i just set it to "salvo" , open the bombdoors (with holding the "open bombdoor" button), arm the bombs and hit the bombrelease button ONCE (only working from pilotposition

). Than all bombs are comming out. Bombdoors are closing automaticlay after rlease...
if you want drop a specific amount of bombs or all one after another you have to set "interval"
Than you can set the intervall length (means how much bombs) and the time (or better distance on ground) after one bomb is relased after the other.
I am working only with shortcuts - but IIRC the bomb'computer' is in the nose if you want manipulate it with the mouse....