Narrative:

I was flying a safety patrol for the united states government. We departed lna at XA40. I switched to auxiliary tanks at XA50. At the time, the 15 gal auxiliary tanks were full. My experience in the aircraft indicated that fuel burn for both engines at patrol power settings (18 inches manifold pressure, 2300 RPM, leaned 100 degrees F rich of peak) was less than 15 gph and the performance tables certainly confirm this. What I did not know was that the 2 lycoming identification-320B engines do not burn fuel at the same rate. The right engine, as it turned out, burned 2 gph more than the left engine. Because of our low altitude, 1000 ft above the ocean, I feathered and secured the right engine when it started to cough and sputter. We made an uneventful single engine landing at key west with 45 gals on board. But, the right auxiliary tank was completely empty.

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Original NASA ASRS Text

Title: RPTR RAN OUT OF FUEL TO R ENG AND FEATHERED THE ENG WHEN IT FIRST STARTED TO SPUTTER. THE RPTR MADE A SAFE SINGLE ENG LNDG.

Narrative: I WAS FLYING A SAFETY PATROL FOR THE UNITED STATES GOVERNMENT. WE DEPARTED LNA AT XA40. I SWITCHED TO AUX TANKS AT XA50. AT THE TIME, THE 15 GAL AUX TANKS WERE FULL. MY EXPERIENCE IN THE ACFT INDICATED THAT FUEL BURN FOR BOTH ENGS AT PATROL PWR SETTINGS (18 INCHES MANIFOLD PRESSURE, 2300 RPM, LEANED 100 DEGS F RICH OF PEAK) WAS LESS THAN 15 GPH AND THE PERFORMANCE TABLES CERTAINLY CONFIRM THIS. WHAT I DID NOT KNOW WAS THAT THE 2 LYCOMING ID-320B ENGS DO NOT BURN FUEL AT THE SAME RATE. THE R ENG, AS IT TURNED OUT, BURNED 2 GPH MORE THAN THE L ENG. BECAUSE OF OUR LOW ALT, 1000 FT ABOVE THE OCEAN, I FEATHERED AND SECURED THE R ENG WHEN IT STARTED TO COUGH AND SPUTTER. WE MADE AN UNEVENTFUL SINGLE ENG LNDG AT KEY WEST WITH 45 GALS ON BOARD. BUT, THE R AUX TANK WAS COMPLETELY EMPTY.

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.