There really isn't any situations where you would want to use bombs with the black shark.
They are unguided and there is no pipper to help you get on target.
Against bunkers. S-13's will do the trick as well as large missiles.
Against soft convoy - your cannon will be more precise, more effective, and gives you stand off ability.
Against hard convoy, well you definitely don't want to fly overhead anything that can shoot back with a good degree of accuracy. So missiles and guns are preferred here.
Against a group of infantry - hmmm is that a stinger in the middle of them? Definitely don't want to overfly infantry too often as RPG soldiers WILL take pot shots at you (not to mention the guys with guns are going to scratch your paint work). Again, the cannon will outrange a stinger and HE shells have area of effect to take out a group. You can also spam with rockets quite effectively.
So, why would you carry bombs? They get you too close to the enemy. They are hard to target correctly, they can take you out as well if you do it wrong.
Leave bombs up to the fixed wing guys that can do it far more effectively.
_________________________
Dip me in chocolate and throw me to the lesbians