Illuminated is not only an explosion risk (see Thai and Philippine write offs)īut also if a pump is left running dry for over approx 10 minutes it will loseĪll the fuel required for priming which will render it inoperative even when the Leaving a fuel pump on with a low pressure light Centre tank LP lights are armed only when their pumps are ON. To illuminate the master caution to avoid spurious warnings at high AoA’s orĪccelerations. Both fuel pump low pressure lights in any tank are required There are two AC powered fuel pumps in each tank there are also EDP’s atĮach engine. On older aircraft the trimmers were accessible from theįlightdeck (below the F/O's FMC) but they have since been removed to a To standardise the total tank capacitance and allows for the replacement Of the fuel gauges is done by capacitance trimmers, these are adjusted
Updated to ensure the accuracy of VNAV speeds, buffet margin and max altitude.įuel quantity is measured by using a series ofĬapacitors in the tanks with fuel acting as the dielectric. The NG has 6 dripsticks in each wing tank and 4 in the centreĬumulative errors it is recommended that the wings are filled once every few The classics have 5 dripsticks in each wing tank and none in the centre Must be determined by using the dripsticks (floatsticks Open or short circuit in a LO-Z to a tank unitĬalibration unit does not operate correctly Gauges considered to be operating normally? Low fuel quantity indication illuminates belowĭigital Fuel Quantity Indicator Error Codes If the gauge is indicating (rather than zero) the gauge may be used. On the Simmonds gauges or error codes 1,3 and 6 on the Smiths gauges. Note: The gauges are still considered to be operating normally with The test, each gauge will display any error codes that they may have. Start a self test of the display and the fuel quantity indicating system. On the Digital Sunburst fuel gauges, pressing the "Qty test" button will The fuel flow indication is integrated over time to calculate the fuel used for each engine. During cruise, the tolerance is less than 0.5%. At engine idle, the system tolerance can be 12%.
The accuracy tolerance of the fuel flow transmitter is a function of the fuel flow. The system tolerance is then +/- 200 KG at any fuel level within the tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.02 (airplane without a densitometer) * 10000 = 200 KG.
The total tolerance for the FQIS system is based on a full tank. The fuel flow indication is integrated over time to calculate the fuel used for each engine.ħ37-600/-700/-800/-900 with densitometer: During cruise, the tolerance is less than 1.5%. The accuracy of the fuel flow transmitter is a function of the fuel flow. The system tolerance is then +/- 300 KG at any fuel level within the tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.03 (airplane with analog indicators) * 10000 = 300 KG. The 737 fuel quantity indication system has the following accuracy tolerances:įQIS accuracy with digital indicators: +/- 2.5 %įQIS accuracy with analog indicators: +/- 3.0% Power to shut off the fuel in an emergency.ĭigital Sunburst Fuel Gauges - Simmonds 4 Tank NG/MAX: The engine spar valves and APU are normally powered by the hotīattery bus but have a dedicated battery to ensure that there is always They were solenoid held andĪutomatically moved back to OFF after one minute. The 1/200's had heater switches these used bleed air to heat theįuel and de-ice the fuel filter. The -1/200 panel also hasīlue VALVE OPEN lights similar to that on the crossfeed valve. The NG/MAX's have separate ENG VALVE CLOSED & SPAR VALVE CLOSED lights in
The fuel panels for the various series have not changed much over The AFM limits are higher, but not normally Upon how many tanks the customer has specified (max 12). Maximum declarable fuel capacity for tech log, nav log, etc is 16,200kgs forģ-Tank Classics, 20,800kgs for NG/MAX's and up to 37,712kgs for BBJ's depending