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The KC-135 IFMP provides the flight crew with the switches, displays, and annunciators used to monitor and control fuel quantity and distribution. The individual tank quantity, total fuel, Center of G... The KC-135 IFMP provides the flight crew with the switches, displays, and annunciators used to monitor and control fuel quantity and distribution. The individual tank quantity, total fuel, Center of Gravity (CG), and boom flow rate data are input into the IFMP in Binary Coded Decimal (BCD) format over the RS-422 data bus. The IFMP converts this BCD data into seven segment information and illuminates the appropriate displays on the front panel. The FMAC computes Fuel quantity, CG, and Aerial Refuel (A/R) and includes individual excitation and indicating electronics for each tank. Each individual tank indicating circuit is independent of all others and is individually powered from its own circuit breaker protected power supply. Tank indicating circuitry commonality begins in the FMAC at the measurement and computation unit where individual tank and total fuel quantities are computed by common processor electronics. The fuel indicating function is performed by the active channel microprocessor. An identical standby channel provides back-up redundancy to the common areas of the tank indicating circuitry. In case of failure in the active system, execution of the CG total fuel, A/R functions and the fuel indicating functions are picked up by the standby channel. Each of these processors is individually powered by its own switching supply. The TIU is an electrically passive device containing 20 externally adjustable trim capacitors that are adjusted at the time of initial installation of the unit. Two trim capacitors are provided for each tank making it possible to calibrate the individual tank indicating circuits. The capacitors are adjusted to calibrate the dry (empty) value of the tank unit to 400.00 (±0.25) pF, and the dry value of the compensators tank unit to 197.50 (±0.25) pF. All 10 tank indicating circuits are functionally equivalent. Since the individual tank sensing circuits are calibrated at the TIU there are no field calibration adjustments required when the IFMP or FMAC is replaced. TIU calibration is required if a TIU, tank unit or compensator tank unit is replaced. In addition, a TIU calibration is required whenever fuel quantity indicating system wiring (between the TIU and fuel probes) is replaced having an effect on an already known accurate fuel quantity indication. All scale factor modifications are handled in the FMAC software for existing aircraft configurations. The MFD uses an active matrix-liquid crystal display (AM/LCD) for both day and night readability and interfaces directly with ARINC 429, ARINC 708A, analog DC, synchro, and discrete signals. The MFD power supply contains the necessary circuitry for Electromagnetic Interference (EMI) monitoring and protection and produces a clamped 28V dc for MFD panel lighting. The MFD replaced mechanical ADI and HSI flight instruments. MFDs installed in the pilot and copilot instrument panels display the following base displays and overlays: 1. ADI base display (default for top MFD) 2. HSI base display (default for bottom MFD) 3. MAP ARC base display 4. WXR/TERR base display 5. HSI ARC base display 6. IMFD (Interactive Multifunctional Display) (bottom MFD) 7. PFD 8. TCAS overlay 9. WXR overlay 10. TERR overlay The navigator MFD can display the following base displays and overlays: 1. HSI base display (default) 2. MAP ARC base display 3. WXR/TERR base display (weather return is on the WXR overlay) 4. HSI ARC base display 5. IMFD 6. TCAS overlay 7. WXR overlay 8. TERR overlay