Kinnayar, while you're getting the training time set up...consider practicing in the TA. When you select the bomb as secondary weapon, you'll find a green cross marking the spot at which the bomb will land. (Dont get confused, because you'll also have a green cross showing where you're primary 50cals will hit.)
With a little practice time -- even without dropping the bomb -- you'll get a feel for how speed, dive angle, and time since last adjustment affect the bomb impact point.