A pneumatic hood for a tissue—or papermaking machine is disclosed. The hood has an inlet to admit dust and air. The inlet is defined, in part, by an inlet flap that is hingedly connected to the body of the hood. The inlet flap is connected to one or more linear actuators, such as pneumatic cylinders, by a linkage such that the linear actuators drive the inlet flap between positions in which the inlet is wider and positions in which the inlet is narrower. Thus, the size of the inlet can be increased to clear large obstructions.