Narrative:

The aircraft engine quit during cruise flight due to fuel exhaustion. The aircraft had been flying for 3 hours and 15 mins. According to the manual, at the given flight conditions, the aircraft should have had enough fuel for over 5 hours of flight. Upon discovery, I followed recommended procedures in aircraft manual for emergency landing, no power. One thing that would help remedy this situation is requiring a more accurate fuel gauge for aircraft. Also, I think the aircraft manual should be reviewed for fuel burn accuracy. Callback conversation with reporter revealed the following information. Reporter claimed that she visually confirmed fuel quantity prior to departure as being to 'the top of the steel ring' in the tank, meaning that the aircraft did indeed have full fuel. Further, the reporter claims to have used book value power settings and mixture leaning procedures. The aircraft was landed out of a 1000' overcast, into a field west/O damage, but field condition was such that the aircraft had to be towed to the airport. A mechanic, called to examine the aircraft, found that the tachometer registered 300 to 500 RPM low, certainly sufficient to invalidate all aircraft flight manual power setting and fuel flow values. This mechanic, also an FBO owner and operator, claimed that 100LL fuel, such as was in the reporter's aircraft, burned at a greater rate than 80 octane fuel, thus reducing aircraft flight manual range and endurance values.

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Original NASA ASRS Text

Title: SMA FORCED LNDG DUE FUEL EXHAUSTION.

Narrative: THE ACFT ENG QUIT DURING CRUISE FLT DUE TO FUEL EXHAUSTION. THE ACFT HAD BEEN FLYING FOR 3 HRS AND 15 MINS. ACCORDING TO THE MANUAL, AT THE GIVEN FLT CONDITIONS, THE ACFT SHOULD HAVE HAD ENOUGH FUEL FOR OVER 5 HRS OF FLT. UPON DISCOVERY, I FOLLOWED RECOMMENDED PROCS IN ACFT MANUAL FOR EMER LNDG, NO PWR. ONE THING THAT WOULD HELP REMEDY THIS SITUATION IS REQUIRING A MORE ACCURATE FUEL GAUGE FOR ACFT. ALSO, I THINK THE ACFT MANUAL SHOULD BE REVIEWED FOR FUEL BURN ACCURACY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. RPTR CLAIMED THAT SHE VISUALLY CONFIRMED FUEL QUANTITY PRIOR TO DEP AS BEING TO 'THE TOP OF THE STEEL RING' IN THE TANK, MEANING THAT THE ACFT DID INDEED HAVE FULL FUEL. FURTHER, THE RPTR CLAIMS TO HAVE USED BOOK VALUE PWR SETTINGS AND MIXTURE LEANING PROCS. THE ACFT WAS LANDED OUT OF A 1000' OVCST, INTO A FIELD W/O DAMAGE, BUT FIELD CONDITION WAS SUCH THAT THE ACFT HAD TO BE TOWED TO THE ARPT. A MECH, CALLED TO EXAMINE THE ACFT, FOUND THAT THE TACHOMETER REGISTERED 300 TO 500 RPM LOW, CERTAINLY SUFFICIENT TO INVALIDATE ALL ACFT FLT MANUAL PWR SETTING AND FUEL FLOW VALUES. THIS MECH, ALSO AN FBO OWNER AND OPERATOR, CLAIMED THAT 100LL FUEL, SUCH AS WAS IN THE RPTR'S ACFT, BURNED AT A GREATER RATE THAN 80 OCTANE FUEL, THUS REDUCING ACFT FLT MANUAL RANGE AND ENDURANCE VALUES.

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.