A conveyance apparatus includes a holding unit configured to hold a roll sheet, a conveyance unit configured to convey the roll sheet in a first direction in which the roll sheet is unrolled and a second direction opposite from the first direction, and a control unit configured to control the drive of the conveyance unit. The cover is slidably placed onto a visor, and covers warning labels, protects the fabric from dust, dirt and other marring materials, and provides indicia about at least one panel of the cover. The input-ripple controller adjusts the size of a ripple command value, which indicates the ripple current that is to be input to a converter circuit, so as to null the difference between the ripple voltages. The thyristor damper circuit dampens an input current associated with the rectified voltage based on the input current and ceases dampening the rectified voltage based on the rectified voltage. Once delivered to a trusted signal transfer point, the selected portion of the signaling message is decrypted, and the signaling message is delivered to the ultimate destination. A system for measuring and machining an airfoil comprising a computer operable for data acquisition and numerically-controlled tool path generation, a numerically-controlled machine, a cutting tool holder comprising a plurality of cutting tools, and a displacement-sensing probe.