C) the enemy make himself a threat to me.
I have several rules regarding attacking planes that are already engaged. The quoted one is by far the most common:
1. If I was trying to fly by and it took a shot at me - it dies, period ->
. Even if there are 5 greenies on his tail I will get in there and blast him infront of their faces. From my POV, if the greenies could not keep him away from me they lost the kill rights over him, and if he avoided the friendlies just to take a shot at me he signals that he desires to die by my guns.
2. The other occasion is when the greenies are playing with their food for too long and make me nervous. I do not like to leave enemies behind me for too long even if they are supposedly engaged by friendlies. Very few players will resist taking a shot at a mosquito even if it means they will get shot down a second later, and I know he will take that shot the moment I let me guard/SA down, or when I am engaged by someone else. P51s, La7s and 190D are the typical enemies in this case, flying around with a gaggle of green uselessly following them. At some point my patience will expire and I'll jump in to kill it.
3. The third is the berserker rage. If I am in a wild furball and start foaming at the mouth, I'll shoot at anyone from any angle.
4. The last case is Yak3. Never let a Yak3 live, period ->
. I'll vulch pick and gang those any chance I get and then hope they bail so I can shoot them in their chute.