I remember from another time a guy called an attack from the six "a silly six attack". Made sense then and still does now. Unfortunately, that's where I always seem to be and in THIS game it is just downright suicidal. It's really tough to get above, ahead, make a u-turn and dive on his 12. A real rare wet dream, so to speak. 
PATIENCE DUDE.
you don't have to be very far above em, and you don't have to attack from their 12.
i tend to start from about 2k horizonatlly, and about 1 or 2k feet above em. i get a little out in front of them, then turn into their flight path. at 1.5 to 1.0k i squeeze the trigger, and generally socre a couple damaging hits. DO NOT turn to follow them. maintain your course....you'll pass below and behind them. as you pass them gently climb, maintaining speed, and slight turn in the direction they're heading. this should reset ou to the same attack position on the other side of them.
repeat and rinse till they manage to kill ya, or you've killed them.
other thing to do is to keep checking your map. if they're near target, judge when you think they need to be in the bombsight to calibrate, or drop, and time your attack accordingly. if they don't have a gunner on board, you can take down at least one of them while he's in the bombardiers position.
never ever attack from the six, or six low. six high works sometimes, but in general, attacking a buff from the six is bad, mkay? at my six co-alt, or six low, you appear pretty stationary from the tailgunners seat. makes for an easy target.
if you DO have to evade gunfire from tha buffs, DO NOT bank hard. that gives the gunner a nice big juicy target. small evasives. and get out of his range, reset and try again.
the very most important thing though, is the very fist line of my post. patience. patience. patience.
hope this helps ya some.
