathematics.

The point is, since maximum convergence distance is 1000 metres, the projectiles won't arc very much above the line of sight, with exception of the slowest projectiles. The situation would be different if you could set convergence to, say, 2000 or 3000 metres, but then this would only be useful if we had an A-10 Warthog in the game with its GAU-8 cannon...