A. Fuel Probe
There are four capacitance-type fuel probes in each wing tank. The outboard fuel probe is installed aft of spar 4, outboard of WCANT 182.00. The midtank fuel probe is between rib 4 and 5, aft of spar 4. The forward inboard fuel probe is forward of spar 3 at WS 12.00. On Airplanes RB-4 thru RB-74 Not Modified by Kit 390-9200, the collector tank probe is located forward of spar 6 and inboard of WS 12.00. On airplanes RB-2, RB-3, RB-75 and After; and Prior Serials Modified by Kit 390-9200, the collector tank probe is installed aft of spar 3 and inboard of the fuel boost pump.
B. Fuel Quantity Indicator
The fuel quantity indicators (28M1, Left; 28M2, Right) are in the lower center cockpit subpanel. The indicators receive 28 VDC from the LEFT FUEL QTY (28CB7) and RIGHT FUEL QTY (28CB8) circuit breakers. Each indicator receives a capacitance signal from the four fuel probes in each wing tank. The indicator displays the remaining left and right wing tank fuel quantity as an analog and digital display in pounds. Each indicator represents the signal as an analog bar display and a three and a half (3 1/2) digit LED readout.
RH gage failed P/N 84-121-4 S/N 0805-172(failed, reads dashes)