In the planes' cfg file, there has to be a declaration for the named Loadouts, such as the "1x250Kg Bomb". There are usually multiple B0x nodes on each plane, and if you put a "BombDummy" (mod name dependent), that will entice the airplane to then "attack" with the dummy bomb, and "strafe" while doing so. Since the bomb is fake, it looks like a strafing run. In other words, you would have node B01 holding the 250kg bomb, and all of the other B nodes holding the BombDummy, as is in your definitions there for that particular plane. But that cfg file has to have the listing for that Loadout, such as
[Loadout 1]
Name=1x250Kg Bomb
Type=3
without that AND the matching entry in the eqp file, they do not function. The "default" loadout does not need a declaration in the cfg file, only the definition in the eqp, as you have there. However, since you did get an attack from the plane, then you most likely do have the declaration in the cfg file. But, do you have all of those B nodes in the dat file for the plane?