Narrative:

I was flying from onp to pao when I decided to stop at oak for fuel. While over sau, the right fuel tank seemed to run dry. I switched to the left tank and headed for oak direct. Fuel estimations had been based on the previous logged flying characteristics of this aircraft, showing actual average fuel consumption to be less than 8 gph. Based on these calculations, the maximum endurance of the aircraft should have been 6 hours 15 mins, or 5 hours 30 mins with a 45 min reserve. Upon approach to oak, my flight time was 5 hours 15 mins. Despite these calculations, the left tank seemed to run dry within approximately 2 mi of runway 15. I set up for maximum glide and searched for a deserted road while heading for airport. I announced 'mayday xx' and said I thought I was out of gas. I then switched the fuel tanks again and pumped the throttle. The engine began running again and continued through landing and taxi to fuel island. This was a long flight and though I considered stopping for fuel at sts, I wanted to get home. Get homeitis was a factor, as was the assumption that the aircraft would always perform at less than 8 gph. The fuel indicators both work, but due to the age of the aircraft, their accuracy is questionable to me. My fuel management practice is to alternate tanks every 30 mins and I use a timer to remind me. None of the tank switches were missed as I record each one on my knee board.

Google
 

Original NASA ASRS Text

Title: A PVT PLT FLYING A C172 FROM ONP TO PAO INADVERTENTLY EXHAUSTED A WING FUEL TANK AND ELECTED TO MAKE A PRECAUTIONARY LNDG AT OAK AFTER SELECTING THE OPPOSITE WING FUEL TANK AND RESTARTING THE ENG.

Narrative: I WAS FLYING FROM ONP TO PAO WHEN I DECIDED TO STOP AT OAK FOR FUEL. WHILE OVER SAU, THE R FUEL TANK SEEMED TO RUN DRY. I SWITCHED TO THE L TANK AND HEADED FOR OAK DIRECT. FUEL ESTIMATIONS HAD BEEN BASED ON THE PREVIOUS LOGGED FLYING CHARACTERISTICS OF THIS ACFT, SHOWING ACTUAL AVERAGE FUEL CONSUMPTION TO BE LESS THAN 8 GPH. BASED ON THESE CALCULATIONS, THE MAX ENDURANCE OF THE ACFT SHOULD HAVE BEEN 6 HRS 15 MINS, OR 5 HRS 30 MINS WITH A 45 MIN RESERVE. UPON APCH TO OAK, MY FLT TIME WAS 5 HRS 15 MINS. DESPITE THESE CALCULATIONS, THE L TANK SEEMED TO RUN DRY WITHIN APPROX 2 MI OF RWY 15. I SET UP FOR MAX GLIDE AND SEARCHED FOR A DESERTED ROAD WHILE HDG FOR ARPT. I ANNOUNCED 'MAYDAY XX' AND SAID I THOUGHT I WAS OUT OF GAS. I THEN SWITCHED THE FUEL TANKS AGAIN AND PUMPED THE THROTTLE. THE ENG BEGAN RUNNING AGAIN AND CONTINUED THROUGH LNDG AND TAXI TO FUEL ISLAND. THIS WAS A LONG FLT AND THOUGH I CONSIDERED STOPPING FOR FUEL AT STS, I WANTED TO GET HOME. GET HOMEITIS WAS A FACTOR, AS WAS THE ASSUMPTION THAT THE ACFT WOULD ALWAYS PERFORM AT LESS THAN 8 GPH. THE FUEL INDICATORS BOTH WORK, BUT DUE TO THE AGE OF THE ACFT, THEIR ACCURACY IS QUESTIONABLE TO ME. MY FUEL MGMNT PRACTICE IS TO ALTERNATE TANKS EVERY 30 MINS AND I USE A TIMER TO REMIND ME. NONE OF THE TANK SWITCHES WERE MISSED AS I RECORD EACH ONE ON MY KNEE BOARD.

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.