Fuel Pump Issues with the 737-800

[Guest airlinecpt7020]

The other evening I was flying a flight from SEA to IAH using the 738, and noticed that the wing tanks drained first and the center tank was not being used. Needless to say after the wing tanks went dry, the engines failed. I followed the checklist, but I still cannot get fuel from the center tank. I talked with a friend of mine who flies 737s for Continental and he had said that usually after takeoff he switches off the left fuel pump and switches x-feed on. He uses fuel from the center tank first, but when it gets to about 5,000 lbs, the he uses fuel from the wing tanks. If anyone could help me with this issue, that would be appreciated. Thank you.

[kmanning 12]

Hi airlinecpt7020First of all, are you loading the fuel using the 737NG Fuel Planner? How much fuel are you loading in the wing tanks in comparison to the center tank? It sounds like the crossfeeds are not set correctly. The wing tanks are usally loaded with about 3 to 4 times more fuel than the center tank. I haven't flown the 737s in a while but if I remember correcly, the center tank uses up the fuel first. When the fuel is used up from the center tank, the center tank fuel pump is switched off and the wing tanks take over. Make sure you use the 737NG Fuel Planner. It will load the fuel correctly. If you are loading the plan with fuel using the flight simulator fuel load program, it won't load correctly, unless you already know how to distribute the fuel. But it's better to use the 737NG Fuel Planner. It sounds like the crossfeeds are not set correctly. Check your manual and be sure. Hope this helps.Ken.

[zubart 5]

This May help.Use fuel from the center tank first. This will extend the life of the airplane structure.But, FAA Airworthiness Directive 2002-19-52 in September 2002 and AD 202-24-51 in November 2002 require flight crews to maintain certain minimum fuel levels in the center fuel tanks when operating any Hydro-Aire fuel pumps. They may be a potential ignition source because of chafed wire bundles in the center fuel tank. No dry running center tank fuel anymore. Inspected airplane's can use an Alternate Operating Procedure. This part of the original FAA Center Tank Fuel AD for 737's NG. Editors note: The following extracts from the AD have been edited to restrict it to information relevant to the 737.2002-24-51 BOEING: Docket No. 2002-NM-309-AD. Applicability: All Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes.To require the flightcrew to maintain certain minimum fuel levels in the center fuel tanks, accomplish the following:Airplane Flight Manual (AFM) Revision: Model 737-600, -700, -700C, -800, and -900(:( For Model 737-600, -700, -700C, -800, and -900 series airplanes: Within 4 days after receipt of this AD, revise the Limitations Section of the AFM to include the following (this may be accomplished by inserting a copy of this AD into the AFM): "CERTIFICATE LIMITATIONS The center tank fuel pumps must be OFF for takeoff if center tank fuel is less than 5,000 pounds (2,300 kilograms) with the airplane readied for initial taxi.Both center tank fuel pump switches must be selected OFF when center tank fuel quantity reaches approximately 1,000 pounds (500 kilograms) during climb and cruise or 3,000 pounds (1,400 kilograms) during descent and landing. The fuel pumps must be positioned OFF at the first indication of fuel pump low pressure.The CWT fuel quantity indication system must be operative to dispatch with CWT mission fuel.Note The CONFIG indicator will annunciate when center tank fuel exceeds 1,600 pounds (800 kilograms) and the center tank fuel pump switches are OFF. Do not accomplish the CONFIG non-normal procedure prior to or during takeoff with less than 5,000 pounds (2,300 kilograms) of center tank fuel or during descent and landing with less than 3,000 pounds (1,400 kilograms) of center tank fuel. NoteIn a low fuel situation, both center tank pumps may be selected ON and all center tank fuel may be used. If the main tanks are not full, the zero fuel gross weight of the airplane plus the weight of center tank fuel may exceed the maximum zero fuel gross weight by up to 5,000 pounds (2,300 kilograms) for takeoff, climb and cruise and up to 3,000 pounds (1,400 kilograms) for descent and landing, provided that the effects of balance (CG) have been considered.If a center tank fuel pump fails with fuel in the center tank, accomplish the FUEL PUMP LOW PRESSURE non-normal procedure.When defueling center or main wing tanks, the Fuel Pump Low Pressure indication lights must be monitored and the fuel pumps positioned to OFF at the first indication of fuel pump low pressure. Defueling with passengers on board is prohibited.The limitations contained in this AD supersede any conflicting basic airplane flight manual limitations." AD 2002-24-51, issued on November 23, 2002, becomes effective upon receipt.Alternate Operation Instructions for B-737 600/700/800/900 Center Tank Fuel AD:Takeoff and Initial climb - Both center tank pumps must be off for takeoff if center tank is less than 5000 pounds. Both center tank fuel pumps ON above 10,000 feet or after pitch attitude has been reduced to begin acceleration to a climb speed of 250 knots or greater if more than 2000 pounds remain in the center fuel tank.Climb and Cruise-Turn on center tank fuel pump OFF during climb or cruise when the center tank fuel quantity reaches 2000 pounds. Open the crossfeed valve to minimize fuel imbalance. When Master Caution and FUEL system annumciator lights illuminate, turn the remaining center tank fuel pump switch OFF without delay and close the fuel crossfeed valve.Descent-Turn one center tank fuel pump switch OFF at the beginning of the descent if less than 3000 pounds of fuel remain in the center tank. Open the crossfeed valve to minimize fuel imbalance. When Master Caution and FUEL system annumciator lights illuminate, turn the remaining center tank fuel pump switch OFF without delay and close the fuel crossfeed valve. If an extended period of level flight is required prior to approach and landing, ie., holding, and fuel remains in the center tank, a single center tank fuel pump switch may be ON if both fuel pumps were previously turned OFF. The fuel crossfeed valve should be opened to prevent fuel imbalance. At the first indication of pump low pressure, the fuel pump must immediately be turned OFF and the crossfeed valve CLOSED. Floyd

[zubart 5]

Where is the Edit button when you need it!Correction to Alternate Operation Instructions for B-737 600/700/800/900 Center Tank Fuel AD:Climb and Cruise-Turn one ........Floyd

[Guest airlinecpt7020]

I took a flight yesterday from Boeing Field, to Las Vegas, and used the cold and dark start. I followed the checklist correctly and noticed that the fuel was not even being used from the center tank. This worries me, for two reasons, one Center of Gravity limitations, as well as when the wing tanks run dry, will the engines cease. I have had this happened to me before, running the wing tanks dry. I found that the fuel did not even run from the center tank. Has this happened to anyone before? I also noticed that the generator switches will not move to the Off position, it kind of seems like there is a setting that has disabled the fuel pumps (kind of an automatic thing) as well as the generators. Let me know what I need to do. ThanksJoseph DaltonPPL/SEL

[Guest airlinecpt7020]

I finally figured out my fuel problem. I did not realize that the generator switches were spring loaded. Here all of this time I had thought that they were in the on position. Thanks again for all of your help.Joseph DaltonPPL/SEL