I have flown at least 3 types that pitch down when power is applied. The pitching direction depends on the position of the engine and the thrust line and drag line.
Point of information.
It is thrust line related to vertical CofG. Very common misconception regarding the drag line. Remember, force couples are a convenient short cut that can be used to quickly determine the effect of two forces when
they are equal.
If T <> D then the combined pitching effect could be either way.
If anyone feels the inclination to tell me I'm talking rubbish, please check your basic physics first
pb