A powered aircraft wing is described including a flexible solid sheet having energy cells integrated with the sheet. The apparatus generally comprises a submersible housing that contains a variable ballast system for selectively controlling the buoyancy of the apparatus, and a detector assembly for locating the conveyance. The RFID reader includes an RFID transceiver circuit, a second pot core half, and a second toroidal wire coil that fits within the second pot core half and is electrically coupled to the transceiver circuit to transmit RF energy and receive modulated RF energy from the first wire coil only when the first pot core half is substantially aligned with and proximate to the second pot core half. Examining the detecting signals to find whether the gas appliance has an abnormal condition; and informing the client end when the abnormal condition is found.