[Deathsight]

It might be a pretty stupid question but I'm having a problem about trap doors on a level bomber or some other types also having a trap-door. The first time I ran into this problem was when I was flying the Avenger, it also happened on other bombers.

So, how am I supposed to open these when for example I have to drop the bombs manually or flying planes using the Soviet level-
bombers Bombsight ?? :oops: