Abstract: A standardized, modular, fuel quantity gaging system suitable for use with aircraft having a plurality of fuel tanks. The system utilizes a standard electronic module, preferably located on the front spar of the center wing box, to house a redundant, centralized, microprocessor-based electronic assembly. This assembly processes the tank-generated fuel quantity signals and produces a digital data stream which is distributed to display units in the cockpit and at the refueling control panel. The digital signals are transmitted over two 2-wire data busses from the standard electronic module to the cockpit and to the refueling panel. One of these buses is active, the other being held in standby, for use as needed. The two busses are part of separate data processing channels extending between the fuel quantity signal multiplexers in the standard electronic module and the indicators in the cockpit and at the refueling panel.

Abstract: This apparatus includes means for measuring capacitance or resistance and means for simulating a selected capacitance value. The apparatus is connectible into a fuel gaging system. When so connected, a selector switch can be operated to make the normal connections between the fuel gaging capacitors and the indicators, so that the indicators produce their normal responses. Alternatively, the selector switch may be operated so that the apparatus measures the capacitance or resistance of various elements in the gaging system. As another selection, a simulated value of capacitance may be inserted in the gaging system to make the indicators in that system respond to the simulated value in addition to the capacitance of the fuel gaging capacitors of the gaging system.

Abstract: This apparatus includes means for measuring capacitance or resistance and means for simulating a selected capacitance value. The apparatus is connectible into a fuel gaging system. When so connected, a selector switch can be operated to make the normal connections between the fuel gaging capacitors and the indicators, so that the indicators produce their normal responses. Alternatively, the selector switch may be operated so that the apparatus measures the capacitance or resistance of various elements in the gaging system. As another selection, a simulated value of capacitance may be inserted in the gaging system to make the indicators in that system respond to the simulated value in addition to the capacitance of the fuel gaging capacitors of the gaging system.