Game Details 5: Bombs

Player bombs are a standard feature in most shoot'em ups and Heli-Cats is no exception. However, it is quickly apparent that this game does not reset back to the full bomb stock after the player helicopter gets hit, only after a continue. So how is the bomb stock increased during a run?
They are replenished by the icon seen in the screenshot above. In this example from mission 2, destroying enough trucks spawns a bomb refill. The location of the bomb refill is dependent on the number of trucks visibly destroyed, with a maximum of two bombs for this mission. Different missions have different objects to destroy and different maximum refills. Some missions do not have bomb refills at all. Use the Training mode to discover where they all are.
The total number of obtainable bomb refills in a single run allows a solo player to use at least two bombs per boss. Thus, knowing the bomb locations can significantly change the strategy towards a 1CC. Also, the player helicopter cannot hold more than three bombs at one time. Any additional bomb above the full stock is converted to 20,000 points. So unless going for score, there is no reason not to bomb away!
(For clarification, the Auto Bomb only activates when down to the last armor. It also disqualifies entry into the online leaderboards when it is first triggered. Auto Bomb is allowed for a 1CC and will get the achievement.)