Narrative:

Aircraft was in cruise, en route via airways to phl. We had burned about 45 mins of fuel from the right tank, and the engine lost power. I switched tanks and engaged the boost pump and the engine immediately restarted. We proceeded to ric and landed as a precautionary measure. WX was 500 ft and less than 2 mi. The landing was uneventful. We declared an emergency in order to get down as quickly as possible after restarting the engine. We troubleshot with maintenance people, determined the probable/possible causes were water in the fuel or a fuel cap that may have worked loose. Proceeded to phl without further incident. Callback conversation with reporter revealed the following information: pilot was flying in light to moderate rain, in IMC conditions. The right tank emptied much faster than the engine used fuel. This indicated that fuel was being siphoned from the tank, but could not be seen because of the rain. FBO mechanics replaced both o-rings in the fuel caps and insured the caps were adjusted properly. There has been no further fuel siphoning since this was done. Tanks were drained to insure no water existed in the tanks. The aircraft has since flown without problems.

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Original NASA ASRS Text

Title: BE-36 PLT LOST ENG PWR UNTIL THE PLT SWITCHED TO THE OTHER FUEL TANK. THE PLT DECLARED AN EMER AND LANDED AT THE NEAREST SUITABLE ARPT.

Narrative: ACFT WAS IN CRUISE, ENRTE VIA AIRWAYS TO PHL. WE HAD BURNED ABOUT 45 MINS OF FUEL FROM THE R TANK, AND THE ENG LOST PWR. I SWITCHED TANKS AND ENGAGED THE BOOST PUMP AND THE ENG IMMEDIATELY RESTARTED. WE PROCEEDED TO RIC AND LANDED AS A PRECAUTIONARY MEASURE. WX WAS 500 FT AND LESS THAN 2 MI. THE LNDG WAS UNEVENTFUL. WE DECLARED AN EMER IN ORDER TO GET DOWN AS QUICKLY AS POSSIBLE AFTER RESTARTING THE ENG. WE TROUBLESHOT WITH MAINT PEOPLE, DETERMINED THE PROBABLE/POSSIBLE CAUSES WERE WATER IN THE FUEL OR A FUEL CAP THAT MAY HAVE WORKED LOOSE. PROCEEDED TO PHL WITHOUT FURTHER INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: PLT WAS FLYING IN LIGHT TO MODERATE RAIN, IN IMC CONDITIONS. THE R TANK EMPTIED MUCH FASTER THAN THE ENG USED FUEL. THIS INDICATED THAT FUEL WAS BEING SIPHONED FROM THE TANK, BUT COULD NOT BE SEEN BECAUSE OF THE RAIN. FBO MECHS REPLACED BOTH O-RINGS IN THE FUEL CAPS AND INSURED THE CAPS WERE ADJUSTED PROPERLY. THERE HAS BEEN NO FURTHER FUEL SIPHONING SINCE THIS WAS DONE. TANKS WERE DRAINED TO INSURE NO WATER EXISTED IN THE TANKS. THE ACFT HAS SINCE FLOWN WITHOUT PROBS.

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.