Narrative:

For about 1 yr, I have flown a single engine 2 passenger aircraft stc'ed for mogas. The mogas with which I filled it came from a service station recommended by other pilots as providing 87 octane unleaded that was free of alcohol or contaminants. I used plastic jerry cans which I visually inspected before each filling to ensure there was no dirt present. Nonetheless, on sampling, I often found brownish contamination in the fuel, along with bubbles. Sometimes 5 sampler cups had to be filled and emptied to obtain clear fuel. An instrument to whom I lent my aircraft, with the help of a certified aircraft mechanic, removed the sampler plugs 7 months ago and poured in kerosene and ball bearings, swirling the mixture around to scour out any corrosion. He also flew the aircraft using AV100. The problem diminished, but traces of bubbles or contamination (brownish film) occasionally reappeared. Before leaving ezf, I filled the tanks with 87 octane unleaded gas from a garage recommended by someone at the airport. I performed a thorough preflight inspection. My flight, calculated at 2.5 hours, became 3 hours. I was flying at 3500'. I encountered engine problems after 3 hours. Normal range under then current conditions would have ben 4.5 hours. The engine suddenly went out, and after wagging the wings, the engine regained power. The engine had never cut out before. I believe the cutout was due, perhaps, to impurities in the fuel. It may also have ben due to inadequate fuel supply, as fuel in the tanks had, during the overall flight, been slightly lower than that indicated on the gauges, and consumption had been slightly higher than usual. Despite the above, the gauges registered about 1/4-1/3 of the total fuel remained. I believe the engine problem was a result of either blockage of the fuel lines or carburetor caused by contamination, or be excessive burning of fuel and improper indication of this on the gauges. Callback conversation with reporter revealed the following: reporter was purchasing fuel at local service stations, carrying it to the aircraft in plastic containers and loading it west/O straining. If his pilot license is restored, he plans to use only AV100 fuel. Suspects he actually ran out of fuel when the engine quit. No injuries or property damage.

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Original NASA ASRS Text

Title: FUEL CONTAMINATION IN ACFT AUTH AUTO FUEL. ENGINE FAILURE. FORCED LNDG.

Narrative: FOR ABOUT 1 YR, I HAVE FLOWN A SINGLE ENG 2 PAX ACFT STC'ED FOR MOGAS. THE MOGAS WITH WHICH I FILLED IT CAME FROM A SVC STATION RECOMMENDED BY OTHER PLTS AS PROVIDING 87 OCTANE UNLEADED THAT WAS FREE OF ALCOHOL OR CONTAMINANTS. I USED PLASTIC JERRY CANS WHICH I VISUALLY INSPECTED BEFORE EACH FILLING TO ENSURE THERE WAS NO DIRT PRESENT. NONETHELESS, ON SAMPLING, I OFTEN FOUND BROWNISH CONTAMINATION IN THE FUEL, ALONG WITH BUBBLES. SOMETIMES 5 SAMPLER CUPS HAD TO BE FILLED AND EMPTIED TO OBTAIN CLR FUEL. AN INSTR TO WHOM I LENT MY ACFT, WITH THE HELP OF A CERTIFIED ACFT MECH, REMOVED THE SAMPLER PLUGS 7 MONTHS AGO AND POURED IN KEROSENE AND BALL BEARINGS, SWIRLING THE MIXTURE AROUND TO SCOUR OUT ANY CORROSION. HE ALSO FLEW THE ACFT USING AV100. THE PROB DIMINISHED, BUT TRACES OF BUBBLES OR CONTAMINATION (BROWNISH FILM) OCCASIONALLY REAPPEARED. BEFORE LEAVING EZF, I FILLED THE TANKS WITH 87 OCTANE UNLEADED GAS FROM A GARAGE RECOMMENDED BY SOMEONE AT THE ARPT. I PERFORMED A THOROUGH PREFLT INSPECTION. MY FLT, CALCULATED AT 2.5 HRS, BECAME 3 HRS. I WAS FLYING AT 3500'. I ENCOUNTERED ENG PROBS AFTER 3 HRS. NORMAL RANGE UNDER THEN CURRENT CONDITIONS WOULD HAVE BEN 4.5 HRS. THE ENG SUDDENLY WENT OUT, AND AFTER WAGGING THE WINGS, THE ENG REGAINED PWR. THE ENG HAD NEVER CUT OUT BEFORE. I BELIEVE THE CUTOUT WAS DUE, PERHAPS, TO IMPURITIES IN THE FUEL. IT MAY ALSO HAVE BEN DUE TO INADEQUATE FUEL SUPPLY, AS FUEL IN THE TANKS HAD, DURING THE OVERALL FLT, BEEN SLIGHTLY LOWER THAN THAT INDICATED ON THE GAUGES, AND CONSUMPTION HAD BEEN SLIGHTLY HIGHER THAN USUAL. DESPITE THE ABOVE, THE GAUGES REGISTERED ABOUT 1/4-1/3 OF THE TOTAL FUEL REMAINED. I BELIEVE THE ENG PROB WAS A RESULT OF EITHER BLOCKAGE OF THE FUEL LINES OR CARB CAUSED BY CONTAMINATION, OR BE EXCESSIVE BURNING OF FUEL AND IMPROPER INDICATION OF THIS ON THE GAUGES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR WAS PURCHASING FUEL AT LCL SVC STATIONS, CARRYING IT TO THE ACFT IN PLASTIC CONTAINERS AND LOADING IT W/O STRAINING. IF HIS PLT LICENSE IS RESTORED, HE PLANS TO USE ONLY AV100 FUEL. SUSPECTS HE ACTUALLY RAN OUT OF FUEL WHEN THE ENG QUIT. NO INJURIES OR PROPERTY DAMAGE.

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.