Narrative:

The intent of the flight was to fly from california city airport to pearce airport at clear lake, ca, (approximately 340 NM) to purchase a glider and aeronautical tow it back to cal city. The route of flight was not direct. On both outbnd and return legs the mountains were xed near tehachapi airport with most of the flight conducted over the san joaquin valley so that suitable emergency landing sites were available along the entire route of flight. The small aircraft was topped off with fuel prior to departing cal city. The flight to pearce was uneventful. A fuel stop was planned at tracy airport approximately 1/3 of the way home on the return trip. 6 gals of usable fuel was measured remaining in the aircraft at tracy. His was done by 'dipping' the tanks with a clear hollow plastic tube that was calibrated in 5 gal increments for that airplane. It was estimated that it would take 2.5 hours to return to cal city. The average fuel consumption rate was estimated at 12 gal/hour. Cruise power setting was 15-17' mp, 2000 RPM at 7500' MLS. At this power setting the aircraft manual predicts a consumption rate of less than 9.7 gal/hour. With this power setting a tow speed of 95 KIAS was maintained. I decided to take on 36 gal of fuel at tracy which would allow 3 hours of flight at 12 gal/hour plus he additional 6 gals of usable already in the aircraft would result in 3.5 hours of fuel for the 2/5 hour flight to cal city. I flew the glider from tracy to porterville. Then I flew the tow plane from porterville to cal city. Approximately 12 mi from cal city airport the glider released. Approximately 10 mi from the airport while descending the engine quit due to fuel exhaustion. A dead stick landing was made on cal city blvd west/O damage to people, property or the airplane. It is not believed that any fuel was lost out of the airplane due to fuel leaks or loose fuel caps. I flew the glider after the fuel stop at tracy and did not see any fuel coming from the tow plane. 80 octane fuel was used an there was no evidence of red dye on the glider or the airplane. If you assume that there was a little less than 6 gals usable remaining at the fuel stop and it took longer than 2.5 hours to get to cal city (tach time was 2.51) and more than 12 gal/hour average was burned and the average tow speed was a little less than 95 KTS then I end up on cal city blvd instead of cal city airport with 10-12 gal reserve. Even more so than before I feel that performance figures from the mfr are overly optimistic. I base that on this incident and other flight testing that I have done for comparision with performance figures. Fuel quantity gauges in single engine airplanes are so unreliable and inaccurate that I believe that they are a hazard by presenting the pilot with false information. The needles on both fuel quantity indicators were still moving after the engine quit. One would assume that there is some fuel in the tanks from this indication. This problem is common to all single engine aircraft that I have flown and not peculiar to this particular airplane. As far as fuel quantity gauges are concerned, the ultimate responsibility for fuel management as well as all other aspects of flight rest with the PIC. Fortunately I was able to handle an emergency landing when it happened to me. But wait a min, things like this aren't supposed to happen to me.

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Original NASA ASRS Text

Title: GLIDER TOWING SMA RUNS OUT OF FUEL ON RUN HOME.

Narrative: THE INTENT OF THE FLT WAS TO FLY FROM CALIFORNIA CITY ARPT TO PEARCE ARPT AT CLR LAKE, CA, (APPROX 340 NM) TO PURCHASE A GLIDER AND AERO TOW IT BACK TO CAL CITY. THE RTE OF FLT WAS NOT DIRECT. ON BOTH OUTBND AND RETURN LEGS THE MOUNTAINS WERE XED NEAR TEHACHAPI ARPT WITH MOST OF THE FLT CONDUCTED OVER THE SAN JOAQUIN VALLEY SO THAT SUITABLE EMER LNDG SITES WERE AVAILABLE ALONG THE ENTIRE RTE OF FLT. THE SMA WAS TOPPED OFF WITH FUEL PRIOR TO DEPARTING CAL CITY. THE FLT TO PEARCE WAS UNEVENTFUL. A FUEL STOP WAS PLANNED AT TRACY ARPT APPROX 1/3 OF THE WAY HOME ON THE RETURN TRIP. 6 GALS OF USABLE FUEL WAS MEASURED REMAINING IN THE ACFT AT TRACY. HIS WAS DONE BY 'DIPPING' THE TANKS WITH A CLR HOLLOW PLASTIC TUBE THAT WAS CALIBRATED IN 5 GAL INCREMENTS FOR THAT AIRPLANE. IT WAS ESTIMATED THAT IT WOULD TAKE 2.5 HRS TO RETURN TO CAL CITY. THE AVERAGE FUEL CONSUMPTION RATE WAS ESTIMATED AT 12 GAL/HR. CRUISE PWR SETTING WAS 15-17' MP, 2000 RPM AT 7500' MLS. AT THIS PWR SETTING THE ACFT MANUAL PREDICTS A CONSUMPTION RATE OF LESS THAN 9.7 GAL/HR. WITH THIS PWR SETTING A TOW SPD OF 95 KIAS WAS MAINTAINED. I DECIDED TO TAKE ON 36 GAL OF FUEL AT TRACY WHICH WOULD ALLOW 3 HRS OF FLT AT 12 GAL/HR PLUS HE ADDITIONAL 6 GALS OF USABLE ALREADY IN THE ACFT WOULD RESULT IN 3.5 HRS OF FUEL FOR THE 2/5 HR FLT TO CAL CITY. I FLEW THE GLIDER FROM TRACY TO PORTERVILLE. THEN I FLEW THE TOW PLANE FROM PORTERVILLE TO CAL CITY. APPROX 12 MI FROM CAL CITY ARPT THE GLIDER RELEASED. APPROX 10 MI FROM THE ARPT WHILE DSNDING THE ENG QUIT DUE TO FUEL EXHAUSTION. A DEAD STICK LNDG WAS MADE ON CAL CITY BLVD W/O DAMAGE TO PEOPLE, PROPERTY OR THE AIRPLANE. IT IS NOT BELIEVED THAT ANY FUEL WAS LOST OUT OF THE AIRPLANE DUE TO FUEL LEAKS OR LOOSE FUEL CAPS. I FLEW THE GLIDER AFTER THE FUEL STOP AT TRACY AND DID NOT SEE ANY FUEL COMING FROM THE TOW PLANE. 80 OCTANE FUEL WAS USED AN THERE WAS NO EVIDENCE OF RED DYE ON THE GLIDER OR THE AIRPLANE. IF YOU ASSUME THAT THERE WAS A LITTLE LESS THAN 6 GALS USABLE REMAINING AT THE FUEL STOP AND IT TOOK LONGER THAN 2.5 HRS TO GET TO CAL CITY (TACH TIME WAS 2.51) AND MORE THAN 12 GAL/HR AVERAGE WAS BURNED AND THE AVERAGE TOW SPD WAS A LITTLE LESS THAN 95 KTS THEN I END UP ON CAL CITY BLVD INSTEAD OF CAL CITY ARPT WITH 10-12 GAL RESERVE. EVEN MORE SO THAN BEFORE I FEEL THAT PERFORMANCE FIGURES FROM THE MFR ARE OVERLY OPTIMISTIC. I BASE THAT ON THIS INCIDENT AND OTHER FLT TESTING THAT I HAVE DONE FOR COMPARISION WITH PERFORMANCE FIGURES. FUEL QUANTITY GAUGES IN SINGLE ENG AIRPLANES ARE SO UNRELIABLE AND INACCURATE THAT I BELIEVE THAT THEY ARE A HAZARD BY PRESENTING THE PLT WITH FALSE INFO. THE NEEDLES ON BOTH FUEL QUANTITY INDICATORS WERE STILL MOVING AFTER THE ENG QUIT. ONE WOULD ASSUME THAT THERE IS SOME FUEL IN THE TANKS FROM THIS INDICATION. THIS PROB IS COMMON TO ALL SINGLE ENG ACFT THAT I HAVE FLOWN AND NOT PECULIAR TO THIS PARTICULAR AIRPLANE. AS FAR AS FUEL QUANTITY GAUGES ARE CONCERNED, THE ULTIMATE RESPONSIBILITY FOR FUEL MGMNT AS WELL AS ALL OTHER ASPECTS OF FLT REST WITH THE PIC. FORTUNATELY I WAS ABLE TO HANDLE AN EMER LNDG WHEN IT HAPPENED TO ME. BUT WAIT A MIN, THINGS LIKE THIS AREN'T SUPPOSED TO HAPPEN TO ME.

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.