Narrative:

The incident occurred during a flight from phn to tys of approximately 3 hours duration. After running exactly 2:20 on the main fuel supply, we selected the auxiliary fuel supply. The engine immediately suffered from fuel deprivation. A system check provided no indication of the cause of the problem. The main fuel supply was reselected and the problem was eliminated. A fuel consumption analysis indicated that the tys destination would be unachievable. I requested an immediate deviation to the nearest airport (loz) to eliminate the potential for further complications. The deviation was authority/authorized and made. This action resulted in a safe landing without further incident. A thorough analysis on the ground indicated that at some time during this or a preceding flight an object or the seat while being installed bumped and turned off the fuel supply valve to the auxiliary system (located under the seat). With the problem idented, an airport with a mechanic available within 1:15 of flying time we refueled the main fuel supply and proceeded without incident to ahn. The mechanic on duty at ahn examined the aircraft, concurred with our diagnosis and certified the aircraft as airworthy. Upon return to our home base of phn, we made arrangements with our local maintenance shop to install a protective flap over the valve to eliminate the potential for this happening again.

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Original NASA ASRS Text

Title: PLT UNABLE TO USE ALL FUEL ABOARD ACFT. MAKES UNSCHEDULED STOP FOR REFUELING. FUEL VALVE UNDER PLT SEAT IS IN OFF POS, WITH NO ACCESS TO IT UNTIL PARKED ON GND.

Narrative: THE INCIDENT OCCURRED DURING A FLT FROM PHN TO TYS OF APPROX 3 HRS DURATION. AFTER RUNNING EXACTLY 2:20 ON THE MAIN FUEL SUPPLY, WE SELECTED THE AUX FUEL SUPPLY. THE ENG IMMEDIATELY SUFFERED FROM FUEL DEPRIVATION. A SYS CHK PROVIDED NO INDICATION OF THE CAUSE OF THE PROB. THE MAIN FUEL SUPPLY WAS RESELECTED AND THE PROB WAS ELIMINATED. A FUEL CONSUMPTION ANALYSIS INDICATED THAT THE TYS DEST WOULD BE UNACHIEVABLE. I REQUESTED AN IMMEDIATE DEV TO THE NEAREST ARPT (LOZ) TO ELIMINATE THE POTENTIAL FOR FURTHER COMPLICATIONS. THE DEV WAS AUTH AND MADE. THIS ACTION RESULTED IN A SAFE LNDG WITHOUT FURTHER INCIDENT. A THOROUGH ANALYSIS ON THE GND INDICATED THAT AT SOME TIME DURING THIS OR A PRECEDING FLT AN OBJECT OR THE SEAT WHILE BEING INSTALLED BUMPED AND TURNED OFF THE FUEL SUPPLY VALVE TO THE AUX SYS (LOCATED UNDER THE SEAT). WITH THE PROB IDENTED, AN ARPT WITH A MECH AVAILABLE WITHIN 1:15 OF FLYING TIME WE REFUELED THE MAIN FUEL SUPPLY AND PROCEEDED WITHOUT INCIDENT TO AHN. THE MECH ON DUTY AT AHN EXAMINED THE ACFT, CONCURRED WITH OUR DIAGNOSIS AND CERTIFIED THE ACFT AS AIRWORTHY. UPON RETURN TO OUR HOME BASE OF PHN, WE MADE ARRANGEMENTS WITH OUR LCL MAINT SHOP TO INSTALL A PROTECTIVE FLAP OVER THE VALVE TO ELIMINATE THE POTENTIAL FOR THIS HAPPENING AGAIN.

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.