"风笛的笛管" can be translated as "the chanter (or drone pipes, depending on specific context) of the bagpipes" in English.
Here, “chanter” refers to the melody pipe in some types of bagpipes, while “drone pipes” refer to the pipes that produce a continuous, unchanging note or notes, providing a harmonic background. Since "风笛" (bagpipes) can have different types and structures, the exact translation might vary slightly based on the specific kind of bagpipes being referred to. In a more general or less technical context, you could also simply say "the pipes of the bagpipes" to convey the idea.