Narrative:

On this date I was flying an small aircraft from majuro, marshall islands, to honolulu as part of a ferry flight from sydney, australia, to camarillo, ca. Approximately 60 NM north of johnston island my last internal ferry tank went dry. This was approximately 2 hours sooner then computed. I immediately recomputed my fuel and determined that I would be unable to safely proceed to honolulu. At about this time the oil pressure gauges became erratic. I requested clearance back to johnston island and requested an emergency landing. On let down the engine became rough and stopped 3 times. The engine ran normal in level flight. The next day I determined that an auxiliary fuel valve on one of the ferry tanks had been knocked slightly open by a manual while in turbulence. This allowed air into the fuel system during let down as a result of the aircraft angle, throwing residual fuel away from the outlet. The oil pressure problem was caused by electrical transmitter problems. The fuel shortage was caused by inaccurate wing tank readings (also electrical) which caused me to pump fuel overboard during transfer from ferry system. There is no way to tell this is happening. On the flight from johnston island to honolulu there was no further problem. I made the mistake of relying only the fuel gauges for accurate readings during transfer. I also should have been using timed transfers.

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Original NASA ASRS Text

Title: GA SMA RESERVE FUEL TANK EXHAUSTION DURING EXTENDED OVERWATER OPERATION. DIVERSION TO ALTERNATE.

Narrative: ON THIS DATE I WAS FLYING AN SMA FROM MAJURO, MARSHALL ISLANDS, TO HONOLULU AS PART OF A FERRY FLT FROM SYDNEY, AUSTRALIA, TO CAMARILLO, CA. APPROX 60 NM N OF JOHNSTON ISLAND MY LAST INTERNAL FERRY TANK WENT DRY. THIS WAS APPROX 2 HRS SOONER THEN COMPUTED. I IMMEDIATELY RECOMPUTED MY FUEL AND DETERMINED THAT I WOULD BE UNABLE TO SAFELY PROCEED TO HONOLULU. AT ABOUT THIS TIME THE OIL PRESSURE GAUGES BECAME ERRATIC. I REQUESTED CLRNC BACK TO JOHNSTON ISLAND AND REQUESTED AN EMER LNDG. ON LET DOWN THE ENG BECAME ROUGH AND STOPPED 3 TIMES. THE ENG RAN NORMAL IN LEVEL FLT. THE NEXT DAY I DETERMINED THAT AN AUX FUEL VALVE ON ONE OF THE FERRY TANKS HAD BEEN KNOCKED SLIGHTLY OPEN BY A MANUAL WHILE IN TURB. THIS ALLOWED AIR INTO THE FUEL SYS DURING LET DOWN AS A RESULT OF THE ACFT ANGLE, THROWING RESIDUAL FUEL AWAY FROM THE OUTLET. THE OIL PRESSURE PROB WAS CAUSED BY ELECTRICAL XMITTER PROBS. THE FUEL SHORTAGE WAS CAUSED BY INACCURATE WING TANK READINGS (ALSO ELECTRICAL) WHICH CAUSED ME TO PUMP FUEL OVERBOARD DURING TRANSFER FROM FERRY SYS. THERE IS NO WAY TO TELL THIS IS HAPPENING. ON THE FLT FROM JOHNSTON ISLAND TO HONOLULU THERE WAS NO FURTHER PROB. I MADE THE MISTAKE OF RELYING ONLY THE FUEL GAUGES FOR ACCURATE READINGS DURING TRANSFER. I ALSO SHOULD HAVE BEEN USING TIMED TRANSFERS.

Data retrieved from NASA's ASRS site as of August 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.