A rigid electrical panel comprising at least a part of an electrical harness of a gas turbine engine, the panel comprising: a rigid material; a flexible printed circuit at least partly embedded in the rigid material, the flexible printed circuit comprising at least one electrical track arranged to carry electrical signals relating to the operation of the gas turbine engine in use, and at least one integral electromagnetic shield; an electromagnetic protection layer at least partially embedded in the rigid material; a flexible printed circuit outlet terminal to which at least the integral electromagnetic shield is electrically connected; and an electrically conductive grounding element to which the electromagnetic protection layer is electrically connected, wherein: the flexible printed circuit outlet terminal is at least a part of an electrical connector; and at least one electrical track of the flexible printed circuit is electrically connected to the flexible printed circuit outlet terminal so as to be able to transfer the electrical signal carried by the track in use out of the panel; characterised in that the electromagnetic protection layer is electrically isolated from the flexible printed circuit and the flexible printed circuit outlet terminal and the electrically conductive grounding element are electrically isolated, such that the integral electromagnetic shield is grounded via the flexible printed circuit outlet terminal and the electromagnetic protection layer is separately grounded via the electrically conductive grounding element. a rigid material; a flexible printed circuit at least partly embedded in the rigid material, the flexible printed circuit comprising at least one electrical track arranged to carry electrical signals relating to the operation of the gas turbine engine in use, and at least one integral electromagnetic shield; an electromagnetic protection layer at least partially embedded in the rigid material; a flexible printed circuit outlet terminal to which at least the integral electromagnetic shield is electrically connected; and an electrically conductive grounding element to which the electromagnetic protection layer is electrically connected, wherein: the flexible printed circuit outlet terminal is at least a part of an electrical connector; and at least one electrical track of the flexible printed circuit is electrically connected to the flexible printed circuit outlet terminal so as to be able to transfer the electrical signal carried by the track in use out of the panel; characterised in that the electromagnetic protection layer is electrically isolated from the flexible printed circuit and the flexible printed circuit outlet terminal and the electrically conductive grounding element are electrically isolated, such that the integral electromagnetic shield is grounded via the flexible printed circuit outlet terminal and the electromagnetic protection layer is separately grounded via the electrically conductive grounding element. the flexible printed circuit outlet terminal is at least a part of an electrical connector; and at least one electrical track of the flexible printed circuit is electrically connected to the flexible printed circuit outlet terminal so as to be able to transfer the electrical signal carried by the track in use out of the panel; characterised in that the electromagnetic protection layer is electrically isolated from the flexible printed circuit and the flexible printed circuit outlet terminal and the electrically conductive grounding element are electrically isolated, such that the integral electromagnetic shield is grounded via the flexible printed circuit outlet terminal and the electromagnetic protection layer is separately grounded via the electrically conductive grounding element.