[Flashman]

Any external bombs on the Hornisse are dropped by pressing the button to fire rockets.
Careful, those bombs don't have delay so make sure you're high to avoid damaging your own plane.

You absolutely right about that one! on a number of occasions I have dropped them at low altitude and blown myself to pieces.

The internal bombs have whatever delay you have set in the aircraft tab, but the externals do not, nor do they have any delay set for the rockets either.