Narrative:

We had just passed north of dsm at FL350 in level cruise in smooth air with unrestr visibility. We noticed an unexplained airspeed decrease and then noted the #1 engine spooling down. The engine flamed out for no apparent reason. We declared an emergency and told ATC that we wanted to divert to dsm. The #1 engine still had indications of N1, N2, egt and fuel flow with good oil temperature, quantity, residual oil pressure and no vibration, so we decided to attempt a relight. We accomplished the driftdown and in-flight engine start procedures as per SOP. At approximately FL210, we successfully relit the engine. We continued the approach to runway 31R at dsm to land without incidence. We terminated the emergency at XA00. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a B737-300 with cfm 56-B3 engines. The reporter said maintenance advised the crew the main fuel control had failed and was replaced.

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Original NASA ASRS Text

Title: A B737-300 IN CRUISE AT FL350 DECLARED AN EMER AND DIVERTED DUE TO #1 ENG SPOOLDOWN CAUSED BY A MALFUNCTIONING MAIN FUEL CTL UNIT.

Narrative: WE HAD JUST PASSED N OF DSM AT FL350 IN LEVEL CRUISE IN SMOOTH AIR WITH UNRESTR VISIBILITY. WE NOTICED AN UNEXPLAINED AIRSPD DECREASE AND THEN NOTED THE #1 ENG SPOOLING DOWN. THE ENG FLAMED OUT FOR NO APPARENT REASON. WE DECLARED AN EMER AND TOLD ATC THAT WE WANTED TO DIVERT TO DSM. THE #1 ENG STILL HAD INDICATIONS OF N1, N2, EGT AND FUEL FLOW WITH GOOD OIL TEMP, QUANTITY, RESIDUAL OIL PRESSURE AND NO VIBRATION, SO WE DECIDED TO ATTEMPT A RELIGHT. WE ACCOMPLISHED THE DRIFTDOWN AND INFLT ENG START PROCS AS PER SOP. AT APPROX FL210, WE SUCCESSFULLY RELIT THE ENG. WE CONTINUED THE APCH TO RWY 31R AT DSM TO LAND WITHOUT INCIDENCE. WE TERMINATED THE EMER AT XA00. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A B737-300 WITH CFM 56-B3 ENGS. THE RPTR SAID MAINT ADVISED THE CREW THE MAIN FUEL CTL HAD FAILED AND WAS REPLACED.

Data retrieved from NASA's ASRS site as of July 2007 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.