B737 flight crew reported diverting enroute after being dispatched with a malfunctioning left wing f...

Narrative:

We departed with a cockpit left main fuel quantity indicator placarded inoperative. Per MEL; we received a fuel slip which indicated a total fuel load of 18;500 pounds. At lift off the airplane was right wing heavy and took about one unit of rudder trim to level the wings in cruise. The left fuel quantity indication decreased reaching zero during cruise at 31;000 feet. Immediately thereafter the left engine started to roll back. We opened the fuel crossfeed valve and the engine recovered and continued to run. Advised ATC and requested immediate turn towards ZZZ. Landing was uneventful. Total fuel at shut down 3500 pounds; all of it in the right main tank. Left main tank had no usable fuel remaining in it; this was determined by sticking the tank. Contract maintenance; in coordination with maintenance control; subsequently placarded the wing left main fuel quantity indicator (in addition to cockpit left main fuel quantity) inoperative. After aircraft was refueled and fuel quantity verified by sticking the left main tank we ferried the aircraft to ZZZ1. The fuel aboard noted on the fuel slip was not what we had aboard the aircraft. Retrain the fueler in the proper procedure for fueling the aircraft with an inoperative fuel quantity gauge or change the procedure. This is a serious safety issue and this flight could have had a much worse conclusion.

Original NASA ASRS Text

Title: B737 Flight crew reported diverting enroute after being dispatched with a malfunctioning left wing fuel quantity indicator.

Narrative: We departed with a cockpit left main fuel quantity indicator placarded inoperative. Per MEL; we received a fuel slip which indicated a total fuel load of 18;500 pounds. At lift off the airplane was right wing heavy and took about one unit of rudder trim to level the wings in cruise. The left fuel quantity indication decreased reaching zero during cruise at 31;000 feet. Immediately thereafter the left engine started to roll back. We opened the fuel crossfeed valve and the engine recovered and continued to run. Advised ATC and requested immediate turn towards ZZZ. Landing was uneventful. Total fuel at shut down 3500 pounds; all of it in the right main tank. Left main tank had no usable fuel remaining in it; this was determined by sticking the tank. Contract maintenance; in coordination with Maintenance Control; subsequently placarded the wing left main fuel quantity indicator (in addition to cockpit left main fuel quantity) inoperative. After aircraft was refueled and fuel quantity verified by sticking the left main tank we ferried the aircraft to ZZZ1. The fuel aboard noted on the fuel slip was NOT what we had aboard the aircraft. Retrain the fueler in the proper procedure for fueling the aircraft with an inoperative fuel quantity gauge or change the procedure. This is a serious safety issue and this flight could have had a much worse conclusion.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1463585
Time
Date	201707
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Weight And Balance Deviation - Procedural Published Material / Policy Deviation - Procedural MEL Inflight Event / Encounter Fuel Issue

B737 flight crew reported diverting enroute after being dispatched with a malfunctioning left wing fuel quantity indicator.